Browsing by Author "Azman H.H."
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Publication Deconstruction of Malaysian agro-wastes with inexpensive and bifunctional triethylammonium hydrogen sulfate ionic liquid(American Institute of Physics Inc., 2018) ;Zahari S.M.S.N.S. ;Amin A.T.M. ;Halim N.M. ;Rosli F.A. ;Halim W.I.T.A. ;Samsukamal N.A. ;Sasithran B. ;Ariffin N.Z. ;Azman H.H. ;Hassan N.H. ;Othman Z.S. ;Faculty of Science and Technology ;Universiti Sains Islam Malaysia (USIM) ;Universiti Selangor (UNISEL)Universiti Kebangsaan Malaysia (UKM)Ionic liquids (ILs) are known to be very effective at deconstructing biomass, but, they are typically 5-20 times more expensive than molecular solvents; this is a major impediment to the utilisation of ILs in biorefinery applications. In view of this, this paper is the first to report a preliminary study on the use of inexpensive and bifunctional triethylammonium hydrogen sulfate ionic liquid, [N2220][HSO4] IL, in deconstructing two Malaysian agro-wastes, oil palm empty fruit bunches (OPEFB) and coconut husk. The [N2220][HSO4] IL was synthesised via simple acid-base neutralisation route between two inexpensive precursors: sulfuric acid, H2SO4, and triethylamine, N222. The results of deconstruction of OPEFB and coconut husk under the applied conditions, IL/H2O (80/20 wt/wt) at 120�C for 2 h, proved that the IL provided bifunctional action as: a Br�nsted acid catalyst that hydrolysed chemical bonds linking carbohydrate-rich-material (cellulose and hemicellulose) and lignin fractions, and; a delignification agent that dissolved lignin, separating the biopolymer from the carbohydrate-rich-material. The outcomes of this study indicate that the deconstruction of Malaysian agro-wastes for isolating valuable biopolymers can be performed in a more economical and effective way using the [N2220][HSO4] IL. - Some of the metrics are blocked by yourconsent settings
Publication Poly(vinylpyrrolidinone)-iron magnetic nanocomposites as sorbents for effective oil removal from water(American Institute of Physics Inc., 2018) ;Zahari S.M.S.N.S. ;Nordin N.F.N.M. ;Kamarudin M.S. ;Mus'ab Sahrim ;Mahat M.M. ;Azman H.H. ;Junid R. ;Endot N.A. ;Faculty of Engineering and Built Environment ;Faculty of Science and Technology ;Universiti Sains Islam Malaysia (USIM) ;Universiti Teknologi MARA (UiTM) ;Universiti Selangor (UNISEL) ;Universiti Malaysia Pahang (UMP)University of LiverpoolPoly(vinylpyrrolidinone)-iron magnetic nanocomposites (PVP-Fe NCs) were synthesised and used as sorbents for the removal of cooking oil from synthetic polluted water. The synthesised nanocomposites (NCs) contained particles with average grain size of 20 to 30 nm and possessed magnetic properties, as evidenced by field emission scanning electron microscopy (FESEM) and vibration sample magnetometer (VSM) analyses. The oil sorption studies revealed that the NCs are capable to remove up to ca. 80% of oil, and this remained constant irrespective of the total oil loading. Significantly, the oil-coated NCs were easily separated from "cleaned" water through a magnetic attraction using a N50 magnet. This approach, therefore, holds great potential to be scaled up and expanded to various water systems in Malaysia such as sea and river. � 2018 Author(s). - Some of the metrics are blocked by yourconsent settings
Publication A Preliminary Study of Catalytic Hydrothermal Conversion of Cellulose to Lactic Acid: Effects of Reaction Temperature and Metal Ion Catalyst(Institute of Physics Publishing, 2020) ;Shahrul Nizan Shikh Zahari S.M. ;Zulastry N.A.Azman H.H.Cellulose biopolymer was converted to lactic acid by catalytic hydrothermal method. The conversion was studied under various temperatures (120 to 190 °C) and types of metal ion catalyst (Pb2+ and Al3+), while the reaction period remained fixed at 3 h. Following the reaction, the recovery of untreated cellulose and the mass loss were determined by gravimetric means. Meanwhile, the resultant liquid products were analysed by high performance liquid chromatography (HPLC) for detecting the targeted products: lactic acid, glucose, and fructose. The study reveals useful insights; elevating the reaction temperature was found to increase the mass loss, so did the yield of the targeted products. On the other hand, using a metal ion catalyst, possessing stronger Lewis acidity character, further enhanced lactic acid production. © Published under licence by IOP Publishing Ltd. - Some of the metrics are blocked by yourconsent settings
Publication Uncatalysed Polycondensation of Lactic Acid to Polylactic Acid under Microwave Irradiation: Effect of Microwave Power(Institute of Physics Publishing, 2020) ;Shahrul Nizan Shikh Zahari S.M. ;Shahrul.zahari ;Mansor M.H. ;Azman H.H.Rosli D.In this study, polycondensation of 88wt% lactic acid (LA) was performed by irradiating LA with microwave at different powers (P=250, 440, 715 and 900W) for 5 min, in the absence of a catalyst. The recovered products were analysed by attenuated total reflectance-infrared (ATR-IR) and thermogravimetric analysis (TGA). It was found that raising microwave power resulted in a significant increase in mass loss, even much higher than the water content of the fresh LA (12wt%). Such an observation was likely to be caused by two occurrences. The first is associated with the evaporation of 12wt% of water molecules in the fresh LA that escalated upon increasing microwave power. This is supported by ATR-IR analysis illustrating a decreasing trend in the intensity of O-H stretching band. The second is linked to the intensified polycondensation of LA to polylactic acid (PLA) when elevating microwave power, forming more ester bonds and consequently eliminating more water molecules. The increased formation ester bonds was evidenced by the shift in Tonset values towards higher temperatures, as exhibited by TGA profiles. As overall, the outcomes of this study could lead to a cost effective and energy saving production of biodegradable plastics, substituting the time-consuming conventional heating. � Published under licence by IOP Publishing Ltd.