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TiO2-SiO2 (30:70) and (70:30) sol particles were first prepared through ClHNO2-EtOH catalysis; and then incorporated into methylated grafted natural rubber (MG49) polymer host. Resultant MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites were characterized through XRD and FTIR analyses. Both MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites had exhibited extensive reduction in semicrystalline phase; but no significant change in structural properties. Low crystalline MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites were further characterized through SEM, TGA and DRA analyses. Both MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites had exhibited different dispersion state on fracture surface. Both MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites had demonstrated significant improvement in thermal properties, and also some improvement in rheological properties.

In this experiment, agarose degradation was conducted under identical hydrolysis conditions, but different substrate and enzyme concentrations. Hydrolysis products i.e., agaro-oligosaccharide were monitored using viscometric and reducing end assay. Hydrolysis yields were found to range between 3.73 and 20.51%. Thereafter, agaro-oligosaccharides with different degree hydrolysis were subjected to various physicochemical analyses and in vitro antioxidant assays. Agaro-oligosaccharides were shown to exhibit high solubility percentages (59.84–86.78%), water absorption capacities (1.5–3.0 g/g) and oil absorption capacities (1.8–4.6 g/g). Agaro-oligasaccharides were also shown to exhibit considerable DPPH and ABTS+ radical scavenging and ferric reducing antioxidant activities; however, this effect depended on the degree hydrolysis.

In this experiment, microwave-assisted extraction (MAE) was applied at different intensity of 300, 450, 600, and 800 W to extract pectin from dragon fruit peels. The microwave-assisted extraction was optimized using a central composite experimental design. The optimal extraction condition was established to be pH 2.07, extraction time of 65 s, and solid-to-liquid ratio of 66.57. The maxima extraction yields at 300, 450, 600, and 800 W were 11.8, 14.9, 17.2 and 18.5%, respectively. Experimental and predicted extraction yields obtained at the different microwave power levels were fitted to second-order response surface model. Microwave-assisted extraction process is effective in obtaining high-quality dragon fruit peel pectin, i.e. GalA content: 59.73–69.68%, DE value: 45.82–46.95%, crystallinity: 15.32–21.22%.

The Cr(III) sorption experiments onto Kappaphycus alvarezii waste biomass were conducted at different pH values (2–6) under the conditions of initial metal concentration of 10–50 mg/L and the chemical compositions of Cr-Cu and Cr-Cd. The Cr(III) sorption capacities were slightly dependent on pH, and the maximum sorption capacity was 0.86 mg/g at pH 3. The sorption capacities increased with increase in the initial metal concentration, whereas it was suppressed by the presence of Cu(II) and Cd(III) in the solution. The Cr(III) sorption equilibrium was evaluated using Langmuir, Freundlich and BET isotherms. The sorption mechanisms were characterised using scanning electron microscopy and Fourier transform infrared spectroscopy. The main mechanisms were ion exchange coupled with a complexation mechanism. Kappaphycus alvarezii waste biomass represents a potential for Cr(III) ion removal from aqueous solution.