反相微乳液法制备形貌可控的铁基纳米粒子

在反相微乳液体系中,用NaBH4还原FeCl2,合成Fe基纳米颗粒.采用TEM、FTIR、XRD和VSM分别对产物的粒径、形貌、物相和磁性能进行了表征.结果表明,改变表面活性剂AOT的浓度(n0)可以得到不同形貌的纳米粒子.同时,合成颗粒的表面被均匀地包覆了表面活性剂AOT,粒子的比饱和磁化强度为3.41×103 emu/kg,几乎无剩磁,具有顺磁性,可作为磁性能稳定的顺磁性材料.     

微乳液法合成羟基磷灰石纳米微晶及其性能研究

在一定的pH值条件下,以DTAC为表面活性剂、正辛醇为助表面活性剂、环己烷为油相形成的微乳液模板,诱导Ca(NO3)2和(NH4)2HPO4在其形成的微反应器中反应,反应物经混合陈化后即可生成片状和长柱状等多种微观形貌的羟基磷灰石纳米微晶(HA).将所得产物在不同温度下焙烧,分别用FTIR、XRD和TEM等对其结构及形貌进行表征,对不同表面活性剂浓度和反应物浓度条件下所得HA的微观形貌分别进行了分析对比.     

利用反相微乳液法制备纳米铜粒子

通过反相微乳液法制备了纳米铜粒子,并用透射电子显微镜(TEM)、电子衍射(SAED)和能谱对铜纳米粒子的形貌和物相进行了表征.在H2O/表面活性剂油酸钠摩尔比(W/O)为11、8时分别制得了粒径为50nm、10nm的铜粒子.结果表明:W/O值对纳米铜粒子的粒径有非常明显的影响,当其值由11降到8时,粒径则从50nm降到了10nm,且更加均匀.探讨了水与表面活性剂的摩尔比对制备的纳米铜颗粒的粒径的影响.     

超声微乳液法制备Ag/AgCl复合纳米颗粒及其光催化性能研究

设计了一种全新的微乳液体系,以十二烷基磺酸钠(SDS)、乙醇、正丁醇和异辛烷的混合物作为复合乳化剂,采用超声微乳液法制备了Ag/AgCl复合纳米颗粒。利用SEM和EDS研究样品的形貌、尺寸及表面组成,通过研究样品对甲基橙降解过程的催化作用证明了样品在可见光下的催化活性。重点研究了反应物浓度对Ag/AgCl颗粒尺寸及形貌的影响,结果表明,Ag/AgCl复合纳米颗粒尺寸主要由微乳液尺寸决定,受反应物浓度的影响较小,反映出本工作提出的超声微乳液制备技术具有较高的工艺稳定性。     

W/O微乳液制备纳米羟基磷灰石的影响因素研究

W/O微乳液制备的纳米羟基磷灰石粉体具有颗粒细小、团聚度低、分散性好、表面活性高等优点。综述了W/O微乳液制备纳米羟基磷灰石的原理;重点论述了影响粉体粒径和形貌的水油比、表面活性剂与助表面活性剂类型、前驱物浓度、反应温度等因素;并初步展望了该领域的研究发展趋势。     

微乳液法制备纳米羟基磷灰石的机理

采用二已基琥珀酰磺酸钠(aerosol OT,AOT)作为表面活性剂,正辛醇作为助表面活性剂,异辛烷为油相,将Ca(H2PO4)2·H2O水溶液和Ca(OH)2饱和溶液作为水相制成反相微乳液,并使两种微乳液反应,制备出呈单分散的球形纳米羟基磷灰石颗粒.通过系统性试验绘制了AOT/异辛烷/Ca(H2PO4)2·H2O水溶液和AOT/异辛烷/Ca(OH)2饱和溶液微乳液的局部三元拟相图,确定了该体系的反相微乳液单相区.采用动态激光散射原理分析了上述微乳液的胶束直径,确定了胶束直径与体系含水量的线性关系,并计算了微乳液胶束的有关参数.分析了羟基磷灰石的反应机理和颗粒的形成过程,并采用紫外可见光吸收光谱,研究了体系含水量对羟基磷灰石超细颗粒形成过程的影响.     

反相微乳液制备纳米SiO2颗粒

微乳液法可以控制纳米颗粒的粒度,在AOT作为表面活性剂的微乳液体系中引入助表面活性剂正丁醇和戊醇,对生成的纳米颗粒起到保护作用,能够形成大小均一、分散良好的纳米SiO2颗粒。随着正丁醇含量的增加纳米SiO2球形颗粒的粒径变大,正丁醇加量0.5mL时粒径为18.7nm,正丁醇加量增加到3mL时粒径达109nm。随着时间的增加,微乳液法制备的纳米SiO2粒径基本保持稳定,而且颗粒变得更加均匀。     

微乳液法制备纳米TiO_2粉体的研究

以硫酸法钛白粉生产中间产物偏钛酸为原料,通过微乳法制备纳米TiO_2粉体,分析微乳法制备纳米粒子的反应过程及机理,研究反应物浓度、水与表面活性剂摩尔比以及表面活性剂用量对纳米颗粒粒径的影响。研究结果显示通过此微乳液体系,在偏钛酸溶液中钛盐摩尔浓度为2.0mol/L、水与表面活性剂摩尔比为50∶1、正己醇与曲拉通X-100的质量比为1∶0.3条件下,制备的TiO_2纳米粉体形状规则,平均粒径为25nm,具有分散度好、粒度分布均匀等特点。     

L-半胱氨酸辅助反相微乳法制备Ag_2S纳米晶

选用TX-100/环己烷/正己醇/水反相微乳体系,以Ag NO_3为Ag源、Na_2S·9H2O为S源、L-半胱氨酸为结构导向剂,室温下制备了高晶化度、直径为10—50 nm的Ag_2S纳米晶,并考察了影响其粒径大小的因素。紫外-可见吸收光谱表明,Ag_2S纳米晶在290 nm处呈现强吸收,与体相Ag2S(1 240 nm)相比,其吸收边发生了明显的蓝移。通过调控微乳体系中ω0(水与表面活性剂物质的量比)、Ag+与L-半胱氨酸的物质的量比、反应物浓度等可以实现对产物尺寸和形貌的调控。     

小尺寸单分散铂纳米粒子的制备

为提高铂催化剂的催化活性,降低催化剂成本,在水/TX-4(壬基酚聚氧乙烯醚)/正丁醇/环己烷微乳液体系中成功制备了粒径2～4nm的单分散铂纳米粒子,并对其进行了TEM和EDS表征。微乳液体系的相图表明,Kw=5∶3,m(S-As)/m(O)=3∶2是制备小尺寸铂纳米粒子的最佳配比。H2PtCl6和NaBH4(过量时)浓度增大时,对产物粒径影响不大,但使粒径的均匀性降低;增溶水量ω增大,粒子粒径增大。CH2PtCl6≤25mmol·L-1,CNaBH4≥100mmol·L-1,ω≤2是制备小尺寸、单分散铂纳米粒子的关键,粒子尺寸可通过改变ω值调节。     

纳米TiO_2在液相中的分散性研究

探讨了纳米TiO2颗粒在水分散介质中的分散工艺,研究了机械搅拌、无机电解质、表面活性剂等对TiO2分散性的影响。研究结果表明,以水作分散介质,通过机械搅拌并加入无机电解质Na4P2O7·10H2O、(NaPO4)6和表面活性剂山梨醇、三乙醇胺、OP-10、SDBS,以及选择合适的pH值可制备出分散稳定性良好的纳米TiO2分散体系。     

掺稀土硫酸盐纳米荧光体的制备及光致发光特性的研究

采用液相沉淀法制备了纳米荧光体CaSO4:Eu,CaSO4:Dy,MgSO4:Dy,研究并对比了产品的光致发光性能.光谱测试表明,CaSO4:Eu呈近紫外窄带发射;Dy3 掺杂碱土硫酸盐因基质不同,发射带有所不同.以CaSO4为基质,Dy3 占据高对称的格位,具有反演对称中心,发射光谱以蓝光发射为主.以MgSO4为基质,Dy3 占据低对称的格位,无反演中心,发射光谱以黄橙光发射为主.结果证明,所合成纳米荧光体表现出优异的发光特性.     

Physicochemical Characterization of Rutaecarpine-Loaded Microemulsion System

To develop an o/w microemulsion system containing poorly water-soluble rutaecarpine, the solubility of rutaecarpine in water, ethanol, various oils, and surfactants were investigated. Among the surfactants and oils tested, Tween 20/PEG 400 and castor oil were chosen as the surfactant system and oil phase of the microemulsion, as rutaecarpine was most soluble in them, respectively. Pseudoternary phase diagrams were constructed to obtain the concentration range of oil, surfactant, and cosurfactant for microemulsion formation, and the stability test of rutaecarpine delivered by microemulsion formation was then evaluated. Pseudoternary phase diagrams show that the areas of microemulsion appeared at those with 0–20% Smix (PEG 400/Tween80 = 60/40), 64–81% water, and 10–20% oil. The rutaecarpine (300 µg/g)-loaded microemulsion composed of 10.8% PEG 400, 7.2% Tween 80, 20% caster oil, and 72% water was physically and chemically stable for at least 6 months. Thus, the microemulsion system composed of castor oil, PEG 400, Tween 80, and water could be a stable dosage form for rutaecarpine.     

Physicochemical characterization of rutaecarpine-loaded microemulsion system

To develop an o/w microemulsion system containing poorly water-soluble rutaecarpine, the solubility of rutaecarpine in water, ethanol, various oils, and surfactants were investigated. Among the surfactants and oils tested, Tween 20/PEG 400 and castor oil were chosen as the surfactant system and oil phase of the microemulsion, as rutaecarpine was most soluble in them, respectively. Pseudoternary phase diagrams were constructed to obtain the concentration range of oil, surfactant, and cosurfactant for microemulsion formation, and the stability test of rutaecarpine delivered by microemulsion formation was then evaluated. Pseudoternary phase diagrams show that the areas of microemulsion appeared at those with 0-20% Smix (PEG 400/Tween80 = 60/40), 64-81% water, and 10-20% oil. The rutaecarpine (300 µg/g)-loaded microemulsion composed of 10.8% PEG 400, 7.2% Tween 80, 20% caster oil, and 72% water was physically and chemically stable for at least 6 months. Thus, the microemulsion system composed of castor oil, PEG 400, Tween 80, and water could be a stable dosage form for rutaecarpine.     

Shape evolution of Cu2S nanostructures in Triton X-100/cyclohexane/water reverse micelles

The shape evolution of Cu₂S nanostructures, which were produced in Triton X-100/cyclohexane/water reverse micelles, was investigated by the transmission electron microscopy technique as a function of aging time, and the effect of the molar ratio of water to surfactant on the size and shape of Cu₂S nanostructures was also discussed. The results suggest that at the initial stage the nucleation process was dominant and the shape of Cu₂S nanostructures was preferably confined by the reverse micelle droplets and took spherical forms. With the extension of the aging time, the growth gradually governed the process and the shape of Cu₂S nanostructures evolved first to nanorods, and then to nanowires gradually. The formation of one-dimensional Cu₂S nanostructures is attributed to a directed aggregation growth process mediated by reverse micelle droplets, which was confirmed by high-resolution transmission electron microscopy. Furthermore, the size and shape of Cu₂S nanostructures can be controlled by changing the molar ratio of water to surfactant.     

Nanoparticles synthesis of tungsten disulfide via AOT-based microemulsions

The tungsten disulfide (WS₂) nanoparticles (most probably inorganic fullerene (IF)) with a narrow size distribution were synthesized by a reverse micelle technique for the first time. The particle size was controlled by varying water-to-surfactant molar ratio (W₀), aging time and reagent concentration. The synthesized WS₂ nanoparticles were characterized by zetasizer, UV–visible spectrophotometers and transmission electron microscopy (TEM). The WS₂ nanoparticles with particle diameter size of 7–12 nm were obtained via 24 h aging time. The particle size was controlled by changing the aging time and molar ratio of water/surfactant. Doubling W₀ increased the amount and particle size of WS₂ by 22 and 26%, respectively. The effect of aging time in the range of 6–24 h was investigated and the complete disappearance of yellowish color at 24 h resulted in an optically clear solution, which was the indication of WS₂ formation with 100% conversion of reactant ((NH₄)₂WS₄) in the batch reactor.     

低酒精润版液改良配方研究

目的研究6501与6502表面活性剂复配后添加到润版液中替代酒精,实现免酒精润版。方法使用润版粉配制标准润版液,加入不同质量分数的6501与6502,测试单一体系的临界胶束浓度;根据复配原理,将6501与6502复配,得出二者最佳配比和添加浓度,获得润版液的最佳配方。结果 6501和6502复配体系最佳质量比为4.36:5.54,复配体系此时的临界胶束浓度为0.1%,配制的润版液各项性能指标均符合要求。结论表面活性剂6501和6502复配实现免酒精润版是可行的,解决了酒精在润版时带来的危害。     

稳态荧光探针法测定脂肪醇聚氧乙烯醚型非离子表面活性剂聚集行为

以芘为荧光探针、二苯甲酮为猝灭剂,采用稳态荧光探针法测定了3种不同结构的脂肪醇聚氧乙烯醚(FAPE)表面活性剂增溶芘后的稳态荧光光谱,建立了FAPE非离子表面活性剂的临界胶束浓度(CMC)和临界胶束聚集数(Nm)的测试方法。确定了荧光探针芘的适宜浓度Cp为6×10-6 mol/L,猝灭剂的适宜浓度CQ取0.06～0.12mmol/L,根据I336/I394与FAPE浓度变化的关系,可得到直链、支链、芳香族的脂肪醇聚氧乙烯醚的临界胶束浓度分别为0.2mmol/L、0.1mmol/L、0.05mmol/L。直链、支链、芳香族的脂肪醇聚氧乙烯醚的临界胶束聚集数依次为1168、255、6.0。结果表明,同系列非离子表面活性剂,不同碳链结构呈现出由直链→支链→芳香族,以及临界胶束浓度和聚集数依次减小的趋势。     

Synthesis and growth of germanium oxide nanoparticles in AOT reversed micelle

Germanium oxide (GeO₂) nanoparticles with a narrow size distribution have been synthesized by a reverse micelle technique. The cubic GeO₂ particles with particle size of 15 nm were obtained as the reaction solution was left standing for 24 h, the particle size and shape can be controlled by changing the molar ratio of surfactant/water (R_w) and the aging time. The effect of R_w and aging time on the particle size was discussed.     

Reverse microemulsion region and composition optimization of the AEO9/alcohol/alkane/water system

A reverse microemulsion method was applied to prepare ceramic inks for formation by jet-printing. Different reverse microemulsion systems were studied and optimized in order to obtain high concentration ceramic inks, and an AEO₉/alcohol/alkane/water system was chosen for preparing these ceramic inks as a result of its excellent water-dissolving characteristics. In this paper, different kinds and amounts of alcohol as a co-emulsifier and n-octane as oil, respectively were used to systematically investigate their effects on the microemulsion region in the quasi-ternary phase diagram of the system studied. These were mixed with water to form reverse microemulsion after vigorous stirring. The microemulsion region was determined and the conditions for maximum water-dissolving were given. Additionally, the effect of temperature on the reverse microemulsion region was studied. It was shown that the AEO₉/n-butanol/n-octane/water reverse microemulsion system exhibited excellent behavior in enhancing the amount of water-dissolving and the best composition for maximum water content was AEO₉:n-butanol:n-octane=25.7%:16.8%:57.7% in mass.