Advanced Materials Research Vols. 93-94

Abstract: The synthesis of phosphorus-containing monomer, methacryloyloxyethyl phenyl benzenephosphonate (MPBP), was carried out. The monomer was successfully prepared as evidenced by 1H NMR, 13C NMR, FT-IR and MS analyses. Subsequently, MPBP was grafted onto natural rubber particles via emulsion polymerization. It was found that as the reaction temperature increased from 40 to 70 oC, percent grafting efficiency increased from 72% to 85%. Transmission electron microscopy (TEM) of the grafted NR showed a semi core-shell morphology. Thermogravimetric analysis (TGA) of grafted NR indicated a two step degradation. Moreover, the grafted polyMPBP promoted the char residue of up to 3.5%. Flame tests revealed that the grafted NR exhibited an increased LOI value (20.5 %) over that of pure NR (17.0 %).

Abstract: The on-chip platinum micro-heater prototypes for thermal cycling equipped with platinum temperature sensor are fabricated. The device has been designed, fabricated and characterized to explore the feasibility of the micro-heater for a fully integrated disposable lab-on-a-chip with the PCR module. The on-chip micro-heater demonstrates that the temperature transitions are shorter by comparison with the conventional PCR temperature routines.

Abstract: This research studied the effect of ion implantation on electrical properties of ISFETs. In the experiments the sensing membrane area were implanted with 3 types of ions (Boron(B), Phosphorus(P), and Arsenic(As)). After the implantation without annealing, the IV-characteristics of Source/Drain (P-N junction) of ISFET were performed and compared with the behaviour before implantation. In addition, the response to acid-alkaline (sensitivity) of ISFET were also studied. From the results the leakage current of source-drain, P-N junction like, decreases significantly after the implantation. However, this process damaged the devices so that the response to acid-alkaline are lost.

Abstract: The mixed matrix membranes were prepared from crosslinked PVA embedded with zeolite 4A that was grafted with PHEMA. The PHEMA was grafted onto the zeolite surface by first, attaching the vinyl-silane onto the zeolite surface and subsequently polymerizing HEMA monomer via the free-radical polymerization. The FT-IR spectroscopy confirmed the successful grafting of PHEMA on the zeolite. The grafting percentage determined by thermalgravimetry analysis (TG) was found to increase with the amount of HEMA monomer. The membrane swelling in water and pure acetone revealed the decreasing trend with increased the zeolite loading. Examined by DSC, the amount of non-freezing bound water decreased with increasing the zeolite in the membranes.

Abstract: The atomic force microscope(AFM) was used to perform surface force measurements in contact mode to investigate surface properties of model systems at the nanoscale. Three different Polydimethylsiloxane (PDMS) compounds were observed. The first consisted of pure PDMS, the second of PDMS blend with the nanoparticles Zinc Oxide(PDMS/ZnO) and the third of PDMS blend with the nanoparticles Zinc Oxide and toluene solvent(PDMS/ZnO/toluene), respectively. Surface morphology and the adhesion force were investigated by using atomic force microscopy. Force–distance curve measurement was performed in a contact mode, which used tip as silicon nitride. Moreover, we found a significantly different of the adhesion force when modified by nanoparticles ZnO and toluene solvent.

Abstract: New approach for the rational synthesis and surface functionalizing of SnO2 films aimed for gas sensors applications was discussed in this paper. It was shown that successive ionic layer deposition (SILD) technology due to its simplicity, low cost, and ability to control the deposition of nanolayers of various materials on rough surface can attract increased interest for those purposes.

Abstract: Silver nanoparticle thin films were deposited on glass substrates by electrostatics spray deposition. Electrostatic spray condition was optimized by varying distance between nozzle and substrate between 20 mm and 60 mm, deposition time was fixed at 5 minute. The surface morphology and optical properties of films were carried out by using Atomic Force Microscope (AFM), Field Emission Scanning Electron Microscopy (FE-SEM) and UV-Vis Spectrophotometer. The results is indicate that the surface morphology of silver nanoparticle thin film show the grain size of film near around 100 nm at distance between nozzle and substrate of 60 mm and the RMS roughness decreases from 9.59 nm to 2.35 nm when distance between nozzle and substrate was increased from 20 mm to 60 mm. The optical absorption spectra showed the main absorption peak at 436 nm. When the distance between the nozzle and the substrate raise, decrease in absorption has been observed.

Abstract: Bismuth vanadate powder was synthesized by a chemical co-precipitation method. Bismuth nitrate and ammonium vanadate were used as the starting precursors. The yellow precipitated powder was formed after adding ammonium hydroxide until the pH of final solution was 7. The powder was filtered and dried at 60 °C for 24h and calcined at 200-400 °C for 2h. The phase of bismuth vanadate powder was studied by X-ray diffraction (XRD). A single phase of monoclinic structure was obtained after calcinations at 200-400 °C for 2h. The morphology and particle size of bismuth vanadate powder were investigated by scanning electron microscopy (SEM). The particle was irregular in shape and highly agglomerated with an average particle size of 0.5 µm in width and 1.5 µm in length.

Abstract: Powder of β-alumina solid electrolyte with general formula Na0.80Li0.20Al5O8 was prepared by solid state reaction according to the ternary systems Li2O-Na2O-Al2O3. All the calcined powders were heated at different temperatures for 1 h. The XRD results indicate that the β-alumina phase started to form at 1100 °C and these consistent with TG/DTA measurements. At constant calcined temperature of 1100 °C, When the dwell times was varied in range 5 h to 15 h, it was found that powder consists of β-alumina as a majority phase with a tiny amount of β-alumina and the β-alumina phase purity is about 82 wt% for dwell time of 10 h. The microstructures of β-alumina particles were seen as a layered structural arrangement with hexagonal shape and strong agglomeration between these particles are clearly seen.

Abstract: Titanium dioxide powder was synthesized by the hydrothermal route with the starting precursors as titanium isopropoxide, ammonium hydroxide and nitric acid. The final of pH value of mixed solution was 1 and treated in the hydrothermal PTFE vessel at 80-100 °C for 3h. The phase of titanium dioxide was characterized by X-ray diffractometer (XRD). The morphology of titanium dioxide was investigated by scanning electron microscope (SEM). The chemical composition of titanium dioxide was examined by energy dispersive X-ray spectrophotometer (EDXS). The photocatalytic degradation of geosmin by titanium dioxide was determined by gas chromatograph coupled with flame ionization detector (GC-FID).