中药水提液膜法分离的微界面作用机理及其分离过程优化研究

Chinese medicine industry has a great realistic demand for the membrane technology. However, the serious membrane fouling problem has restricted the popularization and application of the membrane technology in pharmaceutical industry of traditional Chinese medicine. The common polymers (starch, protein, pectin, tannins, etc.) in traditional Chinese medicine water extract were the major membrane pollutants and the micro-interface between common polymers and membranes was the basis for membrane fouling produced by traditional Chinese medicine water extract. Based on these, this project intends to study the micro-interfacial interaction of the membrane separation process of traditional Chinese medicine water extract from the microscopic scale, and developed the following research work:(1) The physicochemical property parameters of the common polymers and different microfiltration and ultrafiltration membranes were collected using detection techniques including scanning electron microscope, atomic force microscope, infrared spectroscopy and so on. The XDLVO theory in the field of colloids and interface chemistry was used to quantitatively analyze the micro-interfacial interaction.(2) Research methods including molecular simulations, membrane fouling tests and data mining algorithms such as expenditure vector machines, were used to discover and verify the correlation between micro-interfacial interaction and membrane fouling, and to establish a quantitative evaluation system for the membrane fouling of traditional Chinese medicine water extract.(3) By adjusting the environment of the solution, the nature of the membrane surface, etc., the micro-interfacial interaction was regulated and the membrane separation process was optimized. Based the above studies, the micro-interfacial interaction of membrane separation of traditional Chinese medicine water extract and the microscopic mechanism of membrane fouling of traditional Chinese medicine water extract was revealed, and the regulation technology for optimized membrane separation process was formed.

中药制药工业对膜技术具有重大需求，而严重膜污染问题制约了膜技术在中药制药工业中的推广应用。中药水提液中的共性高分子（淀粉、蛋白质、果胶、鞣质等）是其产生膜污染的主要污染物，而共性高分子与膜的微界面作用是中药水提液产生膜污染的作用基础。基于此，本项目拟开展以下工作，研究中药水提液膜法分离的微界面作用：（1）采用扫描电镜、原子力显微镜、红外光谱等检测技术，采集共性高分子、不同微滤及超滤膜的理化性质，运用胶体与界面化学研究领域的XDLVO理论，定量解析二者的微界面作用；（2）采用分子模拟、膜污染试验等方法，应用支持向量机等数据挖掘算法，发现与验证微界面作用与膜污染的相关性，建立中药水提液膜污染的量化评价体系；（3）通过调节溶液环境、膜表面性质等方式，调控微界面作用，优化膜分离过程。通过以上研究，揭示中药水提液膜法分离的微界面作用，阐明中药水提液膜污染微观作用机制，形成优化膜分离过程的调控技术。

严重膜污染是膜技术应用于中药制药过程的关键问题之一。中药水提液中通常含有大量一般无药理活性的成分，如蛋白质、果胶、鞣质、淀粉等植物组织成分，其分子量较大，可称为中药“共性高分子”，是中药产生严重膜污染的主要物质基础。而污染物与膜材料间的微界面作用在很大程度上影响着膜污染行为。.本项目以XDLVO理论为基础，以蛋白质、果胶、鞣质、淀粉等四种中药共性高分子为研究对象，定量探究与解析中药共性高分子与膜材料间的微观作用能。从溶液环境、膜表面性质方面，调控中药共性高分子与膜材料间的微界面作用，优化膜分离过程，建立中药膜污染的有效防控策略。主要研究结果、关键数据是：. （1）XDLVO理论可用于定量解析中药共性高分子与膜材料间的微界面作用。中药共性高分子与PVDF超滤膜的总界面粘附作用能均为负值，表现为相互吸引作用；其与超滤膜间的相互吸引及膜污染强弱顺序依次为：果胶＞淀粉＞鞣质＞蛋白质。极性作用力在膜污染行为中占主导作用。. （2）溶液pH、离子强度对中药共性高分子膜污染行为均具有不同程度的影响。在酸性环境下，中药共性高分子表现出较强的膜污染性；而在中性及碱性环境下，表现出较弱的膜污染性。中药共性高分子膜污染性随溶液离子强度的增大而呈增大趋势。为降低中药膜污染性，可将溶液pH控制在中性及碱性范围；同时根据实际情况，亦可降低溶液离子强度以降低膜污染。. （3）对疏水性膜材料进行表界面亲水化改性是提高膜抗污染性的一条有效途径。将多巴类亲水性物质涂覆/吸附于膜表界面，可有效降低膜表面纯水接触角、增大膜亲水性与膜表面极性，增强膜抗污染性。.本研究从微观角度定量解析了中药共性高分子与膜材料间的微界面作用，有利促进对中药膜污染现象及其机理的深入认知。研究发现，通过调控溶液环境和膜表面性质可调节污染物与膜材料间的微界面作用，从而为降低中药膜污染提供了研究思路与途径，为中药特种防污膜材料的设计与制备提供了研究基础。