共查询到20条相似文献,搜索用时 218 毫秒
1.
采用电导法研究了2种季膦盐类磁性离子液体四丁基膦氯合氯化铁盐([P4444]FeCl4)和十四烷基三丁基膦氯合氯化铁盐([P44414]FeCl4)在水溶液与CTAB形成的胶团相互作用和在非水溶液环己烷中与AOT形成的微乳液中相互作用。研究发现:离子液体[P4444]FeCl4在水溶液和非水溶液中均不和表面活性剂发生作用;[P44414]FeCl4具有长碳链,但其在水溶液和非水溶液中表现出不同于表面活性剂的性质,在水溶液中不与CTAB发生作用,而在AOT/环己烷/水的微乳液体系中,[P44414]FeCl4与AOT在油水界面发生作用,有利于微乳液的形成。 相似文献
2.
3.
以三氯化锑为原料,通过醇解、水解反应,表面活性剂处理,制备了单分散纳米Sb2O3,利用因素轮换法和正交试验,系统地研究了各种因素和水平对于制备单分散纳米Sb2O3的影响,利用沉降法和透射电镜研究了作为分散剂使用的表面活性剂的种类和用量对纳米Sb2O3的形态和粒径影响.结果表明,制备单分散纳米Sb2O3最佳条件是反应温度为318 K,醇化时间为1 h,SbCl3在无水乙醇中的浓度为0.17 g8226;ml-1;表面活性剂对分散和稳定纳米Sb2O3具有重要作用,用1.0 ml的聚乙二醇-400或0.3 g十六烷基三甲基溴化铵处理1g纳米Sb2O3,可以得到单分散的平均粒径约为25 nm的Sb2O3. 相似文献
4.
5.
6.
探讨了用于制备氧化铈纳米粒子的反相微乳体系组成及稳定性,以溴化十六烷基三甲基铵/正丁醇/环己烷/水构成了用于制备纳米氧化铈的W/O微乳液,通过测定体系的电导率的方法确定相点,绘制了溴化十六烷基三甲基铵和正丁醇-环己烷-水反相微乳区拟三元相图.结果表明,表面活性剂与助表面活性剂质量比,即溴化十六烷基三甲基铵与正丁醇的质量比等于1.6时为制备纳米粒子的最佳值,加入硝酸铈会使微乳液的区域减小,随着温度的升高微乳区域略微减小.按实验确定的条件,制备出纳米氧化铈,XRD分析结果表明,纳米氧化铈粒径为19~22 nm. 相似文献
7.
8.
CdTe纳米晶作为一种重要的Ⅱ-Ⅵ族半导体材料,在LEDs、光子学材料和生物标记等方面已被应用。本实验利用CTAB/环己烷/异丁醇/水作为反应介质,氮气保护下在微乳液体系中制备了CdTe纳米颗粒。利用X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子电镜(SEM)表征了CdTe纳米颗粒的形貌和粒径尺寸,研究水与表面活性剂摩尔比以及陈化时间对CdTe纳米颗粒的影响,结果表明当水与表面活性剂摩尔比为40,陈化时间为24h时制备出了产量高,稳定性好的直径为40-50nm的CdTe纳米颗粒。 相似文献
9.
10.
11.
Simple synthesis of surface-modified hierarchical copper oxide spheres with needle-like morphology as anode for lithium ion batteries 总被引:1,自引:0,他引:1
Hierarchical, nanostructured copper oxide spheres were synthesized in a stirred solution of cupric acetate and ammonium hydroxide. Cetyltrimethylammonium bromide (CTAB) was used as a surfactant to modify the surface morphology of CuO spheres. Ordered nano-needle arrays can be formed on the surface of the CuO spheres (instead of disordered nano-leaves) in the presence of CTAB. Each CuO sphere is about 2 μm in diameter and possesses a large number of nano-needles that are about 20-40 nm in width and more than 300 nm in length. The needle-like hierarchical structure can greatly increase the contact area between CuO and electrolyte, which provides more sites for Li+ accommodation, shortens the diffusion length of Li+ and enhances the reactivity of electrode reaction, especially at high rates. After 50 cycles, the reversible capacity of the prepared needle-like CuO can sustain 62.4% and 56.4% of the 2nd cycle at a rate of 0.1C and 1C, respectively. 相似文献
12.
BACKGROUND: Polyaniline (PANI) has attracted much attention in many fields due to its chemical and physical properties, and different nanostructures of PANI changing from one‐dimensional to three‐dimensional have been obtained. By changing the concentration of cetyltrimethylammonium bromide (CTAB), the morphology of hydrochloric acid‐doped polyaniline could be changed from one‐dimensional nanoneedles or nanowires with a network structure (50–100 nm in diameter) to three‐dimensional hollow microspheres (ca 400 nm in outer diameter) via combining interfacial polymerization and self‐assembly process. RESULTS These different nanostructures of PANI were proved using scanning electron and transmission electron microscopies. A plausible mechanism of the formation of the changeable nanostructures of PANI may be different from that of interfacial polymerization without surfactant or a traditional homogenous reaction system using CTAB as surfactant. CONCLUSION The results obtained from Fourier transform infrared spectrometry, X‐ray diffraction and the four‐probe method showed that the molecular structure of PANI does not change with increasing CTAB concentration, but crystallinity and conductivity of PANI increase with surfactant concentration. Copyright © 2007 Society of Chemical Industry 相似文献
13.
Single-crystal hydroxyapatite (HAP) nanorods have been successfully synthesized by the reverse microemulsion method, and characterized by high-resolution transmission electron microscope (HRTEM), infrared spectra (IR), and powder X-ray diffraction (XRD). In this work, the feasibility of using quaternary reverse microemulsion (TX-100 + CTAB/n-butanol + n-hexanol/cyclohexane/water) to prepare hydroxyapatite nanorods with diameter 8–15 nm and length 25–50 nm, is described. The homogeneity in size and shape of hydroxyapatite nanoparticles observed by TEM is probably attributed to the different stabilization functions of different kinds of surfactant on the interfacial film. 相似文献
14.
《Journal of the European Ceramic Society》2019,39(13):3821-3829
Spherical ZrO2 nanoparticles have been successfully synthesized by a reverse micelles (RMs)-mediated sol-gel process. Hydrolysis of zirconium n-propanol solution was confined in the microreactors made of water/cetyltrimethyl ammonium bromide (CTAB)/cyclohexane/n-butanol RMs, as well as investigating the template effects of RMs in particle size and shape control. It was found that there was significant particle size and shape replication between RMs and ZrO2 nanoparticles after polycondensation, indicating that the RMs microreactors stabilized by surfactants could control the nucleation, growth and agglomeration process during the hydrolysis and thus the size and shape of ZrO2 nanoparticles. Furthermore, spherical ZrO2 nanoparticles could be customized in the range of 10–30 nm, and their roundness value was greater than 0.90. 相似文献
15.
16.
分别以阳极氧化铝、玻璃纤维布、玻璃作载体采用溶胶-凝胶法制备TiO2纳米线阵列膜(TiO2/AAO)与TiO2/玻璃、TiO2/玻布光催化剂,用XRD、电子探针和比表面仪进行表征,并对比其光催化不同浓度气相甲醛的降解活性.结果表明:制备的TiO2纳米线线径为26 nm,线长1.2 μm,与其他TiO2载体相比,具有小密度、高比表面积,TiO2/AAO光催化剂有较大反应速率常数及Langmuir吸附平衡常数,在UV下对低浓度气相甲醛有更多的活性吸附中心,这说明对低浓度气体,高比表面积催化剂有重要作用,它能更多地富集低浓度气体,提高光降解率. 相似文献
17.
采用二次阳极氧化工艺制备了高度规则排列的多孔氧化铝(PAA)模板,并利用模板法与溶胶-凝胶法结合的模板组装技术制备了氧化钛纳米线阵列,得到了直径在50 nm左右,线间距约为50 nm的纳米线阵列.研究了模板组装过程不同压力条件对溶胶向模板孔洞中填充度的影响,发现在一定的负压条件下,有利于PAA孔中气体的排出,得到高的溶胶填充度,进而制备出高质量的纳米线阵列.分别通过SEM及XRD技术表征了PAA模板及纳米线的形貌及相结构.SEM观察发现纳米线彼此平行,表面光洁,不存在龟裂,纳米线的长度和直径与所使用模板的厚度和直径一致,表明纳米线的生长受控于模板;XRD分析表明模板为单一的θ-Al2O3晶型,纳米线为锐钛矿型TiO2. 相似文献
18.
单分散二氧化硅超细颗粒的制备 总被引:13,自引:0,他引:13
利用3种不同类型的表面活性剂反胶团体系制备SiO2超细颗粒,并与传统的Stober制备方法进行了对比. 在阴离子表面活性剂AOT和非离子表面活性剂TritonX-100两类体系中,得到了单分散的SiO2超细颗粒.在AOT体系中颗粒粒径随体系水含量w。的增大而增大;而TritonX-100体系中,颗粒粒径随w。的增大而减小;在阳离子表面活性剂(如CTAB,TOMAC)体系中无法得到SiO2超细颗粒.对不同体系所得颗粒的粒径标准偏差及粒度分布进行了对比,结果表明制备粒径小于100 nm的SiO2颗粒,反胶团法明显优于Stober方法,粒径相对标准偏差较低, 而对粒径大于100 nm的颗粒,Stober方法仍不失为一种很好的制备途径. 相似文献
19.
在氧化锌、磷酸固-液反应体系中,以研磨反应代替搅拌反应,辅助表面活性剂对磷酸锌的颗粒尺寸进行可控合成,考察了研磨介质、磨球比例、球料比、固液比、表面活性剂等工艺条件对磷酸锌粒径分布、形貌及团聚状况的影响,并采用SEM、XRD、粒度分布和TEM对纳米磷酸锌做了表征。结果表明,表面活性剂CTAB浓度为9×10-4 mol/L、研磨时间为3 h、锆球为研磨介质、球料质量比为150:1、Φ10 mm与Φ6 mm磨球质量比为1:4、转速为200 r/min、固液比[氧化锌和(磷酸+表面活性剂)的质量比]为1:1时,可以制备粒径分布为59~79 nm、平均粒径为68 nm、无团聚的粒状纳米磷酸锌。 相似文献
20.
以Triton X-100/正己醇/环己烷/水制成W/O微乳反胶团体系,通过测定体系的电导率和观察液晶相的出现确定相点绘制了各体系的拟三元相图,研究了温度、盐浓度和油相组分对W/O微乳液体系稳定性的影响.实验发现助表面活性剂与表面活性剂的配比对微乳液的稳定性有显著影响.随着温度的升高,W/O微乳液稳定区域减小,可通过升高温度对微乳液进行破乳;与以纯环己烷为油相的体系相比,油相中含有少量正己烷的体系具有更优异的性质.所得结果为利用该W/O微乳液体系制备纳米颗粒提供了基础数据. 相似文献