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  • 1.
    Akhtar, Farid
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Keshavarzi, Neda
    Department of Materials and Environmental Chemistry, Stockholm University.
    Shakarova, Dilshod
    Department of Materials and Environmental Chemistry, Stockholm University.
    Cheung, Ocean
    Department of Materials and Environmental Chemistry, Stockholm University.
    Hedin, Niklas
    Department of Materials and Environmental Chemistry, Stockholm University.
    Bergström, L.M.
    Department of Materials and Environmental Chemistry, Stockholm University.
    Aluminophosphate monoliths with high CO2-over-N2 selectivity and CO2 capture capacity2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 99, p. 55877-55883Article in journal (Refereed)
    Abstract [en]

    Monoliths of microporous aluminophosphates (AlPO4-17 and AlPO4-53) were structured by binder-free pulsed current processing. Such monoliths could be important for carbon capture from flue gas. The AlPO4-17 and AlPO4-53 monoliths exhibited a tensile strength of 1.0 MPa and a CO2 adsorption capacity of 2.5 mmol g-1 and 1.6 mmol g-1, respectively at 101 kPa and 0°C. Analyses of single component CO2 and N2 adsorption data indicated that the AlPO4-53 monoliths had an extraordinarily high CO2-over-N2 selectivity from a binary gas mixture of 15 mol% CO2 and 85 mol% N2. The estimated CO2 capture capacity of AlPO4-17 and AlPO4-53 monoliths in a typical pressure swing adsorption (PSA) process at 20°C was higher than that of the commonly used zeolite 13X granules. Under cyclic sorption conditions, AlPO4-17 and AlPO4-53 monoliths were regenerated by lowering the pressure of CO2. Regeneration was done without application of heat, which would regenerate them to their full capacity for CO2 adsorption.

  • 2.
    Amin, Sidra
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan.Department of Chemistry, Shaheed Benazir Bhutto University, Shaheed Benazirabad, Pakistan.
    Tahira, Aneela
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Solangi, Amber
    National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan.
    Beni, Valerio
    RISE Acreo, Research Institute of Sweden, Norrköping, Sweden.
    Morante, J.R
    Catalonia Institute for Energy Research (IREC), Barcelona, Spain.
    Liu, Xianjie
    Department of Physics, Chemistry and Biology, Surface Physics and Chemistry, Linköping University, Faculty of Science & Engineering, Sweden.
    Falhman, Mats
    Department of Physics, Chemistry and Biology, Surface Physics and Chemistry, Linköping University, Faculty of Science & Engineering, Sweden.
    Mazzaro, Raffaello
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ibupoto, Zafar
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Institute of Chemistry, University of Sindh, Jamshoro, Pakistan.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    A practical non-enzymatic urea sensor based on NiCo2O4 nanoneedles2019In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, no 25, p. 14443-14451Article in journal (Refereed)
    Abstract [en]

    We propose a new facile electrochemical sensing platform for determination of urea, based on a glassy carbon electrode (GCE) modified with nickel cobalt oxide (NiCo2O4) nanoneedles. These nanoneedles are used for the first time for highly sensitive determination of urea with the lowest detection limit (1 μM) ever reported for the non-enzymatic approach. The nanoneedles were grown through a simple and low-temperature aqueous chemical method. We characterized the structural and morphological properties of the NiCo2O4 nanoneedles by TEM, SEM, XPS and XRD. The bimetallic nickel cobalt oxide exhibits nanoneedle morphology, which results from the self-assembly of nanoparticles. The NiCo2O4 nanoneedles are exclusively composed of Ni, Co, and O and exhibit a cubic crystalline phase. Cyclic voltammetry was used to study the enhanced electrochemical properties of a NiCo2O4 nanoneedle-modified GCE by overcoming the typical poor conductivity of bare NiO and Co3O4. The GCE-modified electrode is highly sensitive towards urea, with a linear response (R2 = 0.99) over the concentration range 0.01–5 mM and with a detection limit of 1.0 μM. The proposed non-enzymatic urea sensor is highly selective even in the presence of common interferents such as glucose, uric acid, and ascorbic acid. This new urea sensor has good viability for urea analysis in urine samples and can represent a significant advancement in the field, owing to the simple and cost-effective fabrication of electrodes, which can be used as a promising analytical tool for urea estimation.

  • 3.
    Berglund, Linn
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Forsberg, Fredrik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Jonoobi, Mehdi
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Tehran, Karaj, Iran.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Fibre and Particle Engineering, University of Oulu, Oulu, Finland.
    Promoted hydrogel formation of lignin-containing arabinoxylan aerogel using cellulose nanofibers as a functional biomaterial2018In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 8, no 67, p. 38219-38228Article in journal (Refereed)
    Abstract [en]

    In this work, three-dimensional (3D) aerogels and hydrogels based on lignin-containing arabinoxylan (AX) and cellulose nanofibers (CNF) were prepared. The effects of the CNF and the crosslinking with citric acid (CA) of various contents (1, 3, 5 wt%) were evaluated. All the aerogels possessed highly porous (above 98%) and lightweight structures. The AX-CNF hydrogel with a CA content of 1 wt% revealed a favorable network structure with respect to the swelling ratio; nanofiber addition resulted in a five-fold increase in the degree of swelling (68 g of water per g). The compressive properties were improved when the higher CA content (5 wt%) was used; when combined with CNF, there was a seven-fold enhancement in the compressive strength. The AX-CNF hydrogels were prepared using a green and straightforward method that utilizes sustainable resources efficiently. Therefore, such natural hydrogels could find application potential, for example in the field of soft tissue engineering.

  • 4.
    Bhattacharyya, Shubhankar
    et al.
    Synthetic Chemistry Division, Defense R and D Establishment.
    Hatua, Kaushik
    Department of Chemistry, Bengal Engineering and Science University.
    Computational insight of the mechanism of Algar-Flynn-Oyamada (AFO) reaction2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 36, p. 18702-18709Article in journal (Refereed)
    Abstract [en]

    The present DFT investigation supports a previous conclusion of Dean et al. that hydroxylation occurs without epoxide intermediate at room temperature due to a strong electrostatic interaction of peroxide ions with π electrons of CC bonds of chalcone, and 3-hydroxyflavone has been found to be the major product. The calculated activation energy difference (ΔG#) of initial enolization followed by hydroxylation or simultaneous cyclization and hydroxylation has been found to be negligible (∼4 kcal mol-1). On the other hand, epoxide formation requires significant activation energy, which is supposed to occur at high temperatures. In addition, if epoxide is formed, the ring opens by an attack of phenolic oxygen, occurring preferentially at α position via a five-member transition state due to a low activation barrier height (19.82 kcal mol-1 in the gas phase and 19.55 kcal mol-1 in ethanol) compared to that of a six-member transition state (44.41 kcal mol-1 at B3LYP in the gas phase and 38.55 kcal mol -1 in ethanol). It is also observed that the solvation study does not affect the main conclusion of the paper. These findings also support the previous observation of Dean et al. Predicted ΔG# in different DFT functionals are consistent, although the total energy is significantly different

  • 5.
    Bhattacharyya, Shubhankar
    et al.
    Synthetic Chemistry Division, Defence R and D Establishment.
    Pathak, Uma
    Synthetic Chemistry Division, Defence R and D Establishment.
    Mathur, Sweta
    Synthetic Chemistry Division, Defence R and D Establishment.
    Vishnoi, Subodh
    Synthetic Chemistry Division, Defence R and D Establishment.
    Jain, Rajeev
    School of Studies in Chemistry, Jiwaji University.
    Selective N-alkylation of primary amines with R-NH2·HBr and alkyl bromides using a competitive deprotonation/protonation strategy2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 35, p. 18229-18233Article in journal (Refereed)
    Abstract [en]

    Monoalkylation of primary amines using amine hydrobromides and alkyl bromides has been carried out. Under controlled reaction conditions the reactant primary amine was selectively deprotonated and made available for reaction, while the newly generated secondary amine remained protonated, and did not participate in alkylation further. Reaction was carried out under mild reaction conditions and was applicable to a wide range of primary amines and alkyl bromides.

  • 6.
    Carlsson, Daniel O.
    et al.
    Nanotechnology and Functional Materials, Department of Engineering Sciences, Box 534, Uppsala University, Uppsala University, Department of Engineering Science.
    Lindh, Jonas
    Nanotechnology and Functional Materials, Department of Engineering Sciences, Box 534, Uppsala University.
    Nyholm, Leif
    Uppsala University, Department of Chemistry, Angstrom Lab.
    Mattsson, Maria Stromme
    Uppsala University, Department of Engineering Science.
    Mihranyan, Albert
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Cooxidant-free TEMPO-mediated oxidation of highly crystalline nanocellulose in water2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 94, p. 52289-52298Article in journal (Refereed)
    Abstract [en]

    Selective oxidation of C6 hydroxyls to carboxyls through 2,2,6,6,-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation, where the oxidizing species (TEMPO+) is generated by cooxidants, such as NaBrO, NaClO or NaClO2, has become a popular way to modify the surfaces of nanocellulose fibrils in aqueous solutions. Employing highly crystalline nanocellulose from Cladophora sp. algae we demonstrate that the same degree of oxidation (D.O.) can be achieved within approximately the same time by replacing the cooxidants with electrogeneration of TEMPO+ in a bulk electrolysis setup. The D.O. is controlled by the oxidation time and the maximum D.O. achieved (D.O. 9.8%, 0.60 mmol g-1 of carboxylic acids and 0 mmol g-1 aldehydes) corresponds to complete oxidation of the surface-confined C6. This shows that TEMPO+ is not sterically hindered from completely oxidizing the fibril surface of Cladophora nanocellulose, in contrast to earlier hypotheses that were based on results with wood-derived nanocellulose. The oxidation does not significantly affect the morphology, the specific surface area (>115 m2 g-1) or the pore characteristics of the water-insoluble fibrous particles that were obtained after drying, but depolymerization corresponding to ∼20% was observed. For extensive oxidation times, the product recovery of water-insoluble fibrils decreased significantly while significant amounts of charge passed through the system. This could indicate that the oxidation proceeds beyond the fibril surface, in contrast to the current view that TEMPO-mediated oxidation is confined only to the surface.

  • 7.
    Carlsson, Daniel O.
    et al.
    Uppsala University, Department of Engineering Science.
    Mihranyan, Albert
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Stromme, Maria
    Uppsala University, Department of Engineering Science.
    Nyholm, Leif
    Uppsala University, Department of Chemistry, Angstrom Lab.
    Tailoring porosities and electrochemical properties of composites composed of microfibrillated cellulose and polypyrrole2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 17, p. 8489-8497Article in journal (Refereed)
    Abstract [en]

    Composites of polypyrrole and nanocellulose (PPy/nanocellulose) have a high potential as electrodes in energy-storage devices and as membranes for electrochemically controlled ion-exchange systems. In the present work, it is demonstrated that such composites with 42-72% porosity can be produced by using microfibrillated cellulose (MFC) prepared through enzymatic pretreatment or carboxymethylation, or by using different amounts of MFC in the composite synthesis. Together with previous work, this shows that the porosity of PPy/nanocellulose composites can be tailored from 30 to 98% with increments of similar to 10%. Employing the full porosity range of the composites, it is demonstrated that the electrochemical oxidation rate of the materials depends on their porosity due to limitations in the counter ion diffusion process. By tailoring the porosities of PPy/nanocellulose composites, the electrochemical properties can consequently be controlled. The latter provides new possibilities for the manufacturing of electrochemically controlled ion-extraction

  • 8.
    Chen, Long
    et al.
    Department of Chemical and Biomolecular Engineering, The University of Akron, Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Ji, Tuo
    Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Mu, Liwen
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Shi, Yijun
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Brisbin, Logan
    Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Guo, Zhanhu
    Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville.
    Khan, Mohammel A.
    Department of Physics and Astronomy, Louisiana State University, Baton Rouge.
    Young, David P.
    Department of Physics and Astronomy, Louisiana State University, Baton Rouge.
    Zhu, Jiahua
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Facile synthesis of mesoporous carbon nanocomposites from natural biomass for efficient dye adsorption and selective heavy metal removal2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 3, p. 2259-2269Article in journal (Refereed)
    Abstract [en]

    Mesoporous carbon with embedded iron carbide nanoparticles was successfully synthesized via a facile impregnation–carbonization method. A green biomass resource, cotton fabric, was used as a carbon precursor and an iron precursor was implanted to create mesopores through a catalytic graphitization reaction. The pore structure of the nanocomposites can be tuned by adjusting the iron precursor loadings and the embedded iron carbide nanoparticles serve as an active component for magnetic separation after adsorption. The microstructure of the nanocomposites was carefully investigated by various characterization techniques including electron microscopy, X-ray diffraction, surface analyzer, magnetic property analyzer and etc. The newly created mesopores are demonstrated as a critical component to enhance the adsorption capacity of organic dyes and embedded iron carbide nanoparticles are responsible for the selective removal of heavy metal ions (Zn2+, Cu2+, Ni2+, Cr6+ and Pb2+). Isotherm adsorption, kinetic study at three different temperatures (25, 45 and 65 °C) and cycling retention tests were performed to understand the adsorptive behavior of the nanocomposites with organic dyes (methylene blue and methyl orange). Together with the preferable removal of more toxic heavy metal species (Cr6+ and Pb2+), these mesoporous nanocomposites show promising applications in pollutant removal from water. The facile material preparation allows convenient scale-up manufacturing with low cost and minimum environmental impact.

  • 9.
    Chen, Tingjie
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering. Fujian Agriculture and Forestry University, Fuzhou, China.
    Niu, Min
    Fujian Agriculture and Forestry University, Fuzhou, China.
    Wang, Alice
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Wei, Wei
    Fujian Agriculture and Forestry University, Fuzhou, China.
    Liu, Jinghong
    Fujian Agriculture and Forestry University, Fuzhou, China.
    Xie, Yongqun
    Fujian Agriculture and Forestry University, Fuzhou, China.
    Synthesis and characterization of poly-aluminum silicate sulphate (PASS) for ultra-low density fiberboard (ULDF)2015In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, no 113, p. 93187-93193Article in journal (Refereed)
    Abstract [en]

    The poly-aluminum silicate sulphate (PASS) for ultra-low density fiberboard (ULDF) was synthesized in the mixed aqueous solution of sodium silicate and aluminum silicate by sol-gel method. Their preparation conditions were optimized by using a response surface methodology. The effects and interactions of Si/Al molar ratio (X1), pH value (X2) and temperature (X3) on internal bond strength of ULDF were investigated. Research showed that the optimum internal bond strength (10.23 ± 0.64 kPa) was obtained under Si/Al molar ratio of 2:1, pH value of 8, and 50oC. Analyses of the Fourier transform infra-red spectroscopy spectra confirmed that Al-O-Si bonds were formed between polysilicate and Al or its hydrolysate. The particle size analysis showed that the average size of PASS was 7.52 μm. And the part of PASS entered the cell wall and made a contribution to the improvement of mechanical properties of ULDF.

  • 10.
    Chen, Tingjie
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Wu, Zhenzeng
    Fujian Agriculture and Forestry University, Fuzhou, China.
    Wei, Wei
    Fujian Agriculture and Forestry University, Fuzhou, China.
    Xie, Yongqun
    Fujian Agriculture and Forestry University, Fuzhou, China.
    Wang, Alice
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Niu, Min
    Fujian Agriculture and Forestry University, Fuzhou, China.
    Wei, Qihua
    Fujian Agriculture and Forestry University, Fuzhou, China.
    Rao, Jiuping
    Fujian Agriculture and Forestry University, Fuzhou, China.
    Hybrid composites of polyvinyl alcohol (PVA)/Si-Al for improving the properties of ultra-low density fiberboard (ULDF)2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 25, p. 20706-20712Article in journal (Refereed)
    Abstract [en]

    The hybrid composites of polyvinyl alcohol (PVA)/Si-Al were synthesized to improve the thermostability and mechanical properties of ultra-low density fiberboard (ULDF). Their physical and chemical properties were tested by using scanning electron microscopy, Fourier transform infrared spectrometry, X-ray diffractometry, thermogravimetric analysis (TGA), and a microcomputer control electronic universal testing machine. Microstructure results indicated that the distribution of inorganic fillers on the surface of ULDF was improved by the PVA. Analysis of chemical bonds and crystallinity of materials showed that part of the PVA reacted with Si-Al sol, and the other was physically crosslinked in the composite. The thermostability of ULDF decreased with the increasing content of PVA, but the mechanical properties increased. Combined with the TGA and mechanical properties results, a reasonable content of PVA (30%) was obtained. Under this condition, the modulus of rupture, modulus of elasticity, and the internal bond strength of ULDF were 0.35, 24.86, and 0.038 MPa, respectively

  • 11.
    Galstyan, V.
    et al.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Vomiero, Alberto
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Comini, E.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Faglia, G.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Sberveglieri, G.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    TiO 2 nanotubular and nanoporous arrays by electrochemical anodization on different substrates2011In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 1, no 6, p. 1038-1044Article in journal (Refereed)
    Abstract [en]

    The preparation of nanotubular arrays on different substrates and nanoporous structures on titanium foil by means of electrochemical anodization of titanium layer has been investigated. Highly aligned nanotubes of TiO 2 on flexible, rough and flat substrates are reported. Modification of anodization conditions of titanium on specific substrates such as polyethylene terephthalate (PET), conducting glass and granular alumina was found to affect the morphology of TiO 2 nanotubes. Two different kinds of aqueous electrolytes have been applied, containing either glycerol or H 2SO 4, in order to investigate the effect of ion mobility on anodization process. Galvanostatic and potentiostatic anodization modes have been investigated: transition from nanotubes to nanoporous structures has been highlighted in galvanostatic mode, depending on the intensity of anodization current density. These results pave the way for massive production of TiO 2 nanotubes over, in principle, whatever substrate, enabling exploitation of new functional properties derived from the combination of tubes and substrates. This journal is © The Royal Society of Chemistry 2011.

  • 12.
    Garskaite, Edita
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Karlsson, Olov
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Stankeviciute, Zivile
    Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Vilnius, Lithuania.
    Aivaras, Kareiva
    Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Vilnius, Lithuania.
    Jones, Dennis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Sandberg, Dick
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Surface hardness and flammability of Na2SiO3 and nano-TiO2 reinforced wood composites2019In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, no 48, p. 27973-27986Article in journal (Refereed)
    Abstract [en]

    The objective of this study was to explore an effect of the combined inorganic materials on the wood hardness and flame-retardancy properties in a concept of sustainable material management. Herein, the reinforcement of Scots pine (Pinus sylvestris L.) sapwood with sodium silicate and TiO2 nanoparticles via vacuum-pressure technique is reported. Pyrolysis of modified wood was studied by TG-FTIR analysis; the results showed that maximum weight loss for the modified wood was obtained at 40–50 °C lower temperatures compared to the reference untreated wood. The Gram–Schmidt profiles and spectra extracted at maxima absorption from Gram–Schmidt plots indicated chemical changes in wood–inorganic composites. SEM/EDS analysis revealed the presence of Na–O–Si solid gel within the wood-cell lumen and showed that TiO2 was homogeneously distributed within the amorphous Na–O–Si glass-forming phase to form a thin surface coating. EDS mapping further revealed the higher diffusivity of sodium into the cell wall compared to the silicon compound. The presence of amorphous sodium silicate and nano-TiO2 was additionally confirmed by XRD analysis. FTIR spectra confirmed the chemical changes in Scots pine sapwood induced by alkalization. Brinell hardness test showed that the hardness of the modified wood increased with the highest value (44% increase in hardness) obtained for 10% Na2SiO3–nTiO2 modified wood. The results showed good correlation between TG and flammability test; limiting oxygen index (LOI) values for the wood–inorganic composites increased by 9–14% compared to the untreated wood.

  • 13.
    Geng, Shiyu
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Liu, Peng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Plasticizing and crosslinking effects of borate additives on the structure and properties of poly(vinyl acetate)2017In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 13, p. 7483-7491Article in journal (Refereed)
    Abstract [en]

    As an environmentally friendly, low-cost and widely used polymer, poly(vinyl acetate) (PVAc) is worth modifying to achieve better properties. Here, we report on the influence of borate additives on the structure and properties of partially hydrolysed PVAc. In addition to the general crosslinking function of borate additives, an extraordinary plasticizing effect was found. By controlling the pH from 4 to 11 during sample preparation, the plasticizing and crosslinking effects can be shifted. In alkaline conditions, the degree of crosslinking in the PVAc/borate sample is increased; however, this increase declines gradually with an increase in the borate additive content, which impacts the morphology of the PVAc latex particles, as well as the mechanical and thermal properties of the PVAc/borate films. In contrast, in acidic conditions, the PVAc/borate films are plasticized by borate additives; thus, their ultimate mechanical strength, elastic moduli and thermal stabilities decrease, while the water diffusivities increase.

  • 14.
    Hemmilä, Venla
    et al.
    Department of Forestry and Wood Technology, Linnaeus University.
    Adamopoulos, Stergios
    Department of Forestry and Wood Technology, Linnaeus University.
    Karlsson, Olov
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Kumar, Anuj
    Department of Forestry and Wood Technology, Linnaeus University.
    Development of sustainable bio-adhesives for engineered wood panels: A Review2017In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 61, p. 38604-38630Article in journal (Refereed)
    Abstract [en]

    Changes in both formaldehyde legislations and voluntary requirements (e.g. Germany RAL) are currently the driving factors behind research on alternatives to amino-based adhesives; moreover, consumer interest in healthy and sustainable products is increasing in bio-based adhesives. Sources of formaldehyde emissions in wood-based panels as well as different emission test methods have been discussed, and the main focus of this review is on the research conducted on sustainable bio-based adhesive systems for wood panels. Lignin, tannin, protein, and starch have been evaluated as both raw materials and adhesive alternatives to existing amino-based thermosetting adhesives. Adhesion improving modifications of these bio-based raw materials as well as the available and experimental crosslinkers have also been taken into account.

  • 15.
    Karim, Zoheb
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Hakalahti, Minna
    VTT Technical Research Centre of Finland.
    Tammelin, Tekla
    VTT Technical Research Centre of Finland.
    Mathew, Aji P.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Materials and Environmental Chemistry, Stockholm University.
    In situ TEMPO surface functionalization of nanocellulose membranes for enhanced adsorption of metal ions from aqueous medium2017In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 9, p. 5232-5241Article in journal (Refereed)
    Abstract [en]

    The current work demonstrates an innovative approach to develop nanocellulose based membranes with high water permeability, mechanical stability and high functionality via (1) tailoring the composition of the support layer of sludge microfibers/cellulose nanofibers (CNFSL) and (2) in situ TEMPO functionalization of the thin functional layer of cellulose nanocrystals (CNCBE) to enhance the metal ion adsorption capacity. SEM studies showed a porous network structure of the cellulose support layer and a denser functional layer with CNCBE embedded within gelatin matrix. AFM studies indicated the presence of a nanoscaled coating and increased roughness of membranes surface after TEMPO modification whereas FT-IR and conductometric titration confirmed the introduction of carboxyl groups upon TEMPO oxidation. The contact angle measurement results showed improved hydrophilic nature of membranes after in situ TEMPO functionalization. High networking potential of CNFSL made the membrane support layer tighter with a concomitant decrease in the average pore size from 6.5 to 2.0 μm. The coating with CNCBE further decreased the average pore size to 0.78 and 0.58 μm for S/CNCBE and S–CNFSL/CNCBE, respectively. In parallel, a drastic decrease in water flux (8000 to 90 L MPa−1 h−1 m−2) after coating with CNCBE was recorded but interestingly in situ functionalization of top CNCBE layer did not affect water flux significantly. The increase in adsorption capacity of ≈1.3 and ≈1.2 fold was achieved for Cu(II) and Fe(II)/Fe(III), respectively after in situ TEMPO functionalization of membranes. Biodegradation study confirmed the stability of layered membranes in model wastewater and a complete degradation of membranes was recorded after 15 days in soil.

  • 16.
    Karim, Zoheb
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mathew, Aji P.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Kokol, Vanja
    University of Maribor, Institute for Engineering Materials and Design, Smetanova ul. 17, SI-2000 Maribor, Slovenia.
    Wei, Jiang
    Alfa Laval Nakskov A/S, Business Center Membranes, Stavangervej 10, DK-4900, Nakskov, Denmark.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    High-flux affinity membranes based on cellulose nanocomposites for removal of heavy metal ions from industrial effluents2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 25, p. 20644-20653Article in journal (Refereed)
    Abstract [en]

    Fully biobased affinity membrane processing and its application in the removal of heavy metal ions from mirror industry effluents were successfully demonstrated; indicating the potential use of these membranes in point-of-use or point-of-entry water cleaning products that are cheap, environmentally friendly and efficient. Layered cellulose nanocomposite membranes were fabricated using cellulose microfiber sludge as a support layer and cellulose nanocrystals (CNCSL, CNCBE or PCNCSL) in a gelatin matrix as the functional layer. Scanning electron microscopy (SEM) studies revealed the bi-layered morphology of the membrane and well-individualized nanocelluloses in the functional layer. Bubble point measurements confirmed the membrane pore structure in the microfiltration range (5.0-6.1 μm), which provided very high water permeability (900-4000 L h-1 m-2) at <1.5 bars. A tensile strength of 16 MPa in dry conditions and a wet strength of 0.2 MPa, was considered sufficient for use of these membranes in spiral wound modules. Mirror industry effluent laden with metal ions (Ag+ and Cu2+/Fe3+/Fe2+) when treated with cellulose nanocomposite membranes, showed high ion removal capacity, being 100% for PCNCSL followed by CNCBE than CNCSL. The removal of metal ions was expected to be driven by interactions between negatively charged nanocellulose and the positively charged metal ions.

  • 17.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ye, Pengcheng
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zhou, Ming
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    A study of CO2/CO separation by sub-micron b-oriented MFI membranes2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 70, p. 65475-65482Article in journal (Refereed)
    Abstract [en]

    Separation of CO2 and CO is of great importance for many industrial applications. Today, CO2 is removed from CO mainly by adsorption or physical or chemical absorption systems that are energy-intensive and expensive. Membranes are listed among the most promising sustainable and energy-efficient alternatives for CO2 separation. Here, we study CO2/CO separation by novel sub-micron b-oriented MFI zeolite membranes in a temperature range of 258-303 K and at a feed pressure of 9 bar. Under all experimental conditions studied, the membranes were CO2-selective and displayed high CO2 permeance ranging from 17 000 to 23 000 gpu. With decreasing temperature, the CO2/CO selectivity was increasing, reaching a maximum of 26 at 258 K. We also developed a mathematical model to describe the membrane process, and it indicated that the membrane separation performance was a result of selective adsorption of CO2 on the polar zeolite. The heat of adsorption of CO2 on the zeolite is more negative due to the high quadrupole moment and polarisability of the molecule as compared to CO. At the same time, diffusional coupling (correlation effects) at high adsorbed loadings was found to favour the overall CO2/CO selectivity of the membranes by reducing the diffusivity of the lighter CO molecule in the ca. 0.55 nm pores in the zeolite. The model also indicated that the separation performance was limited by the mass transfer resistance in the support and concentration polarisation on the feed side of the membrane.

  • 18.
    Li, Muyang
    et al.
    Michigan State University.
    Pattathil, Sivakumar
    University of Georgia.
    Hahn, Michael G
    University of Georgia.
    Hodge, David
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Identification of features associated with plant cell wall recalcitrance to pretreatment by alkaline hydrogen peroxide in diverse bioenergy feedstocks using glycome profiling2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 33, p. 17282-17292Article in journal (Refereed)
    Abstract [en]

    A woody dicot (hybrid poplar), an herbaceous dicot (goldenrod), and a graminaceous monocot (corn stover) were subjected to alkaline hydrogen peroxide (AHP) pretreatment and subsequent enzymatic hydrolysis in order to assess how taxonomically and structurally diverse biomass feedstocks respond to a mild alkaline oxidative pretreatment and how differing features of the cell wall matrix contribute to its recalcitrance. Using glycome profiling, we determined changes in the extractability of non-cellulosic glucans following pretreatment by screening extracts of the pretreated walls with a panel of 155 cell wall glycan-directed monoclonal antibodies to determine differences in the abundance and distribution of non-cellulosic glycan epitopes in these extracts and assess pretreatment-induced changes in the structural integrity of the cell wall. Two taxonomically-dependent outcomes of pretreatment were identified that both improved the subsequent enzymatic hydrolysis yields but differed in their impacts on cell wall structural integrity. Specifically, it was revealed that goldenrod walls exhibited decreases in all classes of alkali-extractable glycans indicating their solubilization during pretreatment, which was accompanied by an improvement in the subsequent extractability of the remaining cell wall glycans. The corn stover walls did not show the same decreases in glycan abundance in extracts following pretreatment, but rather mild increases in all classes of cell wall glycans, indicating overall weaker associations between cell wall polymers and improved extractability. The hybrid poplar walls were relatively unaffected by pretreatment in terms of composition, enzymatic hydrolysis, and the extractability of cell wall glycans due presumably to their higher lignin content and denser vascular structure.

  • 19.
    Liu, Chang
    et al.
    Nanjing University of Technology, College of Chemistry and Chemical Engineering, Nanjing University of Technology, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Wu, Nanhua
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wang, Jun
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Huang, Liangliang
    School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    Determination of the ion exchange process of K2Ti4O9 fibers at constant pH and modeling with statistical rate theory2015In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, no 90, p. 73474-73480Article in journal (Refereed)
    Abstract [en]

    The ion exchange kinetics of K2Ti4O9 fibers at constant pH was determined precisely by ion-selective electrodes, and activity coefficients of ions in solutions were calculated by the Lu-Maurer equation. It was found that the equilibrium time and TiO2/K2O molar ratio in the solid phase are more sensitive to pH than to water volume. After that, a two-step exchange kinetics model was developed, in which a statistical rate theory base on chemical potential difference between interface was use to describe surface reaction process instead of an empirical exponential equation. The model shows that the resistance of the surface reaction step, which includes hydration of K+ ions on the surface and their transport in the solid phase, is the main resistance of the ion exchange process.

  • 20.
    Liu, Peng
    et al.
    Division of Materials and Environmental Chemistry, Stockholm University.
    Garrido, Beatriz
    Division of Materials and Environmental Chemistry, Stockholm University.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mathew, Aji P.
    Division of Materials and Environmental Chemistry, Stockholm University.
    Adsorption isotherms and mechanisms of Cu(II) sorption onto TEMPO-mediated oxidized cellulose nanofibers2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 109, p. 107759-107767Article in journal (Refereed)
    Abstract [en]

    2,2,6,6-Tetramethyl-1-piperidinyloxy (TEMPO) mediated oxidized cellulose nanofibers (TOCNF) have shown potential in the removal of metal ions from contaminated water owing to their abundant carboxylate groups on their surface, functioning as metal sorption sites. The current work aims to study the kinetics and thermodynamics of the sorption behavior of Cu(II) onto TOCNF, and verify the correlation between Δ[H+] and the corresponding Δ[Cu(II)] in aqueous solution during sorption. Sorption of Cu(II) onto TOCNF was found to be an exothermic process with fast kinetics; reaching equilibrium Cu(II) adsorption in less than 1 min. The sorption data fits well with Langmuir isotherm models. The SEM imaging of the TOCNF after Cu(II) sorption revealed interesting copper-containing nanoparticles, which was further analyzed by using XRD. Besides, a linear correlation between Δ[H+] and the corresponding Δ[Cu(II)] in the solution was found, which indicates that the Cu(II) sorption capacity might be well predicted and calculated by Δ[H+] or pH variation during Cu(II) ion sorption onto TEMPO oxidized nanocellulose fibers and have potential to develop online sensors for tracking metal ion removal. 

  • 21.
    Mu, Liwen
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Shi, Yijun
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Guo, Xiaojing
    Shanghai Institute of Applied Physics, Chinese Academy of Sciences.
    Ji, Tuo
    Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Chen, Long
    Department of Chemical and Biomolecular Engineering, The University of Akron.
    Yuan, Ruixia
    Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Brisbin, Logan
    Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Wang, Huaiyuan
    School of Chemistry & Chemical Engineering, Northeast Petroleum University.
    Zhu, Jiahua
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Non-corrosive green lubricants: strengthened lignin–[choline][amino acid] ionic liquids interaction via reciprocal hydrogen bonding2015In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, no 81, p. 66067-66072Article in journal (Refereed)
    Abstract [en]

    A series of novel green lubricants with dissolved lignin in [choline][amino acid] ([CH][AA]) ionic liquids (ILs) have been synthesized in this work. The effect of lignin on the thermal and tribological properties of the lignin/[CH][AA] lubricants was systematically investigated by means of thermogravimetric analysis, differential scanning calorimetry, and a friction and wear tester. The lignin in [CH][AA] has been demonstrated to be an effective additive to improve thermal stability, reduce the wear rates and stabilize the friction coefficients of lignin/[CH][AA] lubricants. Density function theory calculations on the electronic structure of [CH][AA] ILs reveal the atomic natural charge of ILs and their hydrogen bonding capability with lignin. Moreover, these green lubricants show excellent anti-corrosive properties against commercial aluminum and iron boards. The strong physical adsorption of [CH][AA] ILs onto the steel surface and the reciprocal hydrogen bonding between [CH][AA] ILs and lignin synergistically contribute to the enhanced lubrication film strength and thus the tribological properties of these new lubricants. This work provides a new perspective on utilizing complete bio-products in advanced tribological lubrication systems. In addition, this will open a new application venue for lignin to improve product value in lignocellulosic biomass utilization.

  • 22.
    Mujica-Garcia, Alicia
    et al.
    Dipartimento di Ingegneria Civile e Ambientale, Università di Perugia , Instituto de Ciencia y Tecnología de Polímeros, ICTP-CSIC, Spain.
    Hooshmand, Saleh
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Skrifvars, Mikael
    School of Engineering, University of Borås.
    Kenny, Jose M.
    Dipartimento di Ingegneria Civile e Ambientale, Università di Perugia , Instituto de Ciencia y Tecnología de Polímeros, ICTP-CSIC, Spain.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Peponi, Laura
    Instituto de Ciencia y Tecnología de Polímeros, ICTP-CSIC, Spain.
    Poly(lactic acid) melt-spun fibers reinforced with functionalized cellulose nanocrystals2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 11, p. 9221-9231Article in journal (Refereed)
    Abstract [en]

    Poly(lactic acid)-cellulose nanocrystals (PLA/CNC) nanocomposite fibers with 1% weight fraction of nanocrystals were prepared by melt-spinning. In order to improve the compatibility between the PLA and the CNC, PLLA chains were grafted onto the CNC surface using a “grafting from” reaction. For comparison, melt-spun PLA fibers and nanocomposites with unmodified CNC were also prepared. The morphology, thermal and mechanical properties of the fibers with different draw ratios were evaluated. The results of this research show that the surface modification together with drawing resulted in improved fiber properties, which is expected to depend on the alignment of the CNC and of the PLA molecular chains. The modification is also expected to lead to a flexible interface which also leads to more stretchable fibers. The main conclusion is that PLLA grafting is a very promising way to improve the dispersion of CNC in PLA, creating an interfacial adhesion between the phases and making possible to spun fibers which can be drawn with improved mechanical performance.

  • 23.
    Narang, Kritika
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Fodor, Kristina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Kaiser, Andreas
    Department of Energy Conversion, Technical University of Denmark, Roskilde 4000, Denmark.
    Akhtar, Farid
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Optimized cesium and potassium ion-exchanged zeolites A and X granules for biogas upgrading2018In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 8, no 65, p. 37277-37285Article in journal (Refereed)
    Abstract [en]

    Partially ion-exchanged zeolites A and X binderless granules were evaluated for CO2 separation from CH4. The CO2 adsorption capacity and CO2-over-CH4 selectivity of binderless zeolites A and X granules were optimized by partial exchange of cations with K+ and Cs+, while retaining the mechanical strength of 1.3 MPa and 2 MPa, respectively. Single gas CO2 and CH4 adsorption isotherms were recorded on zeolites A and X granules and used to estimate the co-adsorption of CO2–CH4 using ideal adsorbed solution theory (IAST). The IAST co-adsorption analysis showed that the partially ion-exchanged binderless zeolites A and X granules had a high CO2-over-CH4 selectivity of 1775 and 525 respectively, at 100 kPa and 298 K. Optimally ion-exchanged zeolite X granules retained 97% of CO2 uptake capacity, 3.8 mmol g−1, after 5 breakthrough adsorption–desorption cycles while for zeolite A ion-exchanged granules the reduction in CO2 uptake capacity was found to be 18%; CO2uptake capacity of 3.4 mmol g−1. The mass transfer analysis of breakthrough experimental data showed that the ion-exchanged zeolite X had offered a higher mass transfer coefficient, (κ) through the adsorption column compared to zeolite A; 0.41 and 0.13 m s−1 for NaK4.5Cs0.3X and CaK2.5Cs0.2A, respectively

  • 24.
    Naseri, Narges
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Poirier, Jean-Michel
    Girandon, Lenart
    Educell Ltd., Prevale 9, Trzin.
    Fröhlich, Mirjam
    Educell Ltd., Prevale 9, Trzin.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mathew, Aji P.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    3-Dimensional Porous Nanocomposite Scaffolds Based on Cellulose Nanofibers for Cartilage Tissue Engineering2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 8, p. 5999-6007Article in journal (Refereed)
    Abstract [en]

    Fully bio-based three-dimensional porous scaffold for cartilage repair was prepared via freeze-drying where cellulose nanofibers, which were cytocompatible, were used as mechanical reinforcement (70-90 wt%) in a matrix of gelatin and chitosan (9:1) and crosslinked using genipin. Morphology studies showed that the scaffolds had interconnected pores with favorable pore diameters (< 250 μm) for cell growth. Compression modulus of the scaffolds (1-3 MPa) at room conditions was in the range for natural cartilage and decreased significantly (0.03-0.05 MPa) in phosphate buffered saline (PBS) at 37°C. The high PBS uptake shown by the scaffolds (< 3000 wt%) was attributed to liquid trapped in the pores during immersion in PBS. Furthermore, the scaffolds showed good cytocompatibility towards chondrocytes, which attached and proliferated properly. The scaffolds are considered to have potential in cartilage tissue engineering due to high porosity (≈ 95%) and good mechanical performance that promote cell attachment and extracellular matrix (ECM) production.

  • 25.
    Nyberg, Erik
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Respatiningsih, Catur
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Minami, Ichiro
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Molecular design of advanced lubricant base fluids: hydrocarbon-mimicking ionic liquids2017In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 11, p. 6364-6373Article in journal (Refereed)
    Abstract [en]

    This paper describes the molecular design and tribological evaluation of novel room-temperature ionic liquid (RTIL) lubricants{,} abbreviated as P-SiSOs. The RTILs are designed to mimic hydrocarbons{,} in order to ensure their compatibility with existing tribosystems as well as enable use of conventional additives. Steel-on-steel ball-on-flat reciprocating tribotests performed under atmospheric conditions show that the neat P-SiSOs exhibit favorable performances{,} resulting in friction and wear significantly lower than those in the case of the perfluoropolyether lubricants used as references. Tribotests performed at elevated loads and temperatures indicate the formation of friction-reducing boundary films of the neat P-SiSOs. The tribological performance of the P-SiSO is improved further by the incorporation of additives conventionally used in hydrocarbon oils. When used in a concentration of 5 wt%{,} the additives glycerol monooleate{,} dibenzyl disulfide{,} and oleylamine improve the tribological characteristics of P-SiSO. These results indicate that molecular-designed hydrocarbon-mimicking RTIL lubricants can exhibit suitable performances in the neat form and that their performances can be improved further by using conventional additives{,} as in the case of hydrocarbon base oil-additive systems.

  • 26.
    Pandey, Jaya
    et al.
    Physics Department, University of Lucknow.
    Prajapati, Preeti
    Physics Department, University of Lucknow.
    Shimpi, Manishkumar
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Tandon, Poonam
    Physics Department, University of Lucknow.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Srivastava, Anubha
    Physics Department, University of Lucknow.
    Sinha, Kirti
    Physics Department, University of Lucknow.
    Studies of molecular structure, hydrogen bonding and chemical activity of a nitrofurantoin-L-proline cocrystal: a combined spectroscopic and quantum chemical approach2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 78, p. 74135-74154Article in journal (Refereed)
    Abstract [en]

    Nitrofurantoin (NTF) has been used as an antibacterial drug to treat bacterial infections of the urinary tract. The purpose of this work is to predict the hydrogen bonds (potential synthons) present in the cocrystal of nitrofurantoin-L-proline (NTF-LP) through a computational approach (DFT calculations) and validate using vibrational spectroscopic studies. The present study illustrates the formation and characterization of the cocrystal of NTF-LP. The molecular structure of the NTF-LP cocrystal has been predicted by forming several models on the basis of the hydrogen bonding patterns observed in other NTF cocrystals. A conformational study and potential energy surface scan have been plotted around three flexible bonds of the cocrystal molecule and two stable conformers have been obtained. NBO analysis of the second order perturbation theory of the Fock matrix suggests that interaction n1O(39) → σ*(N13–H21) is responsible for the stabilization of the molecule. Quantum theory of atoms in molecules (QTAIM) explains that all interactions are medium and partially covalent in nature as ∇2ρBCP > 0, HBCP < 0. The molecular electrostatic potential surface (MEPS) of the cocrystal has been visualized for its most electropositive potential in the region of the NH2+ group and most electronegative potential in the vicinity of the COO− group. The HOMO and LUMO energies and electronic charge transfer (ECT) confirms that charge flows from the co-former (LP) to NTF (API). Local reactivity descriptor parameters have been used to predict the reactive sites of the cocrystal and global reactivity descriptor parameters suggest that the cocrystal is softer thus more reactive in comparison to NTF. The experimental and theoretical results support the formation of the cocrystal through the strong hydrogen bond present between the NH group of NTF and carboxylate COO− group of LP and shows that LP is present in the zwitterionic form.

  • 27.
    Papp, Mate
    et al.
    University of Pannonia, Institute of Chemistry, Department of Organic Chemistry, Hungary.
    Szabó, Péter
    University of Pannonia, Institute of Chemistry, Department of Analytical Chemistry, Hungary.
    Sranko, David
    Hungarian Academy of Sciences, Centre for Energy Research, Department of Surface Chemistry and Catalysis, Hungary.
    Skoda-Földes, R.
    University of Pannonia, Institute of Chemistry, Department of Organic Chemistry, Hungary.
    Solvent-free aminocarbonylation of iodobenzene in the presence of SILP-palladium catalysts2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 51, p. 45349-45356Article in journal (Refereed)
    Abstract [en]

    Heterogeneous palladium catalysts were prepared by the immobilisation of palladium on supported ionic liquid phases (SILP) obtained by physisorption or grafting. They were characterised by different techniques such as 13C CP MAS NMR, 31P CP MAS NMR, FT-IR, XPS and ICP. The catalysts were used efficiently under solvent-free conditions. They led to the formation of amide products with good to excellent selectivity. Recyclability at 5–10 bar CO pressure has also been demonstrated. The same reusable catalysts were proved to lead to the selective formation of double carbonylation products under higher pressure in DMF.

  • 28.
    Papp, Máte
    et al.
    Department of Organic Chemistry, Institute of Chemistry, University of Pannonia.
    Szabó, Péter
    Department of Analytical Chemistry, University of Pannonia.
    Srankó, Dávid
    Department of Surface Chemistry and Catalysis, Centre for Energy Research, Hungarian Academy of Sciences.
    Sáfrán, György
    Research Institute for Technical Physics and Materials Science, Hungarian Academy of Sciences.
    Kollár, L.
    Department of Inorganic Chemistry, MTA-PTE Research Group for Selective Chemical Syntheses, University of Pécs.
    Skoda-Földes, R.
    Department of Organic Chemistry, Institute of Chemistry, University of Pannonia.
    Mono- and double carbonylation of aryl iodides with amine nucleophiles in the presence of recyclable palladium catalysts immobilised on a supported dicationic ionic liquid phase2017In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 70, p. 44587-44597Article in journal (Refereed)
    Abstract [en]

    Silica modified with organic dicationic moieties proved to be an excellent support for palladium catalysts used in the aminocarbonylation of aryl iodides. By an appropriate choice of the reaction conditions, the same catalyst could be used for selective mono- or double carbonylations leading to amide and α-ketoamide products, respectively. The best catalyst could be recycled for at least 10 consecutive runs with a loss of palladium below the detection limit. By the application of the new support, efficient catalyst recycling could be achieved under mild reaction conditions (under low pressure and in a short reaction time). Palladium-leaching data support a mechanism with dissolution—re-precipitation of the active palladium species.

  • 29.
    Pathak, Uma
    et al.
    Synthetic Chemistry Division, Defence R and D Establishment.
    Bhattacharyya, Shubhankar
    Synthetic Chemistry Division, Defence R and D Establishment.
    Mathur, Sweta
    Synthetic Chemistry Division, Defence R and D Establishment.
    Selective thioacylation of amines in water: A convenient preparation of secondary thioamides and thiazolines2015In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, no 6, p. 4484-4488Article in journal (Refereed)
    Abstract [en]

    Primary thioamides have been utilised directly in water, without any derivatisation, to selectively thioacylate primary amines. By employing 2-hydroxyethylamines, the reaction can be extended to the preparation of 2-thiazolines via formation of β-hydroxythioamides

  • 30.
    Pathak, Uma
    et al.
    Synthetic Chemistry Division, Defence R and D Establishment.
    Bhattacharyya, Shubhankar
    Synthetic Chemistry Division, Defence R and D Establishment.
    Pandey, Lokesh Kumar
    Synthetic Chemistry Division, Defence R and D Establishment.
    Mathur, Sweta
    Synthetic Chemistry Division, Defence R and D Establishment.
    Jain, Rajeev
    School of Studies in Chemistry, Jiwaji University.
    An easy access to tertiary amides from aldehydes and N,N- dialkylchlorothiophosphoramidates2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 8, p. 3900-3903Article in journal (Refereed)
    Abstract [en]

    A mechanistically unprecedented approach for the formation of tertiary amides from N,N-dialkylchlorothiophosphoramidates and aldehydes has been developed. The reaction occurred via the activation of aldehydes with N,N-dialkylchlorothiophosphoramidates followed by amidation with dialkylamine pendent of the same phosphoramidate

  • 31.
    Singh, Sanjay Kumar
    et al.
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanas.
    Dadhania, Parth
    Pharma Research, Lupin Limited (Research Park), Pune.
    Vuddanda, Parameswara Rao
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Jain, Achint K.
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanas.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Singh, Sanjay
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanas.
    Intranasal delivery of asenapine loaded nanostructured lipid carriers: formulation, characterization, pharmacokinetic and behavioural assessment2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 3, p. 2032-2045Article in journal (Refereed)
    Abstract [en]

    The aim of the present research work was to develop asenapine (ASM) loaded nanostructured lipid carriers (ANLC) for the delivery of drugs in the brain by an intranasal route to enhance therapeutic efficacy. A quality by design approach was used for development and optimization of ANLC. A total of five independent variables were selected, in which three were compositions and two were process variables, while particle size and entrapment efficiency were selected as response variables. The final optimized batch was evaluated by various in vitro characterizations as well as in vivo brain and plasma pharmacokinetic studies. Finally, the ANLC was assessed for efficacy and safety profiling for upto three weeks by a behavior model viz. catalepsy, induced locomotor and paw test in Charles Foster rats. The observed particle size, entrapment efficiency and zeta potential of ANLC was found to be 167.30 +/- 7.52 nm, 83.50 +/- 2.48% and -4.33 +/- 1.27 mV, respectively. Surface characterization studies demonstrated a spherical shape with a smooth surface of ANLC which follows the Korsmeyer-Peppas in vitro release kinetic model (r(2) = 0.9911, n = 0.53). A brain pharmacokinetic study indicated a significantly higher (p < 0.05) peak drug concentration (C-max: 74.13 +/- 6.73 ng mL(-1)), area under the drug concentration-time curve (AUC(0-24) (h): 560.93 +/- 27.85 h ng mL(-1)) and mean residence time (MRT: 7.1 +/- 0.13 h) of ANLC compared to ASM in the brain via an intranasal route. The results of behaviour studies of ANLC showed a significant decrease in extra-pyramidal side effects with increasing antipsychotic effect after 1-2 week(s) of treatment. These findings demonstrate that nanostructured lipid carriers could be a new promising drug delivery system for intranasal delivery of asenapine in the treatment of schizophrenia

  • 32.
    Sngh, Yuvraj N.
    et al.
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanas.
    Vuddanda, Parameswara Rao
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Jain, Achint K.
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanas.
    Parihar, Sarita
    Department of Orthodontics, Institute of Medical Sciences, Banaras Hindu University, Varaansi.
    Chaturvedi, Thakur P.
    Department of Orthodontics, Institute of Medical Sciences, Banaras Hindu University, Varaansi.
    Singh, Sanjay Kumar
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanas.
    Mucoadhesive gel containing immunotherapeutic nanoparticulate satranidazole for treatment of periodontitis: Development and its clinical implications2015In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, no 59, p. 47659-47670Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to alleviate shortcomings in periodontal treatment by utilizing a mucoadhesive gel containing immunotherapeutic ganglioside coated polymeric nanoparticles (G-PNP) bearing satranidazole (SZ). Nanoprecipitation was used to fabricate SZ loaded G-PNP. In our previous deliberations aqueous dispersibility of conventional SZ had raised dose consistency issues. Usage of G-PNP allayed those fears as DSC and XRD data showed that SZ was rendered amorphous (more water dispersible than crystalline SZ) when captured in a polymeric matrix of nanoparticles. G-PNP were added to sodium carboxy methyl cellulose (SCMC 30 NP) gels and compared against SCMC 30 (gel containing conventional SZ) for texture, mucoadhesion, drug release and inhibitory susceptibility of Aggregatibacter actinomycetomicans. Subsequently a 21 day single blind clinical trial comparing the efficacy of SCMC 30 NP and SCMC 30 was conducted. SCMC 30 NP showed a maximum mucoadhesion force (43.27 ± 4.10 gf), low hardness (12.28 ± 0.17 N), moderate gel strength (8.53 ± 0.21 N) and elasticity (5.50 ± 0.03 mm). 'Well' diffusion data revealed qualitatively greater antibacterial activity of SCMC 30 NP. Dissolution studies demonstrated diffusion controlled release of SZ at concentrations above MIC. SCMC 30 NP caused a significant (P < 0.05) decrease in clinical markers of periodontitis, i.e. gingival index and pocket depth as compared to SCMC 30. Also reduction in the plaque index produced by SCMC 30 NP was highly significant (P < 0.01) as compared to SCMC 30 at the end of the 21st day of clinical study. Amelioration of disease was improved due to Th-2 biased immuno shifting mediated by G-PNPs, which increased secretion of anti-inflammatory cytokines like IL-4 and TGF-β from J774 macrophages. Clinical benefits incurred along with ease of application calls for a scaled up investigation of SCMC 30 NP

  • 33.
    Srivastava, Karnica
    et al.
    Physics Department, University of Lucknow.
    Shimpi, Manishkumar
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Srivastava, Anubha
    Physics Department, University of Lucknow.
    Tandon, Poonam
    Physics Department, University of Lucknow.
    Sinha, Kirti
    Physics Department, University of Lucknow.
    Velaga, Sitaram
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Vibrational analysis and chemical activity of paracetamol-oxalic acid cocrystal based on monomer and dimer calculations: DFT and AIM approach2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 12, p. 10024-10037Article in journal (Refereed)
    Abstract [en]

    The study of structural and spectral characteristics of a paracetamol-oxalic acid (PRA-OXA) cocrystal has been carried out using two models (monomer and dimer), with the aim to understand the supramolecular structure and intramolecular interactions within the cocrystal. The cocrystal has been characterized by infrared and Raman spectroscopy combined with quantum chemical calculations molecular electrostatic potential surface (MEPS), frontier orbital analysis and electronic reactivity descriptors were used to understand the role of interactions involved in affecting the chemical reactivity of individual molecules in the cocrystal. It is observed that the C=O, N-H and O-H groups of paracetamol are involved in hydrogen bonds to form cocrystals. NBO analysis suggests that the two types of interactions LP(1)(N8) -> pi*(C9-O10) and LP(2)(O10) -> sigma*(O25-H28) are responsible for the stability of the molecule. AIM analysis suggested that the non-covalent interactions are moderate in nature. The calculated HOMO-LUMO energies reveal that the charge transfer occurs within the cocrystal. Chemical reactivity parameters show that the cocrystal is more active than paracetamol.

  • 34.
    Taher, Mamoun
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Filippov, Andrei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Baets, Patrick De
    Department of Mechanical Construction and Production, Ghent University.
    Glavatskih, Sergei
    Department of Mechanical Construction and Production, Ghent University.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Halogen-free pyrrolidinium bis(mandelato)borate ionic liquids: some physicochemical properties and lubrication performance as additives to polyethylene glycol2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 58, p. 30617-30623Article in journal (Refereed)
    Abstract [en]

    This work reports on the synthesis and physicochemical characterisation of novel halogen-free boron containing ionic liquids (hf-BILs) with dialkylpyrrolidinium cations [CnC1Pyrr]+, n ¼ 4–14, and bis(mandelato)borate anion [BMB]. All the synthesised compounds are liquids at room temperature. It was found that the thermal properties and density of these hf-BILs are affected by the length of the longest alkyl chain connected to the nitrogen atom in the pyrrolidinium cations. Differential scanning calorimetry measurements revealed that glass transition temperatures of these ionic liquids are in the temperature range from 218 to 241 K. Interestingly, the glass transition temperatures follow the “odd– even” effect related to the number of carbons (n) in one of the alkyl chains of [CnC1Pyrr]+. It was also found that hf-BILs' density decreases with an increase in the alkyl chain length of [CnC1Pyrr]+. It is suggested that the “odd–even” effect is associated with the difference in packing and specific interactions of cations and anions of this class of hf-BILs. Their lubricating properties, as 3 wt% additives in polyethylene glycol (PEG), were evaluated in steel–steel contacts. PEG with hf BILs additive provided significantly lower wear and friction compared to the neat PEG and 5W40 engine oil. It was found that shortening the length of the longest alkyl chain in the cations of [CnC1Pyrr][BMB] significantly reduces frictional losses. Antiwear properties of [CnC1Pyrr][BMB] in PEG follow the same trend.

  • 35.
    Talwelkarshimpi, Mayura
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Öberg, Sven
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Giri, Lopamudra
    Solid State and Supramolecular Structural Chemistry Laboratory, School of Basic Sciences, Indian Institute of Technology Bhubaneswar.
    Pedireddi, V.R.
    Solid State and Supramolecular Structural Chemistry Laboratory, School of Basic Sciences, Indian Institute of Technology Bhubaneswar, School of Basic Sciences, Indian Institute of Technology Bhubaneswar.
    Experimental and theoretical studies of molecular complexes of theophylline with some phenylboronic acids2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 49, p. 43060-43068Article in journal (Refereed)
    Abstract [en]

    Molecular complexes of the active pharmaceutical ingredient (API) theophylline, 1 with 4-halophenylboronic acids [4-chlorophenylboronic acid (a), 4-bromophenylboronic acid (b), 4-iodophenylboronic acid (c)], 4-hydroxyphenylboronic acid (d) and 1,4-phenylene-bis-boronic acid (e) have been reported. The complexes were characterized and analysed using the intensity data obtained by X-ray diffraction techniques. All the halo substituted boronic acid complexes are found to be isostructural (1.a, 1.b and 1.c) irrespective of the variations in size and electronegativity of halogen atoms while complexes with non-halogenated boronic acids, 1.d and 1.e, show distinctly different features between themselves as well as with that of 1.a–c, both in two and three-dimensional arrangements. Complexes 1.a–c are noted to be crystallized in the form of sheet structures, which are stacked in three dimensional arrangements, while channels and square grid networks are observed in 1.d and 1.e, respectively. Further the homomeric and heteromeric interactions which occur in the complexes have been analysed by a DFT-D3 method

  • 36.
    Totolin, Vladimir
    et al.
    AC2T research GmbH, Viktor-Kaplan-Strasse 2/C, 2700 Wiener Neustadt, Austria .
    Pisarova, Lucia
    AC2T research GmbH, Viktor-Kaplan-Strasse 2/C, 2700 Wiener Neustadt, Austria .
    Dörr, Nicole
    Minami, Ichiro
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Tribochemistry and thermo-oxidative stability of halogen-free ionic liquids2017In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 77, p. 48766-48776Article in journal (Refereed)
    Abstract [en]

    Heat generation by friction during machine operation causes thermo-oxidative degradation and evaporation of lubricants which in turn generates volatiles. Therefore, having an excellent thermo-oxidative stability is one of the desired prerequisites for the applicability of lubricants in tribological systems. This study reports new insights regarding the thermo-oxidative stability of halogen-free room-temperature ionic liquids (RTILs) as well as fundamental changes in the tribofilm's composition that have a positive impact on their tribological performance at elevated temperatures. In this context, the formation of binary iron phosphates/phosphides based tribofilms from a phosphonium phosphate-based RTIL has been reported for the first time. This RTIL significantly enhances both thermo-oxidative stability and tribological performance of alkylborane–imidazole complexes. A beneficial effect between this RTIL and a conventional friction modifier led to enhanced anti-wear properties supported by the presence of iron phosphide/phosphate tribofilms on the disc surfaces, as detected by XPS.

  • 37.
    Trublet, Mylene
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Maslova, Marina V.
    Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Science Center, Russian Academy of Sciences.
    Rusanova-Naydenova, Daniela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Sorption performances of TiO(OH)(H2PO4)·H2O in synthetic and mine waters2017In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 4, p. 1989-2001Article in journal (Refereed)
    Abstract [en]

    ¨The sorption properties toward Cu2+, Zn2+, Ni2+, Mn2+ and Co2+ ions, in synthetic and industrial waters with pH of 3.9–7.2, and the chemical stability of a titanium phosphate ion-exchanger synthesized at mild conditions and containing solely –H2PO4 groups, TiO(OH)(H2PO4)·H2O (TiP1) are investigated. TiP1 displays the highest Na+ uptake (6.3 meq. g−1) among TiP ion-exchangers and a maximum sorption capacity of ca. 1.55 mmol g−1 (i.e. 3.1 meq. g−1) for the studied ions, which is higher than the ones reported for exchangers composed predominantly of –HPO4 groups. The sorption isotherms were best described by the Temkin model while the Langmuir and the Freundlich models appear to be insufficient in describing all data. TiP1 shows fast kinetics with an equilibrium reached within 10–20 minutes and diffusion processes play a role in the initial period of sorption that is overpowered by chemisorption reactions in the overall rate controlling step. The selectivity order of the metal ions on TiP1 is determined as: Cu2+ > Zn2+ ≫ Mn2+ > Co2+, Ni2+, following the order of stability of MOH+ complexes and the corresponding activation parameters for a water molecule exchange in [M(H2O)6]2+ ions. The surface sorption data are in good correlation with the EDS data for these systems, supporting the idea of chemical sorption with no metal hydroxide precipitation. Additional sorption studies show that the quality of industrial waters after sorption reaches the EU recommendation for drinking water. The faster kinetics and the higher exchange capacity reveal that the presence of –H2PO4 groups strongly enhances the sorption properties of titanium phosphate sorbents.

  • 38.
    Vijayakumar, Mahalingam Rajamanickam
    et al.
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanas.
    Kumari, Lakshmi
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanas.
    Patel, Krishna Kumar
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanas.
    Vuddanda, Parameswara Rao
    Luleå University of Technology, Department of Health Sciences, Medical Science.
    Vajanthri, Kiran Yellappa
    School of Biomedical Engineering, Indian Institute of Technology (Banaras Hindu University).
    Mahto, Sanjeev Kumar
    School of Biomedical Engineering, Indian Institute of Technology (Banaras Hindu University).
    Singh, Sanjay
    Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanas.
    Intravenous administration of trans-resveratrol-loaded TPGS-coated solid lipid nanoparticles for prolonged systemic circulation, passive brain targeting and improved in vitro cytotoxicity against C6 glioma cell lines2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 55, p. 50336-50348Article in journal (Refereed)
    Abstract [en]

    trans-Resveratrol (RSV), a natural molecule isolated from red wine, is widely known for several therapeutic potentials. RSV is proved for cardioprotective, vasodilation, anti-inflammatory, and anticancer effects. Recently, anticancer potential against glioma cells has also been reported. However, the clinical application of RSV in glioma treatment is largely limited because of its rapid metabolism and elimination from systemic circulation thereby exhibiting low biological half-life and poor brain distribution as well. Therefore, the main objective of this study was to enhance the circulation time, biological half-life and passive brain targeting of RSV using D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS)-coated solid lipid nanoparticles (RSV-TPGS-SLN). RSV-TPGS-SLN formulations were prepared by a solvent emulsification evaporation method and evaluated for several nanoparticulate characteristics. In vitro anticancer potential and cellular internalization of nanoparticles were also investigated in C6 glioma cell lines. Pharmacokinetics and biodistribution studies were carried out following intravenous administration in healthy Charles Foster rats. RSV-TPGS-SLN showed significantly higher in vitro cytotoxicity against C6 glioma cell lines and excellent cellular internalization. RSV-TPGS-SLN showed 11.12 and 9.37 times higher area under the curve and plasma half-life than RSV solution, respectively. Moreover, brain distribution of RSV-TPGS-SLN was found to be 9.23 times higher in comparison to that of RSV alone. Thus, we anticipate that the RSV-TPGS-SLN formulation can be applied as a potential tool for improving circulation time, biological half-life and passive brain targeting of RSV, thereby being immensely useful in the treatment of glioma.

  • 39.
    Zhou, Ming
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Rownaghi, Ali
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Synthesis of mesoporous ZSM-5 zeolite crystals by conventional hydrothermal treatment2013In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 3, no 36, p. 15596-15599Article in journal (Refereed)
    Abstract [en]

    Well-defined ZSM-5 crystals with tablet habit, uniform size, controllable silica/alumina ratio, and high mesoporosity were prepared using conventional hydrothermal treatment under stirring. The key to obtaining high mesoporosity of the crystals was to stir a synthesis mixture containing a relatively high concentration of alumina

1 - 39 of 39
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