Grande C D, Tria M C, Felipe M J, Zuluaga F, Advincula R
Department of Chemistry and Department of Chemical and Biomolecular Engineering, University of Houston, 77204-5003, Houston, TX, USA.
Eur Phys J E Soft Matter. 2011 Feb;34(2):15. doi: 10.1140/epje/i2011-11015-x. Epub 2011 Feb 21.
The synthesis of homopolymer and diblock copolymers on surfaces was demonstrated using electrodeposition of a methacrylate-functionalized carbazole dendron and subsequent reversible addition-fragmentation chain transfer (RAFT) "grafting-through" polymerization. First, the anodically electroactive carbazole dendron with methacrylate moiety (G1CzMA) was electrodeposited over a conducting surface (i.e. gold or indium tin oxide (ITO)) using cyclic voltammetry (CV). The electrodeposition process formed a crosslinked layer of carbazole units bearing exposed methacrylate moieties. This film was then used as the surface for RAFT polymerization process of methyl methacrylate (MMA), styrene (S), and tert-butyl acrylate (TBA) in the presence of a free RAFT agent and a free radical initiator, resulting in grafted polymer chains. The molecular weights and the polydispersity indices (PDI) of the sacrificial polymers were determined by gel permeation chromatography (GPC). The stages of surface modification were investigated using X-ray photoelectron spectroscopy (XPS), ellipsometry, and atomic force microscopy (AFM) to confirm the surface composition, thickness, and film morphology, respectively. UV-Vis spectroscopy also confirmed the formation of an electro-optically active crosslinked carbazole film with a [Formula: see text] - [Formula: see text] absorption band from 450-650nm. Static water contact angle measurements confirmed the changes in surface energy of the ultrathin films with each modification step. The controlled polymer growth from the conducting polymer-modified surface suggests the viability of combining electrodeposition and grafting-through approach to form functional polymer ultrathin films.
通过甲基丙烯酸酯官能化咔唑树枝状分子的电沉积以及随后的可逆加成-断裂链转移（RAFT）“接枝聚合”，证明了在表面合成均聚物和二嵌段共聚物。首先，使用循环伏安法（CV）将带有甲基丙烯酸酯部分的阳极电活性咔唑树枝状分子（G1CzMA）电沉积在导电表面（即金或氧化铟锡（ITO））上。电沉积过程形成了带有暴露的甲基丙烯酸酯部分的咔唑单元交联层。然后将该膜用作在游离RAFT试剂和自由基引发剂存在下甲基丙烯酸甲酯（MMA）、苯乙烯（S）和丙烯酸叔丁酯（TBA）进行RAFT聚合过程的表面，从而得到接枝聚合物链。通过凝胶渗透色谱法（GPC）测定牺牲聚合物的分子量和多分散指数（PDI）。使用X射线光电子能谱（XPS）、椭偏仪和原子力显微镜（AFM）分别研究表面改性阶段，以确认表面组成、厚度和薄膜形态。紫外-可见光谱也证实了形成了具有450 - 650nm的[公式：见原文] - [公式：见原文]吸收带的电光活性交联咔唑膜。静态水接触角测量证实了每个改性步骤后超薄膜表面能的变化。从导电聚合物改性表面可控的聚合物生长表明，将电沉积和接枝聚合方法相结合以形成功能性聚合物超薄膜是可行的。
