Characterization of coconut shell powder as a functional material: a morphological and microstructural study

This study presents a detailed SEM study of coconut shell powder at magnifications of 100x, 500x, 600x, and 1000x, and voltages of 10 kV and 15 kV, conducted on August 5, 2025. The SEM micrographs showed a structurally complex, porous, and fibrous micro-structure most likely due to the naturally fibrous lignocellulosic nature of the coconut shell material composed of lignin, cellulose, and hemicellulose. Our analysis indicates a highly mottled distribution of irregularly shaped clusters with a variety of porosity combined with fine filaments and micropores which indicate a high surface area. The brighter zones in the SEM micrographs indicate denser zones or residual mineral content likely to be silica and calcium type minerals. The sequential change in magnification and voltages enabled detailed observation of the overall topography of the powder at both macro and micro levels, which provide insight into the structure imparted by the processing of the coconut shells. The displayed morphology opens up the potential for using powder in adsorption, as a bio-filler, and as a reinforcement in biocomposites. The evident heterogeneity in texture and porosity may be due to the processing stage of grinding or milling and implies the need for further optimising processing techniques. Most importantly the research that is presented here serves as a part of recent investigative methods to realise value from coconut shell as a waste product, illustrating the research capacity for investigating chemically or in terms of functional characteristics relevant to more sustainable employment of coconut waste as well as coconut shell powder.