聚电解质复合物的形成与二乙氨基乙基葡聚糖：电荷比和摩尔质量的影响。

Formation of polyelectrolyte complexes with diethylaminoethyl dextran: charge ratio and molar mass effect.

机构信息

Normandie Université, France; Université de Rouen, Laboratoire 'Polymères, Biopolymères, Surfaces', F-76821 Mont Saint Aignan, France; CNRS UMR 6270 & FR3038, F-76821 Mont Saint Aignan, France.

"Petru Poni" Institute of Macromolecular Chemistry, Al. Gr., Ghica Voda 41A, 700487 Iasi, Romania.

出版信息

Carbohydr Polym. 2014 Nov 26;113:217-24. doi: 10.1016/j.carbpol.2014.07.015. Epub 2014 Jul 17.

DOI:10.1016/j.carbpol.2014.07.015

PMID:25256478

Abstract

The formation of polyelectrolyte complexes (PECs) between carboxymethyl pullulan and DEAE Dextran, was investigated, in dilute solution, with emphasis on the effect of charge density (molar ratio or pH) and molar masses. Electrophoretic mobility measurements have evidenced that insoluble PECs (neutral electrophoretic mobility) occurs for charge ratio between 0.6 (excess of polycation) and 1 (stoichiometry usual value) according to the pH. This atypical result is explained by the inaccessibility of some permanent cationic charge when screened by pH dependant cationic ones (due to the Hoffman alkylation). Isothermal titration calorimetry (ITC) indicates an endothermic formation of PEC with a binding constant around 10(5) L mol(-1). Finally asymmetrical flow field flow fractionation coupled on line with static multi angle light scattering (AF4/MALS) evidences soluble PECs with very large average molar masses and size around 100 nm, in agreement with scrambled eggs multi-association between various polyelectrolyte chains.

摘要

在稀溶液中研究了羧甲基普鲁兰多糖和 DEAE 葡聚糖之间聚电解质复合物（PECs）的形成，重点研究了电荷密度（摩尔比或 pH 值）和摩尔质量的影响。电泳迁移率测量表明，根据 pH 值，电荷比为 0.6（多阳离子过量）和 1（化学计量通常值）时，会发生不溶性 PEC（中性电泳迁移率）。这种非典型结果可以通过 pH 依赖的阳离子屏蔽一些永久性阳离子电荷来解释（由于 Hoffman 烷基化）。等温热滴定法（ITC）表明 PEC 的形成是吸热的，结合常数约为 10（5）L mol（-1）。最后，不对称流场流分离与静态多角度光散射（AF4/MALS）在线联用，证明了可溶性 PEC 具有非常大的平均摩尔质量和 100nm 左右的粒径，与各种聚电解质链之间的 scrambled eggs 多缔合一致。