Search

Fe containing nano ZSM-5 composites (Fe/H-ZSM-5) were successfully prepared by chemical vapor deposition method. The physical properties of Fe/H-ZSM-5 were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), N2 adsorption-desorption isotherm (BET) analysis. Effects of pH and H2O2 concentration were investigated. The best conditions were found to be pH of 3; 0.3 g.L−1 catalyst and reaction time of 60 min at room temperature. The novel Fe/H-ZSM-5 composite exhibited highly photocatalytic performance of RR-195 degradation and the conversion reached to the value of 92.3 % for after 60 min of reaction.

Luffa cylindrica is primarily used as a vegetable, but its dry fiber can be also used as a sponge. L. cylindrica has a ligneous fibrous netting system, in which the fibrous cords are disposed in a multidirectional array, forming a natural mat. In this work, we aim to synthesize a potential material for oil spill cleanup by the graft polymerization of butyl acrylate (BA) onto Luffa fiber (LF) using 2,2′-azobisisobutyronitrile (AIBN) as initiator. The grafting process has been controlled by monomer and AIBN concentrations, reaction time and temperature, in which the optimal condition for the highest graft yield of 40.60% is [AIBN] = 0.035 mol/L, [BA] = 1.50 mol/L, 180 min at 75 °C. The graft copolymer LF-g-BA is structurally characterized by the Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. In the presence of crosslinking agent divinyl benzene, the oil sorption capacity of the synthetic LF-g-BA reaches 20.60 g oil/g sorbent for 48-h treatment. The LF-g-BA material can be seen as a potential sorbent due to its swelling property in non/weak polar mediums and reusable feature.

Cotton fabric was coated by silica sol at different times using dip-coating method. Nano silica coated fabrics were characterized by XRD, FTIR, SEM, EDX, TGA. From SEM result, it showed that fabric surface was coated by nanosilica particles of 20-30 nm size. Nano silica coated fabrics showed the improvement not only flame retardancy (LOI increased from 18.4 to 30.8) but also the tear strength. Tear strength increased from 23 N/mm (cotton fabric) to 29.9 N/mm (fabric coated nanosilica at 3 times).

The extensive ultrasmall-angle X-ray scattering measurements are performed in order to investigate the changes of lamellar grains of poly(styrenesulfonic acid)-grafted poly(ethylene-co-tetrafluoroethylene) polymer electrolyte membranes (ETFE-PEMs) that occur during the alteration of grafting degree (GD) under dry and immersed conditions. The lamellar grains of three series of the samples (polystyrene-grafted ETFE films and dry and hydrated ETFE-PEMs) are formed during the grafting process and develop independently with the change of the lamellar stacks. Interestingly, three series of samples exhibit a very similar trend of lamellar grain at any GD and a significant amount of graft chains is observed directly in the region between the grains (GD £ 59%) and outside of the grain network structures (GD > 59%). This observation indicates: i) The formation of the lamellar grains; ii) The rapid changes in characteristic sizes of the lamellar grains compared with the lamellar stacks; and iii) The newly generated phases consisting of only the graft materials. These findings explain why the lamellar grains and the graft chains play an important role in the higher proton conductivity and compatible tensile strengths of the membranes, compared with Nafion, at the immersed and severe operating conditions.

SiO2 and TiO2 sols were successfully synthesized by using sodium silicate and titanium chloride as Si and Ti sources. SiO2-TiO2 sol coated polyester/cotton fabric was fabricated by deep-coating method and using SiO2, TiO2 sols as coating materials. SiO2-TiO2 coated fabric were characterized by XRD, FTIR, TGA, SEM and EDX. From SEM image, it showed the SiO2, TiO2 particles of 20-30 nm which well deposited on fabric surface. TGA result revealed the significant improvement of thermal resistance and stability of SiO2-TiO2 coated fabric as compared to those of uncoated fabric. Flame retardant performance of SiO2-TiO2 coated fabrics was much better than that of uncoated fabric. Thus, SiO2-TiO2 coated fabric SiO2-TiO2 content of 26wt% showed the UL-94 classification of V-0 and LOI value of 30.3 were obtained. Moreover, mechanical property (tear strength) of SiO2-TiO2 coated fabrics were also improved.

The anomalous thermal denaturing of protein adsorbed to metallic nanoparticles was observed in recent experiments and found a great application potential in bionanotechnology and medical treatments. In this work, based on the Ginzburg–Landau phenomenological formalism, we consider a new simple model to describe the thermal properties of protein-coated metallic nanoparticles. Using this proposed model, the temperature dependence of the maximum extinction as a function of temperature for Bovine serum albumin (BSA) coated gold nanospheres was calculated. We found a further good agreement between the theoretical and experimental values.

The increasing use of metal halide perovskites as light harvesters has stunned the photovoltaic community. The book, Perovskite Solar Cells: Technology and Practices, covers the basics and provides up-to-date research in the field of perovskite photovoltaics—a fast trending branch of the thin film photovoltaic generation. This comprehensive handbook provides a broad and overall picture of perovskite solar cells (PSCs), starting with the history of development and revolution of PSCs. The authors then delve into electron-transporting materials, hole-transporting materials, and lead-free alternatives. An important chapter on tandem solar cells is also included. The chapters discuss how different layers in PSCs are fabricated and function and how their roles are as important as the perovskite layer itself. It explores what has been done and what can probably be done to further improve the performance of this device.

In this article, the influence of the medium refractive index on optical properties of gold nanorods (GNRs) and their surface enhanced Raman spectroscopy application were studied. In particular, GNRs have been applied in biomedical sensors to detect diseases by monitoring the changes in the environment. In this study, the changes in optical properties of GNRs were investigated according to the medium refractive index changes in the cationic surfactant cetyltrimethylammonium bromide (CTAB) during synthesis processes as well as GNR dispersion in different medium refractive indices. For instance, in the solutions with different concentrations of CTAB, GNRs were coated by biomolecules [such as PEG, bovine serum albumin (BSA), and glutathione (GSH)], which have different refractive indices. The fundamental reason for the change in optical properties of GNRs is also elucidated. GNRs have been used to enhance surface Raman scattering to detect indigo molecules. The results showed that due to the surface plasmon resonance effect, the GNRs could strongly enhance the scattering signal of indigo dyes, with the lowest detectable concentration of up to 10−8 M and with an enhancement coefficient of over 2000 times.

The oxidation resistance property of NiCr/Al duplex coating system has been evaluated at 800oC during retention times of 1.5; 3; 4.5 and 6 hours. After the oxidation test, SEM-EDS data indicated the diffusion of aluminum into the NiCr coating, whereas XRD patterns revealed the appearance of new phases (Al3Ni2, Al2O3). In addition, an increase in micro-hardness (up to 518 - 842 Hv) was obtained after oxidation test. These obtained findings indicated that NiCr/Al coating had higher oxidation resistance than NiCr coating.

The formation of carboxymethyl starch (CMS) nanogel with 50 nm less particle size was carried out through a radiation crosslinked process on the electron beam (EB) linear accelerator. Changes of intrinsic viscosities and weight averaged molecular weight in the CMS concentration, which ranged from 3 to 10 mg ml−1 in absorbed doses were investigated. There were some new peaks in the 1H NMR spectra of CMS nanogel compared with those of CMS polymer. These results were anticipated that the predominant intramolecular crosslinking of dilute CMS aqueous solution occurred while being exposed to a short intense pulse of ionizing radiation. Hydrodynamic radius (often called particle size, Rh) and distribution of particle size were measured by a dynamic light scattering technique. The radiation yield of intermolecular crosslinking of CMS solution was calculated from the expression of Gx ( Charlesby, 1960 , Jung-Chul, 2010 ). The influence of the “size effect” was demonstrated by testing culture of Lactobacillus bacteria on MRS agar culture medium containing CMS nanogel and polymer. Results showed that the number of Lactobacillus bacteria growing on nanogel containing culture medium is about 170 cfu/ml and on polymer containing culture medium is only 6 cfu/ml.

On the surfaces of GaN-based light-emitting diodes (LEDs) having an n-side-up vertical electrode structure formed by the laser lift-off, various shapes of photoresist-patterned surface textures were formed by inductively coupled plasma etching and their effect on the light emission efficiencies was investigated. By the formation of various shapes of surface textures, the light output efficiency was increased from 37% to 45% compared to that without surface textures. The increase of light output efficiency was related to the increase of sidewall scattering, the decrease of reflected loss, and the decrease of cavity wall effect that occurs for the vertical LEDs by the increase of sidewall surface area.

The good electrical and morphological characteristics of TiO2 nanofibers and the high extinction coefficient of CH3NH3PbI3 perovskite are combined to obtain a solar cell with a power conversion efficiency of 9.8%. The increase of the film thickness dramatically diminishes the performance due to the reduction in porosity of the TiO2 nanofiber framework. The optimum device ([similar]413 nm film thickness) is compared to a planar device, where the latter produces higher Voc but lower Jsc, and consequently lower efficiency at all measured light intensities. Accepted version