Support used to immobilize proteins, enzymes and microsomes by hydrophobic adsorption. The attractive forces between the hydrophobic phenoxyacetate groups of the support and the hydrophobic surface areas of protein molecules arise from the common repulsion of the aqueous medium. Prepn and properties: L. G. Butler, Arch. Biochem. Biophys. 171, 645 (1975). Applications: J. Dixon et al., Biotechnol. Bioeng. 21, 2113 (1979).