The Experts below are selected from a list of 1374 Experts worldwide ranked by ideXlab platform
Jun Nie - One of the best experts on this subject based on the ideXlab platform.
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Photo-polymeriable chitosan derivative prepared by Michael reaction of chitosan and Polyethylene Glycol Diacrylate (PEGDA).
International journal of biological macromolecules, 2009Co-Authors: Xiaodan Zhang, Jing Han, Guoqiang Song, Jun NieAbstract:N-Alkyled photo-polymeriable chitosan derivative (PEGDA-CS) was synthesized by Michael reaction of chitosan and Polyethylene Glycol Diacrylate (PEGDA) under mild reaction conditions. The chemical structure and physical properties of PEGDA-CS were characterized by FT-IR, 1H NMR, XRD and TG techniques. The degree of substitution (DS) of PEGDA-CS could be calculated from 1H NMR. PEGDA-CS exhibited good solubility in distilled water. XRD analysis showed that PEGDA-CS was amorphous. TG results demonstrated that thermal stability of the derivate was lower than that of chitosan. Antimicrobial test showed that PEGDA-CS had the antimicrobial activity on Escherichia coli. It could photopolymerize under ultraviolet light with 2959 as initiator.
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chitosan Polyethylene Glycol Diacrylate films as potential wound dressing material
International Journal of Biological Macromolecules, 2008Co-Authors: Xiaodan Zhang, Dongzhi Yang, Jun NieAbstract:Michael addition reaction of Chitosan (CS) and Polyethylene Glycol Diacrylate (PEGDA) was carried out successfully in acidic solution. Films with CS/PEGDA weight ratios from 100/0 to 0/100 in 10% increments were analyzed by Fourier transform infrared (FTIR) spectroscopy, Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). Additionally, the films were characterized by measuring mechanical property, swelling property. The potential application of the CS/PEGDA film as wound dressing material was evaluated in vitro by using mouse fibroblasts (L929) as reference cell lines, indirect cytotoxicity assessment indicated that CS/PEGDA films were nontoxic to L929 cell.
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Chitosan/Polyethylene Glycol Diacrylate films as potential wound dressing material
International Journal of Biological Macromolecules, 2008Co-Authors: Xiaodan Zhang, Dongzhi Yang, Jun NieAbstract:Michael addition reaction of Chitosan (CS) and Polyethylene Glycol Diacrylate (PEGDA) was carried out successfully in acidic solution. Films with CS/PEGDA weight ratios from 100/0 to 0/100 in 10% increments were analyzed by Fourier transform infrared (FTIR) spectroscopy, Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). Additionally, the films were characterized by measuring mechanical property, swelling property. The potential application of the CS/PEGDA film as wound dressing material was evaluated in vitro by using mouse fibroblasts (L929) as reference cell lines, indirect cytotoxicity assessment indicated that CS/PEGDA films were nontoxic to L929 cell. ?? 2008.
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Photocuring of mono- and di-functional (meth)acrylates with tris [2-(acryloyloxy)ethyl]isocyanurate
European Polymer Journal, 1999Co-Authors: Jun Nie, Lars Å. Lindén, Jan F. Rabek, Jan EkstrandAbstract:Abstract The photoinitiated polymerization by camphorquinone alone and/or with ethyl-4-dimethylaminobenzoate of mono-functional monomers (hydroxyethyl acrylate, glycidyl methactylate), di-functional monomers (Polyethylene Glycol Diacrylate, triethylene Glycol dimethacrylate), with tri-functional monomer (tris[2-(acryloyloxy)ethyl]isocyanurate) by visible light (>400 nm) has been investigated. The very high photoreactivity of tris[2-(acryloyloxy)ethyl]isocyanurate dominates all photopolymerization in kinetics. The maximum functional group conversion and the volume shrinkage are dependent on the number of functional groups, type of functional groups and the polymerization conditions. The volume shrinkage decreased for filled (70%) composites. Dental formulations based on photocuring of these mono-, di- and tri-functional monomers can be considered for clinical applications.
Ol’ga V. Yarmolenko - One of the best experts on this subject based on the ideXlab platform.
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Conducting properties of nanocomposite polymer electrolytes based on Polyethylene Glycol Diacrylate and SiO2 nanoparticles at the interface with a lithium electrode
Russian Chemical Bulletin, 2018Co-Authors: G. R. Baymuratova, A. V. Yudina, A. A. Slesarenko, Ol’ga V. YarmolenkoAbstract:Nanocomposite polymer electrolytes based on Polyethylene Glycol Diacrylate and 1 M LiBF4 solution in γ-butyrolactone with addition of SiO2 nanoparticles were synthesized and studied. Resistance measurement at the Li/electrolyte and Li/nanocomposite electrolyte interface by the time-resolved electrochemical impedance showed its significant decrease in the presence of SiO2 nanoparticles. Charge-discharge cycling of prototypes of Li/LiFePO4 batteries for 50 cycles also showed the advantage of using nanocomposite polymer electrolytes over electrolytes without SiO2 additives.
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NMR study of the Polyethylene Glycol Diacrylate-LiBF4-1-butyl-3-methylimidazolium tetrafluoroborate-propylene/ethylene carbonate electrolyte system
Russian Journal of Electrochemistry, 2015Co-Authors: Alexander V. Chernyak, Ol’ga V. Yarmolenko, A. V. Yudina, V. I. VolkovAbstract:The 1-butyl-3-methylimidazolium tetrafluoroborate-propylene carbonate-ethylene carbonate system in a reticular polymer electrolyte based on Polyethylene Glycol Diacrylate and LiBF4 was studied by high-resolution and pulsed field gradient NMR. The 1H, 13C, 7Li, and 19F NMR spectra of the electrolyte systems were analyzed. During the electrolyte synthesis, propylene undergoes structural changes in the ionic liquid, which adversely affects the ion conductivity (the maximum conductivity in this system is 8.46 × 10−4 S/cm at 20°C) and the self-diffusion coefficients of the lithium ions. When the propylene carbonate content in the polymer electrolyte increased from 15 to 32 wt %, the proportion of lithium ions with a high self-diffusion coefficient (10−11 m2/s) decreased from 24 to 7%. In the case of ethylene carbonate, this effect was less pronounced, the conductivity in these systems reaching 2.46 × 10−3 S/cm at 20°C. The high-resolution NMR study did not reveal any structural changes in the ionic liquid and ethylene carbonate during the modeling of radical polymerization.
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New polymer electrolytes based on Polyethylene Glycol Diacrylate–LiBF4–1-ethyl-3-methylimidazolium tetrafluoroborate with the introduction of alkylene carbonates
Russian Chemical Bulletin, 2015Co-Authors: Ol’ga V. Yarmolenko, L. M. Bogdanova, A. V. Yudina, A. A. Ignatova, N. I. Shuvalova, Vyacheslav M. Martynenko, Alexander V. Chernyak, V. A. Zabrodin, V. I. VolkovAbstract:Polymer gel electrolytes based on Polyethylene Glycol Diacrylate (PEG DA), salt LiBF4, and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) were synthesized and studied in the presence of propylene carbonate and ethylene carbonate as solvents. The mechanism of ionic transport in the system was studied using electrochemical impedance spectroscopy, liquid mass spectrometry, pulse-field-gradient spin echo NMR spectroscopy. The range of operating temperatures of the gel electrolytes was determined by DSC. The total conductivity at room temperature in these systems is about 10–3 S cm–1. The self-diffusion coefficients on 7Li nuclei in the systems with a solvent attain the values about 10–10 m2 s–1, and in the PEG DA–LiBF4–EMIBF4 system they range from 10–13 to 10–12 m2 s–1. Ternary associates [(EMI)2(BF4)]+ and [Li+(BF4)2]– were found by liquid mass spectrometry to be the main charge carriers.
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Towards the mechanism of Li+ ion transfer in the net solid polymer electrolyte based on Polyethylene Glycol Diacrylate–LiClO4
Journal of Solid State Electrochemistry, 2012Co-Authors: Ol’ga V. Yarmolenko, K. G. Khatmullina, G. Z. Tulibaeva, L. M. Bogdanova, Alexander F. ShestakovAbstract:Ion transport in the new three-dimensional network polymer electrolytes that are completely amorphous in the solid state has been studied on the example of the matrix model with a monomer—Polyethylene Glycol Diacrylate, cross-linked by radical polymerization. The nature of ionic conductivity in solid polymer electrolytes based on Polyethylene Glycol Diacrylate at different concentrations of salt LiClO4 was studied by methods of electrochemical impedance, differential scanning calorimetry analysis, Fourier transform infrared spectroscopy and quantum chemical modeling. The maximum value of conductivity in the range of 20–100 °C is realized at 20 wt% content of LiClO4. The reason for the low conductivity of the SPE studied is the small degree of dissociation of contact ion pairs. At the increase in the salt content associates of contact pairs Li+ClO4−, dimers and trimers (at LiClO4 >20 wt%) are formed. The appearances of trimers are accompanied by a decrease in conductivity due to lowering of contact pair content.
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towards the mechanism of li ion transfer in the net solid polymer electrolyte based on Polyethylene Glycol Diacrylate liclo4
Journal of Solid State Electrochemistry, 2012Co-Authors: Ol’ga V. Yarmolenko, K. G. Khatmullina, G. Z. Tulibaeva, L. M. Bogdanova, Alexander F. ShestakovAbstract:Ion transport in the new three-dimensional network polymer electrolytes that are completely amorphous in the solid state has been studied on the example of the matrix model with a monomer—Polyethylene Glycol Diacrylate, cross-linked by radical polymerization. The nature of ionic conductivity in solid polymer electrolytes based on Polyethylene Glycol Diacrylate at different concentrations of salt LiClO4 was studied by methods of electrochemical impedance, differential scanning calorimetry analysis, Fourier transform infrared spectroscopy and quantum chemical modeling. The maximum value of conductivity in the range of 20–100 °C is realized at 20 wt% content of LiClO4. The reason for the low conductivity of the SPE studied is the small degree of dissociation of contact ion pairs. At the increase in the salt content associates of contact pairs Li+ClO4−, dimers and trimers (at LiClO4 >20 wt%) are formed. The appearances of trimers are accompanied by a decrease in conductivity due to lowering of contact pair content.
Alexander F. Shestakov - One of the best experts on this subject based on the ideXlab platform.
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Towards the mechanism of Li+ ion transfer in the net solid polymer electrolyte based on Polyethylene Glycol Diacrylate–LiClO4
Journal of Solid State Electrochemistry, 2012Co-Authors: Ol’ga V. Yarmolenko, K. G. Khatmullina, G. Z. Tulibaeva, L. M. Bogdanova, Alexander F. ShestakovAbstract:Ion transport in the new three-dimensional network polymer electrolytes that are completely amorphous in the solid state has been studied on the example of the matrix model with a monomer—Polyethylene Glycol Diacrylate, cross-linked by radical polymerization. The nature of ionic conductivity in solid polymer electrolytes based on Polyethylene Glycol Diacrylate at different concentrations of salt LiClO4 was studied by methods of electrochemical impedance, differential scanning calorimetry analysis, Fourier transform infrared spectroscopy and quantum chemical modeling. The maximum value of conductivity in the range of 20–100 °C is realized at 20 wt% content of LiClO4. The reason for the low conductivity of the SPE studied is the small degree of dissociation of contact ion pairs. At the increase in the salt content associates of contact pairs Li+ClO4−, dimers and trimers (at LiClO4 >20 wt%) are formed. The appearances of trimers are accompanied by a decrease in conductivity due to lowering of contact pair content.
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towards the mechanism of li ion transfer in the net solid polymer electrolyte based on Polyethylene Glycol Diacrylate liclo4
Journal of Solid State Electrochemistry, 2012Co-Authors: Ol’ga V. Yarmolenko, K. G. Khatmullina, G. Z. Tulibaeva, L. M. Bogdanova, Alexander F. ShestakovAbstract:Ion transport in the new three-dimensional network polymer electrolytes that are completely amorphous in the solid state has been studied on the example of the matrix model with a monomer—Polyethylene Glycol Diacrylate, cross-linked by radical polymerization. The nature of ionic conductivity in solid polymer electrolytes based on Polyethylene Glycol Diacrylate at different concentrations of salt LiClO4 was studied by methods of electrochemical impedance, differential scanning calorimetry analysis, Fourier transform infrared spectroscopy and quantum chemical modeling. The maximum value of conductivity in the range of 20–100 °C is realized at 20 wt% content of LiClO4. The reason for the low conductivity of the SPE studied is the small degree of dissociation of contact ion pairs. At the increase in the salt content associates of contact pairs Li+ClO4−, dimers and trimers (at LiClO4 >20 wt%) are formed. The appearances of trimers are accompanied by a decrease in conductivity due to lowering of contact pair content.
Xiaodan Zhang - One of the best experts on this subject based on the ideXlab platform.
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Photo-polymeriable chitosan derivative prepared by Michael reaction of chitosan and Polyethylene Glycol Diacrylate (PEGDA).
International journal of biological macromolecules, 2009Co-Authors: Xiaodan Zhang, Jing Han, Guoqiang Song, Jun NieAbstract:N-Alkyled photo-polymeriable chitosan derivative (PEGDA-CS) was synthesized by Michael reaction of chitosan and Polyethylene Glycol Diacrylate (PEGDA) under mild reaction conditions. The chemical structure and physical properties of PEGDA-CS were characterized by FT-IR, 1H NMR, XRD and TG techniques. The degree of substitution (DS) of PEGDA-CS could be calculated from 1H NMR. PEGDA-CS exhibited good solubility in distilled water. XRD analysis showed that PEGDA-CS was amorphous. TG results demonstrated that thermal stability of the derivate was lower than that of chitosan. Antimicrobial test showed that PEGDA-CS had the antimicrobial activity on Escherichia coli. It could photopolymerize under ultraviolet light with 2959 as initiator.
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chitosan Polyethylene Glycol Diacrylate films as potential wound dressing material
International Journal of Biological Macromolecules, 2008Co-Authors: Xiaodan Zhang, Dongzhi Yang, Jun NieAbstract:Michael addition reaction of Chitosan (CS) and Polyethylene Glycol Diacrylate (PEGDA) was carried out successfully in acidic solution. Films with CS/PEGDA weight ratios from 100/0 to 0/100 in 10% increments were analyzed by Fourier transform infrared (FTIR) spectroscopy, Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). Additionally, the films were characterized by measuring mechanical property, swelling property. The potential application of the CS/PEGDA film as wound dressing material was evaluated in vitro by using mouse fibroblasts (L929) as reference cell lines, indirect cytotoxicity assessment indicated that CS/PEGDA films were nontoxic to L929 cell.
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Chitosan/Polyethylene Glycol Diacrylate films as potential wound dressing material
International Journal of Biological Macromolecules, 2008Co-Authors: Xiaodan Zhang, Dongzhi Yang, Jun NieAbstract:Michael addition reaction of Chitosan (CS) and Polyethylene Glycol Diacrylate (PEGDA) was carried out successfully in acidic solution. Films with CS/PEGDA weight ratios from 100/0 to 0/100 in 10% increments were analyzed by Fourier transform infrared (FTIR) spectroscopy, Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). Additionally, the films were characterized by measuring mechanical property, swelling property. The potential application of the CS/PEGDA film as wound dressing material was evaluated in vitro by using mouse fibroblasts (L929) as reference cell lines, indirect cytotoxicity assessment indicated that CS/PEGDA films were nontoxic to L929 cell. ?? 2008.
Chih-chang Chu - One of the best experts on this subject based on the ideXlab platform.
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synthesis characterization and cytotoxicity of photo crosslinked maleic chitosan Polyethylene Glycol Diacrylate hybrid hydrogels
Acta Biomaterialia, 2010Co-Authors: Chao Zhong, Cynthia A Reinhartking, Chih-chang ChuAbstract:Abstract Synthetic hydrogels are important biomaterials for many biomedical applications and hydrogels produced via photo-gelation have shown particular promise. In this paper, we describe a new family of biodegradable hybrid hydrogels fabricated in aqueous solution via long wavelength UV photo-crosslinking using maleic chitosan and Polyethylene Glycol Diacrylate (PEGDA) as precursors. The maleic chitosan precursor was prepared by a simple one-step chemical modification of chitosan, with high yields, and characterized by Fourier transform infrared spectroscopy, 1H NMR and 13C NMR. Maleic chitosan and PEGDA precursors at a wide range of weight feed ratios were mixed in aqueous solution and directly photo-crosslinked for 10 min under a long wavelength UV light (365 nm) using 4-(2-hydroxyethoxy) phenyl-(2-hydroxy-2-propyl) ketone (Irgacure 2959) as photoinitiator. It was observed that as the weight feed ratio of maleic chitosan to PEGDA decreased the pore sizes of the hydrogel samples decreased, thereby increasing the densities of the hydrogel networks and producing a lower swelling ratio and a higher compressive modulus. The molecular weight of PEGDA had a similar effect. Preliminary cell cytotoxicity tests of both the maleic chitosan precursor and maleic chitosan/PEGDA hydrogels, based on the MTT assay and live–dead assay, respectively, showed that these new chitosan-based biodegradable biomaterials were relatively non-toxic to bovine aortic endothelial cells at low dosages.
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Synthesis, characterization and cytotoxicity of photo-crosslinked maleic chitosan–Polyethylene Glycol Diacrylate hybrid hydrogels
Acta biomaterialia, 2010Co-Authors: Chao Zhong, Cynthia A. Reinhart-king, Chih-chang ChuAbstract:Abstract Synthetic hydrogels are important biomaterials for many biomedical applications and hydrogels produced via photo-gelation have shown particular promise. In this paper, we describe a new family of biodegradable hybrid hydrogels fabricated in aqueous solution via long wavelength UV photo-crosslinking using maleic chitosan and Polyethylene Glycol Diacrylate (PEGDA) as precursors. The maleic chitosan precursor was prepared by a simple one-step chemical modification of chitosan, with high yields, and characterized by Fourier transform infrared spectroscopy, 1H NMR and 13C NMR. Maleic chitosan and PEGDA precursors at a wide range of weight feed ratios were mixed in aqueous solution and directly photo-crosslinked for 10 min under a long wavelength UV light (365 nm) using 4-(2-hydroxyethoxy) phenyl-(2-hydroxy-2-propyl) ketone (Irgacure 2959) as photoinitiator. It was observed that as the weight feed ratio of maleic chitosan to PEGDA decreased the pore sizes of the hydrogel samples decreased, thereby increasing the densities of the hydrogel networks and producing a lower swelling ratio and a higher compressive modulus. The molecular weight of PEGDA had a similar effect. Preliminary cell cytotoxicity tests of both the maleic chitosan precursor and maleic chitosan/PEGDA hydrogels, based on the MTT assay and live–dead assay, respectively, showed that these new chitosan-based biodegradable biomaterials were relatively non-toxic to bovine aortic endothelial cells at low dosages.
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synthesis characterization of biodegradable dextran allyl isocyanate ethylamine Polyethylene Glycol Diacrylate hydrogels and their in vitro release of albumin
Carbohydrate Polymers, 2006Co-Authors: Guoming Sun, Chih-chang ChuAbstract:Abstract Based on dextran–allyl isocyanate–ethylamine (Dex-AE) and Polyethylene Glycol–Diacrylate (PEGDA), a pH sensitive biodegradable hydrogel with improved protein release was prepared through UV photo-crosslinking. The Dex-AE precursor was prepared through a two-step chemical modification and characterized by FT-IR and 1H NMR. The effects of reaction conditions on the synthesis of Dex-AE were studied. The interior morphology data by scanning electron microscopy (SEM) revealed that an increase in Dex-AE content led to an initial decrease in pore size of the microstructure of the Dex-AE/PEGDA hydrogels, but a further increase in Dex-AE content resulted in a relatively looser network structure. The swelling data indicated that the swelling ratio depended on the precursor feed ratio and was correlated to the morphology of the microporous network structure. The pH sensitive property of the Dex-AE/PEGDA hydrogels was studied in different pH buffer solutions and was found that these hydrogels were pH sensitive due to the presence of ample pendant amino groups. The ionic strength data demonstrated that the Dex-AE/PEGDA hydrogels exhibit the highest swelling ratio in pure water, but the swelling ratio became lower as the ionic strength of the media increased. The in vitro albumin release from these hydrogels was examined in different pH (3.0, 7.4) buffer solutions. Both the protein loading and release data indicated that the Dex-AE/PEGDA hydrogels had more protein loading and sustained release capability than pure PEGDA hydrogel, and this ability increased as the Dex-AE composition increased; the Dex-AE/PEGDA hydrogel also showed a faster BSA release in a lower pH than a higher pH medium.
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Synthesis, characterization of biodegradable dextran–allyl isocyanate–ethylamine/Polyethylene Glycol–Diacrylate hydrogels and their in vitro release of albumin
Carbohydrate Polymers, 2006Co-Authors: Guoming Sun, Chih-chang ChuAbstract:Abstract Based on dextran–allyl isocyanate–ethylamine (Dex-AE) and Polyethylene Glycol–Diacrylate (PEGDA), a pH sensitive biodegradable hydrogel with improved protein release was prepared through UV photo-crosslinking. The Dex-AE precursor was prepared through a two-step chemical modification and characterized by FT-IR and 1H NMR. The effects of reaction conditions on the synthesis of Dex-AE were studied. The interior morphology data by scanning electron microscopy (SEM) revealed that an increase in Dex-AE content led to an initial decrease in pore size of the microstructure of the Dex-AE/PEGDA hydrogels, but a further increase in Dex-AE content resulted in a relatively looser network structure. The swelling data indicated that the swelling ratio depended on the precursor feed ratio and was correlated to the morphology of the microporous network structure. The pH sensitive property of the Dex-AE/PEGDA hydrogels was studied in different pH buffer solutions and was found that these hydrogels were pH sensitive due to the presence of ample pendant amino groups. The ionic strength data demonstrated that the Dex-AE/PEGDA hydrogels exhibit the highest swelling ratio in pure water, but the swelling ratio became lower as the ionic strength of the media increased. The in vitro albumin release from these hydrogels was examined in different pH (3.0, 7.4) buffer solutions. Both the protein loading and release data indicated that the Dex-AE/PEGDA hydrogels had more protein loading and sustained release capability than pure PEGDA hydrogel, and this ability increased as the Dex-AE composition increased; the Dex-AE/PEGDA hydrogel also showed a faster BSA release in a lower pH than a higher pH medium.