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polyacrylic-acid
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Synthesis and properties of biodegradable hydrogels of κ-carrageenan grafted acrylic acid-co-2-acrylamido-2-methylpropanesulfonic acid as candidates for drug delivery systems
, Article Reactive and Functional Polymers ; Volume 67, Issue 7 , 2007 , Pages 644-654 ; 13815148 (ISSN) ; Barzegar, Sh ; Zeidabadi, F ; Sharif University of Technology
2007
Abstract
Novel types of highly swelling hydrogels were prepared by grafting crosslinked polyacrylic acid-co-poly-2-acrylamido-2-methylpropanesulfonic acid (PAA-co-PAMPS) chains onto κ-carrageenan through a free radical polymerization method. Here, we propose a mechanism for κ-carrageenan-g-PAA-co-PAMPS formation and confirm the hydrogel structure using FTIR spectroscopy. The effect of grafting variables (i.e. concentration of methylenebisacrylamide (MBA), acrylic acid/-2-acrylamido-2-methylpropanesulfonic acid (AA/AMPS) weight ratio, ammonium persulfate (APS), κ-carrageenan, neutralization percent and reaction temperature) were systematically optimized to achieve a hydrogel with a maximum swelling...
Synthesis and Characterization of Flexible Supercapacitors Based on Polymeric Hydrogel
, M.Sc. Thesis Sharif University of Technology ; Shojae, Akbar (Supervisor)
Abstract
Today, supercapacitors are an inseparable component of electronic devices such as hybrid cars, telecommunication equipment, and personal electronic devices, and this device is also used to store clean energy. In this research, polyacrylic acid hydrogel was first synthesized to be used as a supercapacitor electrode and polyaniline was used as an electrically conductive polymer in its structure to improve the electrical properties of this hydrogel. To achieve this structure, the previously synthesized polyacrylic acid hydrogel was immersed in a solution of aniline monomer and other components necessary for the aniline polymerization reaction, and after the soaking process was completed, the...
Optimization of synthesis conditions of a novel carrageenan-based superabsorbent hydrogel by taguchi method and investigation of its metal ions adsorption
, Article Journal of Applied Polymer Science ; Volume 107, Issue 5 , 2008 , Pages 2970-2976 ; 00218995 (ISSN) ; Amini Fazl, M. S ; Barzegar, Sh ; Sharif University of Technology
2008
Abstract
The Taguchi method, a robust experimental design, was used for optimization of synthesis of a novel biopolymer-based superabsorbent hydrogel, kappa-carrageenan (K-C)-g-acrylic acid (AA)-co-2-acrylamido-2- methylpropanesulfonic acid (AMPS). The Taguchi method was applied for the experimental and standard 18 orthogonal arrays (OA) with seven factors and three levels for each factor. In the synthesis of the superabsorbent, N,N'-methylene bisacrylamide (MBA) as crosslinker, ammonium persulfate (APS) as initiator, monomer ratio (AA/AMPS), K-C concentration, Total Monomer, neutralization percent (NU), and reaction temperature were used as important factors. After analyzing with analysis of...
Preparation of Polyelectrolyte-Coated Magnetic Silica Nanocomposite Particles and Investigation of their Application for Enzyme Immobilization and Biodiesel Production
, Ph.D. Dissertation Sharif University of Technology ; Kazemeini, Mohammad (Supervisor) ; Arpanaei, Ayyoob (Supervisor) ; Singh, Gurvinder (Co-Advisor)
Abstract
In this study, polyelectrolyte-coated magnetic silica nanocomposites were prepared via the covalent attachment of polyelectrolytes onto the as-prepared magnetite-silica particles with core-shell structures and average diameter of 210±50 nm, and subsequently applied for the immobilization of lipase molecules. In this regard, polyethyleneimine (PEI) with two molecular weights of 10000 and 750000 and polyacrylic acid (PAA) with two molecular weights of 1800 and 100000 were utilized. The type and molecular weight of the polyelectrolyte molecules greatly impacted the concentration of binding sites on the particles surface and consequently on the lipase immobilization efficiency and loading...
Effects of physicochemical characteristics of magnetically recoverable biocatalysts upon fatty acid methyl esters synthesis from oils
, Article Renewable Energy ; Volume 116 , 2018 , Pages 613-622 ; 09601481 (ISSN) ; Kazemeini, M ; Singh, G ; Arpanaei, A ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
This study reports the importance of physicochemical characteristics of the core-shell structured polymer-coated Fe3O4 cluster@SiO2 nanocomposite particles for designing the biocatalysts used for transesterification of soybean oil. To demonstrate this issue, two different types of polymer molecules such as polyethylenimine (PEI) and polyacrylic acid (PAA) each with two different molecular weights are employed. The highest fatty acid methyl esters (FAMEs) synthesis yield values are achieved by the lipases immobilized onto the low- and high-molecular-weight PEI-coated particles as compared to those of the low- and high-molecular-weight PAA-coated particles (i.e., ∼64.8% and ∼73.1% versus...
Recent advances in the design and applications of amyloid-β peptide aggregation inhibitors for Alzheimer’s disease therapy
, Article Biophysical Reviews ; Volume 11, Issue 6 , 2019 , Pages 901-925 ; 18672450 (ISSN) ; Khazaei, S ; Behnammanesh, H ; Shamloo, A ; Erfani, M ; Beiki, D ; Bavi, O ; Sharif University of Technology
Springer
2019
Abstract
Alzheimer’s disease (AD) is an irreversible neurological disorder that progresses gradually and can cause severe cognitive and behavioral impairments. This disease is currently considered a social and economic incurable issue due to its complicated and multifactorial characteristics. Despite decades of extensive research, we still lack definitive AD diagnostic and effective therapeutic tools. Consequently, one of the most challenging subjects in modern medicine is the need for the development of new strategies for the treatment of AD. A large body of evidence indicates that amyloid-β (Aβ) peptide fibrillation plays a key role in the onset and progression of AD. Recent studies have reported...