原位探测防污高分子材料与液体界面的分子结构

Probing Molecular Structures of Antifouling Polymer/Liquid Interfaces In Situ

海洋生物附着在船体表面会导致严重的燃油消耗的增加,防污高分子材料的研究因此成为对海洋船只运行极其重要的课题。这些高分子可以被用作船只的表面涂层,从而保护船只不受到海洋生物的吸附和生长的影响。两性离子高分子近年来已经逐渐成为潜力巨大的防污材料。研究表明,这些两性离子高分子的表面在水中的强水化作用对于其防污性能有至关重要的影响。在本篇综述中,我们总结了最近通过使用和频(SFG)振动光谱技术来实现的对防污材料的界面分析工作。SFG是一种表面敏感的技术,可以在原位并实时检测界面高分子和水分子的分子结构。我们总结的防污材料包括两性离子高分子,混合电荷式高分子以及两性的拟肽高分子材料。这些材料的界面水研究,以及盐离子对界面水分子作用会被详细讨论。我们也将介绍这些防污材料与蛋白质及海藻之间的作用。以上这些研究清楚地表明了高分子界面强水化与防污性能之间的关联,也显示了SFG是对高分子材料防污机理探索的一个强有力的分析技术。

Marine organisms such as plants,algae or small animals can adhere to surfaces of materials that are submerged in ocean.The accumulation of these organisms on surfaces is a marine biofouling process that has considerable adverse effects.Marine biofouling on ship hulls can cause severe fuel consumption increase.Investigations on antifouling polymers are therefore becoming important research topics for marine vessel operations.Antifouling polymers can be applied as coating layers on the ship hull,protecting it against the settlement and growth of sea organisms.Polyethylene glycol(PEG)is a hydrophilic polymer that can effectively resist the accumulation of marine organisms.PEG-based antifouling coatings have therefore been extensively researched and developed.However,the inferior stability of PEG makes it subject to degradation,rendering it ineffective for long-term services.Zwitterionic polymers have also emerged as promising antifouling materials in recent years.These polymers consist of both positively charged and negatively charged functional groups.Various zwitterionic polymers have been demonstrated to exhibit exceptional antifouling properties.Previously,surface characterizations of zwitterionic polymers have revealed that strong surface hydration is critical for their antifouling properties.In addition to these hydrophilic polymers,amphiphilic materials have also been developed as potential antifouling coatings.Both hydrophobic and hydrophilic functional groups are incorporated into the backbones or sidechains of these polymers.It has been demonstrated that the antifouling performance can be enhanced by precisely controlling the sequence of the hydrophobic-hydrophilic functionalities.Since biofouling generally occurs at the outer surface of the coatings,the antifouling properties of these coatings are closely related to their surface characteristics in water.Therefore,understanding of the surface molecular structures of antifouling materials is imperative for their future developments.In this review,we will summarize our recent advancements of antifouling material surface analysis using sum frequency generation(SFG)vibrational spectroscopy.SFG is a surface-sensitive technique which can provide molecular information of water and polymer structures at interfaces in situ in real time.The antifouling polymers we will review include zwitterionic polymer brushes,mixed charged polymers,and amphiphilic polypeptoids.Interfacial hydration studies of these polymers by SFG will be presented.The salt effect on antifouling polymer surface hydration will also be discussed.In addition,the interactions between antifouling materials and protein molecules as well as algae will be reviewed.The above research clearly established strong correlations between strong surface hydration and good antifouling properties.It also demonstrated that SFG is a powerful technique to provide molecular level understanding of polymer antifouling mechanisms.