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Crustaceans’ shells are one of the resources that can be used as raw materials for chitosan extraction. Chitosan can act as bio-coagulant to remove turbidity through coagulation process. Usage of chitosan extracted from biopolymers are safer and environmentally friendly that can substitute synthetic coagulant such as alum and lime (calcium oxide) which may cause diseases to humans. This study aims to extract chitosan from waste crustaceans’ shells which are crabs (Litopenaeus Vannamei) and shrimps (Matuta Victor) as well as to analyse the effectiveness of chitosan as a natural coagulant. By using the following concentration of chemicals, 0.5N and 1N of HCl for demineralization, 0.5N and 1N of NaOH for deproteinization and, 50% of NaOH for deacetylation. Crab sample A had been the most effective against crab sample B, shrimp sample A and shrimp sample B in terms of conductivity removal percentage, TSS removal percentage, and COD removal percentage, which was 73.02%, 98.93% and 33.95% respectively. In conclusion, crustaceans’ shells contained chitosan has great potential to be used as bio-coagulant.

Nowadays, the application of portable electronics devices such as smartphone, notebook and tablet playing important role in daily life. This portable electronic devices required portable powering sources such as battery. However, the current battery technology containing liquid electrolyte which is hazardous and harmful when leaking. Therefore, the major purpose of this study was to propose a new biodegradable, safe and low cost solid polymer electrolyte (SPEs) mainly from Methylcellulose (MC) doped Ammonium Nitrate (AN). The study was conducted by using casting method as it is the most appropriate technique due to its simplicity and low cost. Methylcellulose (MC) as the host was doped with different weight percentage (wt%)of Ammonium Nitrate (AN) to fabricate SPEs. The result shows the adding of AN onto MC was significantly enhanced the physical properties of SPEs. The loading of 2g MC with 25% AN (MC2_25AN) yield the highest conductivity at 3.5 × 10−7 Sm−1 at room temperature. Furthermore, the MC2_25AN poses a good stability with the lowest swelling rate. Therefore, the use of low cost and biodegradable MC and AN have a great potential to replace the hazardous electrolyte in electrochemical powering sources.

Azido-Terminated Poly(2-isopropyl-2-oxazoline)(N3-PIPOZ) was prepared and it was then functionalized onto reduced graphene oxide (rGO). rGO was prepared from the reduction of graphene oxide (GO) by using hydrazine. The exfoliation of GO was measured using UV-Vis Spectroscopy. As a result, covalent functionalized reduced graphene (rGO-PIPOZ) with good solubility was successfully produced using grafting-on technique. Fourier transform infrared (FTIR) and thermogavimetric analysis(TGA) results proved the attachment of PIPOZ macromolecules onto rGO. rGO-PIPOZ showed best solubility in methanol (MeOH). The production of rGO- PIPOZ can be facilitated to a broad range application of graphene such as in polymer nanocomposites and lithium ion batteries.

Heavy metals have become a serious pollutant in water as a result of its non-biodegradable and toxicity properties. In this research, banana peel was synthesized as bioadsorbent to remove heavy metals from contaminated water. The major problem associated with banana peel bioadsorbent is that the activated carbon produces from biomass materials possess insignificant adsorption capability compared to its commercial counterpart. Besides that, large quantity of banana peel wastes contributes to its significant disposal problem. Thus, the present work is expected to solve the problems of banana peel disposal by converting it into bioadsorbent. The objectives of this research are to synthesize banana peel bioadsorbent and to evaluate heavy metals adsorption performance of the banana peel bioadsorbent. The bioadsorbent were treated using KOH in its preparation. The materials then undergo characterization using FTIR and AAS. The carboxylic and hydroxyl functional groups were confirmed by FTIR. The maximum removal efficiency for Pb and Fe ions were 100% and 64% respectively. The comprehensive utilization of low-cost raw material as bioadsorbent in wastewater activities are highly suggested due to its facile processing, abundantly available and environmental friendly.

Polymer nanocomposites based on polylactic acid (PLA) and graphene (Gr) were blended via melt blending and solution mixing. The properties of hardness and melt flow index (MFI) were investigated with variables of Gr loading from 0.5–2.0 wt.% and the effect of poly(ethylene glycol) (PEG) as plasticizer. The PLA/Gr nanocomposites exhibited higher hardness compared with neat PLA for both methods of nanocomposites preparation which were due to stiffness effect from nanofiller. The loading of PEG in the PLA nanocomposites resulted in the slightly decreasing of hardness. The hardness of PLA and PLA nanocomposites obtained from melt blending were higher than hardness from solution mixing where 2.0 wt.% Gr loading in PLA exhibited maximum value which was 83.1 Shore D. The significant improvement on the MFI could be seen with plasticizer loading compared to unfillled PEG in PLA blends obtained from both methods. Again, the MFI values of PLA/Gr showed from melt blending were higher than exhibited from solution blending method. The highest MFI was 70.6 g/10 min, obtained from 0.5 wt.% Gr loading in PLA/PEG/Gr nanocomposite. The morphology study from Field Emission Scanning Electron Microscopy (FESEM) analysis confirmed the interfacial interaction and homogeneity of Gr in PLA in order to enhance the hardness and MFI properties as discussed above.