Micelle formation from amphiphilic "cylindrical brush"--coil block copolymers prepared by metallocene catalysis.
Micelle formation from amphiphilic "cylindrical brush"--coil block copolymers prepared by metallocene catalysis.
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DOI：
10.1002/anie.200353259
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发表时间：
2004-06
影响因子：
--
通讯作者：
Michael W. Neiser;S. Muth;U. Kolb;J. R. Harris;J. Okuda;Manfred Schmidt
中科院分区：
文献类型：
--
作者：
Michael W. Neiser;S. Muth;U. Kolb;J. R. Harris;J. Okuda;Manfred Schmidt
有机钐（iii）催化剂2的THF溶液中反应2小时。[6]从反应混合物中取出一小份（500 μL）后，加入甲基丙烯酸叔丁酯（tBuMA）。再过两小时后，用乙醇终止聚合，聚合物3-OtBu沉淀。通过核磁共振谱、凝胶渗透色谱、光散射、原子力显微镜和透射电子显微镜对样品进行了研究。合成和表征程序的详细信息见支持性信息。共聚物3-OtBu的AFM图像示于图1中。在圆柱形刷链的末端可以看到亮点，其最有可能源自塌陷的p-tBuMA线圈块（箭头1）。此外，可以看到均聚物刷（箭头2），其显然没有引发线性线圈块。通过NMR光谱给出了形成嵌段共聚物的额外证据，其显示脂肪族质子与芳香族质子的比率从0.8：1增加到0.87：1。从这些数字计算嵌段长度比：DPn（PS-MM）：DPn（ptBuMA）= 2.0。聚合物的聚合度DPw为
organosamarium (iii) catalyst 2 in THF for 2 h as described previously.[6] After a small aliquot (500 μL) had been taken from the reaction mixture, tert-butyl methacrylate (tBuMA) was added. After two more hours the polymerization was terminated by ethanol and the polymer 3-OtBu was precipitated. The sample was investigated by NMR spectroscopy, gel-permeation chromatography (GPC), light scattering, atomic force microscopy (AFM), and transmission electron microscopy (TEM). Details of the synthesis and characterization procedures are given in the Supporting Information. The AFM image of the copolymer 3-OtBu is shown in Figure 1. Bright spots can be seen at the end of the cylindrical brush chains, which most probably originate from the collapsed p-tBuMA coil block (arrow1). Furthermore, homopolymer brushes can be seen (arrow 2), which clearly did not initiate a linear coil block. Additional evidence for the formation of block copolymers is given by NMR spectroscopy, which shows an increase in the ratio of the aliphatic to aromatic protons from 0.8: 1 to 0.87: 1. From these numbers the block-length ratio is calculated: DPn (PS-MM): DPn (ptBuMA)= 2.0. The degree of polymerization DPw of the