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Publications (10 of 11) Show all publications
Nikjoo, D., Perrot, V. & Akhtar, F. (2019). Laminated Porous Diatomite Monoliths for Adsorption of Dyes From Water. Environmental Progress & Sustainable Energy, 38(s1), 377-385
Open this publication in new window or tab >>Laminated Porous Diatomite Monoliths for Adsorption of Dyes From Water
2019 (English)In: Environmental Progress & Sustainable Energy, ISSN 1944-7442, E-ISSN 1944-7450, Vol. 38, no s1, p. 377-385Article in journal (Refereed) Published
Abstract [en]

Structured laminated diatomite monoliths with superior mechanical properties were prepared by controlled freeze-casting of the aqueous suspensions of diatomite powders for wastewater treatment. The directional freezing of suspensions with solids loading of 25, 30, and 37 wt % at cooling from 0.5 to 5 K/min resulted in the formation of lamellar pores and solid walls with the thickness of 12–30 and 14–39 μm, respectively. The increase in solid loading and freezing rate resulted in refinement of the porous structure. Durable monoliths with the mechanical strength of 5.3 MPa were obtained by thermal treatment of the freeze-dried green bodies at 1,373 K. Diatomite monoliths with a pore size of 29.6 μm showed the removal of model dye pollutant Rhodamine B from water by adsorption and long-term water stability. The dye uptake capacity of monolith changed from 1.38 to 17.04 mg/g for the initial dye concentrations between 1.0 and 12.5 mg/L at 298 K and pH = 6, respectively. The adsorption data analysis using Lagergren's pseudo-first-order, pseudo-second-order, and intra-particle diffusion models revealed that diatomite monoliths offered efficient mass transfer in the porous laminated scaffold and to the adsorption sites and bulk diffusion of dye molecules in water was the rate-limiting mechanism for dye removal. © 2018 American Institute of Chemical Engineers Environ Prog, 2018.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
Keywords
porous ceramic, diatomite, freeze‐casting, adsorption, dye uptake
National Category
Other Materials Engineering
Research subject
Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-71352 (URN)10.1002/ep.13064 (DOI)000460576900040 ()2-s2.0-85054712187 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-03-08 (johcin)

Available from: 2018-10-26 Created: 2018-10-26 Last updated: 2019-04-12Bibliographically approved
Velaga, S., Nikjoo, D. & Rao Vuddanda, P. (2018). Experimental Studies and Modeling of the Drying Kinetics of Multicomponent Polymer Films. AAPS PharmSciTech, 19(1), 425-435
Open this publication in new window or tab >>Experimental Studies and Modeling of the Drying Kinetics of Multicomponent Polymer Films
2018 (English)In: AAPS PharmSciTech, ISSN 1530-9932, E-ISSN 1530-9932, Vol. 19, no 1, p. 425-435Article in journal (Refereed) Published
Abstract [en]

The process of drying thin polymer films is an important operation that influences the film structure and solid state, and the stability of the product. The purpose of this work was to study and model the drying kinetics of multicomponent films based on two polymers: hydroxypropyl methylcellulose (HPMC, amorphous) and polyvinyl alcohol (PVA, semicrystalline). The isothermal drying kinetics of the films at different temperatures (40, 60, and 80°C) were studied using thermo-gravimetric analysis (TGA) and convection oven methods. Solid-state characterization tools used in the study included polarization and hot-stage microscopy, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). The drying kinetics of HPMC and PVA films in the TGA apparatus and convection oven were comparable. The three-parameter (Wmax, τ, n) Hill equation successfully modeled the experimental drying kinetics. The time factor τ in the Hill equation nicely explained two drying phases in the films. Solid-state phase changes occurring in the films during dehydration had a bearing on the drying kinetics and mechanisms. TGA can be used as a simple tool to determine the end points in drying processes using ovens or tunnels. The three-parameter Hill equation explained the drying kinetics and diffusion mechanisms of the solvent through the polymer films for the first time. This study advances our understanding of film drying, in particular for pharmaceutically relevant thin films.

Place, publisher, year, edition, pages
Springer, 2018
National Category
Other Health Sciences Other Materials Engineering
Research subject
Health Science; Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-65096 (URN)10.1208/s12249-017-0836-8 (DOI)000419174600040 ()28762212 (PubMedID)
Note

Validerad;2018;Nivå 2;2018-01-23 (andbra)

Available from: 2017-08-15 Created: 2017-08-15 Last updated: 2018-04-11Bibliographically approved
Nikjoo, D. & Aroguz, A. (2017). Dual responsive polymeric bionanocomposite gel beads for controlled drug release systems. Journal of Applied Polymer Science, 134(33), 45143
Open this publication in new window or tab >>Dual responsive polymeric bionanocomposite gel beads for controlled drug release systems
2017 (English)In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 134, no 33, p. 45143-Article in journal (Refereed) Published
Abstract [en]

Scientists are searching potential solutions for cancer treatments as well as ways to avoid the side effects of anti-cancer agents, via targeted drug delivery. The aim of this research is to propose dual responsive beads based on sodium alginate (SA), methylcellulose (MC), and magnetic iron oxide nanoparticles (MIONs) for controlled release of 5-Fluorouracil (5-FU) as model drug. The beads were prepared by the dual crosslinking of SA and MC in the presence of MIONs. The structural, thermal, morphological, magnetic characteristics as well as the release profile of 5-FU were studied. The characterization results showed that the drug molecules and MIONs were well dispersed in the polymeric matrix. The cumulative release percentage was ca. 80% at pH = 4.2 and 40% at pH = 7.2 after 6 h. Thus, the sensitivity of beads on the pH value was verified. Moreover, the release profile exhibited reduction with an increase in the concentration of MIONs under an external magnetic field. The obtained results confirmed the dual sensitive release of 5-FU (i.e., PH/magnetic) that can be used for the targeted and controlled drug delivery systems.

Place, publisher, year, edition, pages
John Wiley & Sons, 2017
National Category
Engineering and Technology Other Materials Engineering
Research subject
Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-65164 (URN)10.1002/app.45143 (DOI)
Available from: 2017-08-17 Created: 2017-08-17 Last updated: 2018-03-05Bibliographically approved
Knutsson, S., Kindahl, T., Engdahl, C., Nikjoo, D., Forsgren, N., Kitur, S., . . . Linusson, A. (2017). N-Aryl-N'-ethyleneaminothioureas effectively inhibit acetylcholinesterase 1 from disease-transmitting mosquitoes. European Journal of Medicinal Chemistry, 134, 415-427
Open this publication in new window or tab >>N-Aryl-N'-ethyleneaminothioureas effectively inhibit acetylcholinesterase 1 from disease-transmitting mosquitoes
Show others...
2017 (English)In: European Journal of Medicinal Chemistry, ISSN 0223-5234, E-ISSN 1768-3254, Vol. 134, p. 415-427Article in journal (Refereed) Published
Abstract [en]

Vector control of disease-transmitting mosquitoes by insecticides has a central role in reducing the number of parasitic- and viral infection cases. The currently used insecticides are efficient, but safety concerns and the development of insecticide-resistant mosquito strains warrant the search for alternative compound classes for vector control. Here, we have designed and synthesized thiourea-based compounds as non-covalent inhibitors of acetylcholinesterase 1 (AChE1) from the mosquitoes Anopheles gambiae (An. gambiae) and Aedes aegypti (Ae. aegypti), as well as a naturally occurring resistant-conferring mutant. The N-aryl-N’-ethyleneaminothioureas proved to be inhibitors of AChE1; the most efficient one showed submicromolar potency. Importantly, the inhibitors exhibited selectivity over the human AChE (hAChE), which is desirable for new insecticides. The structure-activity relationship (SAR) analysis of the thioureas revealed that small changes in the chemical structure had a large effect on inhibition capacity. The thioureas showed to have different SAR when inhibiting AChE1 and hAChE, respectively, enabling an investigation of structure-selectivity relationships. Furthermore, insecticidal activity was demonstrated using adult and larvae An. gambiae and Ae. aegypti mosquitoes.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Medical and Health Sciences Other Materials Engineering
Research subject
Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-65167 (URN)10.1016/j.ejmech.2017.03.050 (DOI)000401677500035 ()28433681 (PubMedID)2-s2.0-85017625955 (Scopus ID)
Available from: 2017-08-17 Created: 2017-08-17 Last updated: 2018-03-05Bibliographically approved
Nikjoo, D. & Akhtar, F. (2017). Porous polymeric membranes as CO2 adsorbents. In: : . Paper presented at International Materials Research Meeting In The Greater Region, Saarbrücken, 6-7 April 2017.
Open this publication in new window or tab >>Porous polymeric membranes as CO2 adsorbents
2017 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Engineering and Technology Other Materials Engineering
Research subject
Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-65168 (URN)
Conference
International Materials Research Meeting In The Greater Region, Saarbrücken, 6-7 April 2017
Available from: 2017-08-17 Created: 2017-08-17 Last updated: 2018-03-05Bibliographically approved
Nikjoo, D. & Akhtar, F. (2017). Structured emulsion-templated porous copolymer based on photopolymerization for carbon capture. Journal of CO2 Utilization, 21, 473-479
Open this publication in new window or tab >>Structured emulsion-templated porous copolymer based on photopolymerization for carbon capture
2017 (English)In: Journal of CO2 Utilization, ISSN 2212-9820, E-ISSN 2212-9839, Vol. 21, p. 473-479Article in journal (Refereed) Published
Abstract [en]

Porous hydrogel copolymers of acrylamide (AAM) and acrylic acid (AAC) were structured in the form of monoliths and granules. AAM-co-AAC porous copolymer monoliths were synthesized using high internal phase emulsion (HIPE) as template and photopolymerization. For granulation, photopolymerization was used for the fabrication of the AAM-co-AAC hydrogel, which was subsequently freeze-granulated. The structural analysis (FTIR and XRD) confirmed the successful synthesis of hydrogel copolymers. The CO2 uptake capacity of structured AAM-co-AAC copolymers was evaluated through adsorption and absorption mechanisms by volumetric and gravimetric methods, respectively. The granules exhibited the CO2 adsorption uptake of 0.8 mmol g-1 at 25 kPa and 298 K. The CO2 and N2 adsorption data demonstrated that the hydrogel copolymers were selective for CO2. Furthermore, the granules were capable of capturing CO2 in the presence of water. The results of absorption of CO2 on water-swollen granules demonstrated that CO2-uptake capacity increases with increasing water content up to 1.8 mmol g-1.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Other Materials Engineering
Research subject
Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-65516 (URN)10.1016/j.jcou.2017.08.007 (DOI)000411443200053 ()2-s2.0-85028456006 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-09-06 (andbra)

Available from: 2017-09-06 Created: 2017-09-06 Last updated: 2018-03-05Bibliographically approved
Velaga, S., Nikjoo, D. & Rao Vuddanda, P. (2016). Drying Kinetics of Polymeric Films: theoretical and experimental studies. In: : . Paper presented at AAPS Annual Meeting and Exposition, Denver, Colorado, November 13-17 2016.
Open this publication in new window or tab >>Drying Kinetics of Polymeric Films: theoretical and experimental studies
2016 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Engineering and Technology Materials Engineering Other Health Sciences Other Materials Engineering
Research subject
Health Science; Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-65341 (URN)
Conference
AAPS Annual Meeting and Exposition, Denver, Colorado, November 13-17 2016
Available from: 2017-08-26 Created: 2017-08-26 Last updated: 2018-04-11Bibliographically approved
Nikjoo, D. & Aroguz, A. (2016). Magnetic field responsive methylcellulosepolycaprolactonenanocomposite gels for targeted and controlled release of 5-Fluorouracil. International Journal of Polymeric Materials, 65(8), 421-432
Open this publication in new window or tab >>Magnetic field responsive methylcellulosepolycaprolactonenanocomposite gels for targeted and controlled release of 5-Fluorouracil
2016 (English)In: International Journal of Polymeric Materials, ISSN 0091-4037, E-ISSN 1563-535X, Vol. 65, no 8, p. 421-432Article in journal (Refereed) Published
Abstract [en]

5-Fluorouracil loaded magnetic field sensitive methylcellulose and polycaprolactone gels were prepared and characterized by FTIR, XRD, TGA, SEM, and VSM. Swelling analysis supplied important information on drug diffusion properties. The release profile of gels was investigated in different buffer solutions and the highest release values were observed at pH = 7.2. Release kinetic was analyzed using an empirical equation to clarify the transport properties of drug. The effects of nanoparticle concentration and applying external magnetic field were investigated on release profile. The results indicated that the drug release decreased by both, applying external magnetic field and increasing the concentration of Fe3O4 nanoparticles.

National Category
Other Materials Engineering
Research subject
Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-61895 (URN)10.1080/00914037.2015.1129954 (DOI)
Available from: 2017-02-09 Created: 2017-02-09 Last updated: 2018-03-05Bibliographically approved
Nikjoo, D. (2014). Design and Synthesis of a Small Set of Thiourea-based Compounds as Inhibitors of AChE1 from Mosquitoes.
Open this publication in new window or tab >>Design and Synthesis of a Small Set of Thiourea-based Compounds as Inhibitors of AChE1 from Mosquitoes
2014 (English)Other (Other academic)
National Category
Other Materials Engineering
Research subject
Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-61924 (URN)
Available from: 2017-02-09 Created: 2017-02-09 Last updated: 2018-03-05Bibliographically approved
Nikjoo, D. & Aroguz, A. Z. (2013). Viscometric Analysis of Miscibility and Interactions for Binary, Ternary Polycarbonate/Brominated Polystyrene + Chloroform Systems at Different Temperatures. Journal of macromolecular science. Pure and applied chemistry (Print), 50(9), 1007-1011
Open this publication in new window or tab >>Viscometric Analysis of Miscibility and Interactions for Binary, Ternary Polycarbonate/Brominated Polystyrene + Chloroform Systems at Different Temperatures
2013 (English)In: Journal of macromolecular science. Pure and applied chemistry (Print), ISSN 1060-1325, E-ISSN 1520-5738, Vol. 50, no 9, p. 1007-1011Article in journal (Refereed) Published
Abstract [en]

Viscosities of ternary systems consist of polycarbonate (PC)/brominated polystyrene (PBrS) in chloroform and their corresponding binary systems were measured at different temperatures (20, 25, and 30°C). All the measurements were carried out at the concentration ranges of 0.1–0.6 g·dL−1. The mass ratio of PC to PBrS was selected as 75:25, 50:50, and 25:75 in the ternary solutions. Two empirical expressions of Huggins and Kraemer equations with three-parameters were used for reproducing of the experimental viscosity data. The fitting parameters were obtained for the corresponding temperatures. The miscibility criteria on the basis of the sign of Δ[η]m based on the difference between experimental and ideal values of [η]m, was calculated by applying the Garcia et al., theoretical equation. The effect of temperature on the viscosity data was also studied. The results from this method were correlated with the miscibility data obtained for the same system by differential scanning calorimeter (DSC) findings.

Place, publisher, year, edition, pages
Taylor & Francis, 2013
National Category
Polymer Technologies Other Materials Engineering
Research subject
Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-61897 (URN)10.1080/10601325.2013.814337 (DOI)000322616500012 ()2-s2.0-84882360474 (Scopus ID)
Available from: 2017-02-09 Created: 2017-02-09 Last updated: 2018-03-05Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4628-3857

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