The study systematically explored the effect of alkali concentration and soaking time on the microstructure and tensile properties of single-cellulosic Buluh Semantan. Scanning electron microscopy and tensile tests were conducted to determine the effects of different alkali treatments on the properties of the single-cellulosic bamboo fibers. In particular, the effects of NaOH concentration and soaking time on the tensile properties of the single-cellulosic bamboo fiber were investigated. The single-cellulosic bamboo fiber was immersed in 2, 4, 6, and 8 wt.% aqueous NaOH solutions for soaking times of 1, 3, 6, 12, 18, and 24 h. The tensile properties of the fiber increased after each alkali treatment. The alkali concentration and soaking time significantly affected the fiber properties. The ultimate tensile strength of the single-cellulosic Buluh Semantan treated with 2 wt.% NaOH for 12 h decreased to 214 MPa relative to the fibers that experienced water retting. The highest tensile strength herein was 356.8 MPa for the single-cellulosic fiber that was soaked for 12 h in 4 wt.% NaOH. Comparatively, the tensile strength of the single-cellulosic bamboo fiber that was soaked for 12 h in 8 wt.% NaOH was 234.8 MPa. The tensile modulus of the single-cellulosic fiber was 12.06 GPa after soaking in 8 wt.% NaOH for 18 h, indicating that a strong alkali treatment negatively affected the stiffness and suitability for use of the fibers in applications. The topography of the fiber surface became much rougher after the alkali treatments due to the removal of hemicellulose and other surface impurities. The alkali treatments substantially changed the morphology of the fiber surface, suggesting an increase in wettability.

This paper discusses the behaviour of different thermophysical properties of CuO water-based nanofluids, including the thermal and hydraulic performance and pumping power. Different experimental and theoretical studies that investigated each property of CuO/water in terms of thermal and fluid mechanics are reviewed. Classical theories cannot describe the thermal conductivity and viscosity. The concentration, material, and size of nanoparticles have important roles in the heat transfer coefficient of CuO/water nanofluids. Thermal conductivity increases with large particle size, whereas viscosity increases with small particle size. The Nusselt number depends on the flow rate and volume fraction of nanoparticles. The causes for these behaviour are discussed. The magnitude of heat transfer rate is influenced by the use of CuO/water nanofluids. The use of CuO/water nanofluids has many issues and challenges that need to be classified through additional studies.

Gigantochloa scortechinii is one of the most well-known bamboo species in Malaysia because of its advantageous physical, morphological and strength properties. This study presented the effect of alkali treatment conditions of single cellulosic bamboo strips fiber following tensile test and optimized the parameters through response surface methodology based on central composite design. Bamboo strips fiber was treated under various alkali concentrations of 2, 4, 6 and 8 wt.% and soaking times of 1, 3, 6, 12, 18 and 24 h. Results showed that the optimum tensile strength at 4 wt.% alkali concentration and 12 h soaking time was improved by 28% compared with water retting condition. The design-Expert software was used to optimize the tensile properties of single cellulosic bamboo strips fiber. The effect of two independent variables, namely, alkali concentration and soaking time, on the optimized tensile properties of a single cellulosic bamboo strips fiber was investigated. Results showed acceptable R² and high R²_Adj correlation coefficients for tensile strength, reaching 0.6926 and 0.9575, respectively. The high R² and R²_Adj correlation coefficients for tensile modulus reached 0.9376 and 0.8931, respectively. Overall results showed that the confirmatory experiments show that the error between predicted and actual values does not exceed 5%. thus, the model can be effectively used to predict tensile properties.

The aim of this study was to investigate the mechanical properties of bamboo mesoparticle/nylon 6 composites. The challenge in this paper is that there has been very limited research done on the effect of fibre loading on the mechanical properties of natural bamboo mesoparticles as reinforcement for nylon 6 in order to reduce the cost of production while maintaining the high composite mechanical properties. The average size of the bamboo mesoparticles used was 0.25 μm. The mesoparticle/nylon 6 composites were prepared by mixing bamboo mesoparticles and nylon 6 using a laboratory blender mixer machine, followed by preparation of samples using an injection moulding machine. The fibre loadings were 9 wt.%, 13 wt.%, and 18 wt.%. The mechanical properties of the composites examined were tensile, flexural, and impact properties, while tensile fracture surfaces of the mesocomposites were examined using scanning electron microscopy. The results showed that 13 wt.% fibre loading has the best tensile strength and modulus with improvements of 15% and 25%, respectively, compared to neat nylon 6. A slight increase in the flexural strength and modulus with increasing fibre loading from 9 to 13 wt.% was observed. However, a lack of performance was observed in the impact strength of the bamboo mesoparticle/nylon 6 composites. Electron microscopic examination revealed no filler clumping aggregation and less void formation when 13 wt.% fibre loading was used, which indicates that a relatively high amount of energy was consumed to break the 13 wt.% bamboo mesoparticle/nylon 6 composites. Overall, the results indicated that the tensile and mechanical properties of bamboo mesoparticle/nylon 6 composites increased with increased fibre loadings.

Fibers are widely used to reinforce polymer composites for various applications because of their mechanical properties and ease of manufacturing. Fiber reinforced polymers are being developed using synthetic fibers and natural fibers, including bamboo, bagasse, etc. The main goal of this work is to optimize the mechanical properties of bamboo mesoparticle/nylon 6 composites using a response surface methodology. The conditions used to achieve an optimal tensile strength, flexural strength, and impact strength were determined using a Box-Behnken design with three operational variables: alkali concentration, particle loading, and particle size. Based on the experimental design, experimental tests were conducted to develop a mathematical model and predict the mechanical properties of the bamboo mesoparticle/nylon 6 composites. The optimal conditions to produce a composite with a maximum tensile strength were achieved at an alkali concentration of 4 wt.%, a particle size of 1 μm, and a particle loading of 13.5 wt.%. The optimum conditions to produce a composite with a maximum flexural strength were achieved at an alkali concentration of 2 wt.%, a particle size of 1 μm, and a particle loading of 13.5 wt.%. Additionally, an alkali concentration of 4 wt.%, a particle size of 1 μm, and a particle loading of 9 wt.% produced a composite with the maximum impact strength. Overall, the results showed that the values predicted using the model correlated with the experimental values.

This study aims to investigate the effect of short-term exposure of water to the mechanical properties of simantan fibres at different heights. Few studies have investigated the mechanical properties of raw natural fibres after water absorption. Bamboo culms were cut at 15 cm above the ground level and then subdivided into bottom, middle and top parts according to their total length. The raw fibres were immersed in distilled water at room temperature for different time durations (6, 24, 48, 72, 96, 168, 336, 504 and 672 h). Tensile, flexural and impact properties were examined before and after water absorption, the tensile fracture of raw fibres were observed by scanning electron microscopy, and the structure properties of raw fibres were examined by Fourier transform-infrared spectroscopy. The result showed that 6 h of immersion time exhibited the best tensile strength and modulus, showing 13.6% and 28% improvement compared with the dry condition. The optimum flexural strength and modulus were 240 MPa and 13.7 GPa, respectively, for the top part under dry condition. Overall results clearly showed that immersion in water for a short time minimally affected tensile strength, modulus and flexural modulus but considerably influenced flexural strength and impact properties.