| Tsoongiodendron odorum and Pinus yunnanensis var. was study to produce SiO2 and SiO2-TiO2 modified wood by Sol-gel. The purpose was to make the SiO2 and TiO2 into the wood, so that new chemical bonds could be formed on the wood surface, and the wood could get hydrophobicity, aging resistance and photocatalysis. In this study, air dry wood of Tsoongiodendron odorum and Pinus yunnanensis var. were used to modify wood surface, soaking into the preparation sol, by gel, aging and drying, and micro high temperature. With scanning electron microscopy (SEM), energy dispersive X-ray analyzer (EDAX) and topographic map analysis, SiO2 and TiO2 thickness, morphology and distribution in wood were study.With the Fourier transform infrared spectrometer (FTIR), structural changes before and after the improvement of wood and the combination of SiO2, TiO2 and the wood was analyzed. By means of X-rad diffractometer (XRD), crystal structure of oxide film was analyzed. Contact angle of the surface characterization of the wood was determined to characterize the wood hydrophobicity by contact angle measuring instrument. Photocatalysis effect was measured to characterize the solution absorbance change wood by UV Spectrophotometry. The hydrophobicity and Photocatalysis on the wood surface were solved by functional improvement, it could be applied to many special occasions, and the use value of the wood would be improved.In this paper, the impact of SiO2 and TiO2 on wood properties was study by masuring the dimensional stability, aging resistance, hydrophobicity and photocatalysis. The main conclusions were as follows:1. The bibulous rate and moisture absorption rate of the SiO2 modified wood and SiO2-TiO2 modified wood were smaller than the blank wood, and the moisture absorption ability was related to species of tree. The color change of modified wood surface was less significant than blank wood after aging. And the wood treated with nitric acid had the best light discoloration resistance. Light discoloration resistance of SiO2-TiO2 modified Tsoongiodendron odorum wood was promoted more than three times than blank wood and resistance of Pinus yunnanensis var. was promoted more than four times.2. The cell wall and cell cavity of modified wood were filled with a large number of SiO2 and TiO2 without changing the wood structure. TiO2 attached to the cell wall in the form of lumps in the wood. SiO2 and TiO2 distributed in wood catheter or cover the wood surface, and the longitudinal penetration depth could be 5 mm. The number of silicon on the surface of the modified wood have obvious increased, the proportion of water increasing was more conducive to the combination of SiO2 and wood. The number of Si and Ti in the SiO2-TiO2 modified wood has obvious increased than blank wood, and number of element content was not obvious related with the species of tree.3. The appearance of Si-O-Si and Si-O-C proved that new material was generated with the Ether bond between SiO2 and the wood. Ti-O-Ti and Ti-O-C proved that with Ether bond between the TiO2 and wood, a new chemical bond was generated, the Ti-O-Si stretching vibration peak proved the chemical bond between SiO2 and TiO2. The position of main diffraction peak of the modified and blank wood was the same,this proved that the structure of the wood itself do not change in the process of modified, and SiO2 was in the amorphous state, and TiO2 was changed to anatase structure with photocatalysis enhanced.4. The contact angle of modified wood was increased significantly than the blank wood, it increase with the increase of the soaking time, The contact angle of the sample can reach above 120°, Hydrophobic was improved obviously. With the difference of the modified and blank wood before and after aging, it proved that the anti-aging performance of the modified wood was significantly greater than the blank wood. The photocatalysis of SiO2-TiO2 modified wood on AO7 was better than blank wood, and the TiO2 photocatalytic degradation ability was high efficiency. |
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