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  • 1.
    Goetz, Lee
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Karim, Zoheb
    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.
    Effect of micropatterned cellulose acetate membranes impregnated with cellulose and chitin nanocrystals on water filtration membrane behavior2016Manuscript (preprint) (Other academic)
  • 2.
    Goetz, Lee
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Naseri, Narges
    Department of Materials and Environmental Chemistry, Stockholm University.
    Nair, Santhosh S.
    Department of Materials and Environmental Chemistry, Stockholm University.
    Karim, Zoheb
    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. Department of Materials and Environmental Chemistry, Stockholm University.
    All cellulose electrospun water purification membranes nanotextured using cellulose nanocrystals2018In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 5, p. 3011-3023Article in journal (Refereed)
    Abstract [en]

    Cellulose acetate (CA) fibers were electrospun on a mesh template to create specific surface and pore structures for membrane applications. The mesh template CA fiber mats were impregnated with cellulose nanocrystals at varying weight percentages. The membranes showed nanotextured surfaces and improved mechanical properties post impregnation. More importantly, the hydrophilicity of the original CA fibers was increased from a hydrophobic contact angle of 102°–0° thereby creating an anti-fouling membrane surface structure. The membranes showed rejection of 20–56% for particles of 0.5–2.0 μm, indicating potential of these membranes in rejecting microorganisms from water. Furthermore, high rejection of dyes (80–99%) by adsorption and potential application as highly functional affinity membranes was demonstrated. These membranes can therefore be utilized as all-cellulose, green, scalable and low cost high flux membranes (> 20,000 LMH) for water cleaning applications in food industry where microorganisms and charged contaminants are to be removed.

  • 3.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Nanocellulose based affinity membranes for water purification: Processing technologies for optimal adsorption of dyes and metal ions2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The aim of current study was to fabricate high flux affinity membrane with mechanical stability, porosity and high functionality for capturing of contaminants (dyes and metal ions) from water. Cellulose nanocrystals (CNCSL) and cellulose nanofibers (CNFSL) as well as a special grade of cellulose nanocrystals (CNCBE) isolated following bioethanol pilot scale process were used for the membrane fabrication. To improve the functionality and adsorption capacity of the membranes, enzymatic phosphorylated CNCSL (PCNCSL) and in situ TEMPO functionalized CNCBE (TEMPO-CNCBE) membranes were adopted. The removal of water contaminants via adsorption on carboxyl, sulphonic and phosphoryl functional groups on nanocellulose based membranes was evaluated. Freeze-drying was used as one approach to fabricate CNCSL based hybrid membranes. In spite of high percentage removal of positively charges dyes, low water flux and mechanical stability was recorded. Very fast and effective process, viz. vacuum-filtration was further used to fabricate layered membranes with improved mechanical properties. CNFSL based support layer was coated with more functional nanomaterials (CNCSL and CNCBE) via dipping. The study showed that it was possible to tailor the specific surface area, pore sizes, water flux and wet strength of the membranes based on drying conditions (105 °C at a load of 100kN and 28 oC at ≈20N) and acetone treatment. This study was further extended to fabricate high flux bi-layered membrane having support layer of micro-sized cellulose sludge and top layer of CNCSL, CNCBE and PCNCSL within gelatin matrix for adsorption. The aim of this approach was to provide mechanical stability without decreasing the water flux significantly. In the final study, to increase the adsorption capacity of CNCBE layered membranes; in situ functionalization (TEMPO oxidation) of top layer was performed. Furthermore, CNFSL was introduced in support layer to understand the structural and functional behavior of CNFSL. All membranes were subjected to pollutants removal [dyes and Ag(I), Cu(II), Fe(II)/Fe(III) metal ions]. Remarkable increase in adsorption capacity towards metal ions was recorded after modification of nanocellulose (phosphorylation and in situ functionalization). The outstanding performance of nanocellulose reveals the possibility of next generation affinity membranes for water purification.

  • 4.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Processing and characterization of membranes based on cellulose nanocrystals for water purification: Nanocellulose as functional entity2014Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Membrane technology is being extensively used in water purification as an energy efficient and low cost process. Nanostructured (NSM) and nanoenabled (NEM) membranes are favored in this context as nanoscaled entities are expected to provide high surface area, high mechanical properties and versatile surface chemistry as well as provide better control on the pore size and distribution, flux and selectivity of the membrane. Biobased nanoparticles as nanocrystals are expected to have a significant advantage in this context. Thus, the main aim of this work was to explore the use of cellulose nanocrystals as functional entities for the fabrication of nanoenabled composite membranes and apply these fabricated membranes for the removal of dyes and metal ions from polluted water. The first study deals with the isolation of cellulose nanocrystals (CNCBE) from wood using the bioethanol pilot scale setup. Cellulose was prepared from wood by diluted acid treatment in the bioethanol plant followed by dewaxing and bleaching. The cellulose was converted into cellulose nanocrystals by mechanical grinding using lab scale homogenizer. The isolated nanoparticles had a diameter of 5-15 nm and formed a thick gel at 2 wt%. X-ray photoelectron spectroscopy illustrated the presence of O=C-O surface functional groups, directly related to the negative zeta-potential values. Fabricated films of CNCBE denoted good mechanical properties, optical properties and cytocompatibility. Thus, a new isolation route that can be followed to produce nanocrystals in large quantities (600 g/ day) has been developed. In a second study, fully biobased nanocomposite membranes of cellulose nanocrystals and chitosan have been fabricated by freeze-drying and crosslinking with gluteraldehyde in vapor phase. The chitosan bound the CNCSL in a stable and nanoporous membrane network with thickness of 250-270 μm. Homogenous dispersion of CNCSL within chitosan matrix was reported based on scanning electron microscopy (SEM). The Brunauer Emmett and Teller (BET) studies showed a decrease in surface area (3.1 to 2.9 m2/g) and average pore size (17 to 13 nm) after crosslinking. The mechanical performance of composite membranes was low, being 0.98 ± 0.4 and 1.1 ± 0.3 MPa of tensile strength for uncross-linked and cross-linked membranes, respectively. In spite of low water flux (64 L m−2 h−1), the composite membranes successfully removed 98%, 84% and 70% respectively of positively charged dyes like Victoria Blue 2B, Methyl Violet 2B and Rhodamine 6G, from a model wastewater after a contact time of 24 h. In the third study layered membranes containing a highly porous support layer and a dense functional layer has been fabricated following a filtration and hot pressing method. Microsized cellulose fibers from sludge bioresidues was used as the support layer to provide mechanical stability and allow water flow without any hindrance. A nanocomposite system of nanocrystals (CNCSL, CNCBE and PCNCSL) with gelatin as matrix was used as the functional layer. Bubble point measurement confirmed the membrane pore sizes (5-6 m), in microfiltration range, which resulted in high water permeability < 4000 Lh-1m-2 at 1.5 bars. Efficient removal of Ag+, Cu2+ and Fe3+ from industrial wastewater was achieved using these membranes. The removal of metal ions was expected to be driven by the electrostatic attraction between negatively charged nanocellulose and the positively charged metal ions. The work has demonstrated that highly efficient water treatment membranes can be fabricated from nanocellulose via tailoring their ability to interact and selectively adsorb heavy metal ions and dyes.

  • 5.
    Karim, Zoheb
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Afrin, Sadaf
    Department of Chemistry, Faculty of Sciences , Aligarh Muslim University .
    Hussain, Qayyum
    Department of Biochemistry, Faculty of Life Sciences , Aligarh Muslim University .
    Danish, Rehan
    Infinity Vacuum Technology , Geomdan Techpart Geomdangondan-Ro 26, Buk-Gu , Daegu .
    Necessity of enzymatic hydrolysis for production and functionalization of nanocelluloses2017In: Critical reviews in biotechnology, ISSN 0738-8551, E-ISSN 1549-7801, Vol. 37, no 3, p. 355-370Article in journal (Refereed)
    Abstract [en]

    Nanocellulose (NC) from cellulosic biomass has recently gained attention owing to their biodegradable nature, low density, high mechanical properties, economic value and renewability. They still suffer, however, some drawbacks. The challenges are the exploration of raw materials, scaling, recovery of chemicals utilized for the production or functionalization and most important is toxic behavior that hinders them from implementing in medical/pharmaceutical field. This review emphasizes the structural behavior of cellulosic biomass and biological barriers for enzyme interactions, which are pertinent to understand the enzymatic hydrolysis of cellulose for the production of NCs. Additionally, the enzymatic catalysis for the modification of solid and NC is discussed. The utility of various classes of enzymes for introducing desired functional groups on the surface of NC has been further examined. Thereafter, a green mechanistic approach is applied for understanding at molecular level

  • 6.
    Karim, Zoheb
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Claudpierre, Simon
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Grahn, Mattias
    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.
    Mathew, Aji P.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Nanocellulose based functional membranes for water cleaning: Tailoring of mechanical properties, porosity and metal ion capture2016In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 514, p. 418-428Article in journal (Refereed)
    Abstract [en]

    Multi-layered nanocellulose membranes were prepared using vacuum-filtration of cellulose nanofibers (CNF) suspensions followed by dip coating with cellulose nanocrystals having sulphate (CNCSL) or carboxyl surface groups (CNCBE). It was possible to tailor the specific surface area, pore structure, water flux and wet strength of the membranes based on drying conditions and acetone treatment. CNF coated with CNCBE showed the highest a tensile strength (95 MPa), which decreased in wet conditions (≈3.7 MPa) and with acetone (2.7 MPa) treatment. The water dried membranes showed pore sizes in nanofiltration range (74 Å) from liquid nitrogen adsorption/desorption data and the acetone treatment increased the average pore sizes to tight ultrafiltration range (194Å) with a concomitant increase (7000%) of the BET surface area. The water flux, also increased from zero to 25 Lm-2h-1 at a pressure differential of 0.45 MPa, for acetone treated ones. The membranes irrespective of the surface functionality showed exceptional capability (≈100%) to remove Ag+, Cu2+ and Fe3+ ions from mirror industry effluents. Surface adsorption followed by microprecipitation was considered as the possible mechanism of ion removal, which opens up a new generation of ultrafiltration membranes with high selectivity towards ions and low-pressure demands.

  • 7.
    Karim, Zoheb
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    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.
    Chitosan based nanocomposite membranes with cellulose nanowhisker as nanoadditive2013Conference paper (Refereed)
    Abstract [en]

    Biobased nanocomposite membranes were prepared using chitosan as te matrix and cellulose nano whisker as the reinforcing phase. Cellulosee production. Atomic force microscopy of the nanowhiskers showed diameters of 10 -20nm and lengths of 250 - 350nm. Nanocomposites were prepared in 1:1, 1:2 and 1:3 ratios to investigate the effect of nanoadditive concentration on the membrane properties. The nanocomposites were prepared by solution mixing followed by freeze-drying, to obtain porous structures with high degree of internal surface area. These nanocomposites were further treated with ammonia vapours to prepare the crosslinked nanocomposites and thereby stabilize it towards moisture and pH variations. The morphology, surface area, crystallinity, porosity, and mechanical properties of prepared membranes were studied. The effect of the nanocomposite composition, crosslinking and the pore size distribution on the water transport through the membranes was also evaluated.

  • 8.
    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.

  • 9.
    Karim, Zoheb
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Khan, Mohd Jahir
    School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi.
    Maskat, Mohamad Yusof
    School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi.
    Adnan, Rohana
    School of Chemical Sciences, Universiti Sains Malaysia, Minden Penang.
    Immobilization of horseradish peroxidase on β-cyclodextrin-capped silver nanoparticles: Its future aspects in biosensor application2016In: Preparative Biochemistry & Biotechnology, ISSN 1082-6068, E-ISSN 1532-2297, Vol. 46, no 4, p. 321-327Article in journal (Refereed)
    Abstract [en]

    This study aimed to work out a simple and high-yield procedure for the immobilization of horseradish peroxidase on silver nanoparticle. Ultraviolet–visible (UV-vis) and Fourier-transform infrared spectroscopy and transmission electron microscopy were used to characterize silver nanoparticles. Horseradish peroxidase was immobilized on β-cyclodextrin-capped silver nanoparticles via glutaraldehyde cross-linking. Single-cell gel electrophoresis (Comet assay) was also performed to confirm the genotoxicity of silver nanoparticles. To decrease toxicity, silver nanoparticles were capped with β-cyclodextrin. A comparative stability study of soluble and immobilized enzyme preparations was investigated against pH, temperature, and chaotropic agent, urea. The results showed that the cross-linked peroxidase was significantly more stable as compared to the soluble counterpart. The immobilized enzyme exhibited stable enzyme activities after repeated uses.

  • 10.
    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.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Mouzon, Johanne
    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.
    Nanoporous membranes with cellulose nanocrystals as functional entity in chitosan: removal of dyes from water2014In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 112, p. 668-676Article in journal (Refereed)
    Abstract [en]

    Fully biobased composite membranes for water purification were fabricated with cellulose nanocrystals (CNCs) as functional entities in chitosan matrix via freeze-drying process followed by compacting. The chitosan (10 wt%) bound the CNCs in a stable and nanoporous membrane structure with thickness of 250-270 μm, which was further stabilized by cross-linking with gluteraldehyde vapors. Scanning electron microscopy (SEM) studies revealed well-individualized CNCs embedded in a matrix of chitosan. Brunauer, Emmett and Teller (BET) measurements showed that the membranes were nanoporous with pores in the range of 13-10 nm. In spite of the low water flux (64 L m-2 h-1), the membranes successfully removed 98%, 84% and 70% respectively of positively charged dyes like Victoria Blue 2B, Methyl Violet 2B and Rhodamine 6G, after a contact time of 24 h. The removal of dyes was expected to be driven by the electrostatic attraction between negatively charged CNCs and the positively charged dyes.

  • 11.
    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.

  • 12.
    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.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Cellulose nanocrystals based nanocompositemembranes for water purification: Process-Property correlation2015Conference paper (Other academic)
  • 13.
    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.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Fully biobased nanocomposite membranes: removal of heavy metals from polluted water2014Conference paper (Refereed)
    Abstract [en]

    Biobased nanoparticles viz cellulose nanocrystals (CNCs) and cellulose nanofiber (CNFs) isolated by mechanical process (grinding) were used to fabricate of fully biobased nanocomposite membranes. Biobased nanofibers were used as support layer via a very simple process of vacuum filtration was used for the fabrication of CNF support layer. In order to coat CNCs or CNCbio on the two sides to CNF layer, the membrane was dipped in a solution of cellulose nanocrystals. Scanning electron microscopy (SEM) confirmed the infusion of functional layer within supportive layer. Tensile strength was measured in dry as well as in wet conditions, illustrated mechanical performances compareble to commercially available membranes. To increase the flux, membranes were treated with acetone for 24 and 72 h. The drastic increase in the flux for acetone treated membranes confirmed the discontinuities of hydrogen . The membranes succefully removed two metal ions Ag+ and As3- from real wastewater, from mirror making and mining industries respectively, within Europe. Complete removal of Ag+ was reported after 24 h of incubation. The study concludes that, the developed membranes having good mechanical stability in wet conditions, high water flux and adsorption efficiency are potential candidates for heavy metal ion remediation of industrial effluents.

  • 14.
    Liu, Peng
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Goetz, Lee
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    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.
    Biobased nanoparticles and membranes for water purification via selective adsorption: Possibilities and challenges2014Conference paper (Refereed)
    Abstract [en]

    With population expansion and industrialization, water pollutions have become one of the biggest threat to human society today. The combination of biotechnology and nanotechnology offers a new and green way to the problems. Cellulose nanofibers cellulose nanocrystals and chitin nanocrystals have nanoscaled diameters and have high specific surface areas, an advantage in membrane technology and the efficiency can be further enhanced using specific functionalization, enabling highly specific interactions with targeted contaminant entities in water. Moreover, the nano-dimensions of the used active species allow the fabrication of compact and ultra-thin multifunctional membranes by introducing an orientation and/or concentration gradient. This novel water purification approach combines the physical filtration process and the adsorption process exploring the capability of the nanocellulose and/or nanochitin (with or without functionalization) to selectively adsorb, store and desorb contaminants from industrial water and drinking water while passing through a highly permeable membranes/ filters. The aim is to tailor membarnes and filters with high flux which reduces pressure and thereby energy consumption while keeping the high selectivity efficiency due to surface adsorption. The results showed highly efficient removal of metal ions (Ag+, Cu2+ and Fe3)+ from mirror making industry using nanocellulose based membranes. High removal efficiency of dyes, nitrates and organic foulants using bio- based membranes/ filters was also confirmed. The nanocellulose and nanochitin based membranes also showed significant resistance to bio-fouling. The scaled up membranes is expected to be used in the form of spiral wound modules, cartridge modules and MBR modules for water treatment in mirror industries, printing industries, mining industries as well as municipal water and storm water in Europe.

  • 15.
    Mathew, Aji P.
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Liu, Peng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Nanocellulose as functional material for water cleaning2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247Article in journal (Refereed)
  • 16.
    Mathew, Aji P.
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Liu, Peng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Nanocellulose for water purification membranes2013In: Production and Applications of Cellulose Nanomaterials, TAPPI Press, 2013, p. 155-156Chapter in book (Refereed)
    Abstract [en]

    Nanocelluloses have demonstrated good adsorption capacity towards dyes, heavy metal ions, pesticides etc. and combined with their good mechanical strength, high surface area, crystallinity and moisture stability are expected to be a promising functional entity in the next generation of nano-enabled membranes. Furthermore, the large number of functional groups present on the surface of these membranes gives a positive approach to modify the surface according to our needs, thus increasing the selectivity of pollutants. When used in combination with biopolymers/ biodegradable polymers can lead to fully biobased water purification membranes.

  • 17.
    Mathew, Aji P.
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Liu, Peng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Bionanocomposite mbranes for water purification: Tailoring the morohology and selectivity for pollutants2013Conference paper (Refereed)
  • 18.
    Mathew, Aji P.
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Liu, Peng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Nanocellulose and functional material for water cleaning2014Conference paper (Refereed)
  • 19.
    Mathew, Aji P.
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Liu, Peng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Nanocellulose and Nanochitin in Membrane Applications2014In: Handbook of Green Materials: Processing Technologies, Properties and Applications, Singapore: World Scientific and Engineering Academy and Society, 2014Chapter in book (Refereed)
  • 20.
    Mathew, Aji P.
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Liu, Peng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Kokol, Vanja
    Saarivouri, Elina
    VTT Technical Research Centre of Finland, Espoo.
    Pajula, Tiina
    VTT Technical Research Centre of Finland, Espoo.
    Bio- nanocomposite membranes and adsorbents for water purification: Performance and environmental impacts2014Conference paper (Refereed)
    Abstract [en]

    NanoSelect project deals with the development of fully biobased membranes and adsorbants containing nanocellulose and nanochtin as functional entities to selectively adsorb and remove contaminants from water. Nanocellulose isolated from bioresources or industrial residues showed potential for removal of contaminants from industrial water. Biobased membranes and adsorbents were prepared using native and surface modified nanocellulose as functional additive by different methods as freeze drying, vacuum filtration or coating on support layers. The prepared membranes/ adsorbents had pore structures in the range of ultra and nanofiltration membrane. The mechanical properties of prepared membranes were studied as a function of nanocomposite composition, processing methods, crosslinking and environmental factors. All membranes were stable in use conditions and showed a tensile strength as high as 10 MPa in wet conditions. The developed membranes showed high flux (16X106 L/h/m2/KPa) as well as high percentage removal of dyes (up to 99%) especially when functionalized nanoparticles were used. The results indicate that cheap and efficient biobased membranes prepared by simple processes as vacuum filtration and coating has great potential as water purification membranes in industrial waste water treatment. Furthermore, the environmental performance of the membranes is evaluated based on LCA methodology. This will contribute to the further product development. In the first phase the presumably most significant elements of the value chain in terms of environmental impacts have been identified.

  • 21.
    Mathew, Aji P.
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Liu, Peng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Khan, Saad Ahmad
    Naseri, Narges
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Process scale up and characterization of wood cellulose nanocrystals hydrolysed using bioethanol pilot plant2014In: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 58, p. 212-219Article in journal (Refereed)
    Abstract [en]

    The paper discusses the isolation of cellulose nanocrystals (CNCBE) from wood resources by integrating the processing with pilot-scale bioethanol processing unit. The nanocrystals were isolated from cellulose obtained by acid pretreatment of wood chips in a bioethanol pilot-scale facility, followed by a series of chemical processes and subsequent homogenization using a lab-scale homogenizer. The isolated nanocrystals had diameters of 5-15 nm, cellulose I crystalline structure and formed a thick semi-transparent gel at low concentration (2 wt%). XPS data showed that these nanocrystals had predominantly O=C-O surface groups which also contributed to its high negative zeta potential. Casted CNCBE films showed excellent mechanical performance (200 MPa of strength, 16 GPa of modulus) and transparency and were also found to be cytocompatible. The developed process route resulted in high-quality nanocellulose crystals with a yield of 600 g/day.

  • 22.
    Mautner, Andreas
    et al.
    Polymer and Composite Engineering (PaCE) Group, Institute for Materials Chemistry and Research, University of Vienna.
    Maples, H. A.
    Polymer and Composite Engineering (PaCE) Group, Institute for Materials Chemistry and Research, University of Vienna.
    Kobkeatthawin, T.
    Polymer and Composite Engineering (PaCE) Group, Institute for Materials Chemistry and Research, University of Vienna.
    Kokol, V.
    University of Maribor, Institute for Engineering Materials and Design, Smetanova ul. 17, SI-2000 Maribor, Slovenia.
    Karim, Zoheb
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Li, K
    Department of Chemical Engineering, Imperial College London, South Kensington Campus.
    Bismarck, A.
    Polymer and Composite Engineering (PaCE) Group, Institute for Materials Chemistry and Research, University of Vienna.
    Phosphorylated nanocellulose papers for copper adsorption from aqueous solutions2016In: Journal of Environmental Science and Engineering A, ISSN 2162-5298, E-ISSN 2162-5301, Vol. 13, no 8, p. 1861-1872Article in journal (Refereed)
    Abstract [en]

    Copper is a major problem in industrial wastewater streams, seriously affecting the quality of potential drinking water. Several approaches, including continuous membrane processes or batch-wise application of adsorbents, are in use to tackle this problem. Unfortunately, these processes suffer from their particular drawbacks, such as low permeance or disposal of saturated adsorbents. However, a combination of these processes could constitute a step towards a more efficient copper removal solution. Here, we present a nanopaper ion-exchanger prepared from cellulose nanofibrils produced from fibre sludge, a paper industry waste stream, for the efficient, continuous removal of copper from aqueous solutions. This nanopaper ion-exchanger comprises phosphorylated cellulose nanofibrils that were processed into nanopapers by papermaking. The performance of these phosphorylated nanopaper membranes was determined with respect to their rejection of copper and permeance. It was shown that this new type of nanopaper is capable of rejecting copper ions during a filtration process by adsorption. Results suggest that functional groups on the surface of the nanopapers contribute to the adsorption of copper ions to a greater extent than phosphate groups within the bulk of the nanopaper. Moreover, we demonstrated that those nanopaper ion-exchangers could be regenerated and reused and that in the presence of calcium ions, the adsorption capacity for copper was only slightly reduced

1 - 22 of 22
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