Facile synthesis,magnetic and optical properties of double-shelled Co3O4 hollow microspheres

Double-shelled Co₃O₄ hollow spheres are successfully synthesized by chemically induced self-assembly in the hydrothermal environment. The morphology, chemical composition, and crystalline structure of the double-shelled Co₃O₄ hollow spheres are characterized by different techniques, such as powder X-ray diffraction (PXRD), Raman spectrum, X-ray photoelectron spectrum (XPS), field emission scanning electron microscope (FESEM), and high resolution transmission electron microscope (HRTEM) with selected area electron diffraction (SAED). Magnetic measurements and optical spectra suggest the double-shelled Co₃O₄ hollow spheres exhibit close to a weak ferromagnetic behaviour and enhanced photogenerated carrier separation. Since this synthetic route is simple, convenient, and “green”, it is possible to extend this synthetic method to preparation of a wide range of the multishelled hollow spheres of metal oxides for semiconductor device applications.     

二氧化钛空心微球的制备及表征

采用模板法制备了可控制球壳厚度的亚微米二氧化钛空心微球.首先利用钛酸四丁酯乙醇溶液和聚苯乙烯粒子制备了二氧化钛/聚苯乙烯复合粒子,在空气中经500℃煅烧除去苯乙烯模板后得到锐钛矿二氧化钛空心微球.透射电镜和扫描电镜观察表明,二氧化钛/聚苯乙烯复合粒子煅烧后体积发生了急剧的收缩,形成具有空心结构二氧化钛微球.电子衍射和X射线衍射分析可知空心微球的二氧化钛球壳为锐钛矿.实验发现当钛酸四丁酯与乙醇的体积比从120提高到110时,二氧化钛空心微球的球壳厚度从20～25 nm增加到45～50nm;以不同粒径的聚苯乙烯粒子作模板,可以得到不同内孔直径的二氧化钛空心微球,其内孔直径比聚苯乙烯模板直径小15%～20%.     

Synthesis and characterization of carbon hollow microspheres

A facile approach was developed for synthesis of carbon hollow microspheres (CHM) via carbonization of the hollow polymer microspheres prepared from polymerization in the presence of l-lysine acted as in situ template. The physical and chemical structures of the samples were investigated by X-ray powder diffraction, Raman spectrum, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). SEM and TEM images show that the products consist of a large scale of monodisperse CHM with a size of about 1.1–1.3 μm. Furthermore, the resulting CHMs possess a surface area of 559 m² g⁻¹ and a pore volume of 0.27 cm³ g⁻¹. The morphology and the size of the as-obtained samples can be controlled by the polymerization temperature, polymerization time, and the dosage of l-lysine. Moreover, a possible formation mechanism of the CHM has been put forward according to the experimental data available.     

有机-无机杂化纳米复合材料合成及性能测试

采用溶胶-凝胶法,以甲基三乙氧基硅烷(MTEOS)和正硅酸乙酯(TEOS)及纳米氧化硅为原料,成功制备了有机-无机杂化纳米复合材料及涂层.以X射线衍射(XRD)、富立叶红外光谱(FTIR)、扫描电子显微镜(SEM)和原子力显微镜(AFM)等手段研究了杂化材料的工艺与结构及性能的关系,并对涂覆于铝合金基体上的纳米复合材料涂层的防腐蚀性能进行了实验检测.结果表明,有机-无机杂化纳米复合材料涂层具有优良的抗腐蚀性能.     

Biomimetic synthesis and characterization of semiconducting hybrid organic-inorganic composite materials based on polyaniline-polyethylene glycol-CdS system

Triple hybrid materials based on polyaniline-polyethylene glycol and cadmium sulphide have been prepared by the duffusion-limited biomimetic route and characterized by a number of spectroscopic, XRD, SEM, thermal and electrical measurements. These hybrid materials have been prepared by controlled precipitation of cadmium sulphide by passing H₂S gas and mixing the resultant colloid with the acidic solution of aniline. In situ polymerization of adsorbed anilinium ions on anionic surface of CdS resulted in hybrids. Water-soluble polyethylene glycol led to diffusion-limited growth of polyaniline and CdS resulting in a nanosized hybrid material as indicated by UV-visible spectra, X-ray diffraction (XRD) and scanning electron microscopy (SEM). AC impedance spectroscopic studies on binary and ternary nanocomposites of polyaniline with polyethylene glycol and cadmium sulphide separately and triple hybrid system have been reported. Equivalent circuits were determined and discussed in the light of contributions made from different sources such as grain, grain boundary and electrode.     

电化学法聚吡咯空心微球的制备及表征

以水为溶剂,对甲苯磺酸和十二烷基苯磺酸钠为支持电解质,采用电化学方法制备了聚吡咯(PPy)空心微球。运用扫描电镜(SEM)对产物的微观形貌进行了表征,发现十二烷基苯磺酸钠的用量对产物的形貌有很大的影响。运用傅立叶红外光谱(FTIR)对产物的结构进行了表征,结果表明,对甲苯磺酸根和十二烷基苯磺酸根离子已经掺杂到聚吡咯分子链上。对聚吡咯进行了交流阻抗谱(EIS)的研究,结果表明聚合电压和聚合时间对EIS曲线有很大的影响。     

Synthesis and characterization of hollow glass–ceramics microspheres

Hollow glass–ceramics microspheres (HGCMs), with the diameter from 10 to 60 μm and the shell thickness less than 2 μm, were successfully fabricated by a simple technique using polyacrylamide microspheres (PAMs) as template. The corresponding HGCM were obtained after a thermal treatment of the core–shell microspheres, which were synthesized with organic template method. The size, morphology and phase composition of synthesized products were determined via XRD, SEM, TGA. The effects of the amount of glass powder, the Hydrophile–Lipophile Balance (HLB) value, the sintering temperature, and the ratio of pre-adsorbed water to the water in the slurry on the morphologies of HGCM have been investigated. The results showed that the agglomeration of HGCM can be reduced by adjusting the HLB value. In addition, the amount of solid beads decreases obviously by reducing ratios and adjusting the HLB value. As the sintering temperature increases, the surface of the HGCM becomes smooth and compact. Meanwhile, computational investigations are carried out to better understand the strengthen effect of taking glass–ceramics materials in the system MgO–Al₂O₃–SiO₂ (MAS) as shell materials.     

One-step synthesis and solvent-induced exfoliation of hybrid organic-inorganic phyllosilicate-like materials

A room-temperature sol-gel-based process was used to produce by direct synthesis talc-like organosilicates having hexadecyl or aminopropyl groups pending in the interlayer space. Thermal analyses, Fourier transform infrared and 13C/29Si solid-state nuclear magnetic resonance spectroscopies confirmed the presence of organic moieties bonded to the inorganic network. Exfoliation of these organoclays in polar solvents such as water for the positively charged magnesium phyllo(aminopropyl)silicate, and in low polar solvents such as toluene and chloroform for hydrophobic magnesium phyllo(hexadecyl)silicate, was investigated by TEM. The ability of these layered magnesium organosilicates to exfoliate in appropriate solvents was exploited for the preparation of transparent self-supporting films and ordered macroporous networks using by latex colloidal crystal templates.     

单分散纳米TiO2的合成及表征

以钛酸四丁酯为原料和三乙醇胺为形态控制剂,采用溶胶-凝胶-水热法可以简单快速地合成单分散的TiO2纳米粒子.研究了反应物料配比、凝胶形成温度、水热处理温度等反应条件对粒子粒径及分散性的影响.采用XRD和TEM等手段对粒子的结构与形貌进行了表征.结果表明,三乙醇胺与钛酸四丁酯物质的量配比为2:1,凝胶形成温度为100℃,水热处理温度为140℃时,所合成的TiO2粒子分散性最好.     

SiO2空心微球的制备表征及摩擦性能

以分散聚合法制备的聚苯乙烯(PS)微球为有机模板, 以正硅酸四乙酯(C₈H₂₀O₄Si)为无机前躯体物料, 通过静电吸附作用成功地制备了纳米 PS-SiO₂ 复合微球和SiO₂单分散空心结构。通过红外(FTIR)、热重(TG)、透射电镜(TEM)、扫描电镜(SEM) 和热重分析仪(TGA)等手段对纳米复合材料进行了表征, 并对产物的抗磨性能进行了测试。结果表明, 该方法可一次性制备大量的复合微球, 这些微球的直径约为0.7 μm, 分散性能良好。在煅烧去除模板后, 得到了保持完整的空心纳米 SiO₂ 结构, 微球的球壳稳定性较好。摩擦实验表明, 添加了2 wt%空心微球的植物油在较低载荷工况下具有优异的减磨性能, 摩擦系数可低至0.058。      

磁性聚乙烯醇缩丁醛微球的制备和性质

运用乳化复合技术制备出磁性聚乙烯醇缩丁醛微球。该微球呈珠状 ,平均粒径为10～ 2 0nm ,具有较大的蛋白质固载量 ,可作为载体对多种酶及蛋白质加以固定。并研究了磁性聚乙烯醇缩丁醛微球制备条件、吸附时间、pH值等对磁性聚乙烯醇缩丁醛微球固定蛋白载量的影响     

基于复合纳米颗粒的有机-无机杂化膜制备与性能表征

采用共混杂化的方法,利用Al2O3/TiO2复合纳米颗粒对疏水性强、易污染的聚偏氟乙烯膜进行改性,以增强其在水相溶液中的应用能力。通过测定纯水通量、截留率和膜表面接触角分别考察膜的透过、分离性能及亲疏水性能。用扫描电镜观察杂化膜的表面形态及断面结构。用傅立叶红外光谱分析杂化膜的化学结构,用X射线衍射分析杂化膜的结晶状态。膜的抗污染性能由料液通量试验考察。改性前后膜的测试结果表明,纳米颗粒的加入改善了聚偏氟乙烯膜的通量、亲水性能和抗污染性能。     

Preparation and characterization of hollow hydroxyapatite microspheres by spray drying method

Hollow hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂) microspheres were prepared using a simple spray drying method. The incorporation of ammonium bicarbonate could produce carbon dioxide and ammonia gas bubbles during the spraying, and thus created a hollow inner structure in the resultant microspheres. The hollow microspheres prepared using different amounts of ammonium bicarbonate were also characterized. These microspheres were composed of nanoparticles with an average crystallite size of 15 nm. A high surface area (80 m²/g) and porosity of the microspheres could be achieved when the concentration of ammonium bicarbonate was about 5 wt.%. Fourier transform infrared results showed that CO₃^2? was incorporated into the HA microspheres. These hollow microspheres have many potential uses such as injectable drug-delivery carriers.     

含季铵荷电基团的有机-无机杂化介孔材料的合成与表征

以十二烷基硫酸钠(SDS)为模板剂,正硅酸乙酯(TEOS)和N-三甲氧基硅丙基-N,N,N-三甲基氯化铵(TSPMNC)为硅源,以NaOH为催化剂,合成出带有季铵荷正电基团的有序介孔材料(QAS)。采用XRD,TGA、BET、SEM,XPS、TEM、FT-IR等手段对产品结构进行了表征和分析。结果表明,产品具有较为均一的六方介孔结构,孔径约为3.5nm,产品中季铵荷电基团的含量约为1.41mmol/g。     

Additive-free and time-saving microwave hydrothermal synthesis of hollow microspheres structured boehmite

In this study, by using Al₂(SO₄)₃ aqueous solution and urea as raw materials, hollow microspheres structured boehmite was successfully synthesized only after 30 min reaction time at 180 °C via an additive-free and time-saving microwave hydrothermal route. The final products were characterized by techniques of X-ray diffraction (XRD), transmission electronic microscope (TEM), scanning electron microscope (SEM) and Fourier transform infrared spectrometry (FTIR). To investigate its crystal form and morphology evolution process, samples subjected to different reaction durations were prepared and characterized. The pivotal influence factors on boehmite morphology, such as reaction temperature, dosage of urea and microwave power range were discussed based on the experiment facts.     

有机-无机杂化壳微胶囊合成及应用研究进展

微胶囊在药物、能源、催化等许多领域具有重要应用,传统微胶囊的壳层一般为单一的有机聚合物、无机物或金属材料。近年来,有机-无机杂化材料优异性能的发现,促进了以有机-无机杂化材料作为壳层的新型微胶囊的研究和发展。概述了有机-无机杂化壳微胶囊的种类、合成方法及应用领域,分析了目前有机-无机杂化壳微胶囊领域存在的问题,展望了本领域未来的发展方向。     

Chemical vapor deposition synthesis and photoluminescence properties of ZnS hollow microspheres

ZnS hollow microspheres were prepared via a facile template-free chemical vapor deposition (CVD) route using metallic zinc powders and sulphur sublimed as reactants. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectrometer (EDX). The results showed that the as-prepared ZnS hollow spheres had uniform size about 4–8 μm in diameter. The growth mechanism of such interesting was discussed. The optical property of the products was also recorded by means of photoluminescence (PL) spectroscopy.     

表面功能化聚苯乙烯磁性微球的制备及表征

以纳米级四氧化三铁(Fe3O4)为磁性载体,以苯乙烯(St)、丙烯酸(AA)和丙烯酸甲酯(MA)为单体,用微悬浮聚合法制备了表面功能化聚苯乙烯磁性微球,并对聚合过程中预处理、温度、Fe3O4/St比、分散剂的影响进行了讨论。扫描电镜照片和磁滞回线显示微球分散性好,具有超顺磁性;热失重-差热分析表明其磁含量高;红外光谱表明微球表面含有羧基基团;通过电导率仪测试,计算出了微球表面羧基含量。结果表明,丙烯酸甲酯改性的羧基磁性微球比丙烯酸改性的性能要好。     

以碳酸钙为模板制备空心羟基磷灰石微球及其表征

以碳酸钙为模板和钙源,与磷酸氢二铵通过水热反应,制备出尺寸均匀、形态规则的空心羟基磷灰石微球。采用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)、透射电镜(TEM)测试制备的样品,结果显示,制备的空心羟基磷灰石微球具有与碳酸钙微球模板相似的形貌,空心,尺寸均匀且形貌规则。并通过改变水热反应时间探索了羟基磷灰石微球的形成机理。此羟基磷灰石空心微球在生物医学领域具有较大的应用前景。