不同尺寸氧化石墨烯掺杂制备超薄自支撑正渗透膜

项目名称： 不同尺寸氧化石墨烯掺杂制备超薄自支撑正渗透膜

项目编号： No.51503205

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 王啸

作者单位： 中国科学院重庆绿色智能技术研究院

项目金额： 20万元

中文摘要： 正渗透膜分离技术是一种高效、低污染的技术。其中，过滤材料是正渗透膜技术的核心。传统的正渗透膜材料多采用活性层与支撑层结合的复合结构，性能稳定，机械性能良好，但膜整体厚度较大，大大限制了膜通量的提升。并且，独立支撑层存在所带来的内浓差极化问题仍未很好解决。本课题首次通过氧化石墨烯掺杂三醋酸纤维素，采用相转变技术制备膜整体厚度小于20微米的超薄自支撑正渗透膜，大幅提高膜的通量。利用氧化石墨烯优异的机械性能和韧性，满足超薄化正渗透膜的使用强度，取代传统的含有独立支撑层的多层膜结构，达到降低内浓差极化影响的目的。利用氧化石墨烯表面丰富的亲水性基团，提高正渗透膜的渗透性能。通过研究氧化石墨烯不同尺寸结构、掺杂量对于上述性能的影响与作用机理，确定性能最优的氧化石墨烯尺寸和掺杂量。并进一步揭示膜厚度与机械性能和渗透性能的关系。为制备具有综合优异性能的超薄自支撑纳米复合正渗透膜材料提供理论基础和技术支撑。

中文关键词： 氧化石墨烯；三醋酸纤维素；自支撑；超薄；正渗透膜

英文摘要： Separation technology based on forward osmosis (FO) membrane is a high effective and low pollution technology for separation. The separation materials are the key of the FO technology. Traditional FO materials are comprised with active layer and supporting layer, which enable the membrane good mechanical stability. However, the multilayer structure results in large membrane thickness that limits the increase of flux. Moreover, the existence of supporting layer results in internal concentration polarization (ICP), which has not been solved yet. In this project, for the first time, graphene oxide (GO) is introduced into cellulose triacetate (CTA) by means of phase inversion. A series of self-supporting membranes with thickness less than twenty micrometers are produced, in order to elevate the flux. Owing to the exceptional mechanical properties and toughness of GO, the mechanical properties of GO/CTA membrane could be improved to meet the requirement for usage. The absence of individual supporting layer of the GO/CTA membrane could largely reduce the effect of ICP. The abundant hydrophilic groups on GO could also be helpful for the increase of permeation property. According to the investigations on the influences of the graphene size and incorporation amount on the above properties, the optimal graphene size and incorporation amount are determined. The effects of the membrane thickness on the mechanical and permeation properties are further revealed. From this study, a theoretical basis and the corresponding technical parameters are established for the development of high performance ultrathin self-supporting FO nanocomposite membranes.

英文关键词： graphene oxide;cellulose triacetate ;self supporting;ultrathin;forward osmosis membrane