Study of the adsorption of tannic acid by clay modified with polyethylenimine - Henriques, Ruan R; Celestino, Gustavo G; Shiguihara, Ana Lucia; Constantino, Vera Regina Leopoldo; Soares, Bluma Guenther; Amin Junior, Jorge (Reunião Anual da Sociedade Brasileira de Química/SBQ, 2018)