Effect of silica bionanoparticles obtained from rice husk for the treatment of wood of Pinus elliottii

Abstract

Renewable products can ensure environmental sustainability, human health, and reduce the use of traditional products that have toxic compounds in their formulation. Therefore, the research aimed to evaluate the biological resistance of Pinus elliottii wood against xylophagous fungi and termites through impregnation with silica bioparticles (SiO₂) obtained from rice husks. To obtain the silica, the material underwent chemical treatment, two cycles of acid leaching with hydrochloric acid, and heat treatment at 500 °C, 550 °C or 600 °C. The purity of the silica obtained was characterized by X-ray fluorescence technique (XRF), and the mean particle size by scanning electron microscopy (SEM). SiO₂ was applied to the specimens at concentrations of 0.5%, 1.0%, and 2.0%, and the impregnated samples were subjected to tests with brown rot fungi (Gloeophyllum trabeum, Rhodonia placenta and Neolentinus lepideus), soft rot (taken from natural forest soil) and xylophagous termites (Nasutitermes corniger and Cryptotermes brevis). The thermal treatments promoted the obtainment of high purity bioparticles, with value of approximately 90% and diameter of 263.7 nm. In the termite test, the smallest loss of mass and damage were for the impregnated samples. Termite mortality increased with the concentration of solutions. SiO₂ was not effective against xylophagous fungi, with no difference between treatments and controls, indicating that resistance was inherent in the wood itself.

Keywords:

• Wood durability
• alternative treatment
• biosilica

Acknowledgments

The authors thank the Coordination for the Improvement of Higher Education Personnel (CAPES), funding code 001, the Espírito Santo Research and Innovation Foundation (FAPES) and the National Council for Scientific and Technological Development (CNPq), Brazil. The Air Quality Laboratory of the Technology Center of the Federal University of Espírito Santo, The National Laboratory of Nanotechnology for Agribusiness - LNNA, EMBRAPA Instrumentation, and The Complexo Agroindustrial Pindobas Ltda., Brazil, for the support provided in this research.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributiors

The article was written through the contributions of all authors and all of them have approved the final version of the article. M.A.N., and S.F.S. extraction and processing of silica bioparticles, wood treatment, biological tests and analyzed the preliminary results. D.J.V.L. assisted in statistical analysis and discussion of results. J.B.P., L.B., and M.A.N. proposed experimental solutions, validated the initial objectives of the project, and wrote the original draft. J.B.P., Y.M.L., and D.J.V.L. helped for reviewing, editing, and correcting both spelling and grammar errors.