Characterization and properties of selected biomass nanofiller reinforce advanced ceramic
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Date
2014-08
Authors
Rukumangatha Rajah, Siva Balan
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Abstract
The aim of this study was to explore the carbon black nanofillers (CNF) from biomass and agricultural wastes as reinforcement material in ceramic application. Biomass from bamboo, bagasse, and oil palm ash was used as the predecessor for producing carbon black nanofillers. Furnace pyrolysis were carried out at 800°C and followed by ball-mill processing to obtain CNFs in the range of 50 nm to 100 nm. The CNFs were added to alumina in varying weight fractions and subjected to vacuum sintering at 1400°C to produce nano bioceramic composites. The physical, chemical, thermal and morphology properties of CNFs and the nano bioceramic composite were studied. The physical property of Vickers hardness, fracture toughness and specific gravity was analysed for the composite. The chemical analysis conducted with pH analysis and fourier transform infrared (FT-IR) for CNFs. The thermal analysis was studied with thermogravimetric analyser (TGA) for CNFs and composite. The morphology studies on the composite and CNF conducted with scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD) for CNFs and composite. The nano bioceramic composite was further analysed for thermal conductivity, electrical conductivity and electrostatic discharge (ESD) measurement.The percentage of carbon was described respectively, as followed: BM-CB > BG-CB > OPA-CB by EDX analysis. The effect of CNFs’ loading on the Vickers hardness (HV20) shows a decrease trend for each series of CNFs, due to the microstructure pinning effect in alumina caused by the nano grain size of CNFs. Similarly, the specific gravity (SG) and fracture toughness decreased as the CNFs’ wt.% increased. It was observed that alumina-CNF ceramic composite becomes lighter and more brittle as the CNFs’ loading increases. The TGA results showed no significant changes in thermal stability between the CNFs compared to carbon blacks. Similarly, the nano bioceramic also showed no significant changes compared to neat alumina. Thermal conductivities of the CNF-alumina composites increased with CNFs loading. The trend in the thermal expansion (CTE), was not significant or behave null same as neat alumina with the increasing of CNFs. The pH and FT-IR analysis on CNFs, revealed bagasse was more acid and bamboo was alkaline in nature. In terms of morphology, the bio nano composite structure was much dependable on the grain structure boundary of CNFs and alumina matrix, which gave an uneven cohesion structure. The electrical analysis on I-V showed an increase of CNF wt. % into the alumina matrix and gave a linear increment in current. At CNF wt 1% and 0.5% the CNF ceramic composite conducts close to 3.0E-10 mA of current compared to 0.05% and 0.1%. The existence of CNFs into alumina maintains the thermal expansion but improves the electrical characteristics. The ESD properties gave a predictable result from insulative nature of alumina to static-dissipative nature of the nano bioceramic with increase of CNF wt. %. The results obtained are highly encouraging and gave a vivid understanding of CNFs’ interaction on the microstructure and properties of the nano bioceramic composite. The observation from this study will give an enhancement on the utilization of advanced fabrication technologies and to maximize the benefit from the agricultural wastes usage as carbon nanofiller materials.
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Keywords
Biomass Nanofiller , Ceramic