基于微流控制备梯度共聚物/双金属纳米粒子复合胶束及双刺激响应性和催化性能

Microfluidic-Based Preparation of Gradient Copolymer/Bimetallic Nanoparticle Composite Micelles and Their Dual-Stimulus Responsiveness and Catalytic Performance

将油酸改性的Fe_(3)O_(4)磁性纳米粒子、丙烯酸和甲基丙烯酸三氟乙酯的梯度共聚物和硝酸银在同轴微流控装置内进行共组装,然后在微流控通道外经透析、还原得到梯度共聚物/磁性Fe_(3)O_(4)纳米粒子/银纳米粒子复合胶束。调节微流控的流速参数,研究内外相流体的流速比对复合胶束粒径及形貌的影响。以动态光散射仪、透射电镜等详细研究了复合胶束的温敏性,并探究了不同温度时复合胶束的催化性能;利用振动样品磁强计测试复合胶束的磁响应性。结果表明,提高内外相流速比会使复合胶束粒径增大。复合胶束表现出温敏性和磁响应性,升高温度会使复合胶束的粒径增大,外加磁场能使复合胶定向聚集并回收再利用。复合胶束可以用作硼氢化钠还原对硝基苯酚反应的催化剂,温度对其表观催化反应速率常数的影响十分明显,并在循环使用3次后仍具有81.9%的催化效率。

Oleic acid-modified Fe_(3)O_(4) magnetic nanoparticles,gradient copolymers of acrylic acid and trifluoroethyl methacrylate and silver nitrate were co-assembled in a coaxial microfluidic device,and then the gradient copolymer/magnetic Fe_(3)O_(4) nanoparticles/silver nanoparticles composite micelles were obtained by dialysis and reduction outside the microfluidic device.The microfluidic parameters were adjusted to study the effect of the flow rate ratio of the inner and outer phase fluids on the particle size and morphology of the composite micelles.The temperature sensitivity of the composite micelles was investigated in detail by dynamic light scattering instrument and transmission electron microscopy,and the catalytic property of the composite micelles was investigated at different temperatures.The magnetic responsiveness of the composite micelles was tested using a vibrating sample magnetometer.The results show that increasing the flow rate ratio of the inner and outer phases would increase the particle size of the composite micelles.The composite micelles exhibit a temperature sensitivity and magnetic responsiveness.Elevated temperature can increase the particle size of the composite micelles.The composite micelles are recycled through aggregation under applied magnetic field.The composite micelles could be used as catalyst for the reduction of p-nitrophenol by sodium borohydride.Temperature sensitivity of the composite micelles has obvious effects on apparent catalytic rate constant.The composite micelles still have the catalytic efficiency of 81.9%after recycling three times.