The recognition of nanocellulose has been prominent in recent years as prospect materials, yet the ineffectiveness of nanocellulose to disperse in an organic solvent has restricted its utilization, especially as a reinforcement in polymer nanocomposite. In this study, cellulose has been isolated and defibrillated as cellulose nanofibrils (CNF) from oil palm empty fruit bunch (EFB) fibers. Subsequently, to enhance its compatibility with UV-curable polyurethane (PU)-based resin, the surface hydrophilicity of CNF has been tailored with polyethylene glycol (PEG), as well as reduced graphene oxide (rGO). The dispersibility of reinforced modified CNF in UV-curable PU was examined through the transmittance interruption of resin, chemical, and mechanical properties of the composite printed using the stereolithographic technique. Evidently, the enhanced compatibility of modified CNF and UV-curable PU was shown to improve the tensile strength and hardness of the composites by 37% and 129%, respectively.
The adoption of high-intensity ultrasonication in the isolation process of cellulose nanofibrils (CNF) as an economical, timesaving, and environmental-friendly process has been explored. Three types of raw organic fibers, i.e., banana pseudostem, oil palm trunk, and kenaf bast were analyzed for the production of CNF using the process mentioned earlier. Before the raw organic fibers were subjected to a high-intensity ultrasonication process, it underwent an alkaline treatment to eliminate the non-cellulosic compounds. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) micrographs confirmed the presence of nanofibrils in all three different types of CNF. The frequency, amplitude, and duration of ultrasonication used in this study were sufficient to produce CNF. Fourier-transform infrared spectroscopy (FTIR) results indicated that the chemical treatment employed in this paper was effective in removing the compounds, especially lignin and hemicellulose. The increase in crystallinity, which is one of the advantages of CNF, was observed from the X-ray diffraction (XRD) results. Hence, it can be deduced that high-intensity ultrasonication could simplify the complex process of CNF isolation compared to the conventional method, widening the utilization and source of CNF in the industry.
Radiopharmaceuticals (RPC) used for diagnostic and therapeutic purposes in nuclear medicine may contaminate surface areas due to spillage during its preparation or accident during RPC transfer from laboratory to the treatment room. Fluorine-18 Fluorodeoxyglucose (18F-FDG) is the most common RPC for positron emission tomography (PET) scan in nuclear medicine due to its ideal annihilation converted energy at 511 keV and short half-life at 109.8 min. Ineffective medical waste management of 18F-FDG may pose a risk to the environment or cause unnecessary radiation doses to the personnel and public. Depending on the incident rate of these events, simple decontamination methods such as the use of chemicals and swabs might not be cost-effective and sustainable in the environment. This study aims to propose an alternative method to decontaminate 18F-FDG by using graphene oxide (GO). GO was synthesised using the Hummers method while the physical morphology was analysed using a field emission scanning electron microscope (FESEM). 18F-FDG adsorption efficiency rate using GO nanolayers was analysed based on the kinetic study of the GO:18F-FDG mixtures. The chemical adsorbability of the material was analysed via UV–vis spectrophotometer to interlink the microstructures of GO with the sorption affinity interaction. Resultantly, the adsorption rate was effective at a slow decay rate and the optical adsorption of GO with 18F-FDG was dominated by the → plasmon peak, which was near 230 nm. By elucidating the underlining GO special features, an alternative technique to isolate 18F-FDG for the decontamination process was successfully proven.
A facile preparation of graphene oxide silver alginate film (GO-Ag) has been constructed for the antibacterial activity. Graphene oxide (GO) was used as a substrate towards arranging of unagglomerated silver nanoparticle (AgNPs) by a simple microwave irradiation on combination of GO and silver complexes in the presence of alginate. The obtained nanocomposite were characterized by using Ultraviolet-visible spectroscopy (UV-Vis) and Xray Diffraction to confirm the formation of film composite. AgNPs with spherical-shape deposited on the GO Alginate layer which displayed a good antibacterial towards E.Coli and Staphylococcus aureus.