The industrial production of palm oil concurrently generates a substantial amount of empty fruit bunch (EFB) fibers that could be used as a feedstock in a lignocellulosebased biorefinery. Lignin byproducts generated by this process may offer opportunities for the isolation of value-added products, such as p-hydroxybenzoate (pBz), to help offset operating costs. Analysis of the EFB lignin by nuclear magnetic resonance (NMR) spectroscopy clearly revealed the presence of bound acetate and pBz, with saponification revealing that 1.1 wt% of the EFB was pBz; with a lignin content of 22.7 %, 4.8 % of the lignin is pBz that can be obtained as a pure component for use as a chemical feedstock. Analysis of EFB lignin by NMR and derivatization followed by reductive cleavage (DFRC) showed that pBz selectively

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Silver nanoparticles and silver-graphene oxide nanocomposites were fabricated using a rapid and green microwave irradiation synthesis method. Silver nanoparticles with narrow size distribution were formed under microwave irradiation for both samples. The silver nanoparticles were distributed randomly on the surface of graphene oxide. The Fourier transform infrared and thermogravimetry analysis results showed that the graphene oxide for the AgNP-graphene oxide (AgGO) sample was partially reduced during the in situ synthesis of silver nanoparticles. Both silver nanoparticles and AgGO nanocomposites exhibited stronger antibacterial properties against Gram-negative bacteria (Salmonella typhi and Escherichia coli) than against Gram-positive bacteria (Staphyloccocus aureus and Staphyloccocus epidermidis). The AgGO nanocomposites consisting of approximately 40 wt.% silver can achieve antibacterial performance comparable to that of neat silver nanoparticles.

Cellulose nanofibrils (CNF) were prepared from kenaf core (KC) using acidified-chlorite bleaching method and followed by disintegration using high speed blender. The effects of disintegration time and acid treatment on the defibrillation of holocellulose were studied. Hemicellulose was found to facilitate defibrillation, as CNF without any acid treatment was fully defibrillated after 30 min. The adsorption kinetics of CNF toward cationic dye cannot be accurately determined due to its quick adsorption performance, in which the equilibrium is achieved immediately after 1 min of contact time. The effects of acid treatment on holocellulose, pH, adsorbent dosage, temperature and dye concentration were studied and optimized. Adsorption data were fitted to both Langmuir and Freundlich models where Langmuir model was found to be the better model to describe the adsorption process. Maximum adsorption capacity was found to be 122.2 mg/g at pH 9, 20 °C for the non-acid treated CNF. The CNF can be regenerated by desorption at low pH where, as much as 70 % of dye adsorbed can be desorbed after 6 cycles of adsorptiondesorption cycle.

Magnetite (Fe 3 O 4 ) nanoparticles prepared using hydrothermal approach were employed to study their potential application as magnetic resonance imaging (MRI) contrast agent. The hydrothermal process involves precursors FeCl 2 Á4H 2 O and FeCl 3 with NaOH as reducing agent to initiate the precipitation of Fe 3 O 4 , followed by hydrothermal treatment to produce nano-sized Fe 3 O 4 . Chitosan (CTS) was coated onto the surface of the as-prepared Fe 3 O 4 nanoparticles to enhance its stability and biocompatible properties. The size distribution of the obtained Fe 3 O 4 nanoparticles was examined using transmission electron microscopy (TEM). The cubic inverse spinel structure of Fe 3 O 4 nanoparticles was confirmed by X-ray diffraction technique (XRD). Fourier transform infrared (FTIR) spectrum indicated the presence of the chitosan on the surface of the Fe 3 O 4 nanoparticles. The superparamagnetic behaviour of the produced Fe 3 O 4 nanoparticles at room temperature was elucidated using a vibrating sample magnetometer (VSM). From the result of custom made phantom study of magnetic resonance (MR) imaging, coated Fe 3 O 4 nanoparticles have been proved to be a promising contrast enhanced agent in MR imaging. #

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A highly porous cellulose nanofibril aerogel loaded with graphene oxide–iron(iii) nanocomposites was produced and used for the treatment of methylene blue in aqueous solution.

Natural fibers such as kenaf have been studied extensively as a reinforcing phase and received major attention recently due to their renewability, biodegradability, and high strength comparable to other synthetic fibers. In this study, nano-crystalline cellulose (NCC) was produced from kenaf core wood using the acid hydrolysis method. Kenaf core was alkali treated with a 4 wt% of sodium hydroxide solution and subsequently bleached using sodium chlorite in acidic buffer. The resulting white, bleached kenaf core was hydrolyzed in 64 wt% sulfuric acid (H 2 SO 4 ) to obtain NCC. The resulting NCC suspension was characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) analysis, and scanning transmission electron microscope (STEM). Hydrolysis with highly concentrated H 2 SO 4 further increased the crystallinity of bleached kenaf core cellulose and reduced the dimension of cellulose to nano scale. FTIR results showed that with each subsequent treatment, hemicellulose and lignin were removed, while the chemical functionalities of cellulose remained after the acid hydrolysis treatment. XRD peaks shown by bleached kenaf core were characteristic of cellulose I, which was reaffirmed by the DSC results. The diameters of NCC obtained from kenaf core were found to be in the range of 8.5 to 25.5 nm with an average aspect ratio of 27.8.