The effect of alkaline hydrogen peroxide (AHP) treatment on reducing lignin content in coffee pulp waste (CPW) was investigated to increase the digestibility and accessibility of cellulose during production of valuable products by enzymatic and biological process. Hydrogen peroxide (H2O2) at various concentrations (2.5, 5, and 7.5% (w/w of substrate)) was mixed into 10% (w/v) of CPW-NaOH solution at 35 °C for 24 h with pH 11.5. The concentration of lignocellulosic content was investigated. The characteristic of crystallinity index, functional groups, and surface morphology of CPW at before and after the treatment have been observed using XRD, FTIR, and SEM analysis, respectively. The results showed that the highest lignin removal was achieved at the addition of 7.5% H2O2which decreased from 16.85% to 8.5%. The concentration of cellulose and hemicellulose in CPW increased from 53% to 64% and 11% to 24%, respectively. The crystallinity index of AHP-treated CPW has increased from 30.83% to 42.08%. A surface morphological destruction on the CPW was getting worse as along with the increase of H2O2concentration. This would be useful to increase the porosity of biomass to give cellulose accessibility by enzyme for further processes.
28 June 2023 in International Journal of Technology
In the presented work, the formation of anodic oxide film on Ti-6Al-4V ELI (Extra Low Interstitial) alloy in 0.02 M trisodium phosphate (Na3PO4) electrolyte solution using various voltages were investigated. The color produced by the anodizing, the intensity of TiO2 content, the thickness of the oxide layer, and the corrosion rate were examined. It was obtained that the color appearance of Ti-6Al-4V ELI could be changed easily by altering the applied voltages. The higher the voltage applied in the anodizing process, the thicker the titanium oxide layer formed. The corrosion resistance analysis in a Simulated Body Fluid revealed that the non-anodized specimen showed a higher corrosion rate compared to the anodized specimen. The increase of oxide layer thickness leads to a significant decrease in corrosion rate and consequently increases the corrosion resistance. In addition, the anodized sample achieved the highest corrosion resistance at 15 V.
5 January 2023 in Journal of Chemical & Engineering Data
The properties of N-isopropylacrylamide copolymerized with N,N-dimethyl(acrylamidopropyl)ammonium propane sulfonate [poly(NIPAM-co-DMAAPS)] prepared with various monomer ratios such as transition temperature, molecular structure, viscosity were systematically investigated in water and Zn(NO3)2 solution. Poly(NIPAM-co-DMAAPS) in water and Zn(NO3)2 solution exhibited a phase transition with a lower critical solution temperature (LCST). The higher ratio of NIPAM monomer in poly(NIPAM-co-DMAAPS), the lower the LCST of the polymer. Furthermore, the transition temperature of poly(NIPAM-co-DMAAPS) with a lower NIPAM concentration were not confirmed both in water nor Zn(NO3)2 solution. The more increase the NIPAM concentration used in the preparation, the more increase the polymer viscosity. Moreover, the more increase the adsorption amount of ions onto the gel, the more increase the polymer transmittance as well.