成相无机盐种类对PEG双水相相平衡影响

摘要

Aqueous two-phase systems composed of PEC with different molecular weight and various salt were investigated by cloud-point measurement at T = 298.15K,respectively. The experimental binodal data of the aqueous two-phase systems were fitted by Merchuk empirical nonlinear expression,and the effect of salt type on phase equilibrium was analyzed. The results displayed that the two-phase forming power for cationic ions followed the order Na2SO4 >MgSO4 > (NH4 ) 2SO4 >Li2SO4,and for anionic ions followed the order Na2SO4>NaClO4NaCl.%不同种类无机盐分别与PEG1000、PEG2000、PEG,4000和PEG6000构成双水相体系,在298.15K下,采用浊点滴定法研究双水相体系相平衡,通过Merchuk经验方程拟合实验点确定双水相体系的双节线,进而考察成相无机盐种类对PEG双水相相平衡的影响.结果表明:具有相同阴离子,易于形成双水相的无机盐顺序为:Na2SO4 ＞MgSO4＞(NH4)2SO4 ＞Li2SO4；而具有相同阳离子,易于形成双水相的无机盐顺序为:Na2SO4＞NaClO4＞＞ NaCl.