Holly F J, Refojo M F
J Biomed Mater Res. 1975 May;9(3):315-26. doi: 10.1002/jbm.820090307.
The wettability characteristics of the contact lens material, PHEMA, with respect to water have been determined by using the sessile drop, and the captive air bubble techniques of contact angle goniometry. It is concluded that on PHEMA gels water does not spread spontaneously. Large hysteresis has been observed in the advancing and receding contact angles. This suggests that this hydrogel surface is capable of changing its free energy through reorientation of the polymer side chains and chain segments depending on the nature of the adjacent phase. The water content of the gels does not appear to have an effect on water wettability in the hydration range investigated. The minor wettability differences among the various gels studied were most likely due to differences in surface structure and segmental mobility due to inherent variations in the method of preparation. Small but consistent differences were found between the contact angles measured by the captive bubble method and those obtained by the sessile drop method, the former values being higher. These differences may not be method-related artifacts and cannot be explained at the present time.
通过使用座滴法和俘获气泡法测量接触角，已确定了隐形眼镜材料聚甲基丙烯酸羟乙酯（PHEMA）相对于水的润湿性特征。得出的结论是，在PHEMA凝胶上，水不会自发铺展。在前进接触角和后退接触角中观察到了较大的滞后现象。这表明，这种水凝胶表面能够根据相邻相的性质，通过聚合物侧链和链段的重新取向来改变其自由能。在所研究的水合范围内，凝胶的含水量似乎对水润湿性没有影响。所研究的各种凝胶之间较小的润湿性差异很可能是由于制备方法的固有差异导致的表面结构和链段迁移率的差异。通过俘获气泡法测量的接触角与通过座滴法获得的接触角之间存在微小但一致的差异，前者的值更高。这些差异可能不是与方法相关的假象，目前无法解释。
