Sixteen-arm star-shaped polymer of s-POSS-(PDMAEMA)16 was synthesized by octakis(dibromoethyl) polyhedral oligomeric silsesquioxane (POSS-(Br)16) initiating 2-(dimethylamino)ethyl methacrylate (DMAEMA) via atom transfer radical polymerization (ATRP) process. The obtained s-POSS-(PDMAEMA)16 showed controllable and reversible pH-responsive behavior at pH = 1–12 and thermoresponsive behavior at 20–60 °C. Typical core/shell micelles (100–130 nm) were formed by s-POSS-(PDMAEMA)16 at pH = 7.8 and transformed into 450–600 nm snowflake-shaped micelles at pH = 6, 400 nm butterfly-shaped micelles at pH = 3, and 20–40 nm spherical particles at pH = 10 due to the different interactions between the PDMAEMA chains and the aqueous solution. When the pH of the solution decreased from 10 to 3, 350–400 nm butterfly-shaped micelles were reformed, demonstrating the reversibility of this process. The soluble-insoluble transition temperature for s-POSS-(PDMAEMA)16 was located between 20 and 60 °C. Furthermore, equilibrium adsorption indicated that s-POSS-(PDMAEMA)16 could adsorb Cr(VI) due to strong electrostatic interactions between its tertiary amines and Cr(VI).

中文翻译：

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基于 pH 和温度响应的 POSS 聚（2-（二甲氨基）乙基甲基丙烯酸乙酯）高效吸附 Cr（VI）

通过八（二溴乙基）多面体低聚倍半硅氧烷（POSS-（Br）16）通过原子转移自由基聚合引发甲基丙烯酸2-（二甲氨基）乙酯（DMAEMA）合成s-POSS-（PDMAEMA）16的十六臂星形聚合物(ATRP) 过程。获得的 s-POSS-(PDMAEMA)16 在 pH = 1-12 时表现出可控和可逆的 pH 响应行为，在 20-60 °C 时表现出热响应行为。典型的核/壳胶束（100-130 nm）由 s-POSS-(PDMAEMA)16 在 pH = 7.8 形成，并在 pH = 6 时转化为 450-600 nm 雪花状胶束，在 pH 值下转化为 400 nm 蝴蝶形胶束= 3，由于 PDMAEMA 链和水溶液之间的相互作用不同，pH = 10 时为 20–40 nm 球形颗粒。当溶液的 pH 值从 10 降低到 3 时，350-400 nm 的蝴蝶形胶束重​​新形成，证明了这个过程的可逆性。s-POSS-(PDMAEMA)16 的可溶性-不溶性转变温度介于 20 和 60 °C 之间。此外，平衡吸附表明 s-POSS-(PDMAEMA)16 可以吸附 Cr(VI)，这是由于其叔胺和 Cr(VI) 之间的强静电相互作用。