Abstract: Sub-wavelength antireflective structures are fabricated by using a soft roll-to-plate nanoimprinting lithography. The proposed methodology employs a modified polyurethane acrylate as a flexible mold due to its high resolution, chemical inertness, polymerization characteristics, and its non-wetting, very low surface energy. Large-format (750mm x 750mm) plastic film with the recombined double-sided sub-wavelength structures is obtained, which has fascinating broadband antireflective effect. The roll-to-plate ultra-voilet nanoimprinting provides the capability of patterning sub-100nm structures, a short period of process time and allows the fabrication of sub-wavelength structure on a large number of flexible or rigid substrates in an economic fashion.
Abstract: A one-pot synthetic method for non-toxic Ni3S2 quantum dots (QDs) was proposed by using commercial available nickel acetate as the precursor. The obtained quantum dots were characterized by photoluminescence spectroscopic, powder X-ray diffraction, and transmission electron microscopy. The maximum fluorescence emission peak of Ni3N2 QDs is at 469 nm under the 365 nm ultraviolet light irradiation in PL Spectra. The TEM data reveals that the predominance of particles with a polyhedron structure and the range of average particle size are between 5 and 11 nm.
Abstract: Palladium nanoparticles (Pd NPs) are the most widely used functional materials for a variety of catalytic reactions. In this work, we synthesized the size-controlled Pd NPs using amyloid fibrils as bio-templates. First, 1mg/ml insulin peptides were incubated at 80°Cfor 3 days to form protein fibrils. Then, layer-by-layer technology was used to prepare Pd-insulin fibrils multilayer film as catalyst by alternatively depositing insulin fibrils and palladium chloride which has been aged at several different temperatures for two days. The chemical compositions of Pd-insulin film were also characterized by X-ray photoelectron spectroscopy (XPS). The Pd-insulin film demonstrated high isolated yield in promoting Suzuki cross-coupling reaction. In addition, the effect of Pd NPs size on the catalytic activity was also discussed.
Abstract: Pd/SiO2 organic-inorganic hybrid materials were prepared by adding PdCl2 into methyl-modified silica sol. The Pd/SiO2 hybrid materials were characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The effects of calcination temperature and Pd-doping on the phase transition of Pd element and the thermal stability of CH3 group in the Pd/SiO2 organic-inorganic hybrid materials were investigated. The results showed that the reduced metallic Pd0 exhibits good thermal stability under H2 atmosphere in the calcination process. Pd element in noncalcined Pd/SiO2 materials exists in PdCl2 form, calcination at 200 °C in a H2 atmosphere produces some metallic Pd0 and calcinations at 350 °C results in the complete transformation of Pd2+ to metallic Pd0. With the increase of calcination temperature, the Pd0 particle sizes increase and the hydrophobic Si−CH3 bands decrease in intensity. As the calcination temperature is greater than or equal to 350 °C, the loading of metallic Pd0 nearly has no influence on the chemical structure but, with the increase of Pd content, the formed Pd0 particle size increases. To keep the hydrophobicity of Pd/SiO2 membrane materials, the optimal calcination temperature is about 350 °C under H2 atmosphere.
Abstract: The aim of the present study was to prepare nanostructured lipid carriers (NLCs) and nanoemulsions (NEs) with different lipid compositions for delivery of phenylethyl resorcinol (PR) and investigate the effect of the lipid composition on the performance of lipid-based nanocarriers. The optimized nanocarriers were evaluated by photon correlation spectroscopy (PCS), Laser diffraction (LD), encapsulation efficiency, in vitro release and in vitro penetration studies. The particle sizes of all the freshly prepared nanocarriers were in the range of 70-200 nm. PR-NLCs showed higher encapsulation efficiency than PR-NEs. A controlled-release behavior of PR-NLCs was observed in in vitro release studies. In vitro penetration studies demonstrated nanocarriers with smaller particles possessed higher penetration ability. According to the present study, nanocarriers with small particle sizes can be considered as a potential drug delivery system for typical application.
Abstract: Surface-enhanced Raman spectroscopy (SERS), having the advantages of high detection sensibility and fast analysis speed, meets the requirements of the detection of sulfur content in simulated gasoline. The optimal preparation conditions of nano-silver substrate which played an important role in enhancing Raman signals was mainly studyed in this paper. Potentiostatic oxidation-reduction method was selected to prepare roughened silver electrode as the nano-substrate. The influences of electrolyte, potential and reduction time were investigated. It shows that bromide ion in electrolytes and nearly balance potential could lead to much better result that relative area intensification factor is equal to 81746.
Abstract: In the hydrothermal system, In (OH)3 nanobelts were obtained. After heat-treatment at 300 °C, In2O3 single crystals nanobelts were produced, which can keep the morphologies and sizes of precursors. The room temperature PL spectra of as-prepared In2O3 nanobelts are also detected. PL peaks of In2O3 nanobelts mainly focused at 458 nm (blue).
Abstract: A series of CeO2-SiO2 composite nanoparticles with different cerium and silica (Ce/Si) mole ratios were synthesized via a coprecipitation method using cerium nitrate, tetraethylorthosilicate and ammonia as raw materials. X-ray diffraction (XRD), fourier transform infrared spectrology (FT-IR), thermogravimetry-differential scanning calorimetry (TG/DSC), transmission electron microscopy (TEM) and energy dispersive analysis of X-ray (EDAX) were used to characterize the CeO2-SiO2 nanoparticles. With the increase of CeO2 content, the crystal of CeO2 grew up gradually and the average crystallite size of the CeO2 decreased. There are Ce-O-Si bonds in the CeO2-SiO2 composite nanoparticles. The particle size of the CeO2-SiO2 composite nanoparticles with a Ce/Si mole ratio of 1 is about 20–30 nm. The dispersion stability of the CeO2-SiO2 composite nanoparticles with a Ce/Si mole ratio of 1 was studied. It was found that cationic and nonionic surfactant could obviously affect the dispersion stability of suspension, but not the anion surfactant. A suspension with CeO2-SiO2 composite nanoparticles at 0.1 wt% was added in 0.1 g/L cationic surfactant CTAB, and its pH value was adjusted within the range of 10-10.5. In this condition, the stable suspension without sedimentation time was successfully obtained.
Abstract: SnO2 nanocrystalline thin films (NCTFs) with high quality and low infrared emissivity were synthesized through a simple hydrothermal process designed by orthogonal design theory. The microstructure, morphology, photoluminescence (PL) property and the infrared emissivity (IRE) property of as-prepared products were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), fluorescence spectrophotometer, and infrared spectroradio meter (ISM) respectively. The results show that two emission peaks are observed in PL spectra, which can be deconvoluted by Gaussian profile fitting into four emission peaks centered at about 380, 420, 460 and 520 nm respectively. The influences of crystallinity, concentration of particles and resistivity on IRE were systematically investigated, revealing that the better crystallinity, higher particle density and better conductivity are favorable for lowering IRE.