Calixarene physisorption onto alkyl-fiinctionalized silica support is presented as an alternative to tethering to reduce synthetic complexity. Three versions of calix[4]arene were synthesized with differing upper rim functional groups: aromatic amine, tert-butyl, and unfunctionalized. Calixarene molecules physisorbed throughout the alkyl layer on the silica following a linear isotherm with a maximum observed loading of 300 mu mol g(-1). Large exothermic adsorption enthalpies (-60 to -260 kJ mol(-1)), attributed to van der Waals interactions, were measured for the calixarene physisorption using flow microcalorimetry; large negative entropies were calculated (-140 to -780 J mol(-1) K-1). Amine-calix[4]arene was physisorbed onto C18-silica (NCS) through solvent evaporation. The myoglobin uptake on NCS (47 mu mol g(-1)) was twice that on C18-silica; additionally, a greater heat of adsorption (-16.9 +/- 2.9 kJ mol(-1)) was observed on NCS than on C18-support (-12.7 +/- 2.2 kJ mol(-1)).