胶体晶体模板法制备ZnS纳米阵列及其物性研究

采用单层聚苯乙烯胶体晶体模板法制备了ZnS二维纳米阵列,通过扫描电子显微镜,X射线衍射仪和光致发光谱仪对ZnS纳米阵列进行表征。结果表明,纳米阵列单元为规则有序的六角排列,其形貌与前驱体的浓度密切相关,制备的ZnS纳米阵列为闪锌矿结构,其紫外发射带位于360nm~400nm。     

ZnS纳米棒的制备及其在聚合物中的应用

用油胺作为溶剂、六水合硝酸锌作为锌源、硫代乙酰胺作为硫源,采用溶剂热法分别在160℃、170℃、180℃下合成了ZnS纳米棒。利用分子荧光光度计、X-射线衍射仪、扫描电子显微镜及能量色散X-射线光谱仪对样品的荧光性能、晶体结构、晶体形貌和元素含量分别进行了表征。结果表明:在170℃下得到直径为200nm六方晶系的ZnS纳米棒荧光性能最好;在激发波长为393nm、发射波长为450nm时,发出明亮的蓝色荧光。将170℃下得到的ZnS纳米棒与环氧树脂(EP)复合,得到ZnS/EP复合薄膜,其荧光效应和发射波长与ZnS纳米棒相比几乎没有改变。     

水热法制备ZnS∶Mn微球及其发光性能研究

采用简单的水热法合成了ZnS∶Mn微球。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外可见吸收光谱(UV-vis)和光致发光谱(PL)等测试手段对其形貌、结构和光学性质进行了分析。结果表明:ZnS∶Mn微球为立方闪锌矿型ZnS结构,且球体由纳米级小微粒组装而成;样品的发光强度随着Mn2+掺杂浓度的增加而增强,当浓度为3%时达到最大值,进而发生了浓度淬灭现象。     

声化学法低温制备α-ZnS纳米粒子及其反应机理

以无水氯化锌,硫代乙酰胺为原料,采用声化学法在低温成功制备了六方纤锌矿相硫化锌(α-ZnS)纳米晶,并对其反应机理作了初步探讨.采用X射线粉末衍射(XRD),示差扫描量热分析(DSC),透射电子显微镜(TEM)以及选区电子衍射分析(SAED)对所制得的纳米粉末进行了表征.结果表明:所制备ZnS为六方纤锌矿结构,粒子尺寸大约在20～30 nm.合成ZnS纳米粒子的形貌接近于球形,选区电子衍射图中三个衍射环分别对应于α-ZnS的(002)、(110)和(112)晶面.在超声辐射下,反应溶液体系首先生成具有六方结构的碱式氯化锌(Zn_5(OH)_8Cl_2·H_2O),为α-ZnS纳米粒子的生长提供了很好的模板.     

铁系硫化物纳米球的简易合成

采用反向胶束软模板法简便地合成了接近单分散的铁系(Fe,Co,Ni)硫化物纳米球,用透射电子显微镜观察到Fe,Co,Ni硫化物纳米球的尺寸分别为40~150 nm,25~75 nm,20~60 nm;用容量分析法测得它们的组成分别是Fe1-xS(x=0.107),CoS2和NiS2;用X射线粉末衍射法表征出它们的结构分别为六方、四方和非晶相,并对其反应和形成机理进行了探讨。     

超声功率对合成ZnS纳米晶的影响

以无水氯化锌、硫代乙酰胺等为起始原料,采用声化学法制备了硫化锌(ZnS)纳米晶。利用X射线衍射、透射电子显微镜对样品进行表征,研究了超声功率对合成产物的粒度及其反应速率的影响。结果表明:所制备ZnS纳米晶粒径在10nm左右,为α-ZnS纤锌矿结构,六方晶系,形貌为球形或近球形。随超声功率增强,ZnS纳米晶晶粒尺寸略有减小。反应时间小于110min时,随超声功率增加,产物的合成速率增大。此后,随着反应时间的延长,合成速率随超声功率的增大出现极值,当反应时间超过110min,反应速率在超声功率为300W处出现极大值。     

应用乳化液膜系统合成CdS与ZnS纳米复合微粒

利用双W/O型乳化液膜系统合成CdS及ZnS纳米微粒,并以W/O/W型乳化液膜系统合成合金型CdxZn1-xS、混合型CdSZnSmixture与核壳型CdScoreZnSshell(或ZnSooreCdSshell)的纳米复合微粒.XRD分析结果显示,CdS会随着界面活性剂Span80浓度增加而使晶型从立方体转变成六方体,而ZnS则没有晶型转变的现象发生.UV/VIS分析光学性质显示CdS及ZnS纳米微粒随着Span80浓度增加,吸收峰的强度均会有变强的趋势.其中CdS吸收波峰会随着Span80浓度增加而往短波长位移,而ZnS吸收波峰的位置不受Span80浓度影响.另外UV/VIS分析结果也显示,CdS纳米微粒的吸收波峰约在459 nm,ZnS纳米微粒的吸收波峰约在321 nm,而Cd0.5Zn0.5S与CdSZnSmixture纳米复合微粒会同时出现CdS与ZnS的吸收波峰.至于CdScoreZnSshell纳米复合微粒则仅会出现外层ZnS的吸收波峰;同样,ZnScoreCdSshell纳米复合微粒只会出现外层CdS的吸收波峰.另外,根据PL(λex=350 nm)的分析结果显示,CdS纳米微粒的放射波峰约在625 nm,ZnS纳米微粒的放射波峰约在537 nm,Cd0.5Zn0.5S纳米复合微粒则在537,572与625 nm三处同时出现明显的放射波峰,而CdSZnSmixture纳米复合微粒则在599 nm处出现不同于CdS与ZnS特征的放射波峰,至于CdScoreZnSshell或ZnScoreCdSshell纳米复合微粒则只会出现外层ZnS或CdS的放射波峰.     

纳米氧化镁制备工艺的研究

以六水硝酸镁和氨水为原料,合成氢氧化镁,研究了制备纳米氧化镁的煅烧及球磨工艺,并用X-射线扫描仪(XRD)、扫描电子显微镜(SEM)进行表征.结果表明:分步煅烧制备的纳米氧化镁比一步煅烧的晶粒尺寸小、团聚少,制备出晶粒尺寸为24.1 nm纳米氧化镁.     

一种新型稀土纳米粒子的可控合成

纳米粒子的粒径与其应用联系紧密,研究发现六方相稀土纳米晶的上转换效率比立方相高,为可控合成一定粒径、六方相的稀土纳米粒子,文章采用溶剂热法,以Na YF4为基质,掺入一定比例在稀土元素Yb及Er,并改变反应温度、稀土掺杂量等影响因素,得出在300℃条件下,合成分散性好的六方相稀土纳米粒子。为稀土纳米粒子的可控合成提供依据,同时对研究稀土纳米材料的应用提供参考。     

Preparation and Luminescent Properties of Mn（1–x）S：Ax/ZnS Nano-Crystallines

采用化学沉淀法合成了Mn（1–x）S：Ax/ZnS（A：Eu,Pr）纳米晶,其结构为闪锌矿结构,平均粒度约4 nm。荧光光谱表明：Mn（1–x）S：Ax/ZnS（A：Eu,Pr）纳米晶除了ZnS本身的缺陷发光和Mn离子的发光外,还出现了新的掺杂离子的发光峰。对应在575 nm和617 nm处发光峰来自于Eu3＋的5D0→7F1和5D0→7F2的跃迁。另外,与纯的Mn（1–x）S：Ax相比,ZnS包覆Mn（1–x）S：Ax后,纳米晶在580nm处的发光性能明显增强。     

Preparation and properties of polythiourethane/ZnS nanocomposites with high refractive index

The inorganic–organic crosslinking polythiourethane/ZnS (PTU/ZnS) nanocomposites with high refractive index and transmittance were successfully prepared. The thiol‐capped ZnS nanoparticles with a diameter of about 5 nm were fabricated into the molecular chains of PTU via the formed covalent bonds between the capped ZnS and the matrix. The investigations demonstrated the ZnS nanoparticles were uniformly dispersed in the PTU matrix even at high contents. The optical studies showed the refractive index of the highly transparent nanocomposite films linearly increased from 1.643 to 1.792 with the increase of the ZnS content. The structure, morphology, and other properties were also characterized by FTIR, NMR, AFM, XRD, DSC, TGA, etc. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Composite polymeric particles with ZnS shells

We report on a preparation of hybrid particles with polymeric cores and ZnS shells. Two types of monodisperse sterically stabilized polystyrene particles with hydroxyl-terminated PEG chains (PS/PEGMA) or β-diketone groups (PS/AAEM) on the surface have been prepared and characterized. Formation of ZnS layer on the surface of submicron particles has been studied by SEM and EDX. Deposition of ZnS on the surface of PS/PEGMA particles is not uniform and leads to formation of ‘raspberry’ morphology with rough surface. It has been found that presence of β-diketone groups on the particle surface leads to formation of well-defined ZnS layers. It has been assumed that such effect is due to the complexation of Zn cations by β-diketone groups leading to nucleation and growth of ZnS crystals on the polymer particle surface. Polymeric particles were completely covered with ZnS if the loaded amount of inorganic material was higher then 40 wt%. The thickness of ZnS layer on the particle surface can be easily varied by changing the ZnS load (in present study maximal thickness of the ZnS shell was 70 nm). It has been found that increase of the ultrasound power leads to considerable increase of the ZnS deposition on the particle surface without strong changes of the particle morphology. Hybrid particles have been investigated with XRD technique and their optical properties were studied by UV-spectroscopy. The colloidal stability of obtained particles was studied by separation analyser. Sedimentation experiments indicate that colloidal stability of obtained composite particles depends strongly on loaded ZnS amount and pH value of the aqueous medium. It has been found that highest sedimentation velocities (or maximum of instability) were determined by ZnS loads, which provide complete coverage of the particle surface. Increase of the ZnS layer thickness led to better stability of hybrid particles in aqueous medium.     

巯基乙酸修饰ZnS纳米颗粒的水相合成及表征

以巯基乙酸(HSCH2COOH, RSH)为表面修饰剂,采用水相合成法制备了表面修饰巯基乙酸的ZnS纳米颗粒. 采用透射电子显微镜、粒度分布、X射线衍射和红外光谱等对ZnS纳米颗粒进行了表征,并对ZnS纳米粒子的制备条件进行了详细的考察. 结果表明,水相合成法的最佳制备条件为：反应pH值8.0, Zn2+:S2-:RSH(摩尔浓度比)为1:1.34:2. 在最佳条件下可制备粒径小(11 nm)且粒度分布窄、分散性好的ZnS纳米粒子,其晶体属面心立方b-闪锌矿结构.     

ZnS-opal与反opal结构ZnS光子晶体的组装

以单分散SiO2微球为基元,在75%～80%湿度、30～45 ℃恒温密闭烘箱中垂直快速组装opal模板;以Zn(NO3)2（0.035 mol/L）、TAA乙醇溶液（0.05 mol/L）为前体,通过溶剂热法充填形成ZnS-opal复合光子晶体;ZnS-opal复合光子晶体在2%～5%的HF溶液中浸泡4～5 h后卸载模板,制得反opal结构ZnS基光子晶体;采用XRD、SEM、ＵV-Vis测试手段对反opal结构ZnS基光子晶体形貌、物相和光学性能进行了表征。结果表明：溶剂热法多次充填可使ZnS纳米晶在模板密堆积形成的空隙中均匀成核;经过酸处理的ZnS-opal中SiO2微球溶解、坍塌,形成蜂窝状三维有序介孔和反opal结构ZnS基光子晶体;相同粒径SiO2微球组装的opal模板、ZnS-opal以及反opal结构ZnS光子晶体均表现出光子带隙特性,但反opal结构ZnS光子晶体带隙位置相比前两者发生了蓝移。     

Hot pressing sintering of zinc sulfide microsphere decorated with nanorods synthesized by the simple refluxing method

A zinc sulfide microsphere decorated with nanorods was synthesized using the refluxing method. Then, the as-obtained ZnS nanostructures were consolidated via the hot pressing (HP) technique. X-ray diffraction, Fourier transforms infrared spectroscopy, high-resolution transmission electron microscopy, field emission scanning electron microscopy (FESEM), diffuse reflectance spectroscopy, and X-ray mapping analyzes were used to characterize the ZnS sample. The effects of various factors such as pH, temperature, and reaction time were investigated on the morphology and particle size of ZnS nanostructures. The formation of sphalerite phase of ZnS nanoparticles was confirmed by the XRD analysis. FESEM also revealed that ZnS nanostructures with the molar ratio 1:1.3 (zinc: sulfur) had a spherical morphology decorated with sulfur nanorods. The ZnS nanostructures were consolidated by hot pressing technique at 860 °C for 2h under vacuum atmosphere. XRD analysis indicated that the sintered ceramic had a sphalerite phase. FESEM study demonstrated that ZnS ceramic had a grain size diameter within the range of 1–3 μm.     

Synthesis and characterization of ZnS/hyperbranched polyester nanocomposite and its optical properties

The ZnS/hyperbranched polyester nanocomposite with higher refractive index was prepared by incorporating the acrylated 2-(2-mercapto-acetoxy)-ethyl ester-capped ZnS nanoparticles into the acrylated Boltorn™ H20 (H20). The acrylated 2-(2-mercapto-acetoxy)-ethyl ester-capped colloidal ZnS nanoparticles were synthesized by the reaction of zinc acetate with thioacetamide in N,N-dimethylformamide. The acrylated hyperbranched polyester was obtained by reacting acryloyl chloride with hydroxyl group of H20. The acrylated H20 plays an important role in stabilizing and dispersing ZnS nanoparticles with a diameter of 1-4 nm. The refractive indices of ZnS/hyperbranched polyester nanocomposites, depending on ZnS content, were determined to be in the ranges of 1.48-1.65.     

Zinc Sulfide/Gallium Phosphide Composites by Chemical Vapor Transport

Chemical vapor transport was employed to prepare ZnS/ GaP composite powders. Spherical, submicrometer, nano- porous ZnS powders were used as a substrate, where GaP was deposited via a transport reaction involving iodine. XRD examinations of the powders with various GaP contents indicated that the powders consisted mainly of solid solutions with small amounts of GaP and ZnS. The powders were then densified to greater than 98% relative densities by cold isostatic pressing followed by hot isostatic pressing at 900^deg;C under 207 MPa. Vickers hardness improved from 1.38 GPa for pure ZnS to 2.82 GPa (13.7 wt% GaP) and fracture toughness increased from 0.50 MPa.m^1/2 for pure ZnS to 0.89 MPa.m^1/2 (21.0 wt% GaP).     

Synthesis and Characterization of ZnS and ZnO Nanoparticles via Thermal Decomposition of Two New Synthesized One-Dimensional Coordination Polymers at Two Different Temperatures

Two new Zn(II) coordination polymers from ligand 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene (bpdh) with different anions, [Zn(μ-bpdh)₂(NCS)₂]_n (1) and [Zn(μ-bpdh)₂(N₃)₂]_n (2) were synthesized and characterized by IR spectroscopy, elemental analyses and X-ray crystallography. The structures of the 1 and 2 may be considered coordination polymers of zinc(II) consisting of metallocyclic chains formed by bridging bpdh ligands, making a one-dimensional array of Zn^II and bpdh in a 1:2 stoichiometry. Different morphologies of ZnS and ZnO nano-particles were obtained by thermolyses of compounds 1–2 in oleic acid at different temperatures under air atmosphere, respectively. The ZnS and ZnO nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).     

Study of Crystallization and Spectral Properties of Zinc Sulfide Nanoparticles in Mesoporous Matrix

The aim of this work is to report the optical and structural properties of ZnS nanoparticles in mesoporous matrix. The samples were obtained by sulfidation of the Zn²⁺ ion-exchange mesopore in a Na₂S solution at room temperature. The final product (ZnS/MCM-41) was characterized by X-ray diffraction (XRD) pattern, transmission electron microscopy, scanning electron microscopy (SEM), infrared spectrometry and UV–Vis spectroscopy. Its crystalline structure and morphology was studied by XRD and SEM. Exciton absorption peaks at higher energy than the fundamental absorption edge of bulk ZnS indicates quantum confinement effects in nanoparticles as a consequence of their small size.     

Field-assisted sintering and phase transition of ZnS-CaLa2S4 composite ceramics

In the present study, zinc sulfide (ZnS) and calcium lanthanum sulfide (CaLa₂S₄, CLS) composite ceramics were consolidated via field-assisted sintering of 0.5ZnS-0.5CLS (volume ratio) composite powders at 800–1050 °C. Through sintering curve analyses and microstructural observations, it was determined that between 800 and 1000 °C, grain boundary diffusion was the main mechanism controlling grain growth for both the ZnS and CLS phases within the composite ceramics. The consolidated composite ceramics were determined to be composed of sphalerite ZnS, wurtzite ZnS and thorium phosphate CLS. The sphalerite-wurtzite phase transition of ZnS was further demonstrated to be accompanied by the formation of stacking faults and twins in the ceramics. It was also found that the addition of the CLS phase improved the indentation hardness of the ceramics relative to pure ZnS by homogeneous dispersion of ZnS and CLS small grains.