Modification of the Surface Properties of Polymers

聚合物与水之间的界面自由能相对较大。因此，蛋白质、血小板和细胞会沉积在其表面。通过改变聚合物的表面性质，可以减少它们与水之间的界面自由，从而减少沉积的热力学驱动力。下面的表面改性技术，采用两种不混溶的液体接触，将进行研究。其中一种液体为水并含有水溶性表面活性剂，而另一种液体为有机化合物，其被选择作为聚合物衬底的溶剂。有机相的密度比水大是方便的。衬底在有机相中被短暂地引入。这软化了它的表面，并允许表面活性剂分子的碳氢链和聚合物底物的表面分子在通过水-有机溶剂界面和水相拔出底物的过程中纠缠。两相体系提供了表面活性剂分子吸附的界面。这种高度定向的表面活性剂层提高了表面活性剂向基体转移的效率。因此，改性聚合物表面与水之间的界面自由能降低到1达因/厘米以下。这可以减少蛋白质、细胞和血小板在这些表面的沉积。将研究蛋白质在未修饰和表面的吸附以及修饰表面的稳定性，以验证该程序的有效性。

The interfacial free energy between a polymer and water is relatively large. As a result, proteins, platelets and cells will deposit upon its surface. By modifying the surface properties of the polymers, one can reduce the interfacial free between them and water, and thus reduce the thermodynamic driving force for deposition. The following surface modification technique, which employs two immiscible liquids in contact, will be investigated. One of the liquids is water and contains a water soluble surfactant, while the other liquid is an organic compound which is selected so as to be a solvent for the polymer substrate. It is convenient for the organic phase to be more dense than water. The substrate is introduced for a short time in the organic phase. This softens its surface and allows the entanglement of the hydrocarbon chains of the surfactant molecules and of the surface molecules of the polymer substrate during the pulling out of the substrate through the water-organic solvent interface and the water phase. The two-phase system provides an interface at which the surfactant molecules adsorb. This highly oriented surfactant layer increases the efficiency of the transfer of surfactant to the substrate. The interfacial free energy between the modified polymer surface and water is thus decreased below 1 dyne/cm. This can reduce the deposition of proteins, cells and platelets on such surfaces. The adsorption of proteins on the non-modified and surface as well as the stability of the modified surface will be investigated to verify the effectiveness of the procedure.