title: Using silane coupling agents to prepare raspberry-shaped polyaniline hollow microspheres with tunable nanoshell thickness.
abstract: In this paper, we present the facile preparation of polyaniline (PANI) hollow spheres by using a silane coupling agent, N-[3-(trimethoxysilyl) propyl]aniline (PAPTMS), as a precursor. The PANI hollow spheres exhibit tunable shell thickness. PAPTMS was used to prepare aniline-modified silica microparticles, ~550 nm in diameter, by the Stöber process. PANI-coated silica core-shell microcapsules (SiO(2)@PANI) were subsequently obtained by performing chemically oxidative polymerization of a specific aniline monomer loading in the presence of the core-shell particles. PANI hollow spheres with tunable PANI shell thicknesses were eventually obtained by immersing the as-prepared core-shell particles in 5 wt% HF aqueous solutions to simultaneously remove the silica cores and further dope the PANI shells. The as-prepared core-shell particles and PANI hollow spheres were characterized using Fourier-transform infrared (FTIR) and (29)Si nuclear magnetic resonance (NMR) spectroscopies. The surface morphologies of the core-shell particles and PANI hollow spheres were investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrical conductivities and optical absorption spectra of the as-prepared core-shell microparticles and the PANI hollow spheres were measured using the standard four-point probe method and ultraviolet-visual (UV-Vis) absorption spectroscopy, respectively.
authors.affiliation: Department of Chemistry and Center for Nanotechnology, Chung-Yuan Christian University, Chung Li 32023, Taiwan, ROC.
authors.forename: Chung-Feng
authors.initials: CF
authors.lastname: Dai
authors.forename: Cheng-Jian
authors.initials: CJ
authors.lastname: Weng
authors.forename: Chao-Ming
authors.initials: CM
authors.lastname: Chien
authors.forename: Ya-Lun
authors.initials: YL
authors.lastname: Chen
authors.forename: Shan-Yuan
authors.initials: SY
authors.lastname: Yang
authors.forename: Jui-Ming
authors.initials: JM
authors.lastname: Yeh