PORE CONNECTIVITY OF ALUMINA AND ALUMINUM BORATE FROM NITROGEN ISOTHERMS

The effects of calcination temperature on the connectivity of pore net works of alumina and aluminium berate samples, prepared by coprecipita tion methods and low-water sol-gel processes, have been investigated b ased on the percolation analysis of their nitrogen adsorption isotherm s. The mean coordination number (Z) was determined with the aid of the recently proposed Seaton theory. Values of Z obtained with this metho d cover the range 2-3, implying a low connection of pores in all the e xamined porous samples. Thermal effects may increase or decrease Z val ues depending on the samples. On the other hand, Z values of aluminium berate samples obtained from the coprecipitation method were slightly larger than those from the sol-gel process. It was also found that fo r sol-gel processed samples, Z values of alumina were slightly larger than that of aluminium berate.