Preparation of fibrous porous materials by chemical activation 2. H3PO4 activation of polymer coated fibers Original Research Article

Fibrous porous materials (FPMs) have been prepared by coating a glass fiber with an aqueous solution of poly(vinyl alcohol) (PVA) and H3PO4, followed by stabilization and heat treatment in air. The H3PO4 was then removed by washing with deionised water and NaOH. The results show that H3PO4 acts as a dehydration agent to promote pyrolytic and thermal crosslinking of PVA at a much lower temperature of 170 °C, leading to FPMs having much higher char yields and surface areas. The activation in air is of benefit to achieve higher surface areas as compared to using N2. Utilizing a fiberglass mat to support coatings of PVA activated with H3PO4 results in much higher specific surface areas. The activation temperature, activation time and concentration of H3PO4 have strong effects on the surface area, pore size distribution and coating content of FPMs.