Characterization of Fine Natural Clay Powder for Reinforcement in Bio Composites for Food Packaging Applications

Imadu C. Cedrick, Abugh Ashwe, Nyior G. Bem

Abstract: Characterization of natural clay powder using spectroscopic techniques as reinforcement in bio composites for food packaging applications was studied. Natural clay was pulverized to fine clay powder of size 100 μm using ball mills. The fine clay powder was subjected to spectroscopy using energy dispersive X-ray fluorescence (EDXRF), Fourier transform infrared (FTIR) and scanning electron microscopy/energy dispersive X-ray (SEM/EDX). The study found that, EDXRF spectra of natural clay powder showed, silica (SiO₂ 34.851 %), alumina (Al₂O₃19.092 %) and Ferric oxide (Fe₂O₃ 2.3475 %). Also, TiO₂ (1.2855 %), K₂O (1.1438 %) and MgO (1.04 %). FTIR spectra of the clay sample revealed eight peaks. Bands at 3690.06446 and 3622.97238 cm^-1 showed presence of hydroxyl linkage. The peak at 3429.15081 cm^-1 is assigned to OH stretching. Bands at 1640.02865 cm^-1 indicates possibility of water of hydration or H-O-H bending of water in the adsorbent due to the hydrous nature of the clay materials. Bands at 998.92654 and 909.47043 cm^-1 respectively correspond to the Al-OH bending vibrations. Si-O stretching vibrations were observed at around 790-678.37549 cm^-1. The results of the FTIR showed no toxic functional group in the sample. SEM of the clay sample showed particle size of 100 μm. EDX result showed silicon with the highest weight concentration of 58.67 %, aluminium 26.55 %. The results showed no toxic or heavy element of concern in the clay. This is a confirmation suggesting that, the clay is safe and could be used for reinforcements in bio composites food packaging applications.