In this study, mercury iodide (HgI2) nanoparticles (NPs) were synthesized by pulsed laser ablation in ethanol at laser fluences of 22.9, 33.1, and 43.3 J/cm2. The effect of laser fluence on the structural and optical properties of HgI2 NPs was studied. X-ray diffraction findings reveal that all synthesized HgI2 samples were polycrystalline in nature with orthorhombic structure. Absorption peak was appeared at 474 nm and the optical energy gap of HgI2 NPs decreases from 2.13 to 2.05 eV as laser fluence increased from 22.9 to 43.3 J/cm2. Zeta potential (ZP) results confirm that the nanoparticles synthesized at 22.9 and 33.1 J/cm2 have high degree of stability. Fluorescence measurements show the presence of several emission bands. Raman spectra of HgI2 NPs show the presence of six vibration modes centered at 15, 29, 37, 44, 51, and 70 cm?1. Fourier transform infrared (FT-IR) results show the presence of two bonds, namely, C–O and Hg-I. Transmission Electron Microscope (TEM) results showed that the formation of spherical nanoparticles for sample prepared at 22.9 J/cm2, 25–75 nm in size. While the nanoparticles synthesized with 33.1 and 43.3 J/cm2 exhibit nanorods and nanotubes morphologies, respectively. The dark I–V characteristics of β-HgI2 NPs/Si heterojunction photodetectors show rectification properties and the junction quality depends on the laser fluence and the best junction characteristics was obtained for heterojunction prepared at 33.1 J/cm2. The white light photosensitivity of the HgI2/p-Si photodetectors was measured at reverse bias under different intensities. The maximum responsivity reached was 3.39A/W at 450 nm for photodetector prepared at 33.1 J/cm2.
Recently, the application of metal oxides such as Fe3O4 nanoparticles have wide interest for environmental remediation and treatment of wastewater especially contaminated with azo dyes owing to its high degradation efficacy and low toxicity. The recovery of magnetic catalysts without losing their efficiency is an essential feature in the catalytic applications. The aim of this article is to investigate and synthesis of magnetically retrievable Fe3O4/polyvinylpyrrolidone/polystyrene (Fe3O4/PVP/PS) nanocomposite for the catalytic degradation of azo dye acid red 18 (AR18). Fe3O4/PVP/PS nanocomposite was prepared in two steps. Firstly, PVP/PS microsphere was synthesized by γ-irradiation polymerization of styrene in presence of PVP solution. Secondly, deposition of Fe3O4 nanoparticles on PVP/PS microsphere was achieved by the alkaline co-precipitation of Fe3+/Fe2+ ions. The chemical structural and morphological properties of PVP/PS microsphere and Fe3O4/PVP/PS nanocomposite were examined by XRD, TEM, DLS, FTIR, EDX and VSM techniques. TEM results showed homogeneous morphology, spherical shaped and well-dispersed Fe3O4 nanoparticles with average particle size of 26 nm around PVP/PS microspheres. The VSM measurements of Fe3O4/PVP/PS nanocomposite exhibit excellent magnetic response of saturation magnetization 26.38 emu/g which is suitable in magnetic separation. The effect of the synthesized Fe3O4/PVP/PS nanocomposite on the catalytic degradation of AR18 in presence of hydrogen peroxide (H2O2) as a heterogeneous Fenton-like catalyst was examined. The catalyst Fe3O4/PVP/PS/H2O2 played basic role in promoting the oxidation degradation efficiency of AR18 of initial concentration 50 mg/L to 94.4% in 45 min with excellent recyclability till the sixth cycles under the best conditions of pH 3, 2% v/v H2O2 and 0.3 g catalyst amount. Furthermore, the Fe3O4/PVP/PS/H2O2 hybrid catalyst system supports high capability for oxidation degradation of mixture of different dyes. The Fe3O4/PVP/PS nanocomposite catalyst had high magnetic and recyclability characters which are acceptable for the treatment of wastewater contaminated by various dyes pollutants.
This work deals with the synthesis of ZnFe2O4 NPs and studies the effect of addition on the physical properties PVDF/PVC blend. XRD affirmed the formation of ZnFe2O4 NPs and HRTEM shows that the size of the prepared ZnFe2O4 NPs ranged from 20 to 55 nm. The effect of ZnFe2O4 on the behavior of PVDF/PVC was studied through XRD, ATR-FTIR, FESEM and UV–Visible spectroscopy. XRD revealed that the addition of ZnFe2O4 NPs enhanced the crystallinity of PVDF/PVC blend system and also confirmed the incorporation of ZnFe2O4 NPs by appearing a diffraction peak at 2θ equals 35°. ATR-FTIR affirmed the interaction between blend sample and ZnFe2O4 NPs by appearing new bands 554 cm?1 and 421 cm?1 which are corresponded to ZnFe2O4 NPs functional group with appearing a new band at 603 cm?1. FESEM showed that the addition of ZnFe2O4 to PVDF/PVC blend improved surface properties, for example, roughness average has been increased from 319 to 414 nm while maximum height increased from 260 to 473 nm for PVDF/PVC and PVDF/PVC/10% ZnFe2O4, respectively. Optical properties and band gap calculations revealed that addition of ZnFe2O4 NPs changes the structure of polyblend samples which results due to the formation of localized states. The removal efficiency of Cd (II) by using PVDF/PVC/10% ZnFe2O4 reached about 50% at pH 6 after 60 min. the absorption mechanism as well as kinetics isotherm have been studied. It is found that adsorption of Cd (II) occurred through the Langmuir mechanism and fellow pseudo-second order isotherm.
The aim of this study was to investigate the association of single nucleotide polymorphisms (SNPs) and haplotypes of potassium voltage-gated channel, KQT-like subfamily, member 1 (KCNQ1) with type 2 diabetes (T2D) in Malaysian Chinese subjects. The KCNQ1 SNPs rs2237892, rs2283228 and rs2237895 were genotyped in 300 T2D patients and 230 control subjects without diabetes and metabolic syndrome. Two logistic regression models of analysis were applied, the first adjusted for age and gender while the second adjusted for age, gender and body mass index. The additive genetic analysis showed that adjusting for body mass index (BMI) even strengthened association of rs2237892, rs2283228 and rs2237895 with T2D (OR = 2.0, P = 5.1 × 10(-5); OR = 1.9, P = 5.2 × 10(-5); OR = 1.9, P = 7.8 × 10(-5), respectively). The haplotype TCA containing the allele of rs2237892 (T), rs2283228 (C) and rs2237895 (A) was highly protective against T2D (Second model; OR = 0.17, P = 3.7 × 10(-11)). The KCNQ1 rs2237892 (TT), and the protective haplotype (TCA) were associated with higher beta-cell function (HOMA-B) in normal subjects (P = 0.0002; 0.014, respectively). This study found that KCNQ1 SNPs was associated with T2D susceptibility in Malaysian Chinese subjects. In addition, certain KCNQ1 haplotypes were strongly associated with T2D. 相似文献
Pretreated wool/acrylic fibre was obtained by a facile amidoximation process. Fibre characterisation (nitrogen content, tensile strength, shrinkage, infrared spectra and X‐ray diffraction) proved the success of the pretreatment. Union dyeing of wool/acrylic fabrics with acid and reactive dyes, namely CI Acid Red 40, CI Acid Blue 25, CI Reactive Red 194 and CI Reactive Blue 25, was obtained using a one‐bath dyeing process. Different factors that may affect the dyeability of the blend fibre, such as dyebath pH, liquor ratio, temperature, time and dye concentration, were evaluated with respect to the dye exhaustion, fixation, colour strength, levelling and fastness properties. Excellent to good fastness was obtained for all samples, irrespective of the dye used. The result of the investigation offers a new viable method for union dyeing of wool/acrylic fibres in a one‐dyebath process. 相似文献
The aim of this study was to investigate the effect of pore-forming hydrophilic additives on the porous asymmetric polyvinylideneflouride (PVDF) ultrafiltration (UF) membrane morphology and transport properties for refinery produced wastewater treatment. PVDF ultrafiltration membranes were prepared via a phase inversion method by dispersing lithium chloride monohydrate (LiCl·H2O) and titanium dioxide (TiO2) nanoparticles in the spinning dope. The morphological and performance tests were conducted on PVDF ultrafiltration membranes prepared from a different additive content. The top surface and cross-sectional area of the membranes were observed using a field emission scanning electron microscope (FESEM) and energy dispersive X-ray (EDX) analysis. The surface wettability of porous membranes was determined by the measurement of a contact angle. The mean pore size and surface porosity were calculated based on the permeate flux. The results indicated that the PVDF/LiCl/TiO2 membranes with lower TiO2 nanoparticles loading possessed smaller mean pore size, more apertures inside the membrane with enhanced membrane hydrophilicity. LiCl·H2O has been employed particularly to reduce the thermodynamic miscibility of dope which resulted in increasing the rate of liquid–liquid demixing process. The maximum flux and rejection of refinery wastewater using PVDF ultrafiltration membrane achieved were 82.50 L/m2 h and 98.83% respectively at 1.95 wt.% TiO2 concentration. 相似文献
In this study, polysulfone (PSF) hollow fiber membranes with enhanced performance for humic acid removal were prepared from a dope solution containing PSF/DMAc/PVP/TiO2. The main reason for adding titanium oxide during dope solution preparation was to enhance the antifouling properties of membranes prepared. In the spinning process, air gap distance was varied in order to produce different properties of the hollow fiber membranes. Characterizations were conducted to determine membrane properties such as pure water flux, molecular weight cut off (MWCO), humic acid (HA) rejection and resistance to fouling tendency. The results indicated that the pure water flux and MWCO of membranes increased with an increase in air gap distance while HA retention decreased significantly with increasing air gap. Due to this, it is found that the PSF/TiO2 membrane spun at zero air gap was the best amongst the membranes produced and demonstrated > 90% HA rejection. Analytical results from FESEM and AFM also provided supporting evidence to the experimental results obtained. Based on the anti-fouling performance investigation, it was found that membranes with the addition of TiO2 were excellent in mitigating fouling particularly in reducing the fouling resistances due to concentration polarization, cake layer formation and absorption. 相似文献
In this study, DS5 DK type nanofiltration membranes were tested to recycle the reactive dye bath effluents. Reactive black 5 (RB5), reactive orange 16 (RO16), reactive blue 19 (RB19) and NaCl were used in the experiments to prepare the synthetic dye and salt mixtures. Effects of feed concentration, pressure and cross flow velocity on the permeate flux and color removal were investigated. Permeate flux increased with increasing pressure for all NaCl solutions. Dye concentration had a significant effect on flux values. Under the fixed NaCl concentrations the flux decreased with increasing dye concentrations. Dye rejections greater than 99% were achieved. Permeate was almost colorless. A gel layer formed by the rejected dye on membrane surface operates as a resistance to the permeation of dyes due to complete rejection of high molecule weight dyes, especially for the low salt concentrations. The presence of salt concentration has an interesting effect on color removal. Color removal decreased with increasing salt concentration. Cross flow velocities had also a significant effect on flux values. The dye formed agglomerates at high NaCl concentrations. High cross flow velocities decreased this effect. 相似文献