Division of Molecular Physics, IFM, Linköping University , 581 83 Linköping, Sweden.
ACS Appl Mater Interfaces. 2014 Jul 23;6(14):11448-58. doi: 10.1021/am502084x. Epub 2014 Jul 1.
Understanding how surface physicochemical properties influence the settlement and adhesion of marine fouling organisms is important for the development of effective and environmentally benign marine antifouling coatings. We demonstrate that the thickness of random poly(HEMA-co-PEG10MA) copolymer brushes affect antifouling behavior. Films of thicknesses ranging from 50 to 1000 Å were prepared via surface-initiated atom-transfer radical polymerization and characterized using infrared spectroscopy, ellipsometry, atomic force microscopy and contact angle measurements. The fouling resistance of these films was investigated by protein adsorption, attachment of the marine bacterium Cobetia marina, settlement and strength of attachment tests of zoospores of the marine alga Ulva linza and static immersion field tests. These assays show that the polymer film thickness influenced the antifouling performance, in that there is an optimum thickness range, 200-400 Å (dry thickness), where fouling of all types, as well as algal spore adhesion, was lower. Field test results also showed lower fouling within the same thickness range after 2 weeks of immersion. Studies by quartz crystal microbalance with dissipation and underwater captive bubble contact angle measurements show a strong correlation between lower fouling and higher hydration, viscosity and surface energy of the poly(HEMA-co-PEG10MA) brushes at thicknesses around 200-400 Å. We hypothesize that the reduced antifouling performance is caused by a lower hydration capacity of the polymer for thinner films, and that entanglement and crowding in the film reduces the conformational freedom, hydration capacity and fouling resistance for thicker films.
了解表面物理化学性质如何影响海洋污损生物的附着和附着，对于开发有效的、环境友好的海洋防污涂料非常重要。我们证明了随机聚（HEMA-co-PEG10MA）共聚物刷的厚度会影响防污性能。通过表面引发原子转移自由基聚合制备了厚度范围从 50 到 1000 Å 的薄膜，并通过红外光谱、椭圆光度法、原子力显微镜和接触角测量进行了表征。通过蛋白质吸附、海洋细菌 Cobetia marina 的附着、海洋藻类 Ulva linza 的游动孢子附着和附着强度测试以及静态浸泡现场测试来研究这些薄膜的抗污性能。这些实验表明聚合物薄膜厚度会影响防污性能，因为存在最佳厚度范围 200-400 Å（干厚度），在这个范围内，所有类型的污损以及藻类孢子的附着都较低。2 周浸泡后的现场测试结果也表明在相同厚度范围内的污损较低。通过石英晶体微天平耗散和水下俘获气泡接触角测量研究表明，在 200-400 Å 左右的厚度下，较低的污损与较高的水合度、粘度和聚（HEMA-co-PEG10MA）刷的表面能之间存在很强的相关性。我们假设，较薄的薄膜聚合物的水合能力较低，导致防污性能降低，而较厚的薄膜中的缠结和拥挤会降低构象自由度、水合能力和抗污性能。
