Sol-Gel法合成锂离子筛前驱体LiMn2O4的研究

采用溶胶-凝胶法、用柠檬酸和乙二醉作为聚合反应的单体合成了正尖晶石结构LiMn2O4的前驱体,研究了反应物摩尔比、pH值及焙烧温度对材料性能的影响,并通过XRD、IR和SEM等方法研究了柠檬酸螯合法合成正尖晶石结构LiMn2O4的溶胶-凝胶过程,探讨了反应机理.研究表明,在Li/Mn摩尔比为0.6、pH值为3.0及焙烧温度为600℃时,合成的正尖晶石结构LiMn2O4的前驱体具有较好的晶粒结构,其一次粒子直径大多在100nm以内.     

SiO2-Al2O3复合体系溶胶-凝胶转变过程的动力学研究

本文以硅酸乙酯和无机铝盐为前驱体,通过水解法制备了TSiO2-Al2O3复合溶胶.通过粘度测量、红外光谱以及热分析等测试手段研究了复合溶胶的溶胶-凝胶转变过程及对应凝胶热分解过程中的动力学,并对上述结果从化学键、电荷密度等方面进行了解释.     

TiO_2/SiO_2复合涂层光致亲水性及其机理研究

以钛酸四丁酯、正硅酸乙酯为前驱体,冰醋酸为水解抑制剂,用溶胶-凝胶法制备了纳米TiO2/SiO2复合粒子。将复合粒子添加到醇酸清漆中,制备出自清洁涂层。研究表明:少量SiO2掺杂在一定程度上抑制了TiO2的晶型转变和晶粒长大,改善了复合涂层的亲水性。利用荧光光谱对亲水性机理进行了验证。     

超疏水/超亲油SiO2薄膜的制备和表征

采用溶胶-凝胶法以正硅酸乙酯和甲基三乙氧基硅烷为共前驱体制备纳米疏水SiO2溶胶,经十二烷基三甲氧基硅烷(dodecyltrimethoxysilane,DTMS)改性后,制备出SiO2粒子薄膜,用红外光谱分析SiO2粒子的化学组成,用透射电镜观察凝胶时间对SiO2粒子形貌的影响,用扫描电镜和接触角表征SiO2涂膜的表...     

SiO2-Al2O3复合体系溶胶-凝胶转变过程的动力学研究

本文以硅酸乙酯和无机铝盐为前驱体，红外光谱以及热分析等测试手段研究了复合溶胶的溶胶述结果从化学键、电荷密度等方面进行了解释。通过水解法制备SiO2-Al2O3复合溶胶。通过粘度测量、凝胶转变过程及对应凝胶热分解过程中的动力学，并对上     

Mn2O3/TiO2太阳光催化性能的研究

以钛酸丁酯和乙酸锰为前驱物,采用溶胶-凝胶(sol-gel)法成功地制备了纳米Mn2O3/TiO2粉体,利用XRD、TEM和TG-DSC对粉体进行了表征.以甲基橙为模型化合物,研究了热处理温度、锰的含量、凝胶pH以及溶液的pH、甲基橙浓度、太阳光照时间和光源等对Mn2O3/TiO3:光催化活性的影响.     

纳米锑掺杂氧化锡的制备及表征(英文)

以无机盐SnCl4·5H2O和SbCl3为初始原料,以乙醇作为溶剂,采用溶胶-凝胶法结合超临界流体干燥(supercritical fluid drying,SCFD)技术制备了纳米锑掺杂氧化锡(antimony doped tin oxide.ATO)粉体.通过热重-差示扫描热分析、X射线衍射、扫描电子显微镜、透射电镜,对前驱体粒子以及ATO粒子的结构进行了分析.探讨了热处理温度、前驱体千燥方式对前驱体以及纳米粒子的形貌、粒径、分散性、晶型、结晶度的影响,并讨论了SCFD技术干燥前驱体的机理.结果表明:采用溶胶-凝胶法结合超临界CO2干燥技术,在给定的反应条件下,能够制得疏松的、良好掺杂的四方型结构的纳米ATO粒子,粒径约15～30nm,分散性好.     

纳米α-Fe2O3粒子的湿法制备

综述了近年来国内外纳米α-Fe2O3粒子的湿法制备.主要介绍了沉淀法、水解法、水热法、溶胶-凝胶法和微乳液法的基本原理和应用,最后讨论了纳米α-Fe2O3粒子制备方法的发展方向.     

无机盐先驱体Al2O3-SiO2-ZrO2复合溶胶制备及稳定性研究

稳定的复合溶胶是制备良好的复合陶瓷膜的基础。笔者以无机盐Al(NO3)3、ZrOCl2.8H2O为前驱体,用正硅酸乙酯引入SiO2,采用溶胶—凝胶法分步水解制备了Al2O3-SiO2-ZrO2复合溶胶,并得出制备性能良好的AlOOH及SiO2-ZrO2溶胶的最佳工艺条件,通过对不同配比的复合溶胶进行研究,得出影响复合溶胶稳定性的主要因素是Si/Zr。     

应用超临界流体干燥技术制备纳米锑掺杂氧化锡的研究

以无机盐SnCl4·5H2O,SbCl3为起始原料,以乙醇为溶剂,采用溶胶-凝胶法制备纳米锑掺杂氧化锡(ATO)粒子.在洗涤除去醇凝胶中的NH+和Cl-后,尝试将超临界流体干燥(Supercritical Fluid Drying,SCFD)技术应用于醇凝胶的干燥.醇凝胶干粉经过高温烧结后,制得了疏松结构的纳米ATO粉体.采用XRD、TG/DSC、FESEM、TEM等分析方法对制得的前驱体干粉、纳米ATO粒子进行表征.XRD结果表明,采用溶胶.凝胶法结合超临界流体干燥技术制得了疏松的、四方型金红石结构的纳米ATO粉体,纳米ATO晶化程度高,并随着烧结温度的升高而升高.TG/DSC分析显示,600℃时前驱体分解完全,得到约78.2%的ATO粒子.从FESEM及TEM照片可以看出,疏松的纳米ATO粒子轻微地贴在一起,粒子的粒径在25 nm左右.经过对超临界CO2干燥技术(SCFD)消除前驱体粒子团聚的机理进行分析,揭示了采用超临界CO2流体干燥醇凝胶能够使前驱体粒子保持松敝的结构.因此采用溶胶-凝胶法结合超临界流体技术制得疏松的前驱体干粉,对最终获得粒径小、低团聚、分散性好的纳米ATO粉体的至关重要.     

Synthesis of Glass-like Cordierite from Metal Alkoxides and Characterization by 27Al and 29Si MASNMR

A sol-gel process for the preparation of glass-like cordierite and ceramic oxide powder is described. Metal alkoxide precursors were dissolved in 2-methoxyethanol and the metal cations were complexed using 2,4-pentanedione to overcome different hydrolysis rates of metal alkoxides which lead to microscopic inhomogeneities during gelation. Heating the gel in an aerated furnace resulted in ultrafine cordierite powder of stoichiometric composition at a relatively low temperature. Cordierite gel and glass were also prepared by other methods and compared with the above gel. The environments of aluminum and silicon in the glass and gels heated at various temperatures were studied using ²⁷Al and ²⁹Si magic angle spinning nuclear magnetic resonance (MASNMR) spectroscopy. Most of the heated gels and the glass showed resonances due to pentacoordinated aluminum along with 4- and 6-coordinated aluminum. The homogeneities of the resulting gels and glass are compared using the MASNMR data.     

溶胶-凝胶法制备氧化硅-氧化铝体系凝胶及合成过程研究进展

氧化硅-氧化铝（SiO₂-Al₂O₃）体系凝胶不仅应用广泛,而且其制备及反应机理还可借鉴到碱激发胶凝材料等领域。通过对溶胶-凝胶法合成氧化硅-氧化铝体系凝胶的制备过程及影响因素和影响规律、凝胶的性质和结构表征及合成机理研究进展进行综述,提出目前仍缺乏有关碱（土）金属离子对凝胶结构性能的影响研究以及硅铝含量变化的定量描述数据,建议拓宽研究范畴,结合核磁共振等检测方法,得出该体系结构性能变化准确数据,为氧化硅-氧化铝体系凝胶的设计和应用夯实基础。     

包覆型铝粉颜料在水性涂料中的应用

以正硅酸乙酯(TEOS)和乙烯基三乙氧基硅烷(VTES)为前驱物,通过溶胶-凝胶反应在铝颜料表面形成了一层致密的包覆层,再通过甲基丙烯酸甲酯(MMA)和丙烯酸(AA)的自由基聚合反应对铝颜料进行第二层包覆,制备了含亲水基团的包覆型铝粉颜料,以此包覆的铝颜料配制了水性铝粉涂料.研究了铝粉及交联剂的用量、涂料黏度和烘烤温度...     

Synthesis of barium titanate using supercritical CO2 drying of gels

BaTiO₃ powders from sol-gel derived gels were prepared using two different drying methods. In addition to the conventional drying of gels in air at 90°C the supercritical CO₂ drying method was also used. Results showed that the properties of BaTiO₃ powder produced by supercritical drying with CO₂ are better. The grain surface is less contaminated as a result of the supercritical drying and the microstructure development during sintering leads to a homogeneous fine-grained microstructure.     

Sol-gel synthesis and fluorescence properties of hybrid nanocomposite materials doped with the Nile Red dye

The hybrid organic-inorganic materials with optical properties are synthesized in the form of gels and thin-layer coatings by the sol-gel method. The fluorescence of the materials synthesized is investigated as a function of the Nile Red concentration and the composition of the precursors forming the hybrid sol-gel matrices. It is demonstrated that the materials synthesized hold much promise for use in the fabrication of optical gas sensors.     

TEOS/MTES协同水解包覆铝颜料的研究

以正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTES)为前驱物、氨水为催化剂,通过溶胶-凝胶反应在铝颜料表面形成了薄而致密的有机-无机包覆层.研究了影响成膜形态的反应因素以及包覆产物的耐酸性.结果发现,当TEOS、MTES、氨水和水的乙醇溶液同时滴入铝颜料溶液,并控制反应配比为铝颜料2 g、MTES 3 g、TEOS ...     

Sol-Gel Synthesis of Lithium Aluminate

LiAlO₂ was prepared by two sol-gel methods using simultaneous hydrolysis of the reagents: aluminum sec -butoxide/ lithium methoxide and aluminum sec -butoxide/LiOH. The resulting ceramic powders were compared with those prepared by two conventional methods (i.e., solid-state fusion and peroxide). The sol-gel method provided powders with a very high γ-LiAlO₂ content after calcining at temperatures as low as 700°C when LiOH was used. The solids were characterized by AAS, DTA, TGA, XRD, and SEM.     

B_2O_3／Al_2O_3催化剂结构和性能的研究

采用溶胶凝胶法和浸渍法,在500℃下焙烧2 h,制备不同组成的B2O3／Al2O3催化剂。通过X射线衍射、热失重、傅立叶红外光谱等测试方法对所制备的催化剂的结构进行表征。通过催化剂与二苯甲酰基甲烷(DBM)配位情况对催化剂的性能表征。研究表明:焙烧获得的主催化剂晶型为γ-Al2O3,添加第二组分B2O3,可以提高与DBM的配位能力,以改善Al2O3的催化活性。     

Hydrolysis in the Aluminum sec-Butoxide—Water—Isopropyl Alcohol System: II, Aging and Microstructure

Solutions representing a wide range of compositions in the aluminum sec -butoxide-water-isopropyl alcohol system were prepared. Solutions were mixed at room temperature, then gelled and evaporated at 80°C. Regions within this system were distinguished where translucent gels formed instead of precipitates or powders. Translucent gels formed in compositions with high water content and high isopropyl alcohol content. The stages of sol-gel process were investigated by Fourier transform infrared spectroscopy in the early stages and in gels before and after solvent evaporation. The microstructure was characterized by nitrogen sorption analysis.     

Zn2+离子掺杂对负载TiO2薄膜光催化活性的影响

以钛酸丁酯和ZnSO₄·7H₂O为原料，采用溶胶-凝胶法在钛片、玻璃、釉面瓷砖、陶瓷、不锈钢和铝片六种载体上制备了Zn²⁺掺杂TiO₂薄膜，讨论了不同Zn²⁺掺杂浓度下不同载体表面上制备的TiO₂薄膜对甲基橙脱色率的影响。结果表明，Zn²⁺对TiO₂薄膜的掺杂效果与载体的类型密切相关，并且不同载体其Zn²⁺掺杂的最佳浓度也不同。Zn²⁺掺杂后，TiO₂薄膜光催化活性提高最大的是釉面瓷砖，其次是钛片、玻璃、陶瓷。不锈钢和铝片上TiO₂薄膜的光催化活性不但没有升高，反而降低了。