Characterization of aloe vera plant and synthesis of zinc oxide from aloe vera leaf using green sol-gel method

Zinc oxide commonly exist physically as a white powder with a chemical formula of ZnO. Zinc oxide uses as colorant, skin protectant and also as bulking agent. It is classed as an inorganic oxide which meant that it need to be synthesized as it is not naturally occurring. Zinc oxide is also a nanoparticle where nanoparticle is an ultrafine particle that are less than 100 nanometer in size and not smaller than 1 nm. As for this research, the aims is to use the synthesized zinc oxide nanoparticle to be used as food packaging material. According to the US Food and Drug Administration, zinc oxide is considered safe to be used as additive in food. The nanoparticle of zinc oxide can improve packaging properties as it can provide an antimicrobial activity to the packaging. The question is that, can zinc oxide be produce without using toxic reagent? Can the toxic reagent is being replace from a different source such as from aloe vera leaf? The objective of this study is to synthesis the ZnO from aloe vera leaf by using sol-gel method and to characterize the nanoparticle that have been synthesize. In order to identify the functional group in the aloe vera leaf, Fourier Transform Infrared Spectroscopy (FTIR) were used. The zinc oxide is synthesis by using sol-gel method. The variable used in synthesis of zinc oxide is by varying the precursor concentration which is the zinc acetate dehydrate, where the concentration are 1.0, 0.8, 0.6, 0.5, 0.4, 0.3 and 0.2 M. The different in concentration is being studied to observe the effect of precursor concentration on the size of nanoparticle. The synthesize nanoparticle are then characterize by using X-ray powder diffraction (XRD) and FTIR analysis. From the FTIR result of aloe vera leaf, the recorded functional group found were OH, C-H, C=O, C=C, C-O-C and C-OH stretch. While for the aloe vera gel, the functional group found are OH stretch, C=C stretch and C=C alkene. The amount of the zinc oxide produce were also recorded. The weight for zinc oxide with precursor concentration 1.0M, 0.8M, 0.6M, 0.5M, 0.4M, 0.3M and 0.2M are 3.93g, 3.43g, 3.09g, 2.84g, 1.84g, 1.79g and 1.46g respectively. Which directly shows that the mass of the zinc oxide produce increase as the concentration of the precursor increase. This is due to more zinc oxide ions can be obtain from the higher amount of zinc acetate dihydrate concentration. The FTIR result for zinc oxide powder synthesized shows that all of the synthesized powder are having metal oxide (zinc oxide) stretch which is in between 1000cm-1 to 600cm-1. Which confirming that all the synthesized powder are zinc oxide. XRD result of zinc oxide with precursor concentration of 1.0M, 0.8M, 0.6M, 0.5M, 0.4M, 0.3M and 0.2M are 45.624nm, 44.634nm, 32.538nm, 31.680nm, 30.465nm, 25.149nm and 17.230nm respectively. Thus the size of the zinc oxide particle decrease as the concentration of the precursor used decreases.