以海藻酸钠(SA)与聚乙烯亚胺(PEI)为原料,制备了一种具有交联网络结构的SAPEI多功能锂硫电池正极水性黏结剂。采用FTIR对其进行了表征,考察了SAPEI黏结剂的黏结性、多硫离子吸附能力及对锂硫电池正极结构和电化学性能的影响。结果表明,S...以海藻酸钠(SA)与聚乙烯亚胺(PEI)为原料,制备了一种具有交联网络结构的SAPEI多功能锂硫电池正极水性黏结剂。采用FTIR对其进行了表征,考察了SAPEI黏结剂的黏结性、多硫离子吸附能力及对锂硫电池正极结构和电化学性能的影响。结果表明,SAPEI黏结剂的黏结强度高于传统商用聚偏氟乙烯(PVDF)黏结剂,反应过程中产生的酰胺键对多硫离子具有吸附作用。使用SAPEI黏结剂的锂硫电池在循环后硫正极呈现出更加均匀的微观形貌结构及更优的电化学性能。在0.2 C倍率下充放电200次后,其放电比容量仍保持在620 m A·h/g,容量保持率可达到72.6%,高于使用PVDF黏结剂的锂硫电池。展开更多
The synthesis and properties of three kinds of hyper-dispersants are studied in this paper, which are non-terminated, carboxyl-terminated and polyethylene imine grafted poly（hydroxyl carboxylic acid） ester. The hype...The synthesis and properties of three kinds of hyper-dispersants are studied in this paper, which are non-terminated, carboxyl-terminated and polyethylene imine grafted poly（hydroxyl carboxylic acid） ester. The hyper-dispersants are synthesized by the materials of 12-hydroxy-stearic acid, stearic acid and polyethylene imine, which are used to improve the dispersion properties of nano titanium dioxide （nano-TiO2） in low-concentration resin solution system. The influences of hyper-dispersants on the viscosity and stability of the system are studied. It is found that polyethylene imine grafted hyper-dispersant has the best dispersion performance in nano-TiO2 dispersion system, and the optimal content of the hyper-dispersant is 4%.展开更多
In past decades, alginate-based multilayer microcapsules have been given important attention in various pharmaceutical investigations. Alginate-poly l lysine-alginate(APA) is studied the most. Due to the similarity be...In past decades, alginate-based multilayer microcapsules have been given important attention in various pharmaceutical investigations. Alginate-poly l lysine-alginate(APA) is studied the most. Due to the similarity between the structure of polyethyleneimine(PEI) and poly-L-lysine(PLL) and also lower price of PEI than PLL, this study was conducted to compare the efficacy of linear(LPEI) and branch(BPEI) forms of PEI with PLL as covering layers in fabrication of microcapsules. The microcapsules were fabricated using electrostatic bead generator and their shape/size, surface roughness, mechanical strength, and interlayer interactions were also investigated using optical microscopy, AFM, explosion test and FTIR, respectively. Furthermore, cytotoxicity was evaluated by comparing the two anionic final covering layers alginate(Alg) and sodium cellulose sulphate(NCS) using MTT test. BPEI was excluded from the rest of the study due to its less capacity to strengthen the microcapsules and also the aggregation of the resultant alginate-BPEI-alginate microcapsules, while LPEI showed properties similar to PLL. MTT test also showed that NCS has no superiority over Alg as final covering layer. Therefore, it is concluded that, LPEI could be considered as a more cost effective alternative to PLL and a promising subject for future studies.展开更多
文摘以海藻酸钠(SA)与聚乙烯亚胺(PEI)为原料,制备了一种具有交联网络结构的SAPEI多功能锂硫电池正极水性黏结剂。采用FTIR对其进行了表征,考察了SAPEI黏结剂的黏结性、多硫离子吸附能力及对锂硫电池正极结构和电化学性能的影响。结果表明,SAPEI黏结剂的黏结强度高于传统商用聚偏氟乙烯(PVDF)黏结剂,反应过程中产生的酰胺键对多硫离子具有吸附作用。使用SAPEI黏结剂的锂硫电池在循环后硫正极呈现出更加均匀的微观形貌结构及更优的电化学性能。在0.2 C倍率下充放电200次后,其放电比容量仍保持在620 m A·h/g,容量保持率可达到72.6%,高于使用PVDF黏结剂的锂硫电池。
基金supported by the Shanghai Leading Academic Disciplines (Grant No.T0105)the Key Laboratory of Science & Technology of Eco-Textile (Donghua University), Ministry of Education of China
文摘The synthesis and properties of three kinds of hyper-dispersants are studied in this paper, which are non-terminated, carboxyl-terminated and polyethylene imine grafted poly（hydroxyl carboxylic acid） ester. The hyper-dispersants are synthesized by the materials of 12-hydroxy-stearic acid, stearic acid and polyethylene imine, which are used to improve the dispersion properties of nano titanium dioxide （nano-TiO2） in low-concentration resin solution system. The influences of hyper-dispersants on the viscosity and stability of the system are studied. It is found that polyethylene imine grafted hyper-dispersant has the best dispersion performance in nano-TiO2 dispersion system, and the optimal content of the hyper-dispersant is 4%.
基金This study was fully funded and supported by Shahid Beheshti University of Medical Sciences(Research grant number.7026)The authors would like to acknowledge Mr.F.Rafraf and Mr.S.M.Foroutanfar for their valuable supports in design of encapsulator device and the graphical parts of this project.
文摘In past decades, alginate-based multilayer microcapsules have been given important attention in various pharmaceutical investigations. Alginate-poly l lysine-alginate(APA) is studied the most. Due to the similarity between the structure of polyethyleneimine(PEI) and poly-L-lysine(PLL) and also lower price of PEI than PLL, this study was conducted to compare the efficacy of linear(LPEI) and branch(BPEI) forms of PEI with PLL as covering layers in fabrication of microcapsules. The microcapsules were fabricated using electrostatic bead generator and their shape/size, surface roughness, mechanical strength, and interlayer interactions were also investigated using optical microscopy, AFM, explosion test and FTIR, respectively. Furthermore, cytotoxicity was evaluated by comparing the two anionic final covering layers alginate(Alg) and sodium cellulose sulphate(NCS) using MTT test. BPEI was excluded from the rest of the study due to its less capacity to strengthen the microcapsules and also the aggregation of the resultant alginate-BPEI-alginate microcapsules, while LPEI showed properties similar to PLL. MTT test also showed that NCS has no superiority over Alg as final covering layer. Therefore, it is concluded that, LPEI could be considered as a more cost effective alternative to PLL and a promising subject for future studies.
