Paula Zanatta, Ezequiel Gallio, Débora Duarte Ribes, Marília Lazarotto, Darci Alberto Gatto and Mário Lúcio Moreira
The objective of this study was modify the surface of the Pinus elliottii with the deposition of TiO2 particles synthesized by the microwave-assisted solvothermal method. Initially, the TiO2 nanoparticles were obtained from the titanium isopropoxide in alcohol at a temperature of 140°C for 60 min in a reaction cell coupled in an adapted microwave system. After the synthesis, the samples of P. elliottii were added to the solution rich in TiO2 and again submitted to the microwave solvothermalization process at 90°C for 60 minutes with a self-generated pressure of 3 bar. Through X-ray Diffraction, it was possible identify that the nanostructures observed by Scanning Electron Microscopy correspond to the anatase crystalline phase. Particles in agglomerates (~ 200 nm) formed a homogeneous cover on the surface and a probable interaction through hydrogen bonds with the OHradicals present in the cell wall of the wood. With the action of the microwave, the molecules tend to align under the influence of the electric field, which made possible an oriented and uniform deposition. In addition, the hydrophobicity measured by the sessile drop analysis showed that the method used transforms the original surface of the wood, from superhydrophilic to hydrophobic. In addition, the treated samples immersed in water for a period of 400 hours, showed strong delay of water absorption. In this way, the method proves its effectiveness in modifying the surface structure of the wood in order to give it appreciable characteristics to increase its durability and stability.
Surface modification, Hydrophobicity, Coating, Microwave