Two Different Methods of Impregnation of Fe₃O₄ Nanoparticles in Wood Composites of Three Tropical Species in Costa Rica

The impregnation of nanoparticles magnetified into wood had been developed by different methods, like surface chemical coprecipitation and vacuum-pressure coprecipitation of magnetic nanoparticles (NPs). However, there is a lack of information on the best method to coprecipitation NPs. Then, the present study has the objective to measure the effects of the impregnation process of wood veneers through two in situ processes (immersion and vacuum-pressure) using a solution of FeCl₃ ⋅6H₂ O, FeCl₂ ⋅4H₂ O and ammonia in three tropical species (Pinus oocarpa, Vochysia ferruginea and Vochysia guatemalensis). It was measured the degree of synthesis of iron NPs using weight and density gains, Fe⁺³ absorption, emission scanning electron microscope (SEM), Fournier transform infrared spectroscopy (FT-IR) and for magnetic properties were measured using vibrating sample magnetometry (VSM). After 5-layer veneer panels were fabricated, we evaluated their physical and mechanical properties. Wood samples impregnated by vacuum-pressure methods showed the higher amount of Fe₃ O₄ NPs formation, which was observed in the SEM, X-ray diffraction (XDR), FT-IR and VSM. Vacuum-pressure on treatment presented higher ferrite signals and better magnetic properties. Vochysia ferruginea presented the greatest magnetization properties. The magnetization treated causes probably a degradation of the cell wall, which weakens its mechanical properties, especially internal bonding.