A reference sample of kaolinite (JCSS-1101b, from Kanpaku, Utsunomiya, Japan) was obtained from the Clay Science Society of Japan. For this sample, a specific surface area of 14.82 m 2 /g for this was reported, as determined by the Brunauer-Emmett-Teller method. In addition, Ikegami et al. measured a cation exchange capacity (CEC) of 62 meq/kg.