介绍了以丙烯酰胺(AM)和二甲基二烯丙基氯化铵(DMDAAC)为原料,过硫酸铵和亚硫酸钠为引发剂,反应体系中加入无机发泡剂盐 A 和抗高温有机物 B,采用水溶液聚合,制备丙烯酰胺-二甲基二烯丙基氯化铵共聚物的方法。考察了引发剂用量和原料单...介绍了以丙烯酰胺(AM)和二甲基二烯丙基氯化铵(DMDAAC)为原料,过硫酸铵和亚硫酸钠为引发剂,反应体系中加入无机发泡剂盐 A 和抗高温有机物 B,采用水溶液聚合,制备丙烯酰胺-二甲基二烯丙基氯化铵共聚物的方法。考察了引发剂用量和原料单体摩尔比对共聚物处理模拟废水的效果,结果表明,在引发剂用量占单体总量的0.15%,单体含量占反应物总量40%,单体摩尔比5:1,发泡剂 A 用量和物质 B 用量各占单体总量4%,反应温度为室温,溶液 pH 值6～7最佳范围内,制备的共聚物处理模拟废水后上清液透光率达90%～95%。展开更多
Enthalpy changes for the protonation of carboxyl group of four α amino acids(glycine,L α alanine,L valine and L serine) were measured in water ethanol mixtures (10－70wt％) at 298.15K using LKB 2277 Bioactivity Moni...Enthalpy changes for the protonation of carboxyl group of four α amino acids(glycine,L α alanine,L valine and L serine) were measured in water ethanol mixtures (10－70wt％) at 298.15K using LKB 2277 Bioactivity Monitor.The corresponding entropy and Gibbs energy changes were also calculated.The results show that both enthalpy changes and entropy changes are favorable to the protonation of carboxyl groups of the investigated amino acids in water ethanol mixtures.However,the influence of the composition of ethanol in the mixed solvents on the enthalpy change and entropy changes is complicated . Both and ,the differences of enthalpy changes and entropy changes in mixed solvents and in pure water respectively,show a minimum approximately at xEtOH=0.1.The effects of side chains on the enthalpy change and entropy changes were also investigated using the proton transfer process between glycine and the other three amino acids.The results demonstrate that the proton transfer processes for alanine and valine are spontaneous but not for serine,which could be interpreted in terms of the electrostatic interaction between amino group and carboxyl group within the molecule and the interaction between carboxyl group and the solvent.展开更多
文摘介绍了以丙烯酰胺(AM)和二甲基二烯丙基氯化铵(DMDAAC)为原料,过硫酸铵和亚硫酸钠为引发剂,反应体系中加入无机发泡剂盐 A 和抗高温有机物 B,采用水溶液聚合,制备丙烯酰胺-二甲基二烯丙基氯化铵共聚物的方法。考察了引发剂用量和原料单体摩尔比对共聚物处理模拟废水的效果,结果表明,在引发剂用量占单体总量的0.15%,单体含量占反应物总量40%,单体摩尔比5:1,发泡剂 A 用量和物质 B 用量各占单体总量4%,反应温度为室温,溶液 pH 值6～7最佳范围内,制备的共聚物处理模拟废水后上清液透光率达90%～95%。
文摘Enthalpy changes for the protonation of carboxyl group of four α amino acids(glycine,L α alanine,L valine and L serine) were measured in water ethanol mixtures (10－70wt％) at 298.15K using LKB 2277 Bioactivity Monitor.The corresponding entropy and Gibbs energy changes were also calculated.The results show that both enthalpy changes and entropy changes are favorable to the protonation of carboxyl groups of the investigated amino acids in water ethanol mixtures.However,the influence of the composition of ethanol in the mixed solvents on the enthalpy change and entropy changes is complicated . Both and ,the differences of enthalpy changes and entropy changes in mixed solvents and in pure water respectively,show a minimum approximately at xEtOH=0.1.The effects of side chains on the enthalpy change and entropy changes were also investigated using the proton transfer process between glycine and the other three amino acids.The results demonstrate that the proton transfer processes for alanine and valine are spontaneous but not for serine,which could be interpreted in terms of the electrostatic interaction between amino group and carboxyl group within the molecule and the interaction between carboxyl group and the solvent.
