Study on membrane fouling by using surface modifying macromolecules for membrane surface modification

本项目的目的是系统地研究膜污染。特别是，已确定的膜表面特性，如表面疏水性/亲油性，表面电荷密度和表面粗糙度，来管理膜污染的影响，将进行研究。为此，将在实验室中通过干-湿相转化技术制备膜。为了改变膜的表面性质，将合成表面改性大分子（SMMs）并将其共混到主体聚合物中。当膜被浇铸时，SMM将迁移到膜表面，从而显著改变膜的表面性质。根据SMM的性质，膜表面变得更加疏水/亲水或带电。通过在凝固浴中加入表面活性剂或电解质可以改变膜的表面粗糙度。将采用各种技术来表征膜表面。将通过测量RO分离小有机分子或UF分离蛋白质时膜的通量减少来研究污染。然后将发现膜表面性质和污染之间的相关性，并确定对膜污染有强烈影响的因素。这一信息将有助于通过在主体聚合物中共混SMM来设计具有减少污染的膜。

The objective of this project is to study membrane fouling systematically. In particular, the effects of the membrane surface properties that have been identified to govern the membrane fouling, such as surface hydrophobicity/philicity, surface charge density and surface roughness, will be studied. For this purpose, membranes will be prepared in the laboratory by dry-wet phase inversion technique. In order to change the surface properties of the membranes, surface modifying macromolecules (SMMs) will be synthesized and blended to the host polymer. SMMs will migrate to the membrane surface while membranes are cast, altering the surface properties of the membranes considerably. Depending on the nature of the SMMs, the membrane surface becomes more hydrophobic/hydrophilic or electrically charged. Surface roughness of the membrane will be changed by adding surfactants or electrolytes in the coagulation bath. Various  techniques will be employed to characterize the membrane surface. Fouling will be studied by measuring the flux reduction of the membranes in separation of small organic molecules by RO or proteins by UF. The correlations will then be found between the membrane surface properties and fouling and the factors that have strong effects on membrane fouling will be identified. This information will be useful for the design of membranes with reduced fouling by blending SMMs in host polymers.