Oschmann Bernd, Lawrence Jimmy, Schulze Morgan W, Ren Jing M, Anastasaki Athina, Luo Yingdong, Nothling Mitchell D, Pester Christian W, Delaney Kris T, Connal Luke A, McGrath Alaina J, Clark Paul G, Bates Christopher M, Hawker Craig J
Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010, Australia.
Center for Nanophase Materials Sciences, Oak Ridge National Laboratories, Oak Ridge, Tennessee 37831, United States.
ACS Macro Lett. 2017 Jul 18;6(7):668-673. doi: 10.1021/acsmacrolett.7b00262. Epub 2017 Jun 13.
The effect of dispersity on block polymer self-assembly was studied in the monodisperse limit using a combination of synthetic chemistry, matrix-assisted laser desorption ionization spectroscopy, and small-angle X-ray scattering. Oligo(methyl methacrylate) (oligoMMA) and oligo(dimethylsiloxane) (oligoDMS) homopolymers were synthesized by conventional polymerization techniques and purified to generate an array of discrete, semidiscrete, and disperse building blocks. Coupling reactions afforded oligo(DMS-MMA) block polymers with precisely tailored molar mass distributions spanning single molecular systems ( = 1.0) to low-dispersity mixtures ( ≈ 1.05). Discrete materials exhibit a pronounced decrease in domain spacing and sharper scattering reflections relative to disperse analogues. The order-disorder transition temperature () also decreases with increasing dispersity, suggesting stabilization of the disordered phase, presumably due to the strengthening of composition fluctuations at the low molar masses investigated.
利用合成化学、基质辅助激光解吸电离光谱和小角X射线散射相结合的方法，在单分散极限下研究了分散度对嵌段聚合物自组装的影响。通过常规聚合技术合成了聚甲基丙烯酸甲酯（oligoMMA）和聚二甲基硅氧烷（oligoDMS）均聚物，并进行纯化，以生成一系列离散、半离散和分散的结构单元。偶联反应得到了具有精确调整的摩尔质量分布的oligo（DMS-MMA）嵌段聚合物，其范围从单分子体系（Đ = 1.0）到低分散度混合物（Đ ≈ 1.05）。相对于分散类似物，离散材料的畴间距明显减小，散射反射更尖锐。有序-无序转变温度（T）也随着分散度的增加而降低，这表明无序相得到了稳定，推测是由于在所研究的低摩尔质量下组成波动增强所致。
