Chemistry Department, DDU Gorakhpur University, Gorakhpur-273009, India.
J Phys Chem B. 2011 Jul 14;115(27):8724-31. doi: 10.1021/jp1095757. Epub 2011 Jun 17.
Polyaniline nanoparticles were synthesized by simple electrochemical polymerization of aniline in systems (a) aniline-sodium dodecyl sulfate (NaDS)-dodecylbenzene sulfonic acid (DBSA)-H(2)O and (b) aniline-NaDS-DBSA-cetyltrimethyl ammonium bromide (CTAB)-H(2)O. Different morphologies including compact and fractal/dendrimer were observed at different experimental conditions. Fractal dimension was calculated by the box counting method. Growth kinetics during electropolymerization of aniline in both of the systems was studied by measuring the weight of polymer aggregates as a function of time. Growth rate was found to be reduced in system (b) due to coordination of CTAB with the growing polyaniline chain. The weight of polymer aggregates was found to depend on field intensity and attains a maximum value at a critical field intensity 4.0 V/cm. Beyond this critical field intensity, the growth rate was decreased due to loss of conjugation and degradation of the polymer backbone. Electropolymerized aggregates were characterized by transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and electrical conductivity measurements. Nanosized polyaniline was formed, with particle diameters in the range of 10-200 nm, as evident by TEM studies and supported by XRD studies. FT-IR spectroscopy established the formation of hyperbranched polyaniline chains. During electropolymerization, oscillations in potential were monitored as a function of time at different experimental conditions. A suitable mechanism for fractal growth of polyaniline was also proposed.
聚苯胺纳米粒子是通过简单的电化学聚合苯胺在系统（a）苯胺-十二烷基硫酸钠（NaDS）-十二烷基苯磺酸（DBSA）-H（2）O 和（b）苯胺-NaDS-DBSA-十六烷基三甲基溴化铵（CTAB）-H（2）O 中合成的。在不同的实验条件下观察到了不同的形态，包括致密和分形/树枝状。分形维数通过盒子计数法计算。通过测量聚合物聚集体的重量随时间的变化来研究在这两个系统中苯胺的电聚合过程中的生长动力学。由于 CTAB 与生长的聚苯胺链的配位，发现系统（b）中的生长速率降低。聚合物聚集体的重量发现依赖于场强，并在临界场强 4.0 V/cm 处达到最大值。超过这个临界场强，由于共轭的损失和聚合物主链的降解，生长速率降低。通过透射电子显微镜（TEM）、粉末 X 射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）和电导率测量对电聚合聚集体进行了表征。通过 TEM 研究和 XRD 研究证实形成了纳米级聚苯胺，粒径在 10-200nm 范围内。FT-IR 光谱证实了支化聚苯胺链的形成。在电聚合过程中，监测了不同实验条件下随时间变化的电位振荡。还提出了一种适合聚苯胺分形生长的合适机制。
