Synthesis of coconut shell nanoparticles via a top down approach: Assessment of milling duration on the particle sizes and morphologies of coconut shell nanoparticles

Published Date
15 November 2015, Vol.159:514–519, doi:10.1016/j.matlet.2015.07.063

Featured Letter

Author 

• Sefiu Adekunle Bello ^a,b,,,
• Johnson Olumuyiwa Agunsoye ^a
• Suleiman Bolaji Hassan ^a

• aDepartment of Metallurgical and Materials Engineering, Faculty of Engineering, University of Lagos, Lagos, Nigeria
• bDepartment of Materials Science and Engineering, Kwara State University, Malete, Nigeria

Received 12 April 2015. Revised 30 June 2015. Accepted 12 July 2015. Available online 14 July 2015.

Highlights

• A novel synthesis of coconut shell nanoparticles via a top down approach was studied.
• •
  Coconut shell powders were milled for a maximum of 70 h and analysed.
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  Absorbance of Co Kα X-ray by particles occurred in the nano-wavelength range.
• •
  There was a decrease in particle sizes with an increment in milling duration.
• •
  New phase was formed due to increased particle surface area during milling.

Abstract

Coconut shell nanoparticles (CSNPs) were synthesised from coconut shell powders using a top down approach. Effects of milling time on the particle morphologies and sizes of CSNPs were studied. CS powders were milled for a maximum of 70 h using ceramic balls and a planetary mill. Milled samples taken at 16, 46 and 70 h were analysed using scanning electron microscope with attached energy dispersive X-ray spectrometer, X-ray diffractometer and UV–vis spectrophotometer. SEM micrographs revealed a difference in morphologies and appearances of the CSNPs. Particle size determination depicted a decrease in CSNPs' sizes with an increment in milling duration. The CSNP size determination from SEM aided with software and XRD aided with Scherrer's equation agrees with each other. This implies that the SEM observed CSNP sizes are in line with XRD crystalline sizes. The decrease in particles' Co Kα X-ray absorbance with increment in milling duration is an indication of reduction in CSNPs' opaqueness. This agrees with fading of brownish colour of CS powders as the milling duration increased. The smaller the wavelength at which maximum absorbance of the Co Kα X-ray occurred the smaller the CSNPs' sizes. Hence, an increase in surface area as the CSNPs' sizes decreased during milling led to particle agglomeration and formation of new compounds.

Keywords

Synthesis

Compounds

Cobalt

X-ray

Milling duration

Nanofillers

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  Corresponding author at: Kwara State University, Materials Science and Engineering, Malete, Kwara State, Nigeria.

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