全氟羧酸离子交换膜内金属硫化物超微粒的制备及其性能

首次以全氟羧酸离子交换膜为生成介质制备出纳米尺寸Ｚｎｓ。ＣｄＳ及Ｐｂｓ超微粒。ＺｎＳ为非晶态，而ＣｄＳ，ＰｂＳ超微粒分别为六方和立方晶型；通过改变膜的含水量得到不同尺寸的ＰｂＳ超微粒，并且随颗粒尺寸减小，其三阶光学非线性极化率ｘ＾（３）增大。     

纳米塑料包装材料的开发应用

一、纳米塑料有着优异的性能 纳米塑料是无机纳米粒子（硅酸盐、碳酸钙、SiO2、TiO2、SiC、Al2O3、云母、石英粉等）以纳米级尺寸（一般为1～100nm）均匀分散在塑料母体树脂中的复合材料,也被称为聚合物基纳米复合材料。根据母体树脂不同可分类为纳米尼龙、纳米聚烯烃、纳米聚酯、纳米聚甲醛等。由于纳米粒子尺寸和彼此间距离非常近,     

全氟羧酸离子交换膜内硫化铅超微粒的光学非线性研究

在全氟羧酸阳离子交换膜中制备出不同颗粒尺寸的ＰｂＳ超微粒，并由吸收光谱及电镜测量结果获得证实。用飞秒激光脉冲对ＰｂＳ超微粒复合膜进行了时间分辨光克尔效应测定，发现ＰｂＳ超微粒具有三阶光学非线性，三阶光学非线性极化率Ｘ（３）约为１０（－１２）ｅｓｕ，光克尔效应响应时间小于１６５ｆｓ，并且发现ＰｂＳ超微粒的光学非线性随着超微粒颗粒尺寸的减小而增大，显示出量子限域效应对于超微粒子光学非线性的贡献。     

全氟羧酸离子交换膜内化铅超微粒的光学非线性研究

在全氟羧酸阳离子交换膜中制备出不同颗粒尺寸的ＰｂＳ超微粒，并由吸收光谱及电镜测量结果获得证实。用习秒激光脉冲对ＰｂＳ超微粒复合膜进行了分辨光克尔效应测定，发现ＰｂＳ超微粒具有三阶光学非线性，三阶光学非线性极化率Ｘ＾（３）约为１０＾－１２ｅｓｕ，光克尔效应时间小于１６５ｆｓ，并且发现ＰｂＳ超微粒的光学非线性随着超微粒颗粒尺寸的减小而增大，显示出量子限域效应对于超微粒子光学非线性的贡献。     

溶胶－凝胶法制备Pb（Zr，Ti）O_3玻璃陶瓷过程中的结构变化

本文介绍溶胶－凝胶法制备均匀ＰｂＺｒ－Ｔｉ－Ｂ－Ｓｉ凝胶玻璃，并通过适当热处理在凝胶玻璃中原位生长Ｐｂ（Ｚｒ；Ｔｉ）Ｏ３微晶的新工艺·利用ＩＲ谱考察了凝胶玻璃中的元素键合结构随温度的变化．结合热分析和ＸＲＤ；ＳＥＭ技术，研究了Ｐｂ（Ｚｒ，Ｔｉ）Ｏ３微晶在凝胶玻璃中的生长过程及该材料的结构特点．发现Ｐｂ２（Ｚｒ，Ｔｉ）２Ｏ６＋ｘ立方焦绿石介稳过渡相的纳米微晶首先出现于该体系中，并在更高的温度下先后完全转变成三方和四方Ｐｂ（Ｚｒ，Ｔｉ）Ｏ３钙钛矿相．电子显微观察结果表明，该工艺制备的Ｐｈ（Ｚｒ；Ｔｉ）Ｏ３玻璃陶瓷具有均匀的细晶结构．     

纳米塑料包装材料的开发应用

一、纳米塑料有着优异的性能 纳米塑料是无机纳米粒子（硅酸盐、碳酸钙、SiO2,TiO2、SiC、Al2O3云母、石英粉等）以纳米级尺寸（一般为1～100nm）均匀分散在塑料母体树脂中的复合材料,也被称为聚合物基纳米复合材料。根据母体树脂不同可分类为纳米尼龙、纳米聚烯烃、纳米聚酯、纳米聚甲醛等。由于纳米粒子尺寸和彼此间距离非常近,具有独特的量子尺寸效应、表面效应、界面效应、体积效应、宏观隧道效应、小尺寸效应和超塑性,使纳米塑料具有独特的物理力学性能,已成为复合材料发展的最尖端产品之一。     

无机纳米粒子增韧改性不饱和聚酯树脂的研究进展

综述了近年来各种无机纳米粒子对不饱和聚酯树脂( UPR)增韧改性的研究现状.重点介绍了无机纳米粒子用量、粒子尺寸、表面改性处理等因素对改性UPR性能的影响.阐述了纳米粒子增韧增强UPR的机理.指出无机纳米粒子改性UPR中存在的问题和可能的发展方向.     

纳米塑料包装材料的开发应用

纳米塑料是无机纳米粒子(硅酸盐、碳酸钙、SiO2、TiO2、SiC、Al2O3、云母、石英粉等)以纳米级尺寸(一般为1～100nm)均匀分散在塑料母体树脂中的复合材料，也被称为聚合物基纳米复合材料。根据母体树脂不同可分类为纳米尼龙、纳米聚烯烃、纳米聚酯、纳米聚甲醛等。由于纳米粒子尺寸和彼此间距离非常近，具有独特的量子尺寸效应、表面效应、界面效应、体积效应、宏观隧道效应、小尺寸效应和超塑性，使纳米塑料具有独特的物理力学性能，已成为复合材料发展的最尖端产品之一。     

改性纳米粒子增强三元乙丙橡胶研究进展

综述了近年来国内外改性纳米粒子/EPDM纳米复合材料的研究进展,着重介绍了炭黑、白炭黑、碳酸钙、二氧化钛和纳米氢氧化物等几种改性纳米粉体增强EPDM进展,阐述了层状硅酸盐/EPDM的插层复合技术,展望了EP-DM纳米复合材料的应用前景.     

纳米氧化亚镍/玻璃微球复合粒子的制备及表征

通过均匀沉淀法,将NiO 复合于玻璃微球表面,制备了纳米NiO/玻璃微球复合粒子。X射线衍射(XRD)、扫描电镜(SEM) 结果表明,经过共沉积后,在玻璃微球表面生成一层具有面心结构的NiO 层,晶粒尺寸大约为14 nm,这些纳米NiO粒子以丝状胶连的形式附着于玻璃微球表面形成镀层。能谱分析(EDS) 结果显示,纳米NiO粒子在玻璃微球表面形成了分布均匀的镀层。傅立叶变换红外光谱仪(FTIR) 表明,所制得的纳米NiO/玻璃微球复合粒子在近红外和远红外波段都表现出良好的红外吸收特性。      

Surface synthesis of PbS nanoparticles on silica spheres by a sonochemical approach

A simple sonochemical approach for the preparation of PbS nanoparticles homogeneously coated on sub-micrometer silica spheres has been described. The transmission electron microscopy and scanning electron microscopy images show that the PbS nanoparticles with size of 30 nm were coated on the silica spheres, without any free nanoparticles. X-ray diffraction reveals that the PbS nanoparticles are of cubic rock-salt structure. Moreover, by dissolving the silica cores with a diluted hydrofluoric acid solution, stable PbS hollow structures were obtained. It is considered that the sonochemical process in which triethanolamine acted as complex agent played an important role for the homogenouse coating of PbS nanoparticles on silica spheres.     

树枝状与球状PbS纳米结构的组装合成及其形成机理研究

以醋酸铅为铅源,硫代乙酰胺为硫源,在表面活性剂SDS单独作用和表面活性剂SDS和CTAB共同作用下可选择性地组装合成出颗粒以相同晶面粘连组装成的单晶树枝状PbS纳米结构和颗粒以不相同晶面粘连组装成的多晶球状PbS纳米结构,而且提高反应物浓度能起到调节树枝状和球状PbS纳米结构尺寸的作用.对树枝状和球状PbS纳米结构的形成机理进行了初探,发现SDS单独作用时其烷基链起到的软模板作用有利于PbS小颗粒组装成树枝状的PbS纳米结构.当反应溶液中再加入适量的CTAB时,它在溶液中形成微胶束起到了软模板作用,迫使颗粒粘连组装成球状PbS纳米结构,有效地限制树枝状结构的生长.     

Synthesis and properties of poly(methyl methacrylate-2-acrylamido-2-methylpropane sulfonic acid)/PbS hybrid composite

The synthesis of a new hybrid composite based on PbS nanoparticles and poly(methyl methacrylate-2-acrylamido-2-methylpropane sulfonic acid) [P(MMA-AMPSA)] copolymer is reported. The chemical synthesis consists in two steps: (i) a surfactant-free emulsion copolymerization between methyl methacrylate and 2-acrylamido-2-methylpropane sulfonic acid and (ii) the generation of PbS particles in the presence of the P(MMA-AMPSA) latex, from the reaction between lead nitrate and thiourea. The composite was studied by scanning electron microscopy (SEM), X-ray diffraction, FTIR spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The microstructure observed using SEM proves that the PbS nanoparticles are well dispersed in the copolymer matrix. The X-ray diffraction measurements demonstrate that the PbS nanoparticles have a cubic rock salt structure. It was also found that the inorganic semiconductor nanoparticles improve the thermal stability of the copolymer matrix.     

A chemical synthesized Al-doped PbS nanoparticles hybrid composite for optical and electrical response

Structural, morphological, optical and electrical investigations of pure and Al-doped lead sulfide (PbS) nanoparticles hybrid composite was synthesized by simple chemical route. The detail analysis of the nanoparticle morphology of hybrid composites through optical investigation, phase purity and crystalline size had been characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), ultraviolet spectroscopy (UV), photoluminescence (PL). The lower angle XRD results confirmed that the phase purity and average crystalline size of the pure and Al doped PbS nanoparticles were determined by using the Debye–Scherrer’s formula. The average grain sizes of the pure and the Al-doped PbS nanoparticles were calculated and found to be 22 and 16 nm respectively. Surface morphology analysis was carried out by using SEM and TEM analysis. The surface morphology of pure and Al doped PbS nanoparticles is without any pinholes or cracks and hence they appear to be densely packed with spherical shaped grains. The optical properties of pure and Al-doped PbS analyzed using UV–Vis. absorption spectroscopy and Photoluminiscence (PL) spectra. The band gap values for the pure and the Al-doped PbS nanoparticles were found to be 1.94 and 2.04 eV respectively. The dielectric properties of the Al-doped PbS nanoparticle composites typical response e.g. dielectric constant, dielectric loss, and AC conductivity were analyzed at various frequencies and temperatures.     

Synthesis of CuS and PbS nanocrystals on the basis of PE/NBR polymer/elastomeric composites for their applications

In this research work, we have presented a chemical method to elaborate the PbS, CuS nanocrystals embedded in a polymer composites matrix. We have used polyethylene and nitrile butadiene rubber PE/NBR as a support for synthesis of lead sulfide (PbS) and copper sulfide (CuS) nanocrystals. The size control and morphology of these (PbS and CuS) nanoparticles have been applied by the method of “layer by layer”. The obtained nanoparticles were characterized by X-ray diffraction (XRD), UV–Vis and Atomic Force Microscopy (AFM). UV–Vis spectroscopy was used to determine simple optical responses, getting the biggest transmittances of CuS and PbS nanoparticles. Measured size of CuS nanoparticles is approximately 5.5–90 nm in different dose. X-ray diffraction (XRD) study confirmed the formation of cubic phase of PbS nanocrystals into the composite matrix. The size of PbS was estimated ∼9 nm. The surface morphology and crystallite sizes were determined by Atomic Force Microscopy measurements.     

Preparation and room temperature photoluminescence characterization of PbS/Si(100) thin films

PbS nanoparticles and smooth nanocrystalline thin films (nc-PbS) were prepared by chemical precipitation from aqueous solutions. Polyethylene oxide and isopropyl alcohol were used as additives in the aqueous solution, which results in the enhancement of the blue luminescence of PbS thin films. The introduction of isopropyl reduced the grain size and increases the optical gap of the PbS particles. The size of PbS particles was estimated to be ~ 3.5 nm. The broad emission bands exhibited were composed by a multiple overlapping peaks. The photoluminescence (PL) intensity was significantly influenced by the excitation wavelength. Indeed, intense blue luminescence was obtained under 230 nm compared to that obtained under 325 nm excitation wavelength. The PL emission from PbS nanoparticles was less intense than the luminescence of PbS thin films. The high PL intensity of the thin films was attributed to the lower density of defects introduced in the thin films during the chemical bath deposition growth process compared the defects density of PbS powder.     

Stability and recrystallization of PbS nanoparticles

The recrystallization and thermal stability of nanocrystalline lead sulfide have been studied by X-ray diffraction and scanning electron microscopy. PbS nanoparticles ranging in size from 10 to 20 nm were prepared by chemical precipitation from aqueous solutions. To assess the thermal stability of the size of PbS nanoparticles, the nanocrystalline powders were annealed in air or under dynamic vacuum (10⁻³ Pa) at a temperature varied from 433 to 930 K in 50-K steps. Annealing at temperatures of up to 700 K increases the particle size only slightly but relieves the lattice strain, suggesting that the nanocrystalline state of lead sulfide is thermally stable in this temperature range. The temperature range 700–900 K, where the particle size increases by a factor of 5–10, corresponds to the secondary recrystallization of nanocrystalline PbS. The temperature 700 K is half the melting temperature of macrocrystalline PbS, indicating that PbS nanoparticles have higher thermal stability in comparison with other nanomaterials.     

Influence of pluronic P123 in modifying the morphological and optical properties of PbS nanocomposite

Pluronic (P123) capped lead sulphide (PbS) nanoparticles were synthesized for the first time by simple wet chemical method. Series of experiments were conducted by changing the concentration of P123 to establish the most suitable conditions for obtaining different morphologies of PbS nanoparticles. The synthesized product has been characterized by powder X-ray diffraction (XRD), UV–Vis spectrophotometry, scanning electron microscopy (SEM), transmission electron Microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and photoluminescence studies. The particle size observed from XRD analysis is around 44–3 nm. Significant “blue shift” from bulk material was observed on the PbS nanoparticles using UV–Vis spectra. A sevenfold increase in photoluminescence intensity has been observed from PbS nanoparticles after surface passivation by P123 agent.     

Coating of TiO2 nanoparticles with PbS thin films and preparation of PbS nanoparticles using a one-pot sonochemical reaction under the multibubble sonoluminescence conditions

Preparations of PbS-coated titanium dioxide (TiO₂) and lead sulfide (PbS) nanoparticles under ultrasonic field at the multibubble sonoluminescence (MBSL) conditions were tested in water solutions. Under the optimal MBSL conditions (20 kHz and 220 W power input), PbS nanoparticles (diameter = 40-50 nm) were prepared by treating lead nitrate and thioacetamide for 20 min in water solutions. The size of PbS nanoparticles was found to be easily increased to about 90 nm in diameter by increasing the reactant concentration twice. A similar sonochemical reaction with TiO₂ nanoparticles (about 20-30 nm in diameter) gave rise to PbS-coated TiO₂ nanoparticles with a core/shell structure. The PbS thin film coating was quite uniform and the average coating depth of PbS on the TiO₂ nanoparticles was about 2-3 nm under the described conditions. It is interesting to note that the coating depth was found to be controlled to 2-10 nm range by increasing the amounts of reactants for Pb and S twice with a sonication time of 30 min.     

Enhanced visible-light-responsive photocatalytic property of CdS and PbS sensitized ZnO nanocomposite photocatalysts

CdS and PbS nanoparticles sensitized ZnO nanorods were synthesized by successive ionic layer adsorption and reaction method. The photocatalytic activity of different structures was evaluated by photocatalytic degeneration yield of methyl orange. Co-sensitization of CdS and PbS nanoparticles on ZnO nanorods showed enhanced photocatalytic activity due to its response at visible light area and the stepwise band gap constructed in ZnO/CdS/PbS nanostructures.