Effect of molecular weight on synthesis and surface morphology of high-density poly(ethylene glycol) grafted layers
Effect of molecular weight on synthesis and surface morphology of high-density poly(ethylene glycol) grafted layers
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DOI：
10.1021/la049359h
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发表时间：
2004-08-03
期刊：
影响因子：
3.9
通讯作者：
Luzinov, I
中科院分区：
文献类型：
--
作者：
Zdyrko, B;Varshney, SK;Luzinov, I
这项工作描述了研究永久接枝的羧酸末端官能化的聚（乙二醇）甲基醚（PEG）链的不同分子量的熔体到表面采用聚（甲基丙烯酸缩水甘油酯）的聚（甲基丙烯酸缩水甘油酯）的膜作为锚定层。接枝导致合成具有非常高的接枝密度的完整的PEG刷。附接的PEG膜的最大厚度强烈地依赖于被接枝的聚合物链的长度。PEG的最大接枝效率接近临界缠结分子量区域。所有接枝的PEG层都处于“刷状状态”，因为层的接枝位点之间的距离低于锚定的大分子的端到端距离。扫描探针显微镜显示，接枝过程导致完整的PEG层与纳米尺度上的表面光滑度。几乎所有的样品都部分或全部覆盖有结晶域，当样品在水下扫描时，结晶域消失。由于PEG的亲水性，具有接枝层的表面表现出低（高达21度）的水接触角。
This work describes studying the permanent grafting of carboxylic acid end-functionalized poly(ethylene glycol) methyl ether (PEG) chains of different molecular weights from the melt onto a surface employing poly(glycidyl methacrylate) ultrathin film as an anchoring layer. The grafting led to the synthesis of the complete PEG brushes possessing exceptionally high grafting density. The maximum thickness of the attached PEG films was strongly dependent on the length of the polymer chains being grafted. The maximum grafting efficiency was close to the critical entanglement molecular weight region for PEG. All grafted PEG layers were in the "brush regime", since the distance between grafting sites for the layers was lower than the end-to-end distance for the anchored macromolecules. Scanning probe microscopy revealed that the grafting process led to complete PEG layers with surface smoothness on a nanometric scale. Practically all samples were partly or fully covered with crystalline domains that disappeared when samples were scanned under water. Due to the PEG hydrophilic nature, the surface with the grafted layer exhibited a low (up to 21degrees) water contact angle.