Author(s): MATTOS, B. D.; TARDY, B. L.; PEZHMAN, M.; KÄMÄRÄINEN, T.; LINDER, M.; SCHREINER, W. H.; MAGALHAES, W. L. E.; ROJAS, O. J.

Summary: Biocides are essential for crop protection, packaging and several other biosystem applications. Therein, properties such as tailored and controlled release are paramount in the development of sustainable biocide delivery systems. We explore the self-similar nano-organized architecture of biogenic silica particles to achieve high biocide payload. The high surface area accessibility of the carrier allowed us to develop an efcient, low energy loading strategy, reaching signifcant dynamic loadings of up to 100mg·g?1. The release rate and responsiveness were tuned by manipulating the interfaces, using either the native hydroxyl surfaces of the carrier or systems modifed with amines or carboxylic acids in high density. We thoroughly evaluated the impact of the carrier-biocide interactions on the release rate as a function of pH, ionic strength and temperature. The amine and carboxyl functionalization strategy led to three-fold decrease in the release rate, while higher responsiveness against important agro-industrial variables. Key to our discoveries, nanostructuring thymol in the biogenic silica endowed systems with controlled, responsive release promoting remarkable, high and localized biocidal activity. The interfacial factors afecting related delivery were elucidated for an increased and localized biocidal activity, bringing a new light for the development of controlled release systems from porous materials.

Publication year: 2018

Types of publication: Journal article

Unit: Embrapa Forestry

Keywords: Atividade biológica, Biocida natural, Biocide delivery system, Biocides, Biogenic silica, Biological activity, Chemical surface modification, Fractal supra structure, Funcionalização de nanopartículas, Functionalization of nanoparticles, Liberação lenta, Material nanoporoso, Mesoporous silica, Modificação química de superfície, Nanobiocida, Nanobiocides, Nanoporous material, Nanotechnology, Nanotecnologia, Natural biocide, Sistema de liberação de biocida, Slow release, Supraestrutura fractal, Sílica biogênica, Sílica mesoporosa, Thymol, Timol