Tannin was successfully extracted from Gelam bark using acetone as the solvent as natural alternatives. The extracted tannin was then used as corrosion inhibitor for mild steel under acidic medium. The gravimetric and electrochemical potentiodynamic corrosion tests were executed at different purified and unpurified tannin concentrations (200-800 ppm) to test the ability to inhibit mild steel corrosion. The results showed that the corrosion rate decreased as tannin concentration increased while the inhibition efficiency increased. The isotherm adsorption found that the Langmuir model was the best model to represent the interaction of tannin inhibitor and the active sites on mild steel surface. The SEM analysis showed that the mild steel morphology changed after the addition of tannin. The presence of blue-black color on the mild steel surface indicated the formation of ferric tannate to protect the surface of mild steel. In conclusion, purified tannin was a better inhibitor compared to unpurified tannin on mild steel in 1 M HCl. � 2018, Malaysian Society of Analytical Sciences. All rights reserved.

Absorption is one of the effective, simple and economical methods to remove oil from oily wastewater. The most widely used approach is to utilize lignocellulosic biomass as oil absorbent. However, the hygroscopic of cellulose have limited the oil-water separation capability of lignocellulosic fibers. In this study, the surface functionality of oil palm empty fruit bunch (EFB) fibers was slightly altered by grafting reduced graphene oxide (rGO). The modified EFB fibers show a distinct morphological and chemical characteristics changes as the surface of fibers has been coated with rGO. This was supported by FTIR analysis with the diminishing peak of hydroxyl group region of EFB fibers. While the surface modification on EFB fibers shows a diminution of a hydrophilic characteristic of 131.6% water absorption in comparison with 268.9% of untreated EFB fibers. Moreover, modified fibers demonstrated an oil-water separation increment as well, as it shows 89% of oil uptake and improved ~17 times of oil selectivity in oil-water emulsion than untreated EFB fibers.

Binderless electrodes of activated carbon monoliths (ACMs) and its composites with graphene are prepared by carbonization and activation of green monoliths consisting of self-adhesive carbon grains and 0�10�wt% KOH-treated graphene. Compared with ACMs, the optimized composite containing 6�wt% graphene exhibits more ordered micro-structures with increased crystallite height, and graphitic sp2 carbons (ID/IG�=�0.49 vs. 0.91) along with enhanced porosity; as revealed by X-ray diffraction, Raman, and N2 adsorption-desorption studies. These modifications lead to increased electrical conductivity (13 vs. 9�S�cm?1) through improved interconnections of carbon particles by graphene, and surface area�~�(800 vs. 456�m2�g?1) due to increased inter-particle spacing. Further, contrary to ACMs, the composite electrodes can offer faster delivery of energy in almost 50% less response time (5 vs. 8�s) due to reduced equivalent series resistance (1.67 vs. 2.65�?) and charge transfer resistance (0.55 vs. 1.33�?). � 2017, Springer-Verlag GmbH Germany.

The recognition of cellulose nanofibrils (CNF) in the past years as a high prospect material has been prominent, but the impractical cellulose extraction method from biomass remained as a technological barrier for industrial practice. In this study, the telescopic approach on the fractionation of lignin and cellulose was performed by organosolv extraction and catalytic oxidation from oil palm empty fruit bunch fibers. The integration of these techniques managed to synthesize CNF in a short time. Aside from the size, the zeta potential of CNF was measured at ?41.9 mV, which allow higher stability of the cellulose in water suspension. The stability of CNF facilitated a better dispersion of Fe(0) nanoparticles with the average diameter size of 52.3�73.24 nm through the formulation of CNF/Fe(0). The total uptake capacity of CNF towards 5-fluorouracil was calculated at 0.123 mg/g. While the synergistic reactions of adsorption-oxidation were significantly improved the removal efficacy three to four times greater even at a high concentration of 5-fluorouracil. Alternatively, the sludge generation after the oxidation reaction was completely managed by the encapsulation of Fe(0) nanoparticles in regenerated cellulose. � 2019, The Author(s).