W/O型微乳法制备淀粉基纳米粒

在正己烷、Span-60和NaOH水溶液的W／O型淀粉微乳液中,进行淀粉与环氧氯丙烷交联反应制备淀粉微球,用质量分数为1％的淀粉水浆液制备出微球的流体力学半径Rb为7．08—113nm,其中粒径不超过100nm的纳米粒在整个微粒体系中占69％,平均粒径为92．2nm。TEM和DLS结果表明,制得的微粒呈圆球形,且微粒的流体力学半径随淀粉水浆液浓度的增加而增大并分布变宽,淀粉水浆液的浓度低有利于淀粉基纳米粒的形成。     

Resolution of α-cyclohexyl-mandelic acid enantiomers by two-phase (O/W) recognition chiral extraction

This paper presents a new chiral separation technology: two-phase (O/W) recognition chiral extraction. Distribution behavior of α-cyclohexyl-mandelic acid enantiomers was studied in the extraction system with D(L)-isobutyl tartrate in 1,2-dichloroethane organic phase and β-CD derivatives in aqueous phase, and the influence of the kind and concentration of extractant and pH on extraction performance was investigated. The experimental results indicate that two-phase (O/W) recognition chiral extraction is of strong chiral separation ability. HP-β-CD, HE-β-CD and Me-β-CD have higher recognition ability for S-CHMA than that for R-CHMA, among which HP-β-CD has the strongest ability; whereas, D-isobutyl tartrate has reversed recognition ability for them. In the extraction system containing HP-β-CD and D-isobutyl tartrate, e.e.% of S-CHMA in aqueous phase reached 27.6% by one stage extraction, and the distribution ratio for R-CHMA(k _R ) and for S-CHMA(k _s ) and separation factor (α) are 2.44, 0.89 and 2.49, respectively. Meanwhile, pH and concentration of extractant have great effects on chiral separation ability. Two-phase (O/W) recognition chiral extraction has great significance for preparative separation of racemic compounds.     

反相微乳液中憎水性纳米金的原位还原法合成

利用十八胺(C18NH2)/正丁醇/正庚烷/HAuCl4(aq)W/O型微乳液体系,在常温的碱促进条件下由正丁醇原位还原氯金酸合成了具有高度单分散的憎水性金纳米粒子。由C18NH2稳定的金纳米颗粒运用紫外可见光谱(UV-vis)、透射电镜(TEM)和X射线衍射(XRD)等分别进行了表征和分析,并探讨了微乳液体系各组分对形成金纳米粒子形貌、尺寸和单分散性的影响。结果显示,随十八胺/氯金酸摩尔比的增加,金粒子的尺寸逐渐减小而单分散性逐渐提高。在正丁醇原位慢还原氯金酸的过程中,实验所选W/O型微乳液模板和表面活性剂十八胺分子对憎水性金纳米粒子的形貌和尺寸仍具有良好的控制作用。     

Preparation of hollow silica nanospheres in O/W microemulsion system by hydrothermal temperature changes

Hollow silica nanospheres with wrinkled or smooth surfaces were successfully fabricated through a hydrothermal method. In this method, oil-in-water microemulsion (composed of cyclohexane, water, ethanol, and cetyltrimethylammonium bromide), and polyvinylpyrrolidone were utilized as template and capping agent, respectively. In such a facile synthesis, we can well realize the morphological transformation of spheres with radially oriented mesochannels to hollow structures of silica nanoparticle only by regulating the hydrothermal temperature from 100 °C to 200 °C. Synthesized samples with different mesostructures were then used as supports to immobilize Candida rugosa lipase (CRL). The immobilized CRL was employed as a new biocatalyst for biodiesel production through the esterification of heptanoic acid with ethanol. The conversion ratio of heptanoic acid with ethanol catalyzed by the immobilized CRL was also evaluated. Results of this study suggest that the prepared samples have potential applications in biocatalysis.     

Triton X-100/C10H21OH/H2O体系微乳液与溶致液晶

关于离子型表面活性剂生成的微乳液与溶致液晶已有不少研究，非离子型表面活性剂生成的微乳液与港致液晶的应用正在引起人们的重视，但由于药物提纯的困难，对其物理化学性质的研究还不多见．本文以非离子表面活性剂TritonX－100／C10H21OH／H2O体系为例，研究了非离子型表面活性剂微乳液和溶致液晶的生成及其结构特性．1实验部分试剂ThitonX－100（Aldrich公司，分析纯）正癸醇（分析纯）、水为一次蒸馏水微乳液区域和层状液晶区域的确定方法及小角x射线衍射测定方法同文献，实验温度20±0．1℃．2结果与讨论2·IThtonX－100、CIOH…     

O／W微乳液中聚吡咯超微粒子的制备

选择合适的ＳＤＢＳ／吡咯／Ｈ２Ｏ三组分Ｏ／Ｗ微乳液与吡咯单体共存的两相体系，以单体相为单体源，在Ｏ／Ｗ三组分微乳液中进行了吡咯聚合，所得聚吡咯粒子大小仅为２～３ｎｍ，分布较均匀，且具有较好的导电性能．     

超微镍粉的微乳液法制备研究

采用水（溶液）／二甲苯／SDS／正戊醇反相微乳液体系,用水合肼还原硫酸镍制备了纳米级（15－100nm)镍微粒,采用XRD、TEM等法对产物进行了鉴定与表征,考察了微乳液体系诸构成因素对纳米级镍制备的影响规律。     

水/油型微乳液中球形及棒状钛酸锶钡纳米粒子的控制合成

Barium strontium titanate nanoparticles with spherical and rod-like morphologies were synthesized in water/Triton X-100/n-hexanol/cyclohexane quaternary reverse microemulsion solution. The influences of the molar ratio of water to surfactant (ω₀) and the concentration of reactants on the morphology and size of barium strontium titanate nanoparticles were studied. The structure, compositions and morphology of the prepared products were characterized by XRD, SAED, ICP, EDS and TEM. The results show that the obtained Ba_0.7Sr_0.3TiO₃ spherical nanoparticles with diameters of 20～100 nm and the Ba_0.7Sr_0.3TiO₃ nanorods with diameters of 70～120 nm and lengths up to 600～800 nm are a single crystal, with a cubic phase. The molar ratio for barium, strontium and titanate in products is about 0.7:0.3:1.     

W／O／W乳液的渗透溶胀与夹带溶胀

研究了W/O/W乳液的溶胀,实验结果表明,渗透溶胀随内外相溶液间的渗透压差、表面活性剂及载体浓度的增大而增加,但随膜粘度的增加而降低,渗透压差较高时,水渗透的影响大于夹带的影响;膜相中含氧化合物对溶胀的影响大于含氮化合物,采用Span 80作乳化剂时,比采用E 644渗透溶胀约高6倍,夹带溶胀也较高;重复聚结再分散使夹带溶胀急剧增加,因而多级混合澄清槽对液膜操作似不适用。     

W/O微乳液体系稳定条件的研究

研究表明[1～4] ,一个好的微乳液体系要求具有稳定范围宽阔 ,对ｐＨ值和温度的变化不敏感等特点。本文研究目的是为了寻找一个适合制备所需功能氧化物粒子的微乳液体系 ,考察研究Ｔｘ 6～Ｃ4Ｈ9ＯＨ/ｃ Ｃ6Ｈ1 2 /Ｈ2 Ｏ体系Ｗ/Ｏ微乳液在不同条件下能稳定存在的组成范围以及温度和不同ｐＨ值对该稳定组成区域的影响。1　实验部分1 1　实验试剂本实验以Ｔｘ 6(烷基聚氧乙烯酚醚 )为表面活性剂 ,Ｃ4Ｈ9ＯＨ(正丁醇 )为助表面活性剂 ,ｃ Ｃ6Ｈ1 2(环己烷 )为油相。除Ｔｘ 6由上海高桥石化三厂提供外 ,其它试剂均为分析纯。1 2　实验内容在 2…     

O/W微乳液中聚苯胺超微粒子的制备

选择合适的ＳＤＢＳ／苯胺／Ｈ２Ｏ三组分Ｏ／２微乳液与苯胺单体共存的两相体系，以单体相为单体源，在Ｏ／Ｗ厂组分微乳液中进行了苯胺聚合，所得聚苯胺粒子大小仅为３ｍ，分布较均匀，且具有较好的导电性能。     

W/O型微乳状液迁移和富集痕量金属离子Cd2+、Cr3+的研究

利用各种分离技术分离和富集金属离子,无论是在环境保护还是在湿法冶金方面都具有重要的意义.油包水型微乳状液因具有独特的物理化学性质,已越来越广泛地应用于金属离子的萃取分离上.     

W/O微乳液中纳米Pd微粒的化学破乳沉积

利用脂肪醇聚氧乙烯醚型非离子表面活性剂Marlipal O13/50、水、环己烷组成的W/O微乳液体系合成纳米Pd微粒, 考察了化学破乳剂作用下纳米Pd微粒的沉积过程. 结果表明, 不同化学破乳剂使纳米Pd微粒沉积的速率顺序为1,4-二噁烷跃四氢呋喃跃甲醇跃乙醇跃正丁醇. 研究了化学破乳剂对微乳液界面张力与两亲因子的影响. 结果表明, 微乳液结构的破坏是界面张力增大的过程, 同时也是两亲性降低而向Lifschitz线逐渐靠近的过程.     

CTMAB-C5H11OH-H2O体系微乳液、液晶及其增溶特性

微乳液、液晶及其增溶作用具有重要的理论意义及应用价值,已引起重视与关注。本文研究了CTMAB-C_5H_(11)OH-H_2O体系微乳液、层状液晶及其对C_7H_(16)的增溶特性。1 实验方法十六烷基三甲基溴化铵(分析纯,简称CTMAB)、正戊醇、正庚烷,皆为分析纯,H_2O为二次蒸馏水。1.2 各向同性区域的测定先以滴定法粗略确定单相区域的相界线,然后在相界线两侧均匀选点配样,于25.0±     

烷基聚葡糖苷微乳液中脂肪酶催化的酯合成反应动力学

在烷基聚葡糖苷C10G1．54／正丁醇／环己烷／磷酸盐缓冲液体系形成的油包水微乳液中,研究了在较高底物浓度下,脂肪酶催化正己酸和正丁醇的酯合成反应动力学及其影响因素。结果表明,在正己酸的初始浓度CHA^0较小时,反应初速率V0随正己酸浓度增大而增大,但随正丁醇表观浓度增大而减小;在CHA^0较大时,反应初速率V0随正丁醇表观浓度增大而增大,但随正己酸浓度增大而减小．在正己酸和正丁醇摩尔浓度之比为3．0左右反应速率最大．这些实验结果与传统的米氏反应不符,为此,从界面膜的构成,尤其是两种底物在界面膜上的分布情况人手进行了探讨．考察了C10G1.54浓度、正丁醇浓度和两者总浓度等对反应初速率V0的影响．     

O／W微乳液中聚邻甲苯胺超微粒子的制备

聚邻甲苯胺具有较高的电导率、较好的贮存电荷的能力和良好的环境稳定性，因而具有较大的应用价值［’－‘j，其合成方法主要有电化学合成法和化学合成法［‘·’J．化学会成法所得聚邻甲苯肢的粒子一般大于100urn．近年来，以表面活性剂聚集体微乳液、溶致液晶为介质，制备超微粒子材料已为人们所关注「’－’］．以微乳液为介质进行聚合反应亦引起重视，但大部分微乳液聚合都是在四组分微乳液（表面活性剂、助表面活性剂、单体和水）中进行‘”·“‘．近年来，某些油溶性单体已成功地在无助表面活性剂的三组分微乳液中聚合［‘’·‘’1…     

Solvent extraction of thorium (IV) with dialkyldithiophosphoric acids

Solvent extraction of thorium (IV) from aqueous solution with dialkyldithiophosphoric acids (RO)₂P(S)SH, (abbreviated Hdtp) in different organic solvents shows that the chain length in Hdtp significantly influence the magnitude of the distribution ratio. The diluent effect and the influence of the inorganic anion present in the aqueous phase was investigated in the Th — di (2-ethyl-hexyl) dithiophosphoric acid (HEhdtp) extraction system. The treatment of the partition data shows that the extraction of Th(IV) in benzene, cyclohexane, chloroform, carbon tetrachloride and n-butanol from perchlorate, chloride and nitrate media occurs via an ion-exchange mechanism. Inorganic anions present in the aqueous phase do not participate in the formation of the extracted species but influence the magnitude of the distribution ratios.     

Synthesis of nanosize europium oxide particles by using W/O microemulsion

Europium hydroxide particles with an average diameter of 10 run and a BET surface area of 127 m2 /g have been prepared by controlled precipitation in the polyoxyethylene octylphenol (Triton X-100) (hex-anol)/cyclohexane/water microemulsion system. After calcination in air at 750℃, the obtained europium hydroxide particles were readily converted to the nanosize Eu2O3 particles with an average size of 30 nm and a high BET surface area of 36.5 m2/g.     

Kinetics of the Esterification Reaction Catalyzed by Lipase in W／O Microemulsions of Alkyl Polyglucoside

A novel kinetic mechanism of esterification reaction of 1-hexanoic acid with 1-butanol,catalyzed by lipase, was studied in water-in-oil microemulsions. The microemulsions were formed by alkyl polyglucoside C10G1.54/1-butanol/cyclohexane/phosphate buffer solution. The restult shows that when the ratio of mol concentration of 1-butanol to 1-hexanoic acid is about 3.0,the initial rate V0 get the maximum values. This phenomenon was explained by the modified fishlike phase diagrams.     

Synergistic Effect of Mixed Cosurfactants on Transdermal Delivery of Indomethacin from O/W Microemulsion

Since large amounts of oils, surfactants and penetration enhancers used in microemulsion systems might lead to seriously skin irritation, the percutaneous absorption and penetration of indomethacin(IMC, model drug) from O/W microemulsion were enhanced by simply changing the composition of cosurfactants. Pseudo-ternary phase diagrams were constructed with mixed cosurfactants at different ratios. Hairless rat skin was used as a barrier for permeation experiments. Four formulations were prepared with fixed oil, surfactant and different cosurfactant content(4%, 20% and 20%, mass fraction), and formulation F4 with menthol added was evaluated to compare the enhancement effect of it with those of mixed cosurfactants. The O/W microemulsion region was the largest when the mass ratio of ethanol/transcutol was 1:1. However, the region changed slightly for the system with incorporated mixed cosurfactants propylene glycol/transcutol. The flux and skin retention of IMC from O/W microemulsion with mixed cosurfactants were much higher than that with single cosurfactant(P<0.01), while incorporation of menthol would only enhance the drug flux through the skin. To conclude, mixed cosufactants could affect the phase behavior and improve the percutaneous absorption and penetration of IMC. Based on this, it provided a promising solution to enhance drug release from microemulsions without raising potential skin damage.