Bacterial cellulose-based carbon nanotube has been synthesized by catalytic graphitization method. Bacterial cellulose (BS) is a source of cellulose produced from fermentation of medium by Acetobacter xylinum. Since it contains unbranch polymer linked by β-1.4 glucopyronose with hydroxil groups, BS is able to use as precursor in synthesis of carbon nanotube. Due to catalytic graphitization, chitosan served as coupling agent and dispersant of catalyst and various concentration of catalyst FeCl3.6H2O also were used. Graphitization was conducted in furnace with inert nitrogen gas atmosphere at 800°C for 2 hours. SEM-EDS were used to evaluate the morphology and semi-quantitative analysis of sample. TEM was used to determine the microstructures and crystallographic. When the chitosan was added 0.5%, its served as coupling agent and dispersant of catalyst with BS. Chitosan improved physical properties, relieved its brittleness, and caused the optical properties of BS. Catalyst of FeCl3.6H2O was used to assist the formation and growth of carbon nanotube. The amount of carbon was not affected by time aging. 0.1 M FeCl3.6H2O was the optimum concentration to produce carbon nanotube with 81, 58% the mass of carbon, plane orientation (002) (100) and the diameter of carbon nanotube is 25 nm.
Exploration of natural compound for the treatment of dental-related problems are gaining of interest for enhancing therapeutic efficacy of the drugs delivery system. In this study, we have prepared terpenoid, which have been isolated from Myrmecodia pendens Merr & Perry from Papua Island, Indonesia, to be encapsulated in Polylactic-co-glycolic acid (PLGA), as the most widely used biodegradable polymer for biomedical applications, through one step single-emulsion method followed by subsequent coating by poly (vinyl alcohol) (PVA). The resultant of terpenoid-loaded PLGA microparticles were characterized systematically through scanning electron microscope and Fourier-transform infrared spectroscopy. In vitro drug release test was evaluated through dialysis method. Antibacterial test was conducted against Enterococcus faecalis as a model for persistent bacteria that causes root canal infections. The results showed that terpenoid-loaded PLGA microparticles were developed in spherical morphology with an average particle size of around 1-2μm. Terpenoid released from PLGA compartment at pH 6.5 and temperature of 37°C through a controlled-release profile mechanism with enhanced prolonged release. The bacterial assay result showed that terpenoid-loaded PLGA microparticles could reduce Enterococcus faecalis, effectively. Eventually, these result show that terpenoid-loaded PLGA microparticles as unique natural product-based extract could be developed as a potential naturally-based drug for dental-related diseases applications.
Various bioceramic materials including zirconia and hydroxyapatite have been developed for various applications. Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) is one of the most interesting features of calcium phosphate-based bioceramic that widely used in various applications especially for bio-application, bone engineering, and dentistry. However, the applications of pristine HAp have limited due to low load bearing applications. The wet chemical precipitation techniques was used to synthesize the solids based on zirconia. Hydroxyapatite and zirconia powder (0-30 weight %) were mixed homogeneously. Structure and morphological were characterized by SEM JEOL-JSM-T330A. The presence of functional group was observed by FTIR. Hardness value of material was measured by using Vickers hardness test measurement. Through this techniques, pure hydroxyapatite precipitate was obtained. Sintering temperature is an important factor that could influence the hardness of zirconia-doped hydroxyapatite. Based on the SEM observation, zirconia-doped hydroxyapatite were developed in blended morphology. FTIR results shows the interaction between hydroxyapatite and zirconia. Increasing zirconia increased the hardness value of zirconia-doped hydroxyapatite. Eventually, these ceramic-based materials could be developed for dental materials applications.
Summary: A new polymer electrolyte membane for fuel cell has been developed between sulfonated polystyrene (sPS) and polyethylene grafted maleic anhydride (PE-g-MAH). This approach requires a precise sulfonate distribution across sPS backbone. Precise distribution of sulfonate groups in sPS can be achieved by gas-liquid heterogeneous sulphonation. Type of solvents, gas carrier flow rate affect the end products of sPS in term of degree of sulphonation and backbone destruction. Polymer electrolyte membrane fuel cell (PEMFC) prepared using sPS prepared by gas-liquid heterogeneous sulphonation. The membrane shows very good performance. The ion exchange capacity as good as commercial products.
MAGNETIC REDUCED GRAPHENE OXIDEAS ADVANCED MATERIALS FORADSORPTION OF METAL IONS. Magnetic Reduced Graphene Oxide (MRGO) is graphene-based material that modified by introducing iron oxide nanoparticles onto the surface of graphene oxide (GO). MRGO exhibit some unique and advanced properties and characteristic including high surface area, superparamagnetic characteristics and adsorption ability against ions and molecules. In this research, MRGO was prepared by the Hummers method, followed by reacting ferrochloride tetrahydrate and ferrichloride hexahydrate through co-precipitation method for the formation of iron oxide nanoparticles on the GO surface. MRGO was prepared with various composition of ferrochloride tetrahydrate. Furthermore, the resultant of MRGO was characterized by Scanning Electron Microscope (SEM), Fourier-transform Infrared (FT-IR) Spectroscopy, and Atomic Adsorption Spectroscopy (AAS). Adsorption characteristics test was conducted against electroplating waste-based metal ion. The SEM results showed that GO exhibited the layered structure meanwhile MRGO exhibit as Feƒ O 4-modified GO layered surfaces. MRGO made by different ferrochloride tetrahydrate differed in the iron oxide nanoparticles formation on the surface of GO. Increasing the composition of ferrochloride tetrahydrate increased the formation of iron oxide nanoparticles. Moreover, MRGO (FeCl‚ .4H‚ O 0.0064 M) is successfully applied as nickel metal ion adsorbents with the adsorption ability of 78,24%. This result showed that MRGO have a potential prospect as an effective and efficient advanced adsorbent material candidate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.