耗散粒子动力学模拟嵌段聚合物刷修饰纳米孔的pH响应门控  

Dissipative Particle Dynamics Simulations on the p H-responsive Gating of Block Copolymer Brush Modified Nanopores

作　　者：王莉[1] 王楚 周健[1] 

机构地区：[1]华南理工大学化学与化工学院,广东省绿色化学产品技术重点实验室,广州510640

出　　处：《高等学校化学学报》2018年第1期85-94,共10页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号：21776093,91334202); 广东省自然科学基金(批准号：2014A030312007); 中央高校基本科研业务费(批准号：SCUT-2015ZP033)资助~~

摘　　要：通过耗散粒子动力学方法,研究了p H响应性嵌段聚合物(聚丙烯酸-聚-2-乙烯基吡啶PAA-P2VP)接枝在纳米孔内的开关效应.探讨了嵌段序列Wall-P2VP-PAA和Wall-PAA-P2VP对响应性开关效应的影响,结果表明,只有Wall-PAA-P2VP嵌段序列才能在不同的环境下形成智能响应性开关.接枝密度对智能响应性开关影响的研究表明,只有在合适的嵌段聚合物链接枝密度下,形成的孔道才能够达到智能开关效应.链长是影响智能开关膜开关效应的另一个重要因素,在链长较短的条件下,无法形成关闭的开关效应;而在链长较长的条件下则可以形成闭合的开关效应.在控制嵌段聚合物的接枝密度和链长的条件下,共聚物刷修饰的纳米膜孔在不同的p H值条件下可以实现智能膜的开关效应.对不同嵌段比对智能膜形成孔大小的影响的研究发现,随着PAA嵌段比例的增大,嵌段聚合物膜孔的大小逐渐减小,直至几乎闭合.研究结果为设计和构建有开关效应的纳米孔提供了一定的理论基础.Dissipative particle dynamics（ DPD） was adopted to investigate the smart gating of nanopores grafted with p H-responsive block copolymers[polyacrylic acid（ PAA）-poly 2-vinyl pyridine（ P2VP） ]. Effects of different block sequences Wall-P2VP-PAA,Wall-PAA-P2VP on the smart gating was studied. The results show that only the Wall-PAA-P2VP block sequence can form smart gates under different p H values. Grafting density is an important factor on structures of smart gates; only with moderate grafting densities,can smart membranes be formed. The chain length is another important factor affecting the smart gating. It shows that the＂closed＂state of smart membranes cannot be formed with short chain lengths; however,the ＂closed＂state can be formed by polymers with longer chain lengths. Under proper grafting density and chain length of block polymers,different-sized smart membranes can be formed under different p H values; the smart gate can be switched from the＂open＂state to the＂closed＂state. Finally,the effect of block ratio on smart gating was also studied. The results show that the size of the block-copolymer-brush-grafted nanopore decreases gradually with the increase of PAA proportion and finally the ＂closed ＂ states are almost formed. This work provides a theoretical basis for designing and constructing nanopores with smart gates.

关 键 词：耗散粒子动力学模拟 纳米孔 嵌段聚合物 p H响应性 智能门控 

分 类 号：O641.3[理学—物理化学]