Mild microwave-assisted synthesis of aluminum-pillared bentonites: Thermal behavior and potential applications

MARIO NINANGO; OLIVIA LOPEZ; GABRIELA PASSARETTI; M.F. HORST; VERÓNICA LASSALLE; IRENE CARABAJAL; ROGELIO DI SANTO; ANDRES CIOLINO; MARCELO VILLAR

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY

SPRINGER

Lugar: Berlin; Año: 2017

1388-6150

Abstract Two types of bentonites were modified using acleaner method to prepare aluminum-pillared clays. Thismethodology involved a purifying stage, an intercalationprocess, and a microwave irradiation step at low energypower. Structural changes induced by pillaring processwere demonstrated by thermal behavior, as well as morphologicalcharacterization. The effect of pillaring processon thermal stability of clays was studied, and the mass lostassociated with the dehydroxylation of the octahedral claysheets was not detected for modified bentonites. In addition,an analysis of their chemical composition and crystallinestructure was also performed. Concerning industrialapplications of these bentonites, two potential uses wereproposed: (1) as reinforcement of different polymersmatrices such as thermoplastic starch (TPS), high-densitypolyethylene (HDPE), and poly (styrene-b-butadiene-bstyrene),SBS; and (2) as removal agent for cadmium (Cd)species present in wastewaters. Bentonite particles reinforcedthermoplastic starch matrix and increased ultravioletbarrier capacity of HDPE composites. Besides, bentonitesimproved the mechanical performance and modified barrierproperties of SBS. Regarding effluents purification, anadequate Cd adsorption from aqueous solutions wasobserved (77%), proving their feasibility to be used as nonconventionalremoval agents.