s The Research about Synthesis and Characterization of SiO2 have been worked. We have synthesized Silica from "petung"bamboo leaf ash as SiO2 source. This step used sol gel methode. SiO2 were characterized by Fourier Transform Infra Red (FTIR) to investigated the stucture andX-Ray Diffaction to know about structure and crystallinity. FTIR spectra show peak at 617,22 cm-1 area that spesific for Si-H bond, peak at 786,96 cm-1 and 1095,57 cm-1 area specific for Si-O-Si bonds. Difractogram of SiO2 show that there are peak at 2θ 21,99; 31,67 and 38,88 were specific for SiO2 that calcinated at 800 o C, while for SiO2 that calcinated at 400 o C there were no peak at 2θ 31,67 dan 38,88. That peaks not shown may be because low crystallinity of SiO2 that calcinated at 400 o C. Calcination temperature greatly affects the crystallinity of SiO2.

Effect of pressing time on physical and mechanical properties of phenolic-impregnated bamboo strips was evaluated. Bamboo strips (Gigantochloa scortechinii) were impregnated with low molecular weight phenol formaldehyde (LMwPF) resin. Samples were submerged in LMwPF resin using a vacuum chamber of 750 mmHg for 1 h before it was released within 1.5 h. Treated strips were dried in an oven with a temperature of 60 °C within 6-9 h. It was hot pressed at 14 kg m-2 and a temperature of 140 °C for 5, 8, 11, 14 and 17 min. The physical and mechanical properties of the test indicated that the properties of phenolic-treated strips have significantly increased as compared to control samples. Dimensional stability (water absorption, thickness swelling and linear expansion) of the phenolic-treated properties were significantly lower than control after 5-min pressing time. The antishrink efficiency (ASE) of phenolic-treated strips increased when pressing time were extended from 5 to 17 min. The mean value of modulus of rupture (MOR) for the control samples (177 N mm-2) showed a significant difference with phenolic-treated strips after 17-min pressing time (224 N mm-2). However, there is no significant difference in compression parallel to grain. The MOE of phenolic-treated strips was 21,777 N mm-2 and for control was 18,249 N mm-2, whereas the compression parallel to grain values for phenolic-treated and control samples were 94 and at 77 N mm-2, respectively.

Malaysia has more than 50 species of bamboo, but few that are utilized commercially. In this study, the physical properties of two of the most popular bamboo species in Malaysia, Gigantochloa scortechinii and Bambusa vulgaris, were evaluated. Moisture content (MC) and shrinkage variation at different height sections at both nodal and internodal categories of the bamboo culm were investigated. A comparison between the height sections and between the nodal and internodal categories, as well as between the species, was carried out. Results indicated a trend of decreasing MC along the culm from base to top, though the difference was not statistically significant. It was also observed that radial shrinkage was slightly greater than tangential shrinkage and was much greater than shrinkage in the longitudinal direction. Nodes appeared to have lower MC and a higher percentage of shrinkage compared to internodes. The shrinkage pattern of the two species of bamboo showed a small radial-to-tangential ratio of 1.15:1, which may have contributed to the dimensional stability of bamboo.

The objective of this study was to quantify the influence of zinc oxide nanoparticles (nano-ZnO) on the water repellency and dimensional stability of beech wood. Beech wood blocks were treated with a nanoZnO solution at four treatment levels (0, 10,000, 20,000, and 40,000 ppm) using a modified dip method. Also, a thermal treatment was performed at 60 and 120 °C. After conditioning the samples, water absorption, volumetric swelling, water repellency effectiveness, and antishrink/anti-swell efficiency were determined within 24 h of soaking time. The results indicated that the nano-ZnO used for wood modification greatly improved dimensional stability and reduced the hygroscopicity of the wood. In addition, the Fourier-transform infrared spectroscopy (FTIR) analysis suggested a strong interaction between the nano-ZnO and the chemical components of wood. The heat treatment effectively improved the effects of nano-ZnO.

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