PPy—COOH/PPy/Ni/Pt多层管状微米马达的制备及其运动性能

Fabrication of PPy—COOH/PPy/Ni/Pt multilayer tubular micromotors and their motion behaviors

利用模板辅助的电化学沉积法成功制备出PPy—COOH/PPy/Ni/Pt多层管状微米马达。实验优化了聚吡咯层的电化学沉积条件:最优电荷沉积量和最优电镀液单体浓度分别为0.5 C和74 mmol·L-1。采用场发射扫描电子显微镜(SEM)、能谱仪(EDS)、3,3′,5,5′-四甲基联苯胺-辣根过氧化物酶(TMBHRP)显色法和光学显微镜对所得管状微米马达的形貌、成分以及运动性能进行表征。SEM图像显示,马达呈中空单锥型,且外表面光滑、内表面粗糙;EDS能谱分析结果表明,C、N、Ni和Pt元素分布于马达中;TMB-HRP显色反应表明,所得管状微米马达外表面含有羧基;运动性能分析表明,燃料浓度的提高可以有效提高管状微米马达的运动速率,当燃料体积分数为4%时,其运动速率可达485μm·s-1。此外,马达的运动方向可以通过外部的磁场进行控制。

PPy--COOH/PPy/Ni/Pt multilayer tubular micromotors were fabricated by using template-assisted electrochemical deposition method. The amount of deposition charge and the concentration of pyrrole for the deposition of PPy layer were optimized. The results show that the optimal amount of deposition charge is 0.5 C and the optimal concentration of pyrrole is 74 mmol/L. Scan electron microscope （SEM）, energy dispersive X-ray spectroscopy （EDS）, 3, 3＇, 5,5＇-tetramethylbenzidine-horseradish peroxidase （TMB-HRP） -based colorimetric method and optical microscope were used to characterize the structure, component and motion behavior of the as-obtained tubular micromotors. SEM images shows that the obtained tubular micromotors were dominated by uniform single cone-shaped structures with smooth outer layer and rough inner layer. EDX mapping analyses clearly reveals the existence of C, N, Ni and Pt within the tubular micromotors. The result of TMB-HRP-based colorimetric method indicates the presence of carboxyl groups on the outer surface of the tubular micromotors. Motion behavior analyses shows the speed of the tubular micromotors can be enhanced effectively with the increase of the fuel concentration. When the concentration of H2O2 was 4%, the speed of tubular micromotors can be increased to 485 μm/s. In addition, the result also shows that the motion of micromotors can be controlled by an external magnetic field.