Stable silver nanoparticles in a sodium-carboxymethylcellulose hydrogel with a substitution degree of 0.65 - 0.85 and polymerization degree of 200 - 600 have been synthesized. Physical, chemical properties and antimic...Stable silver nanoparticles in a sodium-carboxymethylcellulose hydrogel with a substitution degree of 0.65 - 0.85 and polymerization degree of 200 - 600 have been synthesized. Physical, chemical properties and antimicrobial activity of sodium-carboxymethylcellulose hydrogels contained silver nanoparticles were studied. The shape, number and size of silver nanoparticles (SNP) incorporated into the structure of hydrogels of sodium-carboxymethylcellulose were studied by using UV-VIS spectroscopy, transmission electron and atomic force microscopy. It was found that the silver nitrate concentration increase in sodium-carboxymethylcellulose solutions, as well as photoirradiation of the hydrogel lead to the changes of the silver nanoparticles size and shape. The studies have shown that the spherical silver nanoparticles of 5 - 35 nm in the structure of sodium-carboxymethylcellulose hydrogel possess high bactericidal activity. Our results have shown that changing of size and shape of silver nanoparticles contributes to appearance of their biological activity.展开更多
采用动态真空安定性(DVST)方法研究了叠氮化铅(LA)和羧甲基纤维素叠氮化铅(CMC-LA)的热分解过程。利用微分法分析了测试数据。获得了LA和CMC-LA的反应机理函数和表观活化能,剖析了羧甲基纤维素钠晶型控制剂对LA安定性和热分解反...采用动态真空安定性(DVST)方法研究了叠氮化铅(LA)和羧甲基纤维素叠氮化铅(CMC-LA)的热分解过程。利用微分法分析了测试数据。获得了LA和CMC-LA的反应机理函数和表观活化能,剖析了羧甲基纤维素钠晶型控制剂对LA安定性和热分解反应动力学参数的影响。结果表明,在非等温阶段,60~100℃,LA热分解反应的机理函数为Zhuralev-Lesokin-Tempelman方程,表观活化能(Ea)分别是86.53、42.26、39.43、38.09 k J·mol-1和10.84k J"mol-1。在60~70℃,CMC-LA热分解反应的机理函数为Avrami-Erofeev方程,Ea分别是133.02 k J·mol-1和41.87 k J·mol-1,在80~100℃,CMC-LA热分解反应的机理为减速型α-t曲线,Ea分别是43.07、34.34 k J·mol-1和33.46 k J·mol-1。添加羧甲基纤维素钠改变了LA的反应机理函数,使得CMC-LA在60~70℃产气量更小,热安定性更好。展开更多
文摘Stable silver nanoparticles in a sodium-carboxymethylcellulose hydrogel with a substitution degree of 0.65 - 0.85 and polymerization degree of 200 - 600 have been synthesized. Physical, chemical properties and antimicrobial activity of sodium-carboxymethylcellulose hydrogels contained silver nanoparticles were studied. The shape, number and size of silver nanoparticles (SNP) incorporated into the structure of hydrogels of sodium-carboxymethylcellulose were studied by using UV-VIS spectroscopy, transmission electron and atomic force microscopy. It was found that the silver nitrate concentration increase in sodium-carboxymethylcellulose solutions, as well as photoirradiation of the hydrogel lead to the changes of the silver nanoparticles size and shape. The studies have shown that the spherical silver nanoparticles of 5 - 35 nm in the structure of sodium-carboxymethylcellulose hydrogel possess high bactericidal activity. Our results have shown that changing of size and shape of silver nanoparticles contributes to appearance of their biological activity.
文摘采用动态真空安定性(DVST)方法研究了叠氮化铅(LA)和羧甲基纤维素叠氮化铅(CMC-LA)的热分解过程。利用微分法分析了测试数据。获得了LA和CMC-LA的反应机理函数和表观活化能,剖析了羧甲基纤维素钠晶型控制剂对LA安定性和热分解反应动力学参数的影响。结果表明,在非等温阶段,60~100℃,LA热分解反应的机理函数为Zhuralev-Lesokin-Tempelman方程,表观活化能(Ea)分别是86.53、42.26、39.43、38.09 k J·mol-1和10.84k J"mol-1。在60~70℃,CMC-LA热分解反应的机理函数为Avrami-Erofeev方程,Ea分别是133.02 k J·mol-1和41.87 k J·mol-1,在80~100℃,CMC-LA热分解反应的机理为减速型α-t曲线,Ea分别是43.07、34.34 k J·mol-1和33.46 k J·mol-1。添加羧甲基纤维素钠改变了LA的反应机理函数,使得CMC-LA在60~70℃产气量更小,热安定性更好。