Silica materials with different surface functionalities were synthesized by sol-gel method. The isothermal enthalpies of adsorption of human serum albumin (Delta H-ads(HSA)) onto the silica surfaces from buffer solution (pH =7.4) were measured at 298.15K. The values of Delta(ad)sH(HSA) were found to be endothermic. Possible contributions to Delta H-ads(HSA) are discussed. (C) 2010 Elsevier B.V. All rights reserved.