Interfacial Transport in Reversed Micellar Extraction Processes

本项目结合理论和实验研究了与水相接触的反胶束系统的相间传质速率和机制。从低分子量水溶性化合物到球形水溶性蛋白质的一系列溶质将被研究。据推测，相对于蛋白质，低分子量化合物存在不同的传质机制。对于低分子量化合物，由于界面的随机热波动周期性地导致部分界面和直接水相断裂而形成逆胶束胶束中有一些溶质被困在内部。对于高分子量的蛋白质，假设蛋白质接近界面导致部分界面自发断裂形成反胶束，蛋白质被困在反胶束中。本文概述了这两种不同机制的理论模型。这些现象对诸如浓度和温度等因素的依赖性应该是非常不同的，因此，如果能准确地测量传质速率，它们应该很容易区分。为这些实验提出了一种测量传质速率的创新技术：界面干涉法。流体的折射率取决于任何溶解物质的浓度。将使用分束器使相干光束的一部分穿过靠近有机相和水相之间界面的液体层；当与光束的其余部分结合时，将产生干涉带，其分离将与光束通过的溶液层的浓度成正比。通过使用光学工作台和设备仔细控制光束平行于界面的位置，使系统与振动隔离，该技术应该能够准确地确定浓度作为与界面的距离和时间的函数。这些数据可以非常准确地转化为传质速率。结合理论工作，这将对所研究的系统的间相传质提供一个非常完整的图像，并使研究者能够确定所涉及的机制。​该系统对新兴的生物技术产业具有潜在的重要意义。从水溶液中反胶束提取蛋白质可能成为最通用和最有效的生物分离技术之一。这个项目将大大增加其早期商业应用的潜力。

This project consists of combined theoretical and experimental studies of the rates and mechanisms of interphase mass transfer in reverse micelle systems in contact with an aqueous phase. A range of solutes from low molecular weight, water soluble compounds up to globular, water soluble proteins will be studied. It is hypothesized that a different mechanism for mass transfer exists for low molecular weight compounds as opposed to the proteins. For the low molecular weight compounds it is proposed that reverse micelles form because of random thermal fluctuations of the interface which periodically result in part of the interface and the immediate aqueous phase breaking off to form a reverse micelle with some of the solute trapped in the interior. For the higher molecular weight proteins, it is hypothesized that the approach of the protein to the interface results in the spontaneous breaking off of part of the interface to form a reverse micelle, with the protein trapped in the reverse micelle. Theoretical models for these two different mechanisms have been outlined. The phenomena should exhibit very different dependence on factors such as concentration and temperature, so they should be easily distinguished if the mass transfer rate can be measured accurately. An innovative technique for measuring the mass transfer rate has been proposed for these experiments: interfacial interferometry. The refractive index of a fluid is dependent upon the concentration of any dissolved species. A beam splitter will be used to pass one part of a beam of coherent light through a layer of the liquid close to the interface between the organic and aqueous phases; when joined with the rest of the beam interference bands will be produced whose separation will be proportional to the concentration of the layer of solution through which the beam passed. By carefully controlling the position of the beam parallel to the interface with an optical bench and equipment to isolate the system from vibration, the technique should be able to accurately determine concentration as a function of distance from the interface and as a function of time. This data then can be translated very accurately into mass transfer rates. Combined with the theoretical work, this should give a very complete picture of the interphase mass transfer in the systems studied and should enable the investigator to determine the mechanisms involved. This system is one of potentially great importance to the emerging biotechnology industry. Reverse micelle extraction of proteins from aqueous solution may develop into one of the most versatile and effective bioseparation technologies. This project should add greatly to its potential for early commercial applications.