Sol–gel preparation and

论文题目：Sol-gel在无机材料中的应用课程名称：无机合成化学专业名称：应用化学学号：1109341009姓名：高康能成绩：2014年9月29日Sol-gel在无机材料中的应用摘要：介绍了溶胶-凝胶法制备有机-无机杂化材料的原理、分类和制备方法及应用。

关键词：溶胶-凝胶法、无机材料、应用引言随着现代科技的发展，单一性能的材料已不能满足人们的需要。

目前通过两种或多种材料的功能复合，性能互补和优化,无机有机杂化材料是无机材料和有机材料在纳米尺度结合的复合材料，两相间存在强的作用力的结构。

可以克服单一的有机或无机材料的局限性。

同时在光学、力学、电学及电化学等方面呈现出许多新的特性。

因此无机有机杂化材料是材料领域的一个重要的研究方向[1-4]。

1 溶胶凝胶法的基本理论溶胶是指分散在液体中的粒子足够小（100mm）以致可以通过布朗运动保持无限期的悬浮。

凝胶是一种包含液相组分秋游内部网络结构的固体，此时的液相和故乡都呈现一种高度分散的状态。

溶胶-凝胶法一般是以金属及半金属盐作为前躯体（硅酸甲酯（TMOS）、正硅酸乙酯（TEOS）、酞酸丁酯等）在水、互溶剂三维网络结构在成胶的过程及催化剂的存在下发生水解和缩聚反应,，形成SiO2中,若引人掺杂组分,可将其包埋于三维网络结构中用溶胶一凝胶法制备的材料不仅有良好的化学性能、高的光稳定性和透过性,,同时溶胶凝胶过程还具有纯度高、均匀性强、反应条件易于控制并易于实现多种产品构型等优点溶胶-凝胶法是湿化学反应方法之一,不论所用的起始原料称为前驱物为无机盐或金属醇盐,其主要反应步骤是前驱物溶于溶剂水或有机溶剂中形成均匀的溶液,溶质与溶剂产生水解或醇解反应生成物聚集成1nm左右的粒子并组成溶胶,经蒸发干燥转变为凝胶具体过程为图溶剂化、水解反应和缩聚反应。

2 溶胶凝胶的特点溶胶一凝胶法的特点是用液体化学试剂或将粉状试剂溶于溶剂中或溶胶为原料,而不是用传统的粉状物体,反应物在液相下均匀混合并进行反应,反应生成物是稳定的溶胶体系,经放置一定时间转变为凝胶,其中含有大量液相,需借助蒸发除去液体介质,而不是机械脱水。

第40卷第9期2021年9月硅㊀酸㊀盐㊀通㊀报BULLETIN OF THE CHINESE CERAMIC SOCIETY Vol.40㊀No.9September,2021硝酸对溶胶-凝胶法制备AlOOH 胶粒粒度的影响段㊀宁1,张湘泰1,陆成龙2,张银凤1,2,李崇瑞1(1.武汉科技大学资源与环境工程学院,武汉㊀430081;2.湖北理工学院,矿区环境污染控制与修复湖北省重点实验室,黄石㊀435003)摘要:为获得孔径可控的氧化铝滤膜,以异丙醇铝为原料,硝酸为胶溶剂,使用溶胶-凝胶法制备了AlOOH 溶胶,并通过纳米粒度仪㊁Zeta 电位等表征手段,研究了硝酸用量对AlOOH 胶粒粒度及粒度分布的影响㊂结果表明,硝酸与异丙醇铝摩尔比R (n (HNO 3)ʒn (Al(C 3H 7O 3)3))为0.2~0.7时,随着R 增大,AlOOH 胶粒的平均粒径从66.69nm (R =0.2)增大到138.80nm(R =0.7),其粒度分布曲线的半高宽(FWHM)由144.62nm 增加到267.74nm㊂AlOOH 溶胶的粒度增大不是由颗粒团聚引起的,而是硝酸加入增大了异丙醇铝水解反应常数,使单位体积内能发生缩聚的中间产物增加,从而促进了AlOOH 胶粒的生长㊂关键词:溶胶-凝胶法;AlOOH 溶胶;硝酸;粒度;水解反应常数中图分类号:TQ174.6+7㊀㊀文献标志码:A ㊀㊀文章编号:1001-1625(2021)09-3105-09Influence of HNO 3on Particle Size of AlOOH Sol Prepared by Sol-Gel MethodDUAN Ning 1,ZHANG Xiangtai 1,LU Chenglong 2,ZHANG Yinfeng 1,2,LI Chongrui 1(1.School of Resource and Environmental Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;2.Hubei Key Laboratory of Mine Environmental Pollution Control and Remediation,Hubei Polytechnic University,Huangshi 435003,China)Abstract :To obtain an alumina filter membrane with a controllable pore size,AlOOH sol was prepared by the sol-gel method with aluminum isopropoxide used as the raw material and HNO 3as the peptizer.The influence of the amount of HNO 3on the particle size distribution of AlOOH colloidal particles was studied through nano-particle size analysis and Zeta potential measurement.The results show that when the ratio of HNO 3to aluminum isopropoxide R (n (HNO 3)ʒn (Al(C 3H 7O 3)3))is in the range of 0.2to 0.7,the average particle size of the colloidal particles increases with the increase of R ,from 66.69nm (R =0.2)to 138.80nm (R =0.7).The full width at half maxima (FWHM)of the particle size distribution of the colloidal particles increased from 144.62nm to 267.74nm.The reason for the increase of the particle size of AlOOH sol isn t the agglomeration of particles,but the increase of the hydrolysis reaction constant of aluminum isopropoxide,which increases the total amount of the intermediate products per unit volume involved in the polycondensation reaction,thereby promoting the growth of AlOOH colloidal particles.Key words :sol-gel method;AlOOH sol;nitric acid;particle size;hydrolysis reaction constant收稿日期:2021-03-23;修订日期:2021-04-23基金项目:矿区环境污染控制与修复湖北省重点实验室开放基金(2019106)作者简介:段㊀宁(1976 ),女,博士,副教授㊂主要从事水处理工艺及功能材料方向的研究㊂E-mail:dn828@通信作者:张银凤,博士,副教授㊂E-mail:zhangyinfeng2018@ 0㊀引㊀言溶胶-凝胶法由于具有工艺设备简单㊁成本低廉㊁化学成分可控㊁可在相对低温下制备高纯㊁小孔径的陶瓷膜等优点[1-2],被普遍认为是制备陶瓷滤膜最有效的方法之一[3]㊂氧化铝膜具有耐高温㊁耐腐蚀等优点,是目前应用最为广泛的一类无机膜[4-5]㊂溶胶-凝胶法制备氧化铝滤膜的关键是溶胶的制备方法,其对滤膜的孔径及孔径分布等参数有很重要的影响㊂孔径是氧化铝膜的重要参数,对氧化铝膜的选择透过性有巨大3106㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第40卷影响[6]㊂孔径的大小和孔径分布是滤膜质量控制的主要指标㊂只有实现孔径的高度均匀,才能提高滤膜的过滤精度㊂胶粒的粒径分布是影响氧化铝滤膜孔径和孔径分布的直接原因之一,滤膜的孔隙是由涂覆在支撑体上的胶粒交联㊁堆积形成的,其孔径分布及孔的形状则分别取决于胶粒的粒度分布及胶粒的形状[7]㊂故胶粒的粒度直接影响陶瓷膜的孔径大小,胶粒的粒度分布宽度也直接影响着陶瓷膜孔径分布的宽度㊂所以,通过控制溶胶粒径分布来控制陶瓷膜孔径的大小及分布,对调节陶瓷膜的孔径分布十分重要㊂溶胶-凝胶法可以分为金属醇盐水解法和无机盐水解法㊂前者通常加入酸作为胶溶剂,使粒子均匀分散形成胶体体系[8]㊂其中胶溶剂的类型对溶胶的稳定性及其粒度分布有着很大影响㊂刘智信等[9]研究认为在以异丙醇铝为前驱体制备AlOOH溶胶中硝酸是最适合的胶溶剂㊂研究表明[10],硝酸的加入量对AlOOH 溶胶的稳定性有很大影响,硝酸与异丙醇铝的比例R(R=n(HNO3)ʒn(Al(C3H7O3)3),摩尔比,下同)控制在合适范围内,可以制得澄清透明的溶胶㊂当R过小时,沉淀不能完全被胶溶,在容器底部留下沉淀;当R 过大时,制备出的溶胶不稳定易凝胶[11]㊂此外,加入的硝酸也可以作为催化剂促进水解反应[12],提高反应速率,促进水解产物晶粒生长㊂因此,硝酸加入量对AlOOH溶胶的粒径有着很大影响㊂目前,在制备AlOOH溶胶时,硝酸对胶粒的生长和粒度分布的影响的相关报道较少㊂本文以异丙醇铝为前驱体㊁水为反应介质㊁硝酸为胶溶剂制备AlOOH溶胶,并深入研究溶胶-凝胶法中硝酸对水解反应的影响,为在制备中控制氧化铝滤膜的孔径分布提供重要参考㊂1㊀实㊀验1.1㊀试剂与仪器溶胶-凝胶法制备AlOOH溶胶所采用的化学试剂包括:异丙醇铝(上海麦克林公司;分析纯)㊁无水乙醇(上海国药;分析纯)㊁浓硝酸(上海国药;分析纯)㊂试验制备与表征所用仪器设备包括:集热式恒温加热磁力搅拌器(上海力辰邦西仪器科技有限公司, DF-101S)㊁电子天平(上海越平科学仪器有限公司,FA2204C)㊁Zetasizer Nano粒度/电位分析仪(马尔文仪器有限公司(中国),ZEN3690)㊁场发射扫描电子显微镜(日本电子株式会社,JSM-6710Fp)㊁X射线衍射仪(布鲁克科技有限公司,D8A)㊂1.2㊀制备方法以异丙醇铝为原料的AlOOH溶胶制备流程如图1所示㊂准确量取75mL纯水于三口烧瓶中,于85ħ恒温水浴搅拌㊂精确称取11.33g异丙醇铝料,使异丙醇铝与水的摩尔比为1ʒ75,缓慢加入三口烧瓶中,水解1.5h㊂滴加一定量硝酸胶溶剂(见表1),使沉淀分散,继续搅拌1h,得到澄清透明的AlOOH溶胶㊂图1㊀AlOOH溶胶制备流程图Fig.1㊀Preparation process of AlOOH sol表1㊀硝酸胶溶剂加入量Table1㊀Scheme of addition amount of nitric acid peptizer㊀第9期段㊀宁等:硝酸对溶胶-凝胶法制备AlOOH胶粒粒度的影响3107 1.3㊀测试表征将凝胶化的AlOOH溶胶干燥后制成粉末,采用X射线衍射仪(XRD)在扫描范围为5ʎ~90ʎ下对其进行物相分析㊂采用场发射扫描电子显微镜,对两种方式制备的AlOOH胶粒样品进行分析(①将AlOOH溶胶静置至凝胶化后干燥,制得样品;②将AlOOH溶胶稀释于乙醇中,滴于铝片上,待乙醇挥发化之后制得样品)㊂采用Zetasizer Nano粒度/电位分析仪的粒度测量功能对AlOOH溶胶的粒度分布进行分析㊂为避免由颗粒团聚而造成测量误差,将各组溶胶稀释15倍,测定稀释后溶胶的吸光度与折射率,输入激光粒度分析仪,测定粒度分布㊂同时测定未稀释的AlOOH溶胶粒度分布㊂采用Zetasizer Nano粒度/电位分析仪的Zeta电位测量功能对各组溶胶样品进行zeta电位测定㊂2㊀结果与讨论2.1㊀物相分析使用异丙醇铝为前驱体,硝酸与异丙醇铝不同比例R制得AlOOH溶胶样品如图2所示㊂未加入硝酸反应体系白色的异丙醇铝粉末无法在试验时间内完全水解,如图2(a)所示;当R<0.2时,容器底部有大量的白色沉淀,上层为浑浊不透明液体,这说明在硝酸比例过低时,只能呈现出悬浮液的外观,而无法将沉淀分散形成澄清透明的溶胶,如图2(b)所示;当Rȡ0.2时,如图2(c)所示,白色沉淀完全溶解,液体在光线照射下出现丁达尔效应,形成了透明的溶胶㊂图2㊀硝酸与异丙醇铝不同比例R制得AlOOH溶胶样品图Fig.2㊀Graph of AlOOH sol under different R(n(HNO3)ʒn(Al(C3H7O3)3))凝胶化的溶胶干燥粉末的XRD谱图如图3所示㊂由图3可看出,制得的溶胶粉末具有良好的结晶度,产物在衍射角(2θ)为:14.49ʎ㊁28.18ʎ㊁38.34ʎ㊁48.93ʎ㊁49.21ʎ㊁55.22ʎ㊁60.59ʎ㊁64.03ʎ㊁64.98ʎ㊁71.90ʎ位置的衍射峰与标准PDF卡片21-1307勃姆石(AlOOH)的晶面(020)㊁(120)㊁(031)㊁(051)㊁(200)㊁(151)㊁(080)㊁(231)㊁(002)㊁(251)的衍射数据相对应,可知制得溶胶颗粒的成分为勃姆石(AlOOH)㊂2.2㊀硝酸用量对AlOOH溶胶凝胶时间的影响为确定硝酸用量对AlOOH溶胶的凝胶时间影响规律,以获得最佳的硝酸用量,按照表1制备各组样品,并记录凝胶时间(记倾斜45ʎ液面不发生流动的时间点为凝胶时间)㊂硝酸与异丙醇铝比例(R)对凝胶时间的影响如图4所示㊂从图4中可知,随着硝酸用量增加,溶胶的凝胶时间下降,AlOOH溶胶的凝胶时间从288h(R=0.2)下降到了0.2h(R=0.7)㊂凝胶时间是溶胶稳定性的体现,当R=0.7时,制得溶胶的凝胶时间过短,溶胶难以保存,且凝胶化的过程会伴随着黏度上升,使溶胶涂膜的时机难以控制㊂因此,硝酸与异丙醇铝的最佳比例为0.2<R<0.7㊂3108㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第40卷图3㊀干燥后溶胶粉末的XRD 谱Fig.3㊀XRD pattern of dried sol powder 图4㊀硝酸与异丙醇铝比例R 对凝胶时间的影响:(a)凝胶时间曲线;(b)溶胶样品图;(c)凝胶样品图Fig.4㊀Influence of R (n (HNO 3)ʒn (Al(C 3H 7O 3)3))on gelation time:(a)curve of Gelation time;(b)graph of sol sample;(c)graph of gel sample 2.3㊀硝酸用量对AlOOH 胶粒粒径及分布的影响AlOOH 溶胶颗粒不同倍数的SEM 照片如图5所示㊂由图5(a-1)中可看出,样品a 为不规则的微米级颗粒,在高倍下为致密的光滑平面,但无法观测到胶粒,并未体现出纳米颗粒的特征㊂这是因为AlOOH 凝胶的比表面积过大,干燥时因毛细管力严重收缩,导致无法观测到胶粒㊂由图5(b-1)与图5(b-2)可看出,样品b 为粗糙的球形颗粒,粒径均匀,粒径多小于100nm,溶胶颗粒堆积形成众多的孔隙㊂由于溶胶失水收缩速率不一致,在收缩较快处出现一些如下所示的微米级大孔,从更高倍数的图5(b-2)可以看到,大孔并未完全贯通,依然存在大量的溶胶颗粒堆积㊂图5㊀AlOOH 溶胶颗粒的SEM 照片:(a)凝胶化后干燥制得;(b)稀释在乙醇中挥发后制得Fig.5㊀SEM images of AlOOH samples:(a)dried after gelation;(b)dilution in ethanol and evaporation 未稀释的AlOOH 溶胶与稀释15倍的溶胶粒度分布如图6所示㊂由图6可看出,稀释后的溶胶频率分布为类似正态分布的单峰曲线,这表明AlOOH 胶粒分散较好,未出现严重团聚的现象㊂而未稀释的AlOOH 溶胶因团聚表现出多峰曲线㊂为避免团聚影响,将溶胶稀释15倍后使用Zetasizer Nano 粒度分析仪进行分㊀第9期段㊀宁等:硝酸对溶胶-凝胶法制备AlOOH胶粒粒度的影响3109析测量㊂硝酸与异丙醇铝不同比例AlOOH溶胶胶粒的频率/累积分布曲线如图7所示㊂图6㊀AlOOH溶胶样品与溶胶稀释样品的频率分布图Fig.6㊀Frequency distribution of AlOOH sol sample and diluted sol sample图7㊀硝酸与异丙醇铝不同比例AlOOH溶胶胶粒的频率/累积分布曲线Fig.7㊀Frequency and cumulative distribution curves of AlOOH colloidal particles underdifferent R(n(HNO3)ʒn(Al(C3H7O3)3))3110㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第40卷硝酸与异丙醇铝比例R 对AlOOH 溶胶平均粒径的影响如图8所示㊂由图8可看出,在AlOOH 溶胶的制备中,硝酸加入量与胶粒平均粒径呈正相关关系㊂当硝酸与异丙醇铝比例R 为0.2时,溶胶的平均粒径为66.69nm;随着硝酸与异丙醇铝比例R 增大,溶胶的平均粒径逐渐增大至138.80nm(R =0.7)㊂由此可知,增加硝酸加入量,可以显著地提高AlOOH 胶粒的粒径㊂由图7可看出,除了平均粒径外,各组溶胶样品的粒径分布宽度也存在差异㊂粒度分布越窄,表明溶胶颗粒尺寸的均匀性越好,以此制得的氧化铝分离膜的孔径分布也越均匀㊂以粒径分布的半高宽(FWHM)表示粒度分布的宽窄,硝酸与异丙醇铝比例R 对胶粒粒度分布半高宽的影响如图9所示㊂由图9可知,随着硝酸与异丙醇铝比例R 增大,AlOOH 胶粒粒径分布半高宽表现出波动变化,其半高宽由144.62nm(R =0.2)下降到了111.56nm(R =0.3)㊂经过多次波动后增加到267.74nm(R =0.7),说明硝酸加入量增加使粒度分布总体变宽㊂图8㊀硝酸与异丙醇铝比例R 对AlOOH 溶胶平均粒径的影响Fig.8㊀Influence of R (n (HNO 3)ʒn (Al(C 3H 7O 3)3))on average particle size of AlOOHsol 图9㊀硝酸与异丙醇铝比例R 对胶粒粒度分布半高宽的影响Fig.9㊀Influence of R (n (HNO 3)ʒn (Al(C 3H 7O 3)3))on FWHM of frequency distribution of AlOOH sol2.4㊀以颗粒团聚角度分析胶粒粒径变化的原因有研究表明,胶溶剂对粒径的影响机理是改变了Zeta 电位[13-14]㊂根据DLVO 理论,硝酸加入后,电离产生的H +吸附在AlOOH 胶粒表面,NO -3在胶粒附近重新排布,从而在胶粒表面形成双电层[15]㊂胶粒在溶胶体系中受到双电层斥力与范德华引力作用,当酸的加入量较小时,沉淀物表面Zeta 电位较低,斥力不足以使颗粒分散;酸的加入量增加,使胶粒Zeta 电位上升,胶粒之间的斥力增大,溶胶的稳定性逐渐提高而最终形成透明的溶胶;随着酸的加入量进一步增大,过多的电解质反而压缩双电层使Zeta 电位降低,溶胶颗粒之间的距离因斥力降低而减小,使胶粒易团聚,表现为胶粒粒径增大㊂将各组直接制得的未稀释溶胶样品进行粒度分析,绘制其平均粒径-硝酸与异丙醇铝比例R 曲线如图10所示㊂从图10各组未稀释溶胶的平均粒径变化曲线可看,当R 增大时,确实会使胶粒团聚,而导致测得的平均粒径增大㊂从图6的稀释前后粒度分布图可以看出,团聚的原样测得的粒度数据表现为无规律的双峰或多峰图像,而图7所示的稀释溶胶的粒度分布均为近似正态分布的单峰图像,因此测得稀释样品的胶粒团聚程度非常轻㊂硝酸与异丙醇铝比例R 对AlOOH 溶胶Zeta 电位的影响如图11所示㊂从Zeta 电位测试结果可知,随着硝酸与异丙醇铝比例R 的增大,Zeta 电位表现出先上升后下降的趋势㊂其中当R =0.2时,Zeta 电位为26.6mV,随着R 的增大Zeta 电位达到最高(41.2mV;R =0.35),随着R 的进一步增大,Zeta 电位开始下降,最终下降到最低(16.3mV;R =0.7)㊂从上述Zeta 电位与平均粒径的测试结果可看出,当R ɤ0.35时,AlOOH 溶胶的Zeta 电位随着R 的增大而增大,溶胶稳定性增强,颗粒团聚程度变轻,但其平均粒径也随着R 增大而增大㊂因此,Zeta 电位与团聚理论无法解释胶粒增大的原因㊂第9期段㊀宁等:硝酸对溶胶-凝胶法制备AlOOH 胶粒粒度的影响3111㊀图10㊀溶胶样品与溶胶稀释样品的硝酸与异丙醇铝比例R -平均粒径曲线Fig.10㊀R (n (HNO 3)ʒn (Al(C 3H 7O 3)3))-average particle size curve of sol sample and diluted solsample 图11㊀硝酸与异丙醇铝比例R 对AlOOH 溶胶Zeta 电位的影响Fig.11㊀Influence of R (n (HNO 3)ʒn (Al(C 3H 7O 3)3))on Zeta potential of AlOOH sol 2.5㊀硝酸影响AlOOH 胶粒粒径的作用机理为明确AlOOH 胶粒增大的内在原因,需研究AlOOH 胶粒产生的反应过程㊂使用异丙醇铝制备AlOOH溶胶可分为水解反应与缩聚反应[16]㊂具体反应式如下:水解反应如式(1)所示:Al[OCH(CH 3)2]3+n H 2O ңAl[OCH(CH 3)2]3-n (OH)n +n (CH 3)2CHOH (1)缩聚反应可分为脱水缩聚和脱醇缩聚:脱水缩聚如式(2)所示:Al[OCH(CH 3)2]3-n (OH)n +Al[OCH(CH 3)2]3-m (OH)m ң(OH)n -1[CH(CH 3)2O]3-n Al O Al [CH(CH 3)2O]3-m (OH)m -1+H 2O (2)脱醇缩聚如式(3)所示:[CH(CH 3)2O]3-n Al(OH)n +[CH(CH 3)2O]3-m Al(OH)m ң(OH)n [CH(CH 3)2O]2-n Al O Al[CH(CH 3)2O]m (OH)m-1+CH(CH 3)2OH (3)从上述反应式中可以看出,异丙醇铝生成AlOOH 胶粒,第一步的水解反应由异丙醇铝水解生成异丙醇与含有羟基的中间产物,与此同时缩聚反应就立即开始,缩聚反应的进行使中间产物成核并生长㊂反应速率方程可由下列公式表示:d[ Al OCH(CH 3)2]dt =-K hy [Al OCH(CH 3)2][H 2O]-K da [Al OCH(CH 3)2][Al OH](4)d[ Al OH]dt =K hy [ Al OCH(CH 3)2][H 2O]-K dh [ Al OH]2-K da [ Al OCH(CH 3)2][ Al OH](5)d[ Al O Al ]dt =K dh [ Al OH]2+K da [ Al OH][ Al OCH(CH 3)2](6)其中式(4)表示异丙醇铝的反应速率,式(5)代表中间产物的反应速率,式(6)表示AlOOH 胶粒的反应速率,K hy 表示水解反应速率常数,K dh 代表脱水缩聚反应速率常数,K da 表示脱醇缩聚反应速率常数㊂酸在溶胶-凝胶法中,除了作为使胶体体系稳定的胶溶剂外,还可以作为促进水解反应的催化剂[17]㊂在一个反应体系中,速率最慢的步骤为速率控制步骤,其反应速率常数低于其他步骤㊂王焆等[18]的研究认为,在以酸为催化剂的体系中,水解速率远小于缩聚速率㊂在本试验中,未加入硝酸的反应体系中白色异丙醇铝粉末无法在试验时间内完全水解;随着硝酸与异丙醇铝摩尔比R 的增大,白色沉淀溶解的速度加快㊂在本3112㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第40卷试验中,反应速率是由水解反应控制的,硝酸加入量的增大可使水解反应速率增大㊂因此,硝酸影响粒径的机理是通过提高水解反应速率来增大中间产物浓度,使胶粒核周围能参与缩聚反应的物质增加而使胶粒生长加快㊂根据颗粒团聚理论与反应过程分析,绘制图12所示的示意图以描述硝酸影响胶粒生长的机理㊂AlOOH 胶粒的成核与生长是通过缩聚反应进行控制的,其反应物是水解反应产生的中间产物㊂硝酸作为水解反应的催化剂,当硝酸加入量低时,水解反应速率常数K hy小,使得异丙醇铝水解的中间产物在单位体积内浓度小,少量中间产物缩聚后即形成胶粒核,胶粒核生成后仅能与周围少量的中间产物发生缩聚反应,使胶粒核多而生长慢,限制了AlOOH胶粒的增大;当硝酸加入量增大时,水解反应速率常数K hy增大,单位体积内的中间产物浓度随之增加,大量的中间产物缩聚形成胶粒核,且能与更多中间产物发生缩聚反应,使AlOOH胶粒随之增大㊂胶粒生长的同时,溶剂中的H+吸附在胶粒表面形成双电层结构,阻止胶粒互相接近团聚,并形成溶胶㊂异丙醇铝的水解反应速率小,胶粒核在整个反应过程中都将持续产生,而率先产生的AlOOH胶粒核随着反应的进行不断生长,后产生的胶粒核没有足够的中间产物参与缩聚反应,使粒度分布变宽㊂图12㊀硝酸加入量对粒径影响示意图Fig.12㊀Mechanisms of the influence of the amount of nitric acid on the particle size3㊀结㊀论溶胶-凝胶法能够通过控制溶胶的粒径分布来控制滤膜孔径及孔隙率的大小,在氧化铝滤膜的制备中被广泛应用㊂本文以异丙醇铝为原料,硝酸为胶溶剂,利用溶胶-凝胶法制备AlOOH溶胶,通过纳米粒度分析㊁Zeta电位等表征手段,研究硝酸用量对AlOOH胶粒粒度及粒度分布的影响㊂(1)硝酸与异丙醇铝的摩尔比R(n(HNO3)ʒn(Al(C3H7O3)3))为0.2~0.7时,胶粒的平均粒径随着R 增大而增大,从66.69nm(R=0.2)增加到138.80nm(R=0.7);胶粒的粒度分布半高宽不断波动,但硝酸用量增加使粒度分布总体变宽,其半高宽由144.62nm(R=0.2)下降到了111.56nm(R=0.3),后经过多次波动增加到267.74nm(R=0.7)㊂(2)硝酸使AlOOH胶粒平均粒径增大的原因并非是Zeta电位变化而导致的团聚,而是硝酸作为催化剂增大了速率控制步骤 水解反应的反应速率常数,从而使单位体积内可以发生缩聚的中间产物增加, AlOOH胶粒增大㊂参考文献[1]㊀GUO X Z,ZHANG Q L,DING X G,et al.Synthesis and application of several 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收稿日期：2011-08-06作者简介：谷开慧（1978-），女，硕士，讲师，主要从事光学材料研究,E-mail ：249648921@ 。

通讯作者：张希艳（1957-），女，教授，博士师导师，E-mail ：xiyzhang@ 。

长春理工大学学报（自然科学版）Journal of Changchun University of Science and Technology （Natural Science Edition ）第34卷第4期2011年12月Vol.34No.4Dec.2011溶胶-凝胶法制备β-锂霞石纳米粉体谷开慧1，李岩2，房文汇1，郭明1，房丹1，张希艳2，赵文兴3（1.长春理工大学光电信息学院，长春130012；2.长春理工大学材料科学与工程学院，长春130022；3.长春光学精密机械与物理研究所，长春130033）摘要：采用溶胶-凝胶法合成了β-锂霞石超细粉体，利用差热-热重分析仪、X-射线衍射仪、扫描电子显微镜等对溶胶-凝胶的形成以及样品的物相和形貌进行分析。

研究了柠檬酸与金属离子比、溶液的pH 值、成胶温度，粉体灼烧温度和时间等对样品物相和形貌的影响。

结果表明，当柠檬酸与金属离子比为2：1、pH=3、温度控制在65℃时，得到稳定的溶胶，蒸发干燥后的凝胶在900℃~1300℃温度范围进行煅烧，获得了物相纯度较高的β-锂霞石粉体，粒径约20nm~50nm 。

关键词：光学材料；β-锂霞石；超细粉体；溶胶-凝胶法中图分类号：TB333文献标识码：A文章编号：1672-9870（2011）04-0097-03Sol-gel Preparation of-eucrytite Superfine PowdersGU Kaihui 1，LI Yan 2，FANG Wenhui 1，GUO Ming 1，FANG Dan 1，ZHANG Xiyan 2，ZHAO Wenxing 3（1.Changchun University of Science and Technology ，College of Optical and Electrical Information ，Changchun 130012；2.School of Materials Science and Engineering ，Changchun University of Science and Technology ，Changchun 130022；3.Changchun Institute of Optics Fine Mechanics and Physics ；Changchun 130033）Abstract ：β-Eucryptite powders was synthesized through sol -gel method.TG-DSC ，XRD and SEM were employed to study the sol-gel formation ，crystalline phase and morphology of the samples.Effects of citric acid to metal ions ra-tio ，pH value of the solution ，sol and gel temperature and firing temperature and time were studied.Results indicated that clear gel could be obtained when citric acid to metal ions ratio is 2：1，pH value is 3at 65℃.The pure phase β-Eucryptite powders with sizes of 20~50nm were obtained when fired at 900~1300℃.Key words ：optical materials ；β-eucryptite ；superfine powders ；sol-gel method固体材料随温度变化一般会发生膨胀或收缩，材料的热胀冷缩会削弱甚至破坏材料的功能特性，降低精密部件的结构稳定性和安全可靠性。

Al掺杂ZnO厚膜的sol-gel法制备及其气敏性能研究
田野;潘国峰;杨瑞霞
【期刊名称】《电子元件与材料》
【年(卷),期】2010(029)011
【摘要】以硝酸锌、硝酸铝和氢氧化钠为原料,采用sol-gel法制备铝掺杂的纳米氧化锌厚膜(样品),并利用XRD和SEM对其微观结构进行了表征.研究了铝掺杂量和退火温度对ZnO厚膜的气敏性能的影响.结果表明:700℃退火,掺w(Al)为2.9%的样品对体积分数为4.0×10-1的丙酮有很好的选择性,最大灵敏度达到7 779左右,最佳工作温度约为162℃,响应,恢复时间均为1 s,最后讨论了铝掺杂纳米氧化锌的气敏机理.
【总页数】5页(P27-31)
【作者】田野;潘国峰;杨瑞霞
【作者单位】河北工业大学信息工程学院,天津,300130;河北工业大学信息工程学院,天津,300130;河北工业大学信息工程学院,天津,300130
【正文语种】中文
【中图分类】TP212
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1.层状多孔ZnO厚膜的制备及其气敏性能研究 [J], 梅鑫涛;张五星;李爽;吕文中;胡先罗;袁利霞;黄云辉
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因版权原因，仅展示原文概要，查看原文内容请购买。

Preparation and characterization of single-phase α-Fe 2O 3nano-powders by Pechini sol –gel methodYuanting Wu ⁎,Xiufeng WangSchool of Materials Science &Engineering,Shaanxi University of Science &Technology,Xi'an,712081,Chinaa b s t r a c ta r t i c l e i n f o Article history:Received 27November 2010Accepted 1April 2011Available online 8April 2011Keywords:Fe 2O 3Nano-powders PechiniSol –gel method Citric acidIn this work,single-phase α-Fe 2O 3nano-particles were first synthesized via Pechini sol –gel method using citric acid and polyethylene glycol-6000as chelating agents.The structural coordination of as-prepared polymeric intermediates was investigated by FTIR analysis.Thermal behavior of the polymeric intermediates was studied by TG-DTG-DSC thermograms.The structure of the powders calcined at different temperatures was characterized by XRD and FESEM.The single-phase α-Fe 2O 3nano-powders with uniform size were prepared when the polymeric intermediate calcined at 600°C,and the lowest particle size was found to be 30nm.©2011Elsevier B.V.All rights reserved.1.IntroductionHematite (α-Fe 2O 3)is the most stable iron oxide and the most environmentally friendly semiconductor (e.g., 2.1eV)[1].It is traditionally used for red pigment [2],catalysts [3],electrodes [4],gas sensors [5,6],magnetic materials [7],photocatalytic [8]and anticorrosion protective paints.The properties of nano-powders greatly depend on their phase,microstructure and surface character-istics.The importance of single phase iron oxide cannot be ignored as it is crucial for the accurate measurement of electricity and magnetism.In order to prepare homogenous nano-particles of iron oxide,researchers have employed in different routes to facilitate single-phase iron oxide nano-particles such as sol –gel processes [9],w/o microemulsion [10],combustion [11],solvothermal [12],hydro-thermal [13],precursor [14],solvent evaporation etc.However,these methods usually involve special equipment,high temperatures,and the tedious removal of impurities,which are all time-consuming and come at a high monetary cost.The Pechini process has been used for the preparation of nano or sub-micro powders in a variety of metal oxides using inorganic salts as precursors,citric acid as a chelating agent and polyethylene glycol (PEG)as cross-linking agent [15,16].The principle of the Pechini process is based on the ability of weak polybasic acids to chelate the metal ions.The chelates can undergo polyesteri fication with poly-hydroxyl alcohols to form a solid polymer resin with a homogeneous distribution of cations at molecule level [17].The highly branchedpolymer can reduce the cation mobility during heat treatment,so that the product with a good dispersion could be prepared.And Pechini method has better stoichiometric control,lower toxicity and cost.Hence,in the present work,we have carried out a systematic study on Pechini sol –gel method using polyethylene glycol-6000with citric acid for the synthesis of single-phase α-Fe 2O 3nano-powders.The thermal decomposition,microstructure and the crystallinity were respectively investigated by FTIR,TG-DTG-DSC,XRD and FESEM measurements.2.Experimental procedure 2.1.MaterialsCitric acid,FeSO 4·7H 2O and polyethylene glycol (PEG)-6000were of analytical grade and used without further puri fication.2.2.Chemical synthesisThe 0.025mol citric acid,0.005mol FeSO 4·7H 2O and 1.2g of polyethylene glycol (PEG)-6000were added to 50ml of distilled water and ethanol (99.7%).The volume ratio of distilled water to ethanol was 3:2.The mixture was vigorously stirred to obtain a clear yellow-coloured solution.The solution was evaporated at 85°C for 5h,and it turned into a viscous yellow-coloured polymeric gel (resin).Further,the resin was dried at 135°C for 5h and obtained the porous polymeric intermediates (dried gel).The resulting porous materials were calcined at 450,600,720°C for 5h to obtain Fe 2O 3nano-powders.Because the TG curve is different from DTG curve at 510°C,Materials Letters 65(2011)2062–2065⁎Corresponding author.Tel.:+8602986131722;fax:+8602986168059.E-mail address:wuyuanting@ (Y.Wu).0167-577X/$–see front matter ©2011Elsevier B.V.All rights reserved.doi:10.1016/j.matlet.2011.04.004Contents lists available at ScienceDirectMaterials Lettersj o u r na l ho m e p a g e :w w w.e l s ev i e r.c o m /l o c a t e /m a t l e tthe porous materials were then calcined at510°C for2h to show the immediate changes of crystal phase.2.3.Sample characterizationIR spectra were recorded with an FTIR spectrometer(BrukerVT0, Germany)in the range of400–4000cm−1on pressed disks using KBr as binding material.TG-DTG-DSC curves were recorded with thermal analyzer(STA409PC,Germany)in air at a heating rate of10°C/min, using a-Al2O3as a reference.The crystalline phases in calcined powders were identified by the XRD powder method using CuKa (D/max-2200PC,Japan),2θ=10–70°,λ=1.5406Å.The morphol-ogy of the powder was obtained using FE-SEM(JSM-6700F,Japan) micrograph.3.Results and discussionFig.1shows the FTIR spectra of the as prepared polymeric intermediates.The peak observed at3433cm−1is due to the presence of–OH groups in the citric acid and polyethylene glycol derivatives [18].The peak observed at2964cm−1is attributed to the asymmetric stretching of–CH2,–CH3groups present in the organic derivatives [19].The appearance of the band at1741cm−1for–COOH groups [15],the bands at1645and1448cm−1respectively for the asymmetric and symmetric stretching of C=O(△ν=197cm−1) [20],and the bands at1390and1168cm−1for–COO−and C–O strongly suggests that some–COOH groups in citric acid have reacted with polyethylene glycol or with metal ions,while some have not.On the other hand,the peak observed at1282cm−1is also ascribed to the esterification reaction between the citric acid and polyethylene glycol. And a broad band at about611cm−1is assigned to Fe–O in polymeric intermediates.The FTIR spectra revealed that△ν=197cm−1,so citric acid combined with metal ions mainly for the two-tooth complexing and bridge complexing[20].The probable Pechini process is sequential and consists of two steps.Thefirst step represents chelates formation, which initiates the uniform distribution of iron ions.The chelates undergo polyesterification with polyethylene glycol to grow into a polymer network.The polymeric structure is broken down and releases iron as Fe2O3in thefiring process.The–OH and–COOH groups are important for chelates formation.The–OH and–COOH groups easily form hydrogen bonds(–O H O=C).And the–COOH groups easily turn into–COO–groups which form chelates with metal ions.This method makes it simple to obtain phase-pure,ultra-fine powders in a few hours at a suitable temperature.TG-DTG and DSC analysis were performed to investigate the decomposition behavior of the precursor powders,which was due to heat treatment in air,and the thermograms are shown in Fig.2(a)and (b).The TG-DTG and DSC curves reveal that the decomposition occurs in three different weight-loss steps.Thefirst step,corresponding to1% weight-loss,is due to the vaporization of water at temperatures between25and200°C.The second step,corresponding to two exothermic peaks in the DSC curve accompanied by weight-loss of 69%,is observed from200to470°C.An endothermic peak at229°C indicates the deformation of the polymer network mainly due to polyethylene glycol breakup.The endothermic peak at398°C is due to the combustion of citric acid and polyethylene glycol derivatives and the formation of Fe2O3phase,and it is supported by XRD results. Finally,one exothermic peak observed at600°C in the DSC curve,is attributed to the formation of pureα-Fe2O3.It's also confirmed by the corresponding XRD patterns in Fig.3.This step has a weight-loss of 10%,which is due to combustion of the remaining organic compound.Fig.3shows the XRD patterns of powders calcined at different temperatures(450,510,600and720°C).From Fig.3,the observed peaks in XRD pattern for the powders calcined at450°C due to iron oxide.The strong signals at20.3°,24.6°,29.7°and32.6°2θare due to Fe2O3(JCPDS21-0920).Characteristic peaks of iron oxide (α-Fe2O3andγ-Fe2O3)appear in the powders calcined at510°C.The peaks at30.2°,35.6°,43.3°and63.1°2θbelong toγ-Fe2O3(JCPDS39-1346).The observed peaks at24.1°,33.1°,35.6°,40.8°,49.4°,54.0°, 57.5°,62.4°and63.9°2θfor the powders calcined at600°C and above are attributed to theα-Fe2O3(JCPDS33-0664)only.Crystallite size for the synthesized Fe2O3powders was calculated using Scherer's formula.Andγ-Fe2O3(110)peak was used at510°C,whileα-Fe2O3 Fig.1.FTIR spectra of the polymericintermediates.Fig.2.(a)TG-DTG and(b)DSC graphs of the polymeric intermediates.2063Y.Wu,X.Wang/Materials Letters65(2011)2062–2065(104)peak was used at 600and 720°C.It is found to be 21.5,28.9,and 31.0nm respectively for the Fe 2O 3powders calcined at 510,600and 720°C.Fig.4shows SEM images of the Fe 2O 3powders calcined at 450,600and 720°C.The polymeric intermediate has separated to particleswith more or less bridging polymeric materials by heating to 450°C,which is also evident from the TG-DTG and DSC curves and XRD patterns.The α-Fe 2O 3particles obtained at 600°C are spheres with around 30nm particle size.At 720°C,α-Fe 2O 3particles with 50to 100nm in diameter are formed,which are more agglomerated than the one prepared at 600°C.The above results show that remarkable grain growth occurred above 600°C.The particle size of Fe 2O 3calcined at 600°C estimated from FESEM is similar with that calculated from the XRD data.Therefore,the particle size of Fe 2O 3calcined at 720°C estimated from FESEM is larger than that calculated from the XRD data.4.ConclusionsIn summary,single-phase α-Fe 2O 3nano-particles have been synthesized via the Pechini sol –gel method in this paper.The thermal behavior observed in the TG-DTG and DSC curves shows the characteristic decomposition steps of the organic precursors whereas FTIR and XRD spectra are determinants for the detection of traces of Fe 2O 3.The α-Fe 2O 3and γ-Fe 2O 3phases began to form when the dried gel calcined at 450°C.The single phase α-Fe 2O 3nano-powders were obtained while calcined at 600°C and above.The effect of calcination temperature on particle size of synthesized Fe 2O 3nano-powders was investigated and the lowest particle size was found to be 30nm for the α-Fe 2O 3nano-powders calcined at 600°C.AcknowledgementThis study was supported by the Special Foundation of Educational Department of Shaanxi Province (No.09JK362)and the Natural Science Foundation of Shaanxi Province (No.2010JQ6006,No.2009JM6008).References[1]Wen XG,Wang SH,Ding Y,Wang ZL,Yang SH.Controlled growth of large-area,uniform,vertically aligned arrays of α-Fe 2O 3nanobelts and nanowires.J Phys Chem B 2005;109:215–20.[2]Feldmann C.Preparation of nanoscale pigment particles.Adv Mater 2001;13:1301–3.[3]Bell AT.The impact of nanoscience on heterogeneous catalysis.Science 2003;299:1688–91.[4]Yarahmadi SS,Tahir AA,Vaidhyanathan B,Wijayantha KGU.Fabrication ofnanostructured α-Fe 2O 3electrodes using ferrocene for solar hydrogen generation.Mater Lett 2009;63:523–6.[5]Wang Y,Cao JL,Wang SR,Guo XZ,Zhang J,Xia HJ,et al.Facile synthesis of porousα-Fe 2O 3nanorods and their application in ethanol sensors.J Phys Chem C 2008;112:17804–8.[6]Neri G,Bonavita A,Galvagno S,Siciliano P,Capone S.CO and NO 2sensingproperties of doped-Fe 2O 3thin films prepared by LPD.Sens Acturators B 2002;82:40–7.[7]Jing ZH,Wu SH.Preparation and magnetic properties of spherical α-Fe 2O 3nanoparticles via a non-aqueous medium.Mater Chem Phys 2005;92:600–3.[8]Zhang ZH,Hossain MF,Takahashi T.Self-assembled hematite (α-Fe 2O 3)nanotubearrays for photoelectrocatalytic degradation of azo dye under simulated solar light irradiation.Appl Catal B Environ 2010;95:423–9.[9]Liu XQ,Tao SW,Shen YS.Preparation and characterization of nanocrystalline α-Fe 2O 3by a sol –gel process.Sens Actuators B 1997;40:161–5.[10]Chin AB,Yaacob II.Synthesis and characterization of magnetic iron oxidenanoparticles via w/o microemulsion and Massart's procedure.J Mater Process Tech 2007;191:235–7.[11]Sonavane SU,Gawande MB,Deshpande SS,Venkataraman A,Jayaram RV.Chemoselective transfer hydrogenation reactions over nanosized γ-Fe 2O 3catalyst prepared by novel combustion route.Catal Commun 2007;8:1803–6.[12]Chaianansutcharit S,Mekasuwandumrong O,Praserthdam P.Synthesis of Fe 2O 3nanoparticles in different reaction media.Ceram Int 2007;33:697–9.[13]Hu CQ,Gao ZH,Yang XR.Facile synthesis of single crystalline α-Fe 2O 3ellipsoidalnanoparticles and its catalytic performance for removal of carbon monoxide.Mater Chem Phys 2007;104:429–33.[14]Rockenberger J,Scher EC,Alivisatos AP.A new nonhydrolytic single-precursorapproach to surfactant-capped nanocrystals of transition metal oxides.J Am Chem Soc 1999;121:11595–6.[15]Vivekanandhan S,Venkateswarlu M,Satyanarayana N,Suresh P,Nagaraju DH,Munichandraiah N.Effect of calcining temperature on the electrochemical performance of nanocrystalline LiMn 2O 4powders prepared by polyethylene glycol (PEG-400)assisted Pechini process.Mater Lett 2006;60:3212–6.Fig.3.XRD patterns of Fe 2O 3powders calcined at differenttemperatures.Fig.4.SEM images of Fe 2O 3nano powders calcined at (a)450°C;(b)600°C;(c)720°C.2064Y.Wu,X.Wang /Materials Letters 65(2011)2062–2065[16]Mariappan CR,Galven C,Crosnier-Lopez MP,Berre FL,Bohnke O.Synthesis ofnanostructured LiTi2(PO4)3powder by a Pechini-type polymerizable complex method.J Solid State Chem2006;179:450–6.[17]Wang X,Chen XY,Gao LS,Zheng HG,Ji MR,Shen T,et al.Citric acid-assisted sol–gelsynthesis of nanocrystalline LiMn2O4spinel as cathode material.J Cryst Growth 2003;256:123–7.[18]Kemp anic spectroscopy.3rd ed.New York:Palgrave;2002.[19]Hon YM,Fung KZ,Lin SP,Hon MH.Effects of metal ion sources on synthesis andelectrochemical performance of spinel LiMn2O4using tartaric acid gel process.J Solid State Chem2002;163:231–8.[20]Nakamoto K.Infrared spectra of inorganic and coordination compounds.2nd ed.New York:Wiley;1970.2065Y.Wu,X.Wang/Materials Letters65(2011)2062–2065。

综合实验：溶胶-凝胶法制备纳米TiO2微粉1 实验目的：1. 用溶胶-凝胶法制备纳米TiO2微粉。

2．掌握溶胶-凝胶法制备纳米粒子的原理。

3．了解纳米粒子常用的表征手段。

2 实验原理自70年代初发现二氧化钛电极具有光照下分解水的功能以来，有关二氧化钛半导体光催化剂的研究成为环境领域的一个热点。

用半导体光催化分解毒性有机物有两个优点：第一，适当选择催化剂，可以利用太阳能处理毒物，节约能源；第二，一些半导体的光生空穴具有很强的氧化能力，能彻底降解绝大多数有机物质，而且能将它们最后分解为二氧化碳、水和无机物，避免了用化学方法处理带来的二次污染。

制备纳米粒子的方法很多，如化学沉淀法、溶胶-凝胶法、水热法、微乳液法、反相胶团法、气相法等。

溶胶－凝胶法(Sol－Gel法)是指无机物或金属醇盐经过溶液、溶胶、凝胶而固化，再经热处理而成的氧化物或其它化合物固体的方法。

溶胶是指微小的固体颗粒悬浮分散在液相中，并且不停的进行布朗运动的体系。

根据粒子与溶剂间相互作用的强弱，通常将溶胶分为亲液型和憎液型两类。

由于界面原子的Gibbs自由能比内部原子高，溶胶是热力学不稳定体系。

凝胶是指胶体颗粒或高聚物分子互相交联，形成空间网状结构，在网状结构的孔隙中充满了液体(在干凝胶中的分散介质也可以是气体)的分散体系。

并非所有的溶胶都能转变为凝胶，凝胶能否形成的关键在于胶粒间的相互作用力是否足够强，以致克服胶粒－溶剂间的相互作用力。

对于热力学不稳定的溶胶，增加体系中粒子间结合所须克服的能垒可使之在动力学上稳定。

因此，胶粒间相互靠近或吸附聚合时，可降低体系的能量，并趋于稳定，进而形成凝胶。

该方法的优点是：(1)反应温度低，反应过程易于控制；(2)制品的均匀度和纯度高、均匀性可达分子或原子水平；(3)化学计量准确，易于改性，掺杂的范围宽(包括掺杂的量和种类)；(4)从同一种原料出发，改变工艺过程即可获得不同的产品如粉料、薄膜、纤维等；(5)工艺简单，不需要昂贵的设备。

溶胶-凝胶材料的制备及其应用吴明明;赵雄燕;孙占英【摘要】综述了溶胶凝胶技术的应用现状及发展趋势,着重阐述了溶胶-凝胶态物质的制备工艺及该技术在纳米粉体材料、薄膜及涂层材料、纤维材料、有机-无机复合材料等领域的应用.新型溶胶-凝胶反应机理以及溶胶向凝胶转化过程中体系微结构变化规律的研究将是今后该领域发展的主要方向.%The application status and development of sol-gel technology were reviewed.The preparation of sol-gel substance and the application in the nano-powder materials,film and coating materials,fiber materials and organic-inorganic composites were emphatically elaborated.The study on new sol-gel reac-tion mechanism as well as the change law of microstructure in sol-gel process will be the main direction of development in this field.【期刊名称】《应用化工》【年(卷),期】2018(047)004【总页数】4页(P821-824)【关键词】溶胶-凝胶;薄膜及涂层;纤维;有机-无机复合材料【作者】吴明明;赵雄燕;孙占英【作者单位】河北科技大学材料科学与工程学院,河北石家庄 050018;河北科技大学材料科学与工程学院,河北石家庄 050018;河北省材料近净成形技术重点实验室,河北石家庄 050018;河北科技大学材料科学与工程学院,河北石家庄 050018;河北省材料近净成形技术重点实验室,河北石家庄 050018【正文语种】中文【中图分类】TQ427.2溶胶凝胶技术已经成为一门独立的边缘学科[1-2]。

我阅读了《珠光颜料的最新研究进展》知道了光颜料借助于光的透射和反射表现出珍珠般和／或虹彩般的效果。

这种光学效果与不同介质对光折射率的差别密切相关。

珠光颜料可以分为无基材珠光颜料和有基材珠光颜料两种。

无基材珠光颜料由透明或半透明的片状颜料微片组成，包括金属铝片状颜料、天然珍珠素、氯氧化铋、碱式碳酸铅以及薄片状有机颜料等[1]。

金属铝颜料长期以来广泛应用于汽车漆，但其装饰效果不如云母钛珠光颜料，在汽车漆中的应用比例正在减少；天然珍珠素由鱼鳞和鱼鳔通过繁杂的工艺提取而得，价格昂贵，主要应用于高级化妆品；氯氧化铋和碱式碳酸铅有很好的层片状晶体结构和较高的折射率(分别为2．15和2．o)，能产生高光泽，但是它们的密度较大，容易沉积，且氯氧化铋耐光性不好，碱式碳酸铅中游离出来的铅有剧毒，主要应用于钮扣工业和珠宝饰物中[23；一些有机颜料也能制成薄片状，但是它们与典型应用介质的折射率差异较小，产生的珠光效果较弱。

本文得出的结论，认为珠光颜料的发展方向包括以下几个方面：(1)优选颜料基材和包覆材料，更好地利用原材料自身优势，以及它们相互之间的配合，而制得性能突出的层状结构珠光颜料。

(2)通过改善制备工艺，在保持颜料高装饰性和／或功能性的基础上使颜料无毒害、无污染，从而使颜料的应用向化妆品、玩具、食品和药品领域更好地拓展。

(3)简化珠光颜料的生产工艺，同时使颜料的生产向节约资源和节约能源的方向发展。

我学会了，(1)粒度分布HG／T 3744—2004行业标准规定了两种粒度分布的测量方法(2)显微分析光学显微镜能够直接看到颜料的颜色效果，是评价珠光颜料的有力手段。

在暗场下，以偏振光从侧面照射，是表征透明珠光颜料内部特征的最有价值的手段(3)X射线衍射某些珠光颜料要求包覆层获得某种结构相。

(4)随角异色效应表征J·rrl·盖尔用测角分光光度计对随角异色珠光颜料进行了评价["。

颜家振等‘273采用多角度分光光度计。