Sajanlal P R, Sreeprasad T S, Nair A Sreekumaran, Pradeep T
DST Unit on Nanoscience (DST UNS), Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras, Chennai-600 036, India.
Langmuir. 2008 May 6;24(9):4607-14. doi: 10.1021/la703593c. Epub 2008 Mar 27.
A simple and versatile method for the synthesis of a wide range of polyaniline (PANI)-based 1D and 2D gold nanostructures of uniform size distribution with high colloidal stability is demonstrated. All the nanostructures were synthesized from oligoaniline-coated gold nanoparticle precursors. The nanostructures include nanowires of various sizes, nanoplates, and flower-like nanoparticles. These nanowires showed a pH-dependent shape transformation. Needle-like aggregates of Au/PANI were formed as the pH of the nanowire solution changed to 2.5. At higher pH (10.2), nanowires converted into spherical nanoparticles. Core-shell particles of Au/PANI composites have been achieved by the reversal of the pH of the nanowire from 10.2 to 2.9. The morphology of the nanostructures was studied by TEM and SEM. FTIR, UV-vis, XRD, and LDI MS were utilized for the characterization of the chemical composition of the nanostructures. A mechanism for the nanowire growth is proposed.
展示了一种简单且通用的方法，用于合成具有高胶体稳定性、尺寸分布均匀的多种基于聚苯胺（PANI）的一维和二维金纳米结构。所有纳米结构均由寡聚苯胺包覆的金纳米颗粒前驱体制备而成。这些纳米结构包括各种尺寸的纳米线、纳米片和花状纳米颗粒。这些纳米线呈现出pH依赖性的形状转变。当纳米线溶液的pH值变为2.5时，形成了针状的金/聚苯胺聚集体。在较高pH值（10.2）下，纳米线转变为球形纳米颗粒。通过将纳米线的pH值从10.2反转至2.9，实现了金/聚苯胺复合材料的核壳颗粒。通过透射电子显微镜（TEM）和扫描电子显微镜（SEM）研究了纳米结构的形态。利用傅里叶变换红外光谱（FTIR）、紫外可见光谱（UV-vis）、X射线衍射（XRD）和激光解吸电离质谱（LDI MS）对纳米结构的化学成分进行了表征。提出了纳米线生长的机制。
