Visible Light Initiated Thermoresponsive Aqueous Dispersion Polymerization-Induced Self-Assembly
Visible Light Initiated Thermoresponsive Aqueous Dispersion Polymerization-Induced Self-Assembly
复制标题
可见光引发热响应水分散体聚合诱导自组装
DOI：
10.1021/acs.macromol.8b02490
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发表时间：
2019-02-12
期刊：
影响因子：
5.5
通讯作者：
Cai, Yuanli
中科院分区：
文献类型：
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作者：
Ma, Yajie;Gao, Pan;Cai, Yuanli
我们报道了一种更新的聚合诱导热自组装（PITSA）[Figg, C. A.; 等人，《化学科学》2015年，6，1230]。该概念通过在25 - 70℃下可见光引发的双丙酮丙烯酰胺单体的RAFT水分散聚合得到了验证。这种PITSA配方在25℃时产生嵌段共聚物片层，而在60℃（高于成核嵌段的下临界溶液链长（LCSCL））聚合过程中，共聚物形态从球体演变为蠕虫状再到囊泡状。使用单一的光 - PISA配方，可通过反应温度控制颗粒形状和尺寸的均匀性。将反应分散液（70℃）冷却至25℃时，可原位实现囊泡到片层以及囊泡到蠕虫状的转变，从而使最初的自由流动液体转变为物理水凝胶。此外，在加热 - 冷却循环中稀释时，合成的纳米粒子可实现可逆的热响应片层 - 囊泡 - 片层以及蠕虫状 - 囊泡 - 蠕虫状转变。这种热响应光 - PISA配方主要在三个方面对Figg的PITSA方案进行了更新：（1）不存在最低临界溶液温度（LCST）限制；（2）使用单一光 - PISA配方通过反应温度方便地控制颗粒形状和尺寸均匀性；（3）酮官能化囊泡可逆地热响应转变为客户导向的片层或蠕虫状。
We report an updated polymerization-induced thermal self-assembly (PITSA) [Figg, C. A.; et al. Chem. Sci. 2015, 6, 1230]. The concept is validated using visible light initiated RAFT aqueous dispersion polymerization of diacetone acrylamide monomer at 25 - 70 degrees C. This PITSA formulation produces block copolymer lamella at 25 degrees C whilethe copolymer morphology evolves from spheres to worms to vesicles during polymerization at 60 degrees C, which is above the lower critical solution chain length (LCSCL) of the core-forming block. Particle shape and size uniformity can be controlled by reaction temperature using a single photo-PISA formulation. Vesicles-to-lamellae and vesicles-to-worms transitions are achieved in situ upon cooling reaction dispersions (70 degrees C) to 25 degrees C, leading to the transformation of initially free -flowing liquids to physical hydrogels. Moreover, reversible thermoresponsive lamellae-to-vesicles-to-lamellae and worms-to-vesicles-to-worms transitions of as -synthesized nanoparticles are achieved in dilution in a heating-cooling cycle. This thermoresponsive photo-PISA formulation updates Figg's PITSA protocol mainly in three aspects: (1) the absence of LCST limitation, (2) user-friendly control of particle shape and size uniformity by reaction temperature using a single photo-PISA formulation, and (3) reversible thermoresponsive transition of the ketone-functionalized vesicles to customer-guided lamellae or worms.