Encapsulation and controlled release of isothiazolinones in zeolite NaY (FAU)

LEGNOVERDE, MARÍA S.; BASALDELLA, ELENA I.; MARDONES, LUCAS; GARGIULO, NICOLA; ROQUE, LEYANET BARBERIA; BELLOTTI, NATALIA

Journal of Environmental Chemical Engineering

Elsevier

Año: 2022 vol. 10

2213-3437

NaY zeolite, an ordered, large pore molecular sieve pertaining to the FAU zeolitestructural group, was studied as a novel matrix for the efficient preparation of asupported isothiazolinone-based biocide, and the results were compared to thosecorresponding to mesoporous silicas. To analyze the possibility of reducing the biocideecotoxicity by encapsulation, a commercial biocide used for latex preservation(CMIT/MIT) was incorporated in the NaY zeolite structure by using two differentmethodologies: equilibrium adsorption (Zeo/Bio sample) and impregnation by totalwetting (Zeo/Impreg sample). In the corresponding release tests, despite the largedifference in the initial biocide amount released, the shape of the curve is nearly thesame for both methods. Microbiological tests against fungi and bacteria wereperformed. The obtained results were compared to those previously obtained usingmesoporous ordered silica SBA-15 and mesoporous foam MCF matrices(mesoporous/biocide samples named SBA-15/Bio, SBA-15/Impreg and MCF/Bio andMCF/Impreg respectively). For the Staphylococcus aureus the results from agar welldiffusion assay shows that the inhibition zone is about 64 mm for Zeo/Impreg and about55 mm for Zeo/Bio. As regards all the other materials, the inhibition zone does notexceed 46 mm. In the case of Escherichia coli, Zeo/Bio and Zeo/Impreg have aninhibition zone of about 43 and 37 mm, respectively. No one of the other materialsshows an inhibition zone larger than 30 mm. Zeo/Impreg showed a greater inhibitionzone against fungi (47 mm versus Chaetomium globosum and 53 mm versus Alternariaalternata, respectively) than SBA-15 and MCF impregnated with bicide.