A novel route for the dispersion of fibers for the preparation of fiber reinforced porous composites

A method for the dispersion of fibers for the preparation of fiber reinforced porous silica composites through direct foaming method is discussed. Glass fibers (∼ 20–25 mm long and 10 μm diameter) up to 10 wt.% are successfully dispersed in smaller amounts and pooled together after decanting off the excess water followed by addition of hydrophobized silica powder. The dispersion thus obtained is found to be stable for several days. The influence of fiber-to-powder ratio (FPR) in obtaining fiber dispersions free of entanglements, as well as, the feasibility of making porous silica composites using the dispersion is also examined. The porous composite tiles thus produced with 7 wt.% fiber content have a porosity of ∼ 88 vol.%.