期刊文献+
共找到28篇文章
< 1 2 >
每页显示 20 50 100
层状钙钛矿型Sm_(2-2x)Sr_(1+2x-2y)Ca_(2y)Mn_2O_7(x=0.2,0.3,0.4,0.5;y=0,0.2,0.3)的溶胶凝胶合成及电性能研究(英文) 被引量:1
1
作者 刘佳雯 陈刚 +2 位作者 李中华 迟欣 张治国 《无机化学学报》 SCIE CAS CSCD 北大核心 2006年第4期705-708,共4页
Layered perovskite manganites with a nominal chemsitry of Sm2-2xSr1+2x-2yCa2yMn2O7 (x=0.2, 0.3, 0.4, 0.5; y=0, 0.2, 0.3) were prepared using sol-gel method. The crystal structures of these compounds were studied by X-... Layered perovskite manganites with a nominal chemsitry of Sm2-2xSr1+2x-2yCa2yMn2O7 (x=0.2, 0.3, 0.4, 0.5; y=0, 0.2, 0.3) were prepared using sol-gel method. The crystal structures of these compounds were studied by X-ray diffraction (XRD) and FTIR absorption spectra. The absorption peaks become weaker and move a little to higher frequency with increasing of Sm/Sr concentration. As the Sm doping increases to x=0.2 and x=0.3, the absorption peaks show a cubic structure character, reflecting that the samples suffer from a transition from tetragonal structure to cubic structure. This coincides with the X-ray diffraction results. The high temperature electrical properties were studied by conventional four-probe method. Although all samples exhibit the semiconductive behavior, lnρ-1 000/T curves are not linear and they obey the small polaron hopping mechanism. Moreover, the resistivity decreases with x reducing. This is due to that Sm doping increases the Jahn-Teller ion Mn3+ / Mn4+ ratio, and decreases the eg bandwidth. 展开更多
关键词 溶胶-胶合 层状钙钛矿 电性能
下载PDF
X、U铁氧体的溶胶-凝胶合成及微波性能研究 被引量:18
2
作者 张海军 姚熹 +1 位作者 张良莹 吴明忠 《功能材料》 EI CAS CSCD 北大核心 2003年第1期39-40,43,共3页
 以柠檬酸铁、碳酸钡、硝酸钴、硝酸锌以及柠檬酸等为原料,采用sol gel工艺合成了Ba2Zn2Fe28O46(Zn2 X)、Ba2Co2Fe28O46(Co2 X)、Ba4Zn2Fe36O60(Zn2 U)、Ba4Co2Fe36O60(Co2 U)铁氧体。采用XRD、SEM对其相成分和显微结构进行研究。并对...  以柠檬酸铁、碳酸钡、硝酸钴、硝酸锌以及柠檬酸等为原料,采用sol gel工艺合成了Ba2Zn2Fe28O46(Zn2 X)、Ba2Co2Fe28O46(Co2 X)、Ba4Zn2Fe36O60(Zn2 U)、Ba4Co2Fe36O60(Co2 U)铁氧体。采用XRD、SEM对其相成分和显微结构进行研究。并对其复介电常数、复磁导率在100MHz~6.0GHz下的变化规律进行了对比。结果表明,铁氧体试样的磁导率虚部随测试频率的变化曲线上显示出非常明显的由自然共振引起的共振峰。 展开更多
关键词 溶胶-胶合 微波性能 柠檬酸 X型铁氧体 U型铁氧体
下载PDF
BaPbZnCo-Y型铁氧体的柠檬酸溶胶-凝胶合成及其微波性能研究 被引量:5
3
作者 张海军 姚熹 +1 位作者 张良莹 吴明忠 《功能材料》 EI CAS CSCD 北大核心 2003年第1期37-38,43,共3页
 采用柠檬酸sol gel工艺合成了Ba2-zPbzZn1.2Co0.8Fe12O22(z=0.0、0.5、1.0、1.5)Y型铁氧体。采用XRD、SEM对其相成分、显微结构进行研究。并对其复介电常数和复磁导率在1MHz~6GHz下的变化规律进行了研究。结果表明,铁氧体的复介电常...  采用柠檬酸sol gel工艺合成了Ba2-zPbzZn1.2Co0.8Fe12O22(z=0.0、0.5、1.0、1.5)Y型铁氧体。采用XRD、SEM对其相成分、显微结构进行研究。并对其复介电常数和复磁导率在1MHz~6GHz下的变化规律进行了研究。结果表明,铁氧体的复介电常数基本不随测试频率的变化而变化,其μ″谱上显示出非常明显的由自然共振引起的共振峰,该共振峰随铁氧体粉末热处理温度的升高移向低频。 展开更多
关键词 柠檬酸 溶胶-胶合 微波性能 Y型铁氧体
下载PDF
煅烧温度对溶胶-凝胶合成BCZT纳米粉体的影响 被引量:2
4
作者 吉祥 王传彬 +2 位作者 李诵斌 沈强 张联盟 《人工晶体学报》 CSCD 北大核心 2017年第11期2178-2182,2189,共6页
针对传统固相反应法制备粉体存在的成分偏离和引入杂质等问题,采用溶胶-凝胶方法合成了0.5Ba(Zr_(0.2)Ti_(0.8))O_3-0.5(Ba_(0.7)Ca_(0.3))TiO_3(BCZT)无铅纳米粉体,主要研究了煅烧温度对其结构和形貌的影响。TG-DSC、XRD、SEM、TEM、F... 针对传统固相反应法制备粉体存在的成分偏离和引入杂质等问题,采用溶胶-凝胶方法合成了0.5Ba(Zr_(0.2)Ti_(0.8))O_3-0.5(Ba_(0.7)Ca_(0.3))TiO_3(BCZT)无铅纳米粉体,主要研究了煅烧温度对其结构和形貌的影响。TG-DSC、XRD、SEM、TEM、FTIR等测试结果表明:在900~1100℃的温度范围内,溶胶-凝胶合成的BCZT粉体表现为单一的立方相结构;随着煅烧温度的升高,粉体的结晶性逐渐增强,颗粒尺寸增大;适宜的粉体煅烧温度为900℃,与传统固相反应法相比可降低约400℃;在此煅烧温度下得到的BCZT粉体粒径均匀,尺寸约50~60 nm,结晶良好,成分均匀。 展开更多
关键词 溶胶-胶合 BCZT粉体 煅烧温度 粉体结构 形貌
下载PDF
络合溶胶-凝胶法制备Ba_(0.7)Sr_(0.3)TiO_3陶瓷粉体 被引量:3
5
作者 李涛 王征 +1 位作者 姜胜林 李光兴 《华中科技大学学报(自然科学版)》 EI CAS CSCD 北大核心 2006年第10期4-6,共3页
以硝酸钡、硝酸锶、钛酸丁酯和柠檬酸为前驱体原料,采用络合溶胶-凝胶法制备出纳米级Ba0.7Sr0.3TiO3(BST)陶瓷粉体,并对材料组织结构和形貌进行了表征.结果表明:通过前驱体pH的控制可得到均匀的溶胶和凝胶.BST干凝胶经600℃热处理2 h后... 以硝酸钡、硝酸锶、钛酸丁酯和柠檬酸为前驱体原料,采用络合溶胶-凝胶法制备出纳米级Ba0.7Sr0.3TiO3(BST)陶瓷粉体,并对材料组织结构和形貌进行了表征.结果表明:通过前驱体pH的控制可得到均匀的溶胶和凝胶.BST干凝胶经600℃热处理2 h后出现钙钛矿结构的特征峰,但伴随有BaCO3的杂质峰.当煅烧温度达到950℃时,可得到结晶良好、单相的Ba0.7Sr0.3TiO3,晶粒粒径约为80 nm. 展开更多
关键词 钛酸锶钡 陶瓷粉体 Pechini溶胶-胶合
下载PDF
一步溶胶-凝胶法制备乙烯基功能化二氧化硅微球及其表征 被引量:2
6
作者 高爱环 郝向英 +1 位作者 操江飞 徐梦漪 《电镀与涂饰》 CAS CSCD 北大核心 2019年第16期898-903,共6页
以乙烯基三乙氧基硅烷(VTES)为硅源、乙醇和水为溶剂,氨水为催化剂,通过一步溶胶?凝胶法制备了粒径分布为2~11μm的乙烯基功能性二氧化硅微球(V-SiO2)。探究了温度、水硅比、醇硅比、氨硅比和对合成反应及产物形貌的影响,并对产物进行... 以乙烯基三乙氧基硅烷(VTES)为硅源、乙醇和水为溶剂,氨水为催化剂,通过一步溶胶?凝胶法制备了粒径分布为2~11μm的乙烯基功能性二氧化硅微球(V-SiO2)。探究了温度、水硅比、醇硅比、氨硅比和对合成反应及产物形貌的影响,并对产物进行了热重(TG)、扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)、接触角测量等方面的表征。结果表明:30~50℃时,VTES水解?缩聚反应完全;水硅比越大,体系凝胶时间越长;醇硅比越大,产物球形越规整;氨硅比越大,产物粒径分布范围越窄。产物V-SiO2是具有反应潜能的超疏水材料,可用于分离、检测、陶瓷制造等领域,也可用作引入其他成分的基础材料。 展开更多
关键词 功能性二氧化硅微球 乙烯基三乙氧基硅烷 溶胶-胶合 疏水性
下载PDF
锂离子电池正极材料Li_(1.2)Ni_(0.16)Co_(0.12)Mn_(0.52)O_2的溶胶-凝胶制备与电化学性能研究
7
作者 魏俊超 赵陈浩 《山东化工》 CAS 2014年第6期1-3,共3页
以柠檬酸作为螫合剂,通过简单的溶胶-凝胶法制备了富锂层状氧化物Li1.2Ni0.16Co0.12Mn0.52O2纳米颗粒。X射线衍射(xRD)和透射电子显微镜(TEM)结果显示:尺寸在100—300nm的产物具有良好的六方层状结构。作为锂离子电池正极活... 以柠檬酸作为螫合剂,通过简单的溶胶-凝胶法制备了富锂层状氧化物Li1.2Ni0.16Co0.12Mn0.52O2纳米颗粒。X射线衍射(xRD)和透射电子显微镜(TEM)结果显示:尺寸在100—300nm的产物具有良好的六方层状结构。作为锂离子电池正极活性物质。在0.1C电流密度和2.0-4.7V电压区间,Li1.2Ni0.16Co0.12Mn0.52O2电极的初始放电比容量为245.9mAh·g-1;在0.5C的电流密度下。经过60次循环容量保持率达到97.3%;同时在5C这样高的电流密度下,放电容量也能稳定在115.8mAh·g-1。 展开更多
关键词 溶胶-胶合 富锂层状氧化物Li1 2Ni0 16Co0 12Mn0 52O2 高性能 锂离子电池
下载PDF
Gd_(2-x)Eu_xWO_6红色荧光粉的溶胶-凝胶合成及其荧光性能分析 被引量:3
8
作者 张丽霞 梁利芳 +2 位作者 黄天梅 易敏 庞起 《稀土》 EI CAS CSCD 北大核心 2012年第2期40-44,共5页
利用溶胶-凝胶法制备系列Gd2-xEuxWO6红色荧光粉,XRD测试表明Gd2-xEuxWO6具有单斜晶系结构;在298 nm或395 nm激发下,荧光粉主要发射出对应于Eu3+5的D0→7F2能级跃迁的612 nm红光;当Gd2-xEuxWO6中Eu3+的掺杂量为50%时,荧光粉612 nm红光... 利用溶胶-凝胶法制备系列Gd2-xEuxWO6红色荧光粉,XRD测试表明Gd2-xEuxWO6具有单斜晶系结构;在298 nm或395 nm激发下,荧光粉主要发射出对应于Eu3+5的D0→7F2能级跃迁的612 nm红光;当Gd2-xEuxWO6中Eu3+的掺杂量为50%时,荧光粉612 nm红光强度最强;在合成过程中适当添加聚乙二醇(PEG)和柠檬酸能改善荧光粉的红光发射强度。 展开更多
关键词 红色荧光粉 溶胶-胶合 Gd2WO6基质 Eu3+发光性能
原文传递
四氧化三铁/二氧化硅复合磁性纳米粒子的制备与表征 被引量:7
9
作者 朱霞萍 彭道锋 《精细石油化工》 CAS CSCD 北大核心 2010年第4期57-60,共4页
实验以溶胶-凝胶法,将粒径约10 nm的Fe_3O_4纳米粒子分散在SiO_2凝胶中,制备Fe_3O_4/SiO_2复合磁性纳米粒子。以透射电镜、X射线衍射和磁性能测试对复合纳米粒子进行了表征。结果表明,Fe_3O_4/SiO_2复合纳米粒子呈球形,粒径约46 nm;试... 实验以溶胶-凝胶法,将粒径约10 nm的Fe_3O_4纳米粒子分散在SiO_2凝胶中,制备Fe_3O_4/SiO_2复合磁性纳米粒子。以透射电镜、X射线衍射和磁性能测试对复合纳米粒子进行了表征。结果表明,Fe_3O_4/SiO_2复合纳米粒子呈球形,粒径约46 nm;试样中磁性物质为纳米Fe_3O_4,包履层为非晶SiO_2;Fe_3O_4/SiO_2纳米粒子具有超顺磁性,比饱和磁化强度26 emu/g,磁响应性随Si/Fe摩尔比增加明显下降。该法制备的磁性纳米粒子粒径均匀,分散性良好,并克服了Fe_3O_4粒子制备过程中普遍存在的氧化问题。 展开更多
关键词 复合纳米粒子 二氧化硅 溶胶凝胶合成 磁性
下载PDF
介孔TiO_2的制备及光催化降解黑液的影响因素 被引量:1
10
作者 林会亮 周国伟 +1 位作者 刘颖 孟庆海 《纸和造纸》 北大核心 2007年第2期69-72,共4页
以钛酸四丁酯(TBOT)为前驱体,三嵌段共聚物(P123)为模板剂,溶胶-凝胶法合成了孔径分布均匀的介孔TiO_2,用小角X射线衍射(SAXRD)、X射线粉末衍射(XRD)、透射电子显微镜(TEM)等分析手段对产物结构和光学性能进行了表征。考察了光照时间、... 以钛酸四丁酯(TBOT)为前驱体,三嵌段共聚物(P123)为模板剂,溶胶-凝胶法合成了孔径分布均匀的介孔TiO_2,用小角X射线衍射(SAXRD)、X射线粉末衍射(XRD)、透射电子显微镜(TEM)等分析手段对产物结构和光学性能进行了表征。考察了光照时间、催化剂的用量、初始pH、通氧方式等对降解制浆黑液的影响因素。结果表明:介孔TiO2具有较高的催化活性,在催化剂用量为1.5g·L^(-1)、初始pH=6、连续通氧条件下降解效果最佳,光照反应12h后,黑液CODCr和色度去除率分别可达89.7%和92.6%。 展开更多
关键词 介孔TIO2 光催化降解 溶胶-胶合工艺 黑液
下载PDF
Sol-gel synthesis and photoluminescence of LaPO_4:Eu^(3+) nanorods 被引量:6
11
作者 高锐 钱东 李卫 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第3期432-436,共5页
Monoclinic LaPO4 nanostructures with uniform rod shape have been successfully synthesized by a simple sol-gel method.The procedure involves formation of homogeneous,transparent,metal-citrate-EDTA gel precursors,follow... Monoclinic LaPO4 nanostructures with uniform rod shape have been successfully synthesized by a simple sol-gel method.The procedure involves formation of homogeneous,transparent,metal-citrate-EDTA gel precursors,followed by calcination to promote thermal decomposition of the gel precursors to yield the LaPO4 nanoparticles.Their morphologies and structures were characterized by XRD,TEM,TG-DSC and HRTEM.The results indicate that single monoclinic phase LaPO4 nanorods are readily obtained at 800 ℃ within 3 h.Furthermore,photoluminescence(PL) characterization of the Eu3+-doped LaPO4 nanocrystals was carried out.The effects of calcination temperatures and Eu3+ doping content on the PL properties were elaborated in detail.Room-temperature photoluminescence(PL) characterization reveals that the optical brightness as well as the intensity ratio of 5D0-7F1 to 5D0-7F2 is highly dependent on the calcination temperature,and the Eu0.05La0.95PO4 nanophosphor shows the relatively promising PL performance with the most intense emission. 展开更多
关键词 LAPO4 Eu doping SOL-GEL NANORODS PHOTOLUMINESCENCE
下载PDF
Structure,morphology and opto-magnetic properties of Bi_2MoO_6 nano-photocatalyst synthesized by sol-gel method 被引量:3
12
作者 V.UMAPATHY A.MANIKANDAN +2 位作者 S.ARUL ANTONY P.RAMU P.NEERAJA 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第10期3271-3278,共8页
Bismuth molybdate (Bi2MoO6) nano-particles (NPs) were synthesized using bismuth nitrate, ammonium molybdate, citric acid and ethyl cellulose by a simple sol-gel method. The structure, morphology, opto-magnetic and... Bismuth molybdate (Bi2MoO6) nano-particles (NPs) were synthesized using bismuth nitrate, ammonium molybdate, citric acid and ethyl cellulose by a simple sol-gel method. The structure, morphology, opto-magnetic and photocatalytic properties of the obtained powder were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, high resolution scanning electron microscopy (HRSEM), energy dispersive X-ray (EDX), ultraviolet-visible diffuse reflectance spectra (DRS), photoluminescence (PL) spectra and vibrating sample magnetometer (VSM) techniques. The XRD, FT-IR and EDX results indicate that the resultant powder is pure and single phase crystalline Bi2MoO6 with orthorhombic structure. The HRSEM image shows that the morphology of obtained powder consists with well defined nano-particles structure. The VSM results show superparamagnetic behavior of the obtained nano-particles. The photocatalytic activity of Bi2MoO6 nano-particles was performed. The addition of TiO2 catalyst enhances the photocatalytic activity of Bi2MoO6 nano-particles. The catalysts Bi2MoO6, TiO2 and mixed oxide catalyst Bi2MoO6-TiO2 nano-composites (NCs) were tested for the photocatalytic degradation (PCD) of 4-chlorophenol (4-CP). It is found that the PCD efficiency of Bi2MoO6-TiO2 NCs is higher than that of pure Bi2MoO6 and TiO2 catalysts. 展开更多
关键词 Bi2MoO6 NANOSTRUCTURE sol-gel synthesis optical properties magnetic properties PHOTOCATALYST
下载PDF
Synthesis of NiMoO_4 nanoparticles by sol-gel method and their structural,morphological,optical,magnetic and photocatlytic properties 被引量:2
13
作者 V.UMAPATHY P.NEERAJA +1 位作者 A.MANIKANDAN P.RAMU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第8期1785-1793,共9页
Nickel molybdate(NiMoO4)nanoparticles(NPs)were synthesized by sol-gel method.Utilizing water as solvent providescrystalline nanostructures.These nanocrystals were structurally characterized by X-ray diffraction,energy... Nickel molybdate(NiMoO4)nanoparticles(NPs)were synthesized by sol-gel method.Utilizing water as solvent providescrystalline nanostructures.These nanocrystals were structurally characterized by X-ray diffraction,energy dispersive X-ray analysis(EDX),and Fourier transform infrared spectra.Compositional stoichiometry was confirmed by EDX technique.The size and shapewere observed by scanning electron microscopy(SEM)and transmission electron microscope(TEM).It was found that the obtainedNPs were pure and single phase crystalline with monoclinic structure.The optical properties were studied by ultraviolet-visiblediffuse reflectance spectroscopy(UV-Vis-DRS)and photoluminescence(PL)measurements at room temperature.The magneticproperties were studied by vibrating sample magnetometer(VSM)and results showed superparamagnetic behavior of the obtainednanoparticles.Photocatalytic activity of NiMoO4was studied.The photocatalytic activity of NiMoO4was enhanced with the additionof TiO2.The catalysts NiMoO4,TiO2and NiMoO4-TiO2nanocomposites(NC)were tested for photocatalytic degradation(PCD)of4-chlorophenol(4-CP).It was found that PCD efficiency of NiMoO4-TiO2NC was higher than that of pure NiMoO4and TiO2. 展开更多
关键词 NiMoO4 TiO2 NANOSTRUCTURE sol-gel synthesis optical properties magnetic properties PHOTO-CATALYSIS monoclinic structure
下载PDF
Er^(3+)-activated silica inverse opals synthesized by the solgel method 被引量:2
14
作者 A. Chiappini C.Armellini +11 位作者 A. Chiasera Y. Jestin M. Ferrari M. Mattarelli M. Montagna E. Moser C. Tosello L. Zampedri G. Nunzi Conti S. Pelli R. M. Almeida G. C. Righini 《Optoelectronics Letters》 EI 2007年第3期184-187,共4页
We present the details of the sol-gel processing used to realize inverse silica opal,where the silica was activated with 0.3 mol% of Er3+ ions. The template(direct opal) was obtained assembling polystyrene spheres of ... We present the details of the sol-gel processing used to realize inverse silica opal,where the silica was activated with 0.3 mol% of Er3+ ions. The template(direct opal) was obtained assembling polystyrene spheres of the dimensions of 260 nm by means of a vertical deposition technique. The Er3+-activated silica inverse opal was obtained infiltrating,into the void of the template,the silica sol doped with Er3+ ions and subsequently removing the polystyrene spheres by means of calcinations. Scanning electron microscope showed that the inverse opals possess a fcc structure with a air hollows of about 210 nm and a photonic band gap,in the visible range,was observed from reflectance measurements. Spectroscopic properties of Er3+-activated silica inverse opal were investigated by luminescence spectroscopy,where,upon excitation at 514.5 nm,an emission of 4I13/2 → 4I15/2 of Er3+ ions transition with a 21 nm bandwidth was observed. Moreover the 4I13/2 level decay curve presents a single-exponential profile,with a measured lifetime of 18 ms,corresponding a high quantum efficiency of the system. 展开更多
关键词 铒掺杂 活性硅 反opal结构 溶胶-胶法
下载PDF
Preparation and Application of the Sol–Gel Combustion Synthesis-Made CaO/CaZrO_3 Sorbent for Cyclic CO_2 Capture Through the Severe Calcination Condition 被引量:5
15
作者 王保文 宋小勇 +1 位作者 王宗华 郑楚光 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第9期991-999,共9页
Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the se... Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the severe calcination condition so as to obtain the concentrated C02 stream. In this research, CaO/CaZrO3 sorbents were synthesized using the sol-gel combustion synthesis (SGCS) method with urea as fuel. The cyclic reaction performance of the synthesized sorbents was evaluated on a lab-scaled reactor system through calcination at 950 ℃ in a pure C02 atmosphere and carbonation at 650 ℃ in the 15% (by volume) C02. The mass ratio of CaO to CaZr03 as 8:2 (designated as CasZr2) was screened as the best option among all the synthesized CaO sorbents for its high CO2 capture capacity and carbonation conversion at the initial cycle. And then a gradual decay in the C02 capture capacity was observed at the following 10 successive cycles, but hereafter stabilized throughout the later cycles. Furthermore, structural evolution of the carbonated CasZr2 over the looping cycles was investigated. With increasing looping cycles, the pore peak and mean grain size of the carbonated CasZr2 sorbent shifted to the bigger direction but both the surface area (SA) ratio and surface fractal dimension Ds decreased. Finally, morphological transformation of the carbonated CasZr2 was observed. Agglomeration and edge rounding of the newly formed CaC03 grains were found as aggravated at the cyclic carbonation stage. As a result, carbonation of CasZr2 with C02 was observed only confined to the external active CaO by the fast formation of the CaC03 shell outside, which occluded the further carbonation of the unreacted CaO inside. Therefore, enough attention should be paid to the carbonation stage and more effective activation measures should be explored to ensure the unreacted active CaO fully carbonatPd river the extended Ioonin cycles. 展开更多
关键词 C02 captureCalcium looping cyclesCaO/CaZr03 sorbentSol-gel combustion synthesis method
下载PDF
Preparation and Characterization of M-Type Barium Ferrite Fibers via Aqueous Sol-Gel Process 被引量:1
16
作者 龚彩荣 范国樑 +1 位作者 宋崇林 吕刚 《Transactions of Tianjin University》 EI CAS 2007年第2期117-120,共4页
BaFe12O19 fibers was prepared via an aqueous sol-gel process using Fe(OH)(HCOO)2 synthesized in laboratory and Ba(CH3COO)2 as the original materials and citrate as the chelate. The rheological behaviour of spinn... BaFe12O19 fibers was prepared via an aqueous sol-gel process using Fe(OH)(HCOO)2 synthesized in laboratory and Ba(CH3COO)2 as the original materials and citrate as the chelate. The rheological behaviour of spinnable sol was characterized on rheometer, and the development of gel fibers to barium ferrite fibers was studied by IR, TG and XRD. Morphology observation of the fibers was given on SEM, and the diameter of the obtained fibers was between 5 and 10 um corresponding to different additives. The additives affected the surface tension of the precursor sol which had close relation to the microstructure of fibers. Sucrose and hydroxyethylic cellulose could improve the surface tension while diethanolamine and hexadecylamine reduce that of the decylamine as an additive, well-structured BaFe12O19 precursor sol. And using diethanolamine or hexafibers could be obtained. 展开更多
关键词 barium ferrite FIBER ADDITIVE MICROSTRUCTURE SOL-GEL synthesis
下载PDF
Synthesis of CaCu_3Ti_4O_(12)powders and ceramics by sol-gel method using decanedioic acid and its dielectric properties 被引量:2
17
作者 王茂华 周芙 +1 位作者 王秋丽 姚超 《Journal of Central South University》 SCIE EI CAS 2012年第12期3385-3389,共5页
The CaCu3Ti4O12 xerogels, powders and ceramics were prepared through the sol-gel method using two kinds of organic acid (decanoic acid and decanedioic acid). The xerogels, powders and ceramics were characterized by ... The CaCu3Ti4O12 xerogels, powders and ceramics were prepared through the sol-gel method using two kinds of organic acid (decanoic acid and decanedioic acid). The xerogels, powders and ceramics were characterized by the methods of TG-DTG, FT-IR, XRD, SEM and TEM. The dielectric properties of the ceramics were also measured. The results indicated that the powders calcined at 850 ℃ for 2 h are both nanometer scale particles. After sintering, the ceramics mainly consist of the CaCu3Ti4O12 phase. Compared with the powders prepared using monoacid, the particle size of the powders prepared using diacid obviously increases, and the grain size, the relative density and the whole permittivity of the ceramics increase as well. Specially, the ceramic prepared using decanedioic acid has higher relative density (97.3%), dielectric constant (316 808) and lower dielectric loss (0.242 5) at 30 ℃ (10 kIaz) 展开更多
关键词 CACU3TI4O12 sol-gel method decanedioic acid PERMITTIVITY
下载PDF
Synthesis and Characterization of Sol-Gel Derived MgO/CNTs Nanocomposite 被引量:2
18
作者 Ali Asghar Hosseini Farshad Taleshi +1 位作者 Mahmoud Tajbakhsh Maryam Farhang 《Journal of Chemistry and Chemical Engineering》 2010年第7期29-34,共6页
In this research, synthesis of magnesium oxide-multi walled carbon nanotube (MgO/MWCNTs) nanocomposite is reported using sol-gel method in which magnesium nitrate is added to aqueous solution. The structure of MWCNT... In this research, synthesis of magnesium oxide-multi walled carbon nanotube (MgO/MWCNTs) nanocomposite is reported using sol-gel method in which magnesium nitrate is added to aqueous solution. The structure of MWCNTs and MgO/MWCNTs composite has been characterized by analyzing the X-ray diffraction pattern (XRD), Fourier Transform Infrared (FT-IR) spectra and Scanning Electron Microscopy (SEM) images. Experimental results indicate that the surface of purified MWCNTs sample is covered homogenously by a layered of MgO nanoparticles. 展开更多
关键词 MgO/MWCNTs nanocomposite spectroscopy SOL-GEL SEM.
下载PDF
Synthesis of nanosize MnO_2 and its performence 被引量:1
19
作者 顾大明 魏杰 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2003年第2期205-207,共3页
Sol sol gel method and solid phase redox reaction were respectively applied in preparation of Nanosize MnO 2 powders. The experiments showed that only Mn 2O 3 could be obtained from ignition of Mn(Ⅱ) in the muffle fu... Sol sol gel method and solid phase redox reaction were respectively applied in preparation of Nanosize MnO 2 powders. The experiments showed that only Mn 2O 3 could be obtained from ignition of Mn(Ⅱ) in the muffle furnace in air, and Mn 2O 3 had to be disproportionated in acids to gain MnO 2. The analysis of XRD and TEM technique revealed that the diameters of nanosize MnO 2 obtained by sol gel method was 35~45 nm and the x in MnO x was 1 9; the particle size of MnO 2 produced from solid phase redox reaction was 10~20 nm and the x in MnO x equaled 1 94. The test results have proved that the discharge property of alkaline manganese battery could be improved by nanosize MnO 2. 展开更多
关键词 solid phase synthesis sol gel nanosize MnO 2 discharge properties
下载PDF
Mesoporous Silica Materials Synthesized via Sol-Gel Methods Modified with Ionic Liquid and Surfactant Molecules
20
作者 Cun-ying Xu Ru-lan Tang +1 位作者 Yi-xin Hua Peng-xiang Zhang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2008年第6期596-600,共5页
Mesoporous silica materials were synthesized via a sol-gel method employing a room temperature ionic liquid (1-butyl-3-methylimidazolium tetrafiuoroborate, [bmim][BF4]) as a new solvent medium and further modified w... Mesoporous silica materials were synthesized via a sol-gel method employing a room temperature ionic liquid (1-butyl-3-methylimidazolium tetrafiuoroborate, [bmim][BF4]) as a new solvent medium and further modified with surfactant (hexadecyl-trimethyl-ammonium bromide, CTAB) as a pore templating material. The synthesized samples were characterized by the transmission electron microscopy, X-ray diffraction, and N2 adsorption-desorption techniques. The results indicated that the mesoporous silica synthesized by using [bmim][BF4] and CTAB as mixed templates showed better mesostructural order and smaller pore size, compared with mesoporous silica materials synthesized by using single [bmim][BF4] as template under the same conditions. This indicates that the presence of surfactant can affect the microstructures of silica prepared by'the present synthesis method. 展开更多
关键词 Mesoporous silica Ionic liquid SURFACTANT
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部