Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, United States; Particle Engineering Research Center, University of Florida, Gainesville, FL 32611, United States.
Particle Engineering Research Center, University of Florida, Gainesville, FL 32611, United States.
J Colloid Interface Sci. 2015 May 1;445:60-68. doi: 10.1016/j.jcis.2014.12.061. Epub 2014 Dec 29.
Dryness and discomfort are the main reasons for dropouts in contact lens wearers. Incorporating surfactants in lens formulations could improve wettability and lubricity, which can improve comfort. We have focused on incorporating polymerizable surfactants in hydroxyethyl methacrylate lenses to improve comfort, while minimizing the potential for surfactant release into the tears. The surfactants were added to the polymerization mixture, followed by UV curing and extraction of leachables in hot water. Wettability and lubricity were characterized by measuring the contact angle and coefficient of friction. Lenses were also characterized by measuring transmittance, loss and storage moduli and ion permeability. Incorporation of surfactants significantly reduced contact angle from 90° for p-HEMA gels to about 10° for 2.43% (w/w) surfactant loading in hydrated gel. The coefficient of friction also decreased from about 0.16 for HEMA gels to 0.05 for the gels with 2.43% surfactant loading. There was a good correlation between the contact angle and coefficient of friction suggesting that both effects can be related to the stretching of the surfactant tails near the surface into the aqueous phase. The water content was also correlated with the surfactant loading but the contact angle was more sensitive suggesting that the observed improvements in wettability and lubricity arise from the protrusion of the surfactant tails in into the liquid, and not purely from the increase in the water content. The gels were clear and certain compositions also have the capability to block UVC and UVB radiation. The results suggest that incorporation of polymerizable surfactants could be useful in improving surface properties without significantly impacting any bulk property.
干燥和不适是隐形眼镜佩戴者放弃佩戴的主要原因。在隐形眼镜配方中加入表面活性剂可以提高润湿性和润滑性，从而提高舒适度。我们专注于在羟乙基甲基丙烯酸酯镜片中加入可聚合的表面活性剂，以提高舒适度，同时将表面活性剂释放到泪液中的潜在风险降到最低。将表面活性剂加入聚合混合物中，然后进行 UV 固化，并在热水中提取可浸出物。通过测量接触角和摩擦系数来表征润湿性和润滑性。还通过测量透光率、损耗和存储模量以及离子渗透性来表征镜片。与 p-HEMA 水凝胶相比，添加表面活性剂可使接触角从 90°显著降低至约 10°，对于 2.43%（w/w）的表面活性剂负载量，水凝胶的含水量增加。摩擦系数也从 HEMA 水凝胶的约 0.16 降低到 2.43%表面活性剂负载量的水凝胶的 0.05。接触角和摩擦系数之间存在良好的相关性，表明这两种效应都可以与表面活性剂尾部在表面附近拉伸到水相有关。水含量也与表面活性剂负载量相关，但接触角更敏感，这表明观察到的润湿性和润滑性的提高是由于表面活性剂尾部突出到液体中，而不仅仅是由于水含量的增加。凝胶是透明的，某些成分还具有阻挡 UVC 和 UVB 辐射的能力。结果表明，在不显著影响任何体相性质的情况下，加入可聚合的表面活性剂可能有助于改善表面性质。
