An amorphous silica with distinct bimodal pore structure containing both ma
cropores and mesopores was prepared from an acidified solution of water gla
ss in the presence of poly(acrylic acid) by inducing phase separation toget
her with gelation. Both of pore sizes of the macropores and the mesopores c
an be controlled in the ranges from 1 to 10 mum and from 4 to 30 mm, respec
tively.