聚合物修饰的纳米通道膜中物质的传输及其分析应用

发布时间：2018-01-14 14:18

本文关键词：聚合物修饰的纳米通道膜中物质的传输及其分析应用　出处：《湖南大学》2015年博士论文　论文类型：学位论文

【摘要】：纳流控(Nanofluidics)研究的是流体在纳米通道中的传输行为,它要求通道至少有一个维度低于100 nm。当通道的尺度从微米下降到纳米时,由于尺寸的缩小,比表面积的增大,各种表面力如位阻作用、范德华力和静电力对物质的传输将起着重要的影响,许多在纳米尺度下特有的传输现象都根源于此。例如,在纳米通道中双电层的厚度与通道的尺度相当,这会导致双电层的重叠,产生离子传输选择性、离子的富集与耗散和离子整流等纳流控现象。研究和利用纳流控传输现象对于理解发生在纳米限域空间中的各种作用力,操控分子和离子在其中的传输,发展能够用于检测和分离的纳流控器件等都具有重要意义。近年来由于纳米通道的制备和加工技术的进步,为纳流控研究提供了良好的实验平台。本论文就是在这样的背景下,以核径迹刻蚀的聚碳酸酯(PCTE)膜为模板,采用层层自组装(LBL)的方法,构建了不同聚合物修饰的纳米通道阵列膜,通过对纳米通道所在溶液环境的调控,开展了基于纳米通道的传输现象的研究,并探索了其在分离和检测等方面的应用。具体研究工作包括以下四个方面:1.将聚电解质通过层层自组装的方法修饰到PCTE膜中,构建了表面带正电荷或负电荷的纳米通道膜,研究了在电解质浓度梯度下,水通过这些荷电纳米通道的传输现象。结果表明,在一定电解质浓度范围内,水通过荷电纳米通道膜的传输方向可以从装有电解质溶液的一侧流向纯水的一侧,这是一种异常的渗透现象。为此建立了一个简洁的模型来说明产生这些异常效应的条件,即在电解质浓度梯度下,由于阴、阳离子扩散速度不同,会在荷电纳米通道膜的两侧形成膜扩散电势,同时由于荷电通道壁对反离子的吸引会形成双电层,膜扩散电势作用于双电层,会产生诱导电渗,因此水的传输是诱导电渗和浓差扩散共同作用的结果。通过调节通道的表面电荷、电解质的浓度和电解质的类型,当诱导电渗大于水的浓差扩散且方向相反时,就能产生异常渗透现象。根据这一水传输的模型,中性分子和离子通过荷电纳米通道的传输行为,也可通过建立电解质浓度梯度来进行调节。该工作有助于理解水在荷电纳米通道膜中的传输行为,同时也为纳流控器件中流体流向的调控提供了一种新思路。2.在上一个研究工作的基础上,利用电解质浓度梯度在荷电纳米通道膜的两侧形成膜扩散电势,实现了荷正电纳米通道膜离子选择性的调节。由于膜电势在通道膜两端的建立会产生诱导电渗和诱导电泳,阴、阳离子在通道中的传输是由扩散、诱导电渗和诱导电泳三者共同作用决定的。调节磷酸浓度梯度、传输时间和进样液体积,可以改变离子传输的通量甚至选择性。以甲基紫精(MV2+)和1,5-萘二磺酸钠(NDS2-)为例,纳米通道膜对MV2+的分离选择性可达到19.5。这种调节纳米通道离子选择性的方法无需在通道壁上修饰刺激响应性材料,也不用对通道壁或者通道两侧施加外加电场,具有节能、经济和易于操作等特点,有望在纳流控器件中实现离子的传输和分离。3.采用层层自组装的方法,将聚丙烯胺(PAH)修饰到PCTE膜中,构建了具有p H响应的纳米通道,并结合甘露醇使硼酸酸性增强的原理,实现了硼酸的检测。该纳米通道表面富含-NH2,对NDS2-的传输表现出明显的p H响应特性。如果固定甘露醇的浓度,NDS2-的传输通量随硼酸浓度增大而增大,从而实现了硼酸的检测,检测限为0.07 m M。相对于滴定法而言,这种基于纳米通道的硼酸检测方法试剂消耗少,便于操作。该工作为纳米通道中物质传输调控的应用提供了一种新的思路,即通过物质间的相互作用产生能够影响通道传输的环境,从而实现对相关物质的检测。4.利用自组装技术将聚乙烯醇(PVA-124)修饰到PCTE膜中,构建了一种对硼酸根和顺式羟基化合物具有级联识别响应的纳米通道,具有IMP(蕴涵)逻辑门性质。首先,PVA与硼酸根结合形成带负电荷的PVA-硼酸根复合物,增加了通道表面的负电荷,阻碍NDS2-在通道中的传输,显示通道对硼酸根有响应,且响应是可逆的;此后再加入顺式羟基化合物,又能将结合到PVA上的硼酸根竞争下来,减少了通道表面的负电荷,促进NDS2-在通道中的传输,显示通道对顺式羟基化合物有响应,且响应也是可逆的,不同的顺式羟基化合物对通道的响应程度不同。这种识别模式有望用于构建纳米传感器件,以及进行硼的生理功能的模拟。
[Abstract]:Nanofluidic (Nanofluidics) is the study of transfer behavior of fluid in nano channel in the channel, it requires at least one dimension less than 100 nm. when the channel scales from microns down to nanometer, the size is reduced, the increase of surface area of various surface forces such as steric effect, static force and van Edward the power of mass transport will play an important influence, many unique on the nanoscale transport phenomena are rooted in this. For example, the thickness of electric double layer and channel in nano channel in size, which will lead to the overlapping of electric double layer, ion transport selectivity, ion concentration and ion and dissipation rectifier nanofluidic phenomenon. The research and utilization of nanofluidic transport phenomena occurred in the limit for understanding the nano forces in the domain space, manipulation of molecules and ions in the transmission, development can be used for the detection and isolation of nanofluidic devices It is of great significance. In recent years due to the nano channel fabrication and processing technology, provides a good experimental platform for the research of microfluidic. This paper is in this context, the nuclear track etched polycarbonate (PCTE) membrane as template, using layer by layer self-assembly (LBL) method, construct nanotube membranes of different polymer modified, through the regulation of the nano channel where the solution environment, carried out the research of transport phenomena based on the nano channel, and explore its application in separation and detection. The specific research work includes the following four aspects: 1. the method of polyelectrolyte by self-assembly modification the PCTE membrane, constructed the nano channel membrane surface with positive or negative charge, in the study of the electrolyte concentration gradient, water transport phenomena through these charged nano channel. The results show that in a certain electrolysis Mass concentration range, the water through the transmission direction of charged nanochannel membrane from the electrolyte solution is arranged on one side of one side of the flow of water, which is an abnormal phenomenon of osmosis. So as to establish a simple model to illustrate the effect of abnormal conditions in the electrolyte concentration gradient, due to Yin that cation diffusion speed is different, will be on both sides of the charged nano channel film formed by film diffusion potential, at the same time as the charged channel wall on the attraction of counter ions to form double layer film, diffusion potential effect on electric double layer, produced by electro osmosis, so water transport is induced by electroosmosis and concentration diffusion interaction the results of surface charge. By regulating channel type, concentration of electrolyte and electrolyte, when induced by electroosmosis than water concentration diffusion and in the opposite direction, can produce abnormal infiltration phenomenon. According to the water transmission mode Type, neutral molecules and ions through the transmission behavior of charged nano channel, but also through the establishment of electrolyte concentration gradient to adjust. This work helps to understand the water in charged nano channel in the film transmission behavior, but also for the regulation of nano fluid flow in microfluidic devices provides a new way of basic research work.2. in a on both sides using electrolyte concentration gradient in charged nano channel film formed by film diffusion potential, the regulation of positively charged nano channel membrane ion selective. Because the membrane potential induced electroosmosis and electrophoresis induced, established from both ends of the transmission channel film Yin, in the channel is composed of cations diffusion induced by electroosmosis and electrophoresis determined effect induced by three. Regulation of phosphate concentration gradient, transmission time and sample solution volume, can change the ion transport flux even with methyl viologen selectivity. (MV 2+) and two 1,5- naphthalene sulfonate (NDS2-) as an example, methods of separation selectivity to MV2+ nanotube membranes can reach 19.5. the regulation of ion selective nano channel without modification in the channel wall of stimuli responsive materials, nor to wall on both sides of the channel or channel applied electric field, has the advantages of energy saving, economical and easy to operation, is expected to achieve the transmission and separation of.3. ions through layer by layer self-assembly method in microfluidic devices, the polyacrylamide (PAH) modified PCTE film, with the construction of nano channel P H response, and combined with the principle of mannitol boric acid enhanced, realized the detection of the nano boric acid. The surface of the channel is rich in -NH2, P H transmission showed obvious response to NDS2-. If the concentration of mannitol fixed, flux of NDS2- increases with the increase of the concentration of boric acid, boric acid in order to achieve the detection, the detection limit is 0.07 M M. relative to the titration, the reagent boric acid nano channel detection method based on consumption, easy to operate. Provides a new way for application of the work material nano channel transmission control, namely through interaction between substances produced can affect the channel transmission environment, so as to realize the detection of related substances by.4. the use of self assembly technology of polyvinyl alcohol (PVA-124) modified PCTE film, build a nano channel response cascade identification for borate and CIS hydroxyl compounds, with IMP (Yun Han) logic gate properties. First, the combination of PVA and borate formed PVA- borate complexes with negative charge and increase the negative charge surface of the channel, the transmission block in the channel of an NDS2- display channel in response to the borate, and the response is reversible; then adding CIS compounds of formula hydroxyl, and can be combined to PVA on the boron Radical competition down, reduce the negative charge of the surface of the channel, to promote NDS2- transmission in the channel, display the channel in response to CIS hydroxyl compounds, and the response is reversible, different smoothness of the channel response type hydroxyl compounds. This pattern is expected to use different recognition to construct nano sensors, and the simulation of physiological function boron.

【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1;O631

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