Department of Chemistry, University of Patras, GR-26504 Patras, Greece.
Foundation for Research and Technology-Hellas, Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Stadiou Str, GR-26504 Rio-Patras, Greece.
ACS Appl Mater Interfaces. 2023 Mar 1;15(8):11193-11207. doi: 10.1021/acsami.3c01017. Epub 2023 Feb 14.
Humidity-responsive materials have attracted increasing attention for their potential use in various applications, e.g., sensors, soft robotics, and human-machine interfaces. Much effort has been focused on the use of ionic liquids for the construction of humidity-responsive sensors; yet, not enough attention has been paid on the susceptibility of the used poly(ionic liquid)s to microorganisms. This is especially relevant to the wide use of the polymers for biomedical applications, e.g., wearable body-condition sensors or healthcare control systems. We herein describe the development of dual functional, self-standing, monolayer antimicrobial membranes derived from cross-linked copolymers functionalized with ionic liquids. In a first step, random copolymers of poly(4-vinylbenzyl -alkyl imidazolium chloride--acrylic acid), P(VBCImC--AA20), were synthesized bearing aliphatic chains of different lengths (where = 1, 4, 8, 12, 16 carbon atoms) to investigate the effect of hydrophobicity/hydrophilicity on the humidity-responsive properties of the copolymer and its antimicrobial activity. The aforementioned copolymers were later blended with the complementary reactive copolymers of poly(cetyl trimethylammonium 4-styrene sulfonate--glycidyl methacrylate), P(SSAmC--GMA20), to provide highly stable films and coatings through thermal cross-linking. The membrane P(VBCImC--AA20)/P(SSAmC--GMA20) with a molar ratio of 3:1 (mol AA/mol GMA) exhibited immediate and high response to moisture through folding or flipping motions when placed on a wet filter paper or on the palm of a hand. The inhibition of growth for selected bacterial species (, , and ) on the copolymer membranes was dependent on the length of the imidazolium alkyl chain and the species. Additionally, in the case of the cross-linked P(VBCImC--AA20)/P(SSAmC--GMA20) membranes, the overall efficacy was very high against all microorganisms tested, which, combined with their high humidity responsiveness, enables their potential application.
湿度响应材料因其在各种应用中的潜在用途而受到越来越多的关注，例如传感器、软机器人和人机界面。人们已经投入了大量的精力来使用离子液体构建湿度响应传感器；然而，对于所使用的聚（离子液体）对微生物的敏感性，人们并没有给予足够的关注。这对于聚合物在生物医学应用中的广泛使用尤其重要，例如可穿戴身体状况传感器或医疗保健控制系统。在此，我们描述了由功能化离子液体的交联共聚物制备的双功能、自立、单层抗菌膜的开发。在第一步中，合成了带有不同长度脂肪链的聚（4-乙烯基苄基-烷基咪唑𬭩氯化物-丙烯酸）的无规共聚物 P(VBCImC-AA20)，以研究疏水性/亲水性对共聚物的湿度响应性能及其抗菌活性的影响。后来，将上述共聚物与互补的反应性共聚物聚（十六烷基三甲基铵 4-苯乙烯磺酸盐-甲基丙烯酸缩水甘油酯）P(SSAmC-GMA20)混合，通过热交联提供高度稳定的薄膜和涂层。摩尔比为 3:1（mol AA/mol GMA）的膜 P(VBCImC-AA20)/P(SSAmC-GMA20)在放置在湿滤纸或手掌上时，通过折叠或翻转运动，对水分表现出即时和高度的响应。共聚物膜对选定细菌物种（，，和）的生长抑制取决于咪唑𬭩烷基链的长度和物种。此外，对于交联的 P(VBCImC-AA20)/P(SSAmC-GMA20)膜，对所有测试的微生物的整体效果非常高，这与它们的高湿度响应能力相结合，使其具有潜在的应用前景。
