original pore vol occupied by carbon 18 31 15 thorizbrace after heatporous carbon treatmentproduct at 1600 u00b0 c wt carbon 93 7 82 4 sup 4 92 1 95 7surface area calculated sup 3 500m sup 2 g sup 1 300m sup 2 g sup 1 600m sup 2 g sup 1 600m sup 2 g sup 1surface area measured sup 1 525m sup 2 g sup 1 664m sup 2 g sup 1 563m sup 2 g sup 1particle porosity 89 81 90 90 __________________________________________________________________________ sup 1 surface areas measured by the bet method using nitrogen adsorption at 196 u00b0 c sup 2 assuming a density of carbon structure of 1 47g cm sup 3 sup 3 calculated from weight carbon of composite material assuming exact replication of the original surface of the template material sup 4 the relatively low value indicates the presence of undissolved silica and suggests that a digestion time of more than 1 hour is required part of the measured surface area probably arises from the residual silica the isotherms for adsorption of nitrogen by the initial porous carbon product of example 2 and for the heat treated product are shown in fig1 for three temperatures 78 u00b0 c 130 u00b0 c and 196 u00b0 c the isotherm for 196 u00b0 c shows a very steeply rising portion at very low partial pressures in contrast to the isotherm which is obtained at the same temperature for the template material a liquid chromatographic column 250 mm in length 5 mm in bore is packed with the porous carbon product of example 1 the column is supplied with eluent consisting of a mixture of 92 parts.