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The present work proposed a novel approach for transferring high-risk heavy metals tometal complexes via green chemistry remediation. The method of remediation of heavy metals developed in the present work is a great challenge for global environmental sciences and engineering because it is a totally environmentally friendly procedure in which black tea extract solution is used. The FTIR study indicates that black tea contains enough functional groups (OH and NH), polyphenols and conjugated double bonds. The synthesis of copper complex was confirmed by the UV-vis, XRD and FTIR spectroscopic studies. The XRD and FTIR analysis reveals the formation of complexation between Cu metal complexes and Poly (Vinyl Alcohol) (PVA) host matrix. The study of optical parameters indicates that PVA-based hybrids exhibit a small optical band gap, which is close to inorganic-based materials. It was noted that the absorption edge shifted to lower photon energy. When Cu metal complexes were added to PVA polymer, the refractive index was significantly tuned. The band gap shifts from 6.2 eV to 1.4 eV for PVA incorporated with 45 mL of Cu metal complexes. The nature of the electronic transition in hybrid materials was examined based on the Taucs model, while a close inspection of the optical dielectric loss was also performed in order to estimate the optical band gap. The obtained band gaps of the present work reveal that polymer hybrids with sufficient film-forming capability could be useful to overcome the drawbacks associated with conjugated polymers. Based on the XRD results and band gap values, the structure-property relationships were discussed in detail.

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The motive of this study is to lessen the dependence on nondegradable plastic packaging by developing alternative material; reinforced poly(lactic acid) (PLA) with kenaf fiber (KF) biocomposite using available plastic processing machineries. For that reason, this study focuses on fabrication of PLA-KF biocomposite using intermeshing co-rotating twin-screw extruder and then injection molded for mechanical characterization. The effect of KF loading from 0 to 20 wt% was studied. No coupling agent was added due to high affinity of PLA and KF and both components are hydrophilic in nature. The average of KF aspect ratio is 30. Tensile properties and flexural properties show similar trend where significant improvement was attained at 20 wt% KF content. Scanning electron micrograph of tensile fracture specimen has revealed the hypothesis of interaction between fiber and matrix which subsequently amplified the tensile properties. It is an interesting finding where the experimental value of tensile modulus was 15% higher than theoretical tensile modulus at 20 wt% KF. Additionally, PLA-KF bicomposite produced, has high specific strength and specific modulus. This could suggest that KF may be incorporated into PLA to reduce mass of the end product and substantially reduce the cost of raw materials. As expected, impact strength however decreases with KF content.