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Cobalt ferrite (CoFe2O4) nanopowder was successfully synthesised by the coprecipitation method. For the entire experiment, natural iron sand from the Bengawan Solo River is used as an iron (Fe) cation source. The effect of the annealing temperature of a coprecipitated CoFe2O4 sample from natural iron sand was investigated. The presence of strong metal oxide bond groups at the tetrahedral and octahedral sites is revealed by fourier transform infrared (FTIR) spectral results, owing to the CoFe2O4 characteristic. Then the X-ray diffraction (XRD) pattern confirmed the formation of a single-phase CoFe2O4 with face centred cubic (FCC) crystal structure closely matched to reference data ICDD221086. The crystalline parameters such as lattice parameter and crystallite size modify with the increase of annealing temperature. The saturation magnetisation (Ms) decreases as the annealing temperature rises. In addition, the coercive fields (Hc) increases as the annealing temperature rises. As a result, the annealing temperature affects the performance of the CoFe2O4 photocatalyst. The photocatalytic performance of the annealing temperature sample at 300°C was found to be the best. [ABSTRACT FROM AUTHOR]

Polylactic-acid–starch-based polymer composite (PLA/TPS) has good thermal stability for biocomposites. However, the physical and mechanical properties of PLA/TPS do not meet the standards. It needed additives to enhance its physical and mechanical properties. The aim was to improve the physical and mechanical properties of PLA/thermoplastic starch using sucrose. In addition, this study evaluated the enhancement of thermal properties of PLA/thermoplastic starch using sucrose. This study used sucrose as an additive to enhance the PLA/TPS composite. The addition of sucrose inhibits the degradation of biocomposites. This means that thermal stability increases. The thermal stability increased because the degree of crystallinity increased with the addition of sucrose, which was also proven in the XRD result. The addition of sucrose caused the morphology of the biocomposite to have pores. The FESEM results showed that biocomposites with the addition of sucrose had pores and gaps. These gaps result from low adhesion between polymers, causing a decrease in the mechanical and physical properties of the sample. Based on the FTIR spectra, biocomposite PLA/TPS blends with the addition of sucrose still have many hydroxyl groups that will lead to attracting other molecules or ions, such as oxygen or water. This phenomenon affects the physical and mechanical properties of materials. The physical and mechanical properties increased with sucrose addition. The best composite was prepared using 3% sucrose. This is because sucrose has a crystalline structure that affects the properties of biocomposites. However, the addition of 3% sucrose was not as effective as that of neat PLA. [ABSTRACT FROM AUTHOR]