Novel compositions for removing impurities such as, protein aggregates, from a sample containing a protein of interest, e.g., an antibody. Such compositions can be used prior to the virus filtration step during protein purification, to remove aggregates and protect the virus filter from fouling, therefore improving virus filter capacity. A porous solid support including a co-polymer having at least two monomers, wherein at least one of the monomers comprises acrylamide and at least a second monomer comprises a hydrophobic binding group, where the solid support selectively binds protein aggregates, thereby to separate the monomeric protein of interest from the protein aggregates. The method can be performed under neutral to high pH and high conductivity conditions.