Solid State Phenomena Vols. 124-126

Abstract: This paper is to develop an antibacterial fabric by mainly radiation grafting technique. Because a fabric should be soft and comfortable, so antibacterial materials need to be very small in size to graft on the fabric. This work used nanosized antibacterial solution or powder, Nylon and PET fibers, as starting materials to prepare antibacterial fabric products. Two radiation synthetic processes were used in the paper, 1. the nanosized silica powder or solution containing silver (named Ag/SiO2) was introduced to Nylon or PET (Polyethylene terephthalates) fabric by means ofγ-ray irradiation method. 2. the nanosized silver particles in solution were reduced and deposited on the surface of fabric used by radiation reduction technique. The microscope TEM & SEM (transmission and scanning electron microscope) and ICP(Induced coupled plasma)…etc were utilized to analyze the characteristics of antibacterial fiber products. In addition, these antibacterial fibre products prepared by radiation reduction method were also subjected to test the antibacterial effect.The results showed that silver-Nylon and silver-PET antibacterial fiber have good antibacterial effects against Staphylococcus aureus , especially the Ag-PET fiber having the better effect than Ag-Nylon fiber.

Abstract: It is very important to study the effects of various factors on synthesis of carbon nanomaterials for controlled synthesis, which plays a significant role in realizing desired nanostructures or nanodevices for applications. In this report, we employed iron nitrate solution with different concentration, such as 1 mol/l, 0.1 mol/l, 0.01 mol/l, and saturated iron nitrate solution as catalyst precursor solution and studied the effects of concentration of catalyst precursor solution on carbon nanostructures that were synthesized by ethanol catalytic combustion (ECC) process. We have characterized the as-grown carbon nanostructures by employing scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for deep understanding.

Abstract: The physicochemical characteristics (SEM, N2 adsorption, FT-IR, MASNMR) of samples from kinetics (10 min, 20 min, 30 min, 1 h and 3h) of hydrolysis of tetraethyl orthosilicate (TEOS) gives new insight into the synthesis of nanosphere. The particle sizes are increased with time, however, the surface areas decreased. FT-IR investigation reveals the presence of high intensed silanol groups of 960 cm-1 at 10 min, which reduced on progress of the reaction time. This suggests the partial hydrolysis and condensation of alkoxy groups in TEOS. 29Si MASNMR analysis shows the presence three different silica species(Q4, Q3 and Q2) in 10 and 20 min samples. The intensity of Q2 species decreases with time and other species concentration were increased.

Abstract: Carbon nanotube (CNT) gas sensors for NOx gas detection were prepared. CNTs were grown on an Al2O3 substrate with interdigital Pt-electrodes (Al2O3 ceramic substrate) using both pulsed laser deposition (PLD) and thermal chemical vapor deposition (CVD) method. In this method, Al buffer layer and Fe catalytic thin film were prepared on the substrate by PLD method and then CNTs were grown by thermal CVD method. Surface images of CNTs on the substrates were observed by SEM, and the gas sensing property specific to NO gas was measured. Resistance of the prepared CNTs gas sensor decreased with increase of sensor temperature, and it decreased with increase of NO gas concentration at room temperature.

Abstract: We present the adsorption characteristics of uranyl ions on a new and innovative composite which was composed of a carboxymethylated polyethyleneimine (CM-PEI) and an activated carbon (F400) with a nanopore less than 2 nm in diameter. In this study, we examined the adsorption phenomena of uranyl ions on the CM-PEI/F400 composite and evaluated the adsorption data using various isotherm models. It was found that the adsorption of uranyl ions on the CM-PEI/F400 composite obeys the Langmuir isotherm model. In addition, it was observed that pH of solutions had great influence on the adsorption capacity of uranyl ions on the CM-PEI/F400 composite. Specially, the adsorption capacity of uranyl ions was linearly increased with an increase of pH at pH > 3.0.

Abstract: Amorphous and nanocrystalline Si films were prepared by plasma enhanced chemical vapor deposition (PECVD). The films were deposited with a RF power of 100 W, while substrates were under DC biases varying from 0 to -600 V. The size as well as the concentration of Si nanocrystallites increased with raising the DC bias; the PL emission wavelength was shifted from 400 to 750 nm. A model for the nanostructural variation in the nc-Si:H films was suggested to describe the change in the size and concentration of the nanocrystallites as well as the amorphous matrix depending on the DC bias conditions.

Abstract: CaWO4 was prepared by solvothermal reaction of Na2WO4.2H2O and calcium salts (CaCl2.2H2O, Ca(NO3)2.4H2O and Ca(CH3COO)2) in solvent containing a variety of glycerol/water ratios at 160 oC for 6 h. By using XRD, SEM, TEM and ED, the products compose of nano-sized CaWO4 particles with scheelite structure but different morphologies. Interplanar spaces between (101) planes were determined from HRTEM image, ED patterns and XRD spectra are 0.424, 0.474 and 0.476 nm, respectively. Luminescent intensities of the products prepared in pure water are the highest and their central peaks are the same at 444 nm. In addition, Ca, W and O were detected using EDX.

Abstract: Nano-structured polymer stamps were prepared from porous anodic alumina templates. Prepolymers were poured onto the highly ordered porous anodic alumina templates, and they were cured by UV-irradiation. Simple separation of the elastic stamp from the nanoporous aluminum oxide leads to well replicated nano-stamps. The nanopatterns on the stamp were transferred as ultrahigh-density nanopore arrays on various substrates which are potentially applicable to the fabrication of ultrahigh-density metallic or semiconductor nanodot arrays for magnetic storage devices or display devices.

Abstract: Atomic layer deposition (ALD) has been used in advanced applications where thin layers of materials with precise thickness down to the nanometer scale are needed. Using anodic oxidation, we prepared the porous alumina. Anodic oxidation was carried out in 5
C 0.3M oxalic acid with anodizing voltages (~ 40 V) and two step anodization method. SEM shows that, these porous anodic oxides are well aligned and organized into high-density uniform arrays. Afterward, titanium dioxide thin films were coated by ALD on the porous anodic aluminum oxide. ALD films were influenced by the deposited interface morphology between Al2O3 and TiO2 and narrow channel of ~ 10 nm was obtained by controlling ALD cycle.

Abstract: In the present work, surface treatment of surgical implant Titanium alloy with micro bioactive nanotube was experimented. Surface treatment of Ti-6Al-4V bio-implant carried out by giving alkali hydrothermal and heat treatment. The specimens were treated in 1M NaOH at 100, 150, 200°C for different holding time of 2 hr, 4 hr, 6hr, 12 hr, 24hr & 48 hr. The hydrogel layer generated during the alkali treatment was crystallized to sodium titanate (Na2Ti6O13) and resulted into the formation of nano sized tubes on heat treatment. X-ray Diffractrometry (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) revealed the different phases and surface morphology of these nanorods. The biocompatibility test done using Simulate Body Fluid (SBF) showed that the Hydroxyapatite (HAp) was well formed at the sodium titanate nanotube layer generated on the Ti-6Al-4V specimen. The best condition for this increase in surface biocompatibility was optimized to 6 hours hydrothermal treatment under 200°C using 1 M NaOH followed by 1 hour heat treatment at 600°C.