title: Evaluation of short cycles of ultrasound application in nanoemulsions to obtain nanocapsules.
abstract: Ultrasound is widely used in several chemical reactions and other process, including production of nanocapsules by in situ polymerization. In this work, the main objective was to evaluate the impacts and viability of successive ultrasound application in nanoemulsions to obtain nanocapsules. Initiator potassium persulfate (KPS) concentration, number of ultrasound cycles and reaction time influences on polymerization efficiency and droplet size were evaluated. This work revealed the successful in situ production of nanocapsules using successive shorts cycles of ultrasound. Number of cycles was the only parameter that not exerted significant influence in polymerization yield. Particle size decay was observed in all nanoemulsions after the first ultrasound application, the same was not observed in further cycles. Gravimetric assessment showed remarkable increase of monomer conversion, indicating that once started polymerization continued at least until 28 days after ultrasound application. Concluding, ultrasound short cycles can be used with no harm to formulation, if carefully performed and, furthermore is a potential cost-effective route for polymerization reactions.
authors.affiliation: Escola de Farmácia, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto CEP 35400-000, Brazil.
authors.forename: Simone Pinto
authors.initials: SP
authors.lastname: Carneiro
authors.affiliation: Escola de Farmácia, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto CEP 35400-000, Brazil.
authors.forename: Ricardo Machado
authors.initials: RM
authors.lastname: Cruz
authors.affiliation: Escola de Farmácia, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto CEP 35400-000, Brazil. Electronic address: orlando@ef.ufop.br.
authors.forename: Orlando David Henrique
authors.initials: ODH
authors.lastname: Dos Santos
keywords: In situ polymerization; Initiator; Nanocapsules; Nanoemulsions; Ultrasound polymerization