添加盐对水性介质中2-基乙基甲酸盐RAFT聚合物的作用
Csilla György1, Jacob S Wagstaff1, Saul J Hunter2
1Dainton Building, Department of Chemistry, Brook Hill, University of Sheffield, Sheffield, South Yorkshire S3 7HF, U.K.
Macromolecules
|July 29, 2024
概括
在2-乙基甲酸盐 (HEMA) 的水性聚合过程中添加盐显著影响了动力学和形态学. 较高的盐度加快了聚合速率,并影响了聚二甲基氧乙烯酸) -PHEMA块共聚物的自我组装.
科学领域:
- 聚合物化学 聚合物化学
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
背景情况:
- 可逆添加碎片化链转移 (RAFT) 聚合是一种受控的激素聚合技术.
- 在水性介质中的聚合诱导自我组装 (PISA) 为纳米结构提供了一条绿色和高效的途径.
- 盐对水性聚合动力学和由此产生的共聚合物形态的影响需要进一步研究.
研究的目的:
- 调查添加的化 (NaCl) 对2-乙基甲酸盐 (HEMA) 的RAFT聚合物的影响.
- 探索不同盐度对聚二甲基氧乙烯酸化胆) -PHEMA (PMPC-PHEMA) 块共聚合物纳米物体通过PISA形成的形态学的影响.
- 阐明盐度,单体溶解度,聚合动力学和最终纳米结构 (球体,虫,囊泡) 之间的关系.
主要方法:
- 使用PMPC宏链转移剂在不同NaCl度的水性介质中进行HEMA的RAFT聚合.
- 通过单体转换测量对聚合动学的表征.
- 使用传输电子显微镜 (TEM) 和动态光散射 (DLS) 来分析生成的双块共聚合物纳米物体的形态分析.
- 粘度测量以评估虫轮长度. 粘度测量以评估虫轮长度.
主要成果:
- 高HEMA转换 (>99%) 迅速实现,由于较早的细胞核形成,在较高的NaCl度下观察到更快的速度.
- 一个伪相图显示,球体,虫和囊泡可以形成高达2.5M NaCl.
- 在3M NaCl下,只能得到动力捕获的球体,这表明向乳液聚合物的转变.
- 盐度的增加导致囊泡的大小和虫轮长度的系统减少.
结论:
- 添加的盐度是水性PISA配方中的关键参数,显著影响单体溶解度和聚合动力学.
- 盐度直接影响自组装的PMPC-PHEMA块共聚合物纳米物体的形态和尺寸.
- 这项研究提供了一种新的PISA配方,通过盐度对纳米结构形成进行可调节的控制.
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