Synthesis and characterization of graphite oxide and 2-methyl-4-chlorophenoxy acetic acidgraphite oxide (mcpa-go) nanocomposite with its controlled release property / Norilyani Izzati Hasanuddin

The graphite oxide and 2-methyl-4chlorophenoxy acetic acid- graphite oxide (MCPA-GO) nanocomposite were successfully synthesized by using improved Hummer's method and ion-exchange method respectively. In this study, MCPA-GO nanocomposite was synthesized at various concentration of MCP A ranging from 0.1 to 0. 7 M to lowering its toxicity and increase the drugs/herbicides loading efficiency. Meanwhile, the graphite oxide was prepared with the use the graphite powder as starting material. Graphite oxide and MCPA-GO nanocomposite were characterized using Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD) and Carbon Hydrogen Nitrogen and Sulphur analyzer (CHNS). The FTIR spectra of MCPA-GO nanocomposite was showed resemblance peaks of the MCPA and graphite oxide indicated the inclusion of MCP A into the graphite oxide. As for XRD pattern, there was increasing in the basal spacing of the nanocomposite from the graphite oxide which by 9.3 A to 9.7 A. Other than that, the percentage loading of MCP A in the nanocomposite was calculated to be 98.0 % (w/w) based on the CHNS result. Next, the controlled release ofMCPA-GO nanocomposite was done in two different solution which were in sodium chloride solution (NaCl) and sodium carbonate solution (Na2CO3). The release of MCP A into these solution was found to be dependent to the anion in the order of Na2CO3 > NaCl with the percentage release of 66 % and 10 % respectively. It proved that this release property exhibits the potential application of graphite oxide as effective nanocarrier of herbicides

Treatment of palm oil mill effluent by poly(L-lactic acid)-poly(ethylene glycol)/silica membrane

Biodegradable membrane technology has received an increasing interest in many fields of applications exclusively to preserve the earth. A renewable polymer such as poly(L-lactic acid) (PLLA) often being introduced with reinforcement material to improve the characteristics of membranes itself. Herein, this study highlights the development of membrane from poly(L-lactic acid)-poly(ethylene glycol) (PLLA-PEG) copolymer with silica (SiO2 ) in the treatment of palm oil mill effluent (POME) wastewater. We hypothesized that the incorporation of SiO2 as a nanofiller promoted PLLA-PEG/ SiO2 membrane to have a porous and higher number of pores on the membrane surface. Therefore, the effect of silica amount added in the PLLA-PEG copolymer membrane was also investigated and examined by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Based on FTIR analysis, the presence of the urethane (-NHCOO-) functional group indicated the formation of PLLAPEG copolymer and SEM micrographs showed porous surface on the membranes with increasing pores size in a favor of SiO2 amount added. Also, the surface wettability of membranes was evaluated through water contact angle which render hydrophilic characteristics. These membranes were subsequently applied for POME filtration where the test resulted in significant discolouration of POME. Furthermore, the high percentage removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solid (TSS) up to 99.5% empowers the treated POME wastewater to be within the range set by the Malaysian Department of the Environment

Physicochemical Characterization and Controlled Release Formulation on Intercalated 2-Methyl-4-chlorophenoxy Acetic Acid-Graphite Oxide (MCPA-GO) Nanocomposite

In this present work, herbicide named 2-methyl-4-chlorophenoxy acetic acid (MCPA) was intercalated into the graphite oxide through ion-exchange method to produce a MCPA-GO nanocomposite as an herbicide delivery system. The formation of MCPA-GO nanocomposite was confirmed by using PXRD, Fourier Transform Infrared Spectroscopy (FTIR), Thermal Gravimetric Analysis (TGA), UV-Visible Spectroscopy and Accelerated Surface Area Surface (ASAP). As for PXRD pattern, there was increasing in the basal spacing of the nanocomposite from the graphite oxide which by 9.3 Å to 9.7 Å indicated that MCPA has succesfully inserted into the interlayers of the graphite oxide. Meanwhile, FTIR spectrum shown the appearance of a new peak in MCPA-GO nanocomposite at 1308 cm-1 represent the functional group of carboxylate (COO-).  This peak is very necessary for the confirmation of anionic form of MCPA inserted into the interlayers of graphite oxide. The controlled release property was also done for further investigation by using various aqueous medias to determine the percentage release of MCPA from the nanocomposite. The percentage of herbicide release in Na3PO3 solution was higher than in Na2CO3 and NaCl solution, proved that the release properties exhibits the potential application of graphite oxide as effective nanocarrier of herbicides. MCPA-GO nanocomposite suggested to be most promising herbicide since it can lower the toxicity of precursor MCPA, high biocompability, and more efficient in herbicide delivery system

Poly(lactic acid)-poly(ethylene glycol)/Magnesium Silicate Membrane for Methylene Blue Removal: Adsorption Behavior, Mechanism, Ionic Strength and Reusability Studies

In this work, the effect of magnesium silicate (MgSiO3) as a filler on poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) membrane was investigated towards the enhancement of adsorption capacity for removal of cationic dye. The preparation and fabrication of membranes were performed through copolymerization and phase inversion techniques. Analysis of functional groups, tensile strength, morphology and surface wettability were employed in the characterization of the membranes. After the addition of MgSiO3, it was found that the PLA-PEG/MgSiO3 membrane presented a higher hydrophilic property with improved mechanical strength. Next, the adsorption of methylene blue (MB) was optimized using response surface methodology (RSM) with the parameters mass of membrane and initial concentration of MB solution. The effects of pH and ionic strength were also examined to determine the mechanism involved during adsorption processes, which later were found to be electrostatic interaction and ion-exchange mechanism. From the isotherms and kinetics studies, the PLA-PEG/MgSiO3 membrane was well fitted by the Freundlich model and pseudo second order model, respectively. This membrane also demonstrated reusable character of up to six cycles