Syntheses, characterization and adsorption properties for Pb2+ of silica-gel functionalized by dendrimer-like polyamidoamine and 5-sulfosalicylic acid

SEM images of APSG, PAMAM-1.0SSASG, PAMAM-2.0SSASG, PAMAM-3.0SSASG and PAMAM-4.0SSASG.