含氟梯度共聚物/银纳米粒子复合胶束的微流控制备及温敏性

Microfluidic Preparation and Temperature Sensitivity of Fluorinated Gradient Copolymer/Silver Nanocomposite Composite Micelles

首先通过微流控组装法制备丙烯酸-甲基丙烯酸三氟乙酯梯度共聚物/银离子复合胶束,然后通过硼氢化钠还原复合胶束上的银离子,最终得到梯度共聚物/银纳米粒子复合胶束(PAA-grad-TFEMA/Ag NPs复合胶束),其中银纳米粒子分布在复合胶束的亲水壳层。在确定PAA-grad-TFEMA自组装发生的临界含水量的基础上,结合计算模拟对形成复合胶束的微流控组装过程进行分析,并探讨了外相溶液中电解质含量对复合胶束形态结构的影响,详细研究了PAA-grad-TFEMA/Ag NPs复合胶束的温敏性。结果表明,内、外相溶液在微通道内快速混合,使混合溶液的水含量很快到达PAA-grad-TFEMA的临界水含量以上(质量分数8%),因此复合胶束能顺利通过微流控组装法形成,并且外相溶液中NaCl浓度对PAA-grad-TFEMA/Ag NPs复合胶束的形态、尺寸具有明显的影响。PAA-grad-TFEMA/Ag NPs复合胶束因共聚物链段具有梯度结构,在40~65℃表现出温敏性,复合胶束平均尺寸随温度升高而减小。

Acrylic acid-trifluoroethyl methacrylate gradient copolymer(PAA-grad-TFEMA)/silver ion composite micelles were first prepared by microfluidic assembly method,and then the silver ions on the composite micelles were reduced by sodium borohydride.Finally,the gradient copolymer/silver nanoparticle composite micelles(PAA-grad-TFEMA/Ag NPs composite micelles)were obtained,in which Ag NPs were loaded on the hydrophilic shell of the composite micelles.Based on the determination of the critical water content for the self-assembly of PAA-grad-TFEMA,the microfluidic assembly process to generate composite micelles was analyzed with the help of computational simulation.In addition,the influence of electrolytes on the morphology and sizes of the composite micelles were discussed and the temperature sensitivity of the composite micelles was studied in detail.The results as follows,the internal-phase solution rapidly mixes with the external-phase solution in the microchannel,causing that the water content of the mixed solution quickly reaches above the critical content of PAA-grad-TFEMA(mass fraction of 8%).Therefore,the composite micelles were formed by microfluidic assembly method,and the concentration of NaCl in the external-phase solution performs an obvious effect on the morphology and sizes of PAA-grad-TFEMA/Ag NPs composite micelles.PAA-grad-TFEMA/Ag NPs composite micelles exhibit the temperature sensitivity from 40℃to 65℃due to the gradient structure of the copolymer segments.The average size of the composite micelles decreases with the increasing temperature.