Layer-by-Layer Hydrogen-Bonded Antioxidant Films of Linear Synthetic Polyphenols
Layer-by-Layer Hydrogen-Bonded Antioxidant Films of Linear Synthetic Polyphenols
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DOI：
10.1021/acs.macromol.9b02512
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发表时间：
2020-02-11
期刊：
影响因子：
5.5
通讯作者：
Sukhishvili, Svetlana A.
中科院分区：
文献类型：
--
作者：
Hlushko, Raman;Ankner, John F.;Sukhishvili, Svetlana A.
我们报道了线性抗氧化聚合物中多酚悬垂基团的化学结构在其组装和层间（LbL）膜内的链混合以及界面组装的抗氧化性能中的作用。当与聚环氧乙烷（PEO）在氢键膜内组装时，抗氧化聚合物聚（3,4-二羟基苄基甲基丙烯酰胺）（P2HMA）和聚（3,4- s-三羟基苄基甲基丙烯酰胺）（P3HMA）分别含有儿茶酚和胆碱类基团，生成的膜具有截然不同的结构和功能。其中，基于儿茶酚的P2HMA在LbL薄膜中呈线性沉积，每一步的质量增量较小，而P3HMA/PEO薄膜的增长呈强指数增长。利用氘化PEO （dPEO）创建标记层的中子反射技术揭示了这些薄膜中链混合和分层的巨大差异。正如自由基清除实验所证明的那样，膜结构的差异强烈影响膜的抗氧化性能。组装后的P3HMA完全可以清除2,2'-氮基-双（3-乙基苯并噻唑-6-磺酸）（ABTS（中心点+））自由基阳离子，但在组装后的P2HMA中，自由基清除仅限于LbL膜顶部约35 nm处，突出了LbL膜结构对抗氧化性能的影响。
We report on the role of the chemical structure of polyphenol pendant groups in linear antioxidant polymers in their assembly and chain intermixing within layer-by-layer (LbL) films, as well as in the antioxidant performance of interfacial assemblies. When assembled with poly(ethylene oxide) (PEO) within hydrogen-bonded films, the antioxidant polymers-poly(3,4-dihydroxybenzyl methacrylamide) (P2HMA) and poly(3,4,S-trihydroxybenzyl methacrylamide) (P3HMA)-which contain catechol- and gallol-like moieties, respectively, generated films with drastically different structure and functionality. Specifically, while catechol-based P2HMA deposited within LbL films linearly with a low increment of mass increase per step, the growth of P3HMA/PEO films was strongly exponential. Dramatic differences in chain intermixing and layering in these films are revealed by the application of neutron reflectometry using deuterated PEO, dPEO, to create marker layers. Differences in film structure strongly affected film antioxidant performance, as demonstrated by the radical scavenging assay. While assembled P3HMA was fully available for scavenging 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(center dot+)) radical cations, in assembled P2HMA, radical scavenging was restricted to the top similar to 35 nm of the LbL film, highlighting the effect of LbL film structure on antioxidant performance.