Controllable Synthesis of Highly Conductive Polyaniline Coated Silica Nanoparticles Using Self-Stabilized Dispersion Polymerization

Highly conductive silica/polyaniline (PANi) core/shell nanoparticles (NPs) were synthesized in various diameters (from 18 to 130 nm) using self-stabilized dispersion polymerization. The polymerization was carried out in an aqueous/organic liquid system at −30 °C. In this system, the organic phase plays a key role in directing para-direction oriented polymerization of the PANi on the surface of silica NPs. Because of its para-direction polymerized structure, the synthesized silica/PANi core/shell NPs exhibited enhanced electrical conductivity (25.6 S cm^–1) compared with NPs (1.4 S cm^–1) prepared by homogeneous polymerization. The conductivities and BET surface areas were 25.6 S cm^–1/170 m² g^–1 (18 nm in diameter), 22.5 S cm^–1/111 m² g^–1 (35 nm in diameter), 18.3 S cm^–1/78 m² g^–1 (63 nm in diameter), and 16.4 S cm^–1/53 m² g^–1 (130 nm in diameter). In this series, increased para-coupling along the polymer backbone was elucidated using several characterization techniques, including Fourier transform infrared (FTIR), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) spectroscopy. As-prepared silica/PANi core/shell NPs exhibited capacitance as high as 305 F g^–1

Single-Step Affinity Purification for Fungal Proteomics ▿ †

A single-step protein affinity purification protocol using Aspergillus nidulans is described. Detailed protocols for cell breakage, affinity purification, and depending on the application, methods for protein release from affinity beads are provided. Examples defining the utility of the approaches, which should be widely applicable, are included