Synthesis of porous carbon materials utilizing polymer particles

Abstract

A series of colloidally stable near-monodisperse polyacrylonitrile (PAN) latex particles with a submicrometer diameter were synthesized by either dispersion or emulsion polymerization and examined for their performance in the preparation of highly stable latex foams. Poly(N-vinylpyrrolidone) was used as a colloidal stabilizer, which adsorbed at PAN particle surface. The PAN particles were extensively characterized using scanning electron microscopy, fourier transform infrared spectroscopy, and dynamic light scattering method. Submicrometer-sized PAN latex particles were invariably adsorbed at air-water interface and stabilized foams generated by simple hand-shaking or using a foam column, with no additives (e.g., surfactant, salt, or cosolvent) being required to induce latex destabilization. The foams stabilized with the PAN particles could keep their 3 dimensional porous structures even after drying. Scanning electron microscopy studies indicate near close-packed PAN particles within the dried foam, which suggests high colloid stability for the PAN particles prior to their adsorption at the air-water interface. Annealing the particulate foams up to 1000℃ under nitrogen atmosphere led to black-colored materials. Thermogravimetry and fourier transform infrared spectroscopy studies and scanning electron microscopy observation confirmed that porous carbon materials were successfully synthesized from the PAN latex-stabilized particulate foam. This particulate foam-based method should be advantageous because only particles, water and air are required, and production on an industrial scale is much more likely compared to a template-based synthetic route. Potential applications for these porous carbon materials include catalyst supports and novel electronic and optical devices.