Sodium silicate from rice husk ash (RHA) was transformed to functionalized silica with 3-(chloropropyl) triethoxysilane (CPTES) via a simple sol-gel technique in a one-pot synthesis. The Si-29 MAS NMR of the organo-silica complex (RHACCI) showed the presence of T-2, T-3, Q(3) and Q(4) silicon centers. The C-13 MAS NMR showed that RHACCI had three chemical shifts at 10.37, 26.70 and 47.69 ppm consistent with the three carbon atoms of the CPTES moiety. The presence of carbon, silicon and chlorine was determined by a combination of elemental analysis and EDX study. (C) 2008 Elsevier Inc. All rights reserved.