SDS/苯甲醇/H2O体系的相行为与结构

SDS／苯甲醇／H2O体系能生成胶束、微乳液、层状液晶、六角状液晶等分子有序组合作，它们之间转换关系可以从凝聚能理论得到解释．来甲酸在O／W微乳液中的分配系数K＝168，表明绝大多数苯甲醇被增溶于SDS胶束相内．随重量比本甲醇／SDS增加，层状液晶中的do值几乎不变，溶剂渗透率略有增加，六角状液晶中圆柱缔合体的半径r值几乎不变，溶剂渗透率增加．     

Study on surfactant coating of polymeric nanoparticles for controlled delivery of anticancer drug

Biodegradable nanoparticles loaded with anticancer drug paclitaxel and appropriately coated with polyvinyl alcohol (PVA), polyethylene glycol (PEG) as well as d--tocopheryl polyethylene glycol 1000 succinate (TPGS) were produced and characterised by various analysis techniques such as laser light scattering (LLS) for particle size and size distribution, scanning electron microscopy (SEM) and atomic force microscopy (AFM) for particle morphology, X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared-Photoacoustic Spectroscopy (FTIR-PAS) for surface chemistry, and high performance liquid chromatography (HPLC) for drug encapsulation efficiency (EE) and in vitro release kinetics. The emphasis was given to the possible effects of surface coating on the physicochemical and pharmaceutical properties of paclitaxel loaded nanoparticles. It was found that the type and amount of the surfactant could significantly affect the drug EE in the nanoparticles, the particles characteristics and their in vitro release behaviour. The surfactants dominated on the nanoparticles surface and the coated nanoparticles displayed in spherical shape with relative smooth surface within the resolution scope of the equipment. The particle size and size distribution showed close relation to the surface coating, which may also be responsible for the drug encapsulation efficiency and the in vitro release kinetics. A favourable formulation of drug loaded nanoparticles of desired properties could be obtained by optimising the fabrication parameters.     

单分散磁性P(St/BA/MAA)微球的制备

在共沉淀法合成超细磁流体的基础上 ,以苯乙烯 (St)、丙烯酸丁酯 (BA)和甲基丙烯酸 (MAA)为共聚单体 ,在不同的介质体系中采用无皂乳液聚合法制备了单分散 ,粒径范围为 80～ 2 30nm的磁性P(St BA MAA)微球 .详细探讨了介质极性、磁流体中表面活性剂含量对磁性高分子微球粒径和单分散性的影响 .实验结果表明 ,在一定范围内随介质极性降低 ,磁性高分子微球的单分散性提高 ,随表面活性剂用量增加 ,单分散性变差 .总体来看 ,磁性高分子微球的单分散性与其表面静电斥力密切相关 ,过大或过小的静电斥力均会导致磁性高分子微球单分散性的降低 .     

Vesicle formation between single-chained cationic surfactants and ribo-oligonucleotides

Recently,we reported that deoxyribo-oligonucleotides could induce single chained cationic surfactant aggregation to form vesicles.In this paper,we will present that ribo-oligonucleotides can also induce vesicle formation,and compared with deoxyribo-oligonucleotides,ribo-oligonucleotides exhibit a higher inductive efficiency.     

Stripping Voltammetric Determination of Uranium Traces in Sea Water Samples: Effect of Surfactants on the Measurements

The variables affecting determination of ultra trace levels of uranium (VI) in aqueous samples by differential pulse cathodic stripping voltammetry using chloranilic acid as the complexing agent have been examined in detail. Effect of organic surfactants on the voltammetric behavior has been studied. Electrochemical impedance measurements reveal the effect of adsorption of different surfactants on the adsorption pre-concentration step of uranium-chloranilic acid complex. Additionally, to better understand the analytical feature of the method, physicochemical aspects of the preconcentration process has been studied. Adsorption of uranium-chloranilic acid complex follows the Langmuir adsorption isotherm. Analysis results on sea water samples from India are reported.     

Characterization of surfactant complex mixtures using Raman spectroscopy and signal extraction methods: Application to laundry detergent deformulation

This paper presents the analysis of surfactants in complex mixtures using Raman spectroscopy combined with signal extraction (SE) methods. Surfactants are the most important component in laundry detergents. Both their identification and quantification are required for quality control and regulation purposes. Several synthetic mixtures of four surfactants contained in an Ecolabel laundry detergent were prepared and analyzed by Raman spectroscopy. SE methods, Independent Component Analysis and Multivariate Curve Resolution, were then applied to spectral data for surfactant identification and quantification. The influence of several pre-processing treatments (normalization, baseline correction, scatter correction and smoothing) on SE performances were evaluated by experimental design. By using optimal pre-processing strategy, SE methods allowed satisfactorily both identifying and quantifying the four surfactants. When applied to the pre-processed Raman spectrum of the Ecolabel laundry detergent sample, SE models remained robust enough to predict the surfactant concentrations with sufficient precision for deformulation purpose. Comparatively, a supervised modeling technique (PLS regression) was very efficient to quantify the four surfactants in synthetic mixtures but appeared less effective than SE methods when applied to the Raman spectrum of the detergent sample. PLS seemed too sensitive to the other components contained in the laundry detergent while SE methods were more robust. The results obtained demonstrated the interest of SE methods in the context of deformulation.     

改性二氧化硅纳米颗粒提高二氧化碳泡沫稳定性的研究

通过纳米二氧化硅的硅烷化改性, 使其在高矿化度盐水中可以稳定存在的前提下, 研究了改性纳米颗粒与阳离子表面活性剂十二烷基三甲基氯化铵混合体系的溶液稳定性及协同稳定CO₂泡沫的效果. 研究结果表明, 无机盐离子对改性纳米颗粒与阳离子表面活性剂间的静电吸引力具有屏蔽作用, 且矿化度越高, 屏蔽效果越明显, 从而混合溶液更易于在高盐水中稳定; 纳米颗粒表面的活性剂吸附层受二者浓度的影响, 进而影响了颗粒的亲/疏水性; 当混合体系中的表面活性剂浓度低于临界胶束浓度(CMC)时, 混合溶液与CO₂的界面张力高于单独活性剂溶液, 而当活性剂浓度高于CMC时, 对CO₂-溶液界面张力几乎无影响, 最低界面张力可降至6 mN/m左右; 改性纳米颗粒的加入可以进一步提高CO₂体相泡沫半衰期一倍以上, 但受二者浓度比例的影响; 纳米颗粒的加入有效提高了多孔介质中泡沫的表观黏度, 最大增幅由20 mPa·s增至55 mPa·s左右, 泡沫黏度增加接近3倍, 增强了CO₂泡沫驱的封堵作用.     

Facile fabrication of pomponlike microarchitectures of lanthanum molybdate via an ultrasound route

Pomponlike La₂(MoO₄)₃ microstructures assembled with single-crystalline nanoflakes have been facilely fabricated via a surfactant-assisted ultrasound route for the first time. Various synthesis conditions were examined, such as the surfactant concentration, the molecular structure of surfactants, and the pH value. The obtained pomponlike microstructures were characterized by X-ray diffraction (XRD), (field-emission) scanning electron microscopy [(FE)SEM], transmission electron microscopy (TEM), and nitrogen adsorption/desorption isotherms. It has been revealed that a minimum concentration of sodium dodecylsulfate (SDS) was required for the formation of pomponlike La₂(MoO₄)₃ microstructures. When the SDS concentration is above 0.02 mol L⁻¹, the pomponlike microstructures become more perfect, and the size is also increased with the increasing SDS concentration. Under the same sonication, similar pomponlike microstructures were obtained when a cationic surfactant, cetyltrimethyl ammonium bromide (CTAB), was used instead of the anionic surfactant SDS, indicating that the hydrophobic alkyl chains are an important factor for the formation of the pomponlike La₂(MoO₄)₃ microstructures. It is also found that the pomponlike La₂(MoO₄)₃ microstructures can only be obtained within an optimal pH range of 8.0–9.0 under sonication. Based on TEM, Fourier transform infrared spectroscopy (FT-IR) and solubilization experiment, a formation mechanism of pomponlike La₂(MoO₄)₃ microstructures was proposed, in which the collaborative action of surfactants and sonication plays a key role. Furthermore, the porosity of the pomponlike La₂(MoO₄)₃ microstructures were discussed.     

Colorimetric and ratiometric fluorescent detection of sulfite in water via cationic surfactant-promoted addition of sulfite to α,β-unsaturated ketone

Three fluorescent probes were constructed by incorporating an α,β-unsaturated ketone to a coumarin fluorophore. The selective addition of sulfite to the alkene of TSP assisted by cetyltrimethyl ammonium bromide (CTAB) micelle can be visualized by dramatic color and ratiometric fluorescence changes. In CTAB–PBS system, the fluorescence intensity ratio at 465 nm and 592 nm (I₄₆₅/I₅₉₂) and the absorbance ratio at 390 nm and 470 nm (A₃₉₀/A₄₇₀) were linearly proportional to sulfite concentration in the range of 0.5–150 μM, and the detection limit was 0.2 μM. Good selectivity and competition of TSP1 towards sulfite over several anions and biological thiols were acquired. Probe TSP1 was used to detect sulfite in three realistic samples (mineral water, sugar and white wine) with good recovery.     

Straightforward Method for the Preparation of Lysine-Based Double-Chained Anionic Surfactants

Double-chained surfactants with potential biocompatibility have been prepared in high yields by lysine acylation with four natural saturated fatty acids (C₆ to C₁₂) and with cis-undec-5-enoic acid. The surfactants were found to assemble into nanotubules in aqueous medium and, when mixed with a commercial cationic surfactant, to spontaneously form liposomes.