在可逆添加碎片链转移水性乳液聚合过程中进行小角度X射线散射研究
Emma E Brotherton1, Fiona L Hatton1, Amy A Cockram1
1Dainton Building, Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , South Yorkshire S3 7HF , United Kingdom.
Journal of the American Chemical Society
|August 1, 2019
概括
这项研究展示了RAFT水性乳液聚合物的第一次现场微角X射线散射 (SAXS) 监测. 研究人员开发了一种新的反应细胞,可以实时观察区块共聚物自组装成球体,虫和囊泡.
科学领域:
- 聚合物化学
- 材料科学
- 纳米技术
背景情况:
- 聚合诱导自组装 (PISA) 是创建块共聚合物纳米结构的多功能方法.
- 在现场微角X射线散射 (SAXS) 提供了对自组装过程的宝贵见解.
- 之前的SAXS现场研究在RAFT水性乳液聚合中由于技术挑战而受到限制.
研究的目的:
- 开发和展示一个新的SAXS实地研究RAFT水性乳液聚合的方法.
- 研究PGMA-PMOEMA块共聚物在水溶液中的自我组装机制.
- 为控制纳米结构形态 (球体,虫,囊泡) 建立相位图.
主要方法:
- 使用可逆添加碎片链转移 (RAFT) 水性乳液聚合.
- 采用设计用于高效和现场SAXS分析的新型反应单元.
- 研究了用PGMA前体块聚合二甲基乙烯酸 (MOEMA).
- 根据共聚物度和形态构建了一个相图.
主要成果:
- 在70°C下在2小时内达到高单体转化率 (> 90%).
- 成功合成了固体稳定的PGMA-PMOEMA球体,虫和囊泡.
- 通过调整反应条件来证明对形态的可重复控制.
- 通过现场SAXS观察纳米结构从细胞核到最终形态的动态演变.
结论:
- 在现场开发的SAXS技术克服了研究RAFT水性乳液PISA的先前局限性.
- 这种方法提供了前所未有的实时洞察力,
- 这些发现大大提高了基于PISA的纳米材料的理解和合理设计.
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