新型聚电解质复合膜结构与超高渗透性能的研究。

Studies on structures and ultrahigh permeability of novel polyelectrolyte complex membranes.

机构信息

MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.

出版信息

J Phys Chem B. 2010 Jun 24;114(24):8100-6. doi: 10.1021/jp102707z.

DOI:10.1021/jp102707z

PMID:20518508

Abstract

This work studies the aggregation structures and free volumes of novel polyelectrolyte complex membranes (PECMs) and correlates the two with their ultrahigh permeability to water. Solution-processable PECs between poly(2-methacryloyloxy ethyl trimethylammonium chloride) (PDMC) and sodium carboxymethyl cellulose (CMCNa) were prepared in a two-step method, i.e., precipitation in HCl and redispersion in NaOH. PECMs were subsequently made in a solution casting method. Chemical and aggregation structures of PECs solids were characterized by FT-IR, element analysis (EA), zeta potential, transmission electron microscopy (TEM), and dynamic light scattering (DLS). Surface and cross-section structures of PECMs were characterized by a field emission scanning microscopy (FESEM) and an atomic force microscopy (AFM). Free volume of PECMs was characterized by positron annihilation lifetime spectroscopy (PALS). The free volume of PECMs is larger than that of component polyelectrolyte and is ascribed to the unique aggregation structures of PECMs. Moreover, PALS shows that a long lifetime component (tau(4)) exists with PECMs, indicating that there are water channels in PECMs. Due to these channels, PECMs showed ultrahigh permeability and selectivity.

摘要

这项工作研究了新型聚电解质络合物膜（PECMs）的聚集结构和自由体积，并将两者与其对水的超高透过率相关联。通过两步法，即在 HCl 中沉淀和在 NaOH 中再分散，制备了聚（2-甲基丙烯酰氧基乙基三甲基氯化铵）（PDMC）和羧甲基纤维素钠（CMCNa）之间的可溶液处理 PEC。随后通过溶液浇铸法制备 PECM。通过傅里叶变换红外光谱（FT-IR）、元素分析（EA）、zeta 电位、透射电子显微镜（TEM）和动态光散射（DLS）对 PEC 固体的化学和聚集结构进行了表征。通过场发射扫描电子显微镜（FESEM）和原子力显微镜（AFM）对 PECM 的表面和横截面结构进行了表征。通过正电子湮没寿命谱（PALS）对 PECM 的自由体积进行了表征。PECM 的自由体积大于组成聚电解质的自由体积，这归因于 PECM 的独特聚集结构。此外，PALS 表明 PECM 中存在长寿命组分（tau(4)），表明 PECM 中有水通道。由于这些通道，PECM 表现出超高的透过率和选择性。