包载槲皮素P/O/W多重皮克林乳液的制备及表征

为解决槲皮素溶解度低透皮性能差的问题，以疏水二氧化硅AEROSIL?R202、亲水二氧化硅AEROSIL?200为乳化剂，一缩二丙二醇和甘油为内醇相，制备水包油包醇（P/O/W）多重Pickering乳液，用其对槲皮素进行了包载。考察了内醇相（一缩二丙二醇和甘油）质量分数、疏水二氧化硅AEROSIL?R202质量分数、水乳比、亲水二氧化硅AEROSIL?200质量分数对P/O/W多重Pickering乳液性能的影响，得到最佳制备条件为：内醇相〔m（甘油）：m（一缩二丙二醇）=6：4〕质量分数为20%、疏水二氧化硅质量分数为3%、m（水）：m（初乳）=5：5、亲水二氧化硅质量分数为2%。对各相染色用激光共聚焦显微镜（CLSM）观察证明，成功制备了P/O/W多重Pickering乳液。X射线衍射仪（XRD）结果表明，槲皮素经多重乳液包载后结晶峰消失，表明该多重乳液对槲皮素有良好的包载效果。离心法测定包载槲皮素P/O/W多重乳液载药量达0.45 %± 0.02%。体外透皮实验和猪皮CLSM显示，槲皮素经该多重乳液包载后透皮性能得到改善，这主要是由于槲皮素在内醇相〔m（甘油）：m（一缩二丙二醇）=6：4〕中的溶解度可达60±2.1 mg/g，远大于在水 (<0.5 μg/g)或油 (<1 mg/g)中的溶解度。     

Effect of triacylglycerol species on the crystallizing behavior of a model water/oil emulsion

The crystallizing behavior of a model water/oil (W/O) emulsion with different fat formulas was investigated. The model W/O emulsion was stored in a programmable oven under a temperature fluctuation cycle of 5 °C for 12 h and 20 °C for another 12 h. Crystal growth was observed using a polarization microscope, until the crystals were over 100 μm in diameter, which causes texture degradation. We examined whether the texture degradation is related to the fatty acid formula and the triglyceride formula by carbon number. We also examined the effect of the triglyceride species concentration estimated from the fatty acid formula on the texture degradation. The palmitic acid content was related with texture degradation at high concentration among the fatty acid species. The triglyceride content was not related with texture degradation. Triacylglycerol species with palmitic acid such as tripalmitate (PPP) and 1,3‐dipalmitoyl‐2‐oleoyl‐glycerol (POP) were related with texture degradation. The summed up concentration of three triglycerides [PPP, POP and 1,2‐dipalmitoyl‐3‐oleoyl‐glycerol (PPO)] was related with texture degradation.     

Synthesis and characterization of hollow zeolite microspheres with a mesoporous shell by O/W/O emulsion and vapor-phase transport method

Hollow microspheres of ZSM-5 with a mesoporous shell have been synthesized through formation of amorphous hollow SiO₂/Al₂O₃ microspheres by sol–gel process in multiple oil–water–oil emulsions and transformation of the amorphous species into zeolite by water–organic vapor-phase transport treatment at 160 °C for 8 days. The morphology of the amorphous and zeolite spheres observed by scanning electron microscopy shows no significant change whereas the molar ratio of Si/Al increases from 6 to 20 during the transformation. The structural feature of zeolite was characterized by X-ray diffraction and ²⁹Si and ²⁷Al magic-angle spinning nuclear magnetic resonance. Transmission electron microscopy and N₂ adsorption–desorption isotherms indicate that uniform mesopores in the shell of zeolite spheres arise from the interstices among zeolite crystallites.     

Simultaneous synchrotron radiation X-ray diffraction-DSC analysis of melting and crystallization behavior of trilauroylglycerol in nanoparticles of oil-in-water emulsion

Crystallization, polymorphic transformation, and melting behavior of nanoparticles of trilauroylglycerol (LLL) in oil-in-water (O/W) emulsion were examined initially by DSC, and then by simultaneous synchrotron radiation small-angle (SAXS) and wide-angle (WAXS) X-ray diffraction and DSC (SR-SAXS /WAXS/DSC). The O/W nanoparticles emulsions having average diameters of 42 to 120 nm were prepared by application of mechanical shear using a high-pressure homogenizer. The following results were obtained: (i) The DSC study showed that the melting temperature of the stable β form of LLL was reduced from 46.7 (bulk) to 26.5–44.0°C (nanoparticles); this variation as assumed to be due to the size distribution of the nanoparticles. Crystallization temperature was also reduced from 18.9 (bulk) to −9.5±0.5°C (nanoparticles). These results were consistent with those of previous studies of nanoparticles of fats obtained in the O/W emulsion. (ii) The results obtained by the SR-SAXS/WAXS/DSC technique during the cooling process to −20°C showed that the first-occurring polymorph of LLL in the bulk liquid was β′, whereas α was first nucleated and transformed to β′ around −10°C during cooling in the nanoparticles. (iii) The SR-SAXS/WAXS/DSC data taken during the heating process from −20°C after the crystallization showed that β′ transformed to β around 0°C and that the melting of β started at 30°C and ended at 44°C. The present study showed that forming nanoparticles of LLL in the O/W emulsion having the diameters of 42 to 120 nm reduced the melting and crystallization temperatures and increased the transformation rate of α→β′→β in comparison to the LLL crystals formed in the bulk phase.     

Investigation of O/W emulsion separation and redispersion using fibrous PTFE bed coalescer

A series of fiber beds consisted of woven PTFE fiber mesh were used to investigate the influence of bed porosity (gradient porosity), permeability, specific surface area of bed, and superficial velocity on coalescence and separation process. It is found that too small bed porosity will not give better separation performance, for the reason of redispersion. The separation efficiency does not depend on the pore size but on the surface area of bed when the porosity is above 0.850. And a rapid drop of separation efficiency takes place above the porosity of 0.903. For effective separation of liquid droplets from a fluid stream, the gradient increasing porosity is the most favorable structure, which is effective to avoid redispersion of coalesced droplets.     

Design of a super-hydrophilic/super-oleophobic g-C3N4/Ti(OH)4/PFOA nanocomposite coated mesh as a smart nanofilter with robust anti-fouling properties for separation of oil and water emulsions

The design and development of efficient approaches for water–oil separation have had widespread interest. This study aimed to synthesize nanocomposites based on Ti(OH)₄ and g-C₃N₄ nanosheets (CN-NS) to show experimentally that the inclusion of Ti(OH)₄ nanoparticles of 9.2 nm size into CN-NS leads to an improved oil-water separation efficiency and anti-fouling performance. So, a novel, reusable, and recyclable super-hydrophilic/underwater super-oleophobic CN-NS/Ti(OH)₄ nanocomposite-coated stainless steel mesh was developed to separate oil-in-water emulsions. Super-wettability was obtained in the CN-NS/Ti(OH)₄ nanocomposite with WCA = 0° and UOCA = 154°, respectively, showing significant super-hydrophilicity and underwater super-oleophobicity. Surface hydrophilicity increased after anchoring Ti(OH)₄ on the CN-NS surface, resulting from oxygen-containing functional groups and consequently making defects on the mesh surface. Enhanced underwater oleophobicity of nanocomposite coated mesh is attributed to its higher surface roughness, which is a result of its micro-nano meter and mesoporous hierarchical structure. Moreover, the self-cleaning property of the as-prepared mesh was demonstrated by visible light irradiation on the contaminated mesh. In addition, perfluorooctanoic acid (PFOA) reduced energy in CN-NS/Ti(OH)₄/PFOA mesh, resulting in a super-hydrophilic/super-oleophobic mesh. The CN-NS/Ti(OH)₄/PFOA nanocomposite-coated filter was observed to separate water from a 1 wt% water-in-oil emulsion at 0.2 bar pressure with a filtration flux of 317.2 L m⁻² h⁻¹ and 95% separation efficiency.     

De-emulsification of 2-ethyl-1-hexanol/water emulsion using oil-wet narrow channel combined with low-speed rotation

Low-speed rotation of disc in an internal circulation of a novel de-emulsification with rotation-dise horizental contactor (RHC-D) realized de-emulsification for O/W emulsions due to repeated coalescence in oil-wet narrow channels at a low rotation speed. For three emulsions included ethanol/water/2-ethyl-1-hexanol, ethanol/water/2-ethyl-1-hexanol/SDS (Sodium Dodecyl Sulfonate) and 2-ethyl-1-hexanol/water/SDS emulsion, deemulsification ratios of oil phase could reach 1, 1 and 0.67 respectively at 170 r·min^-1, and de-emulsification ratios increased obviously after agitating 10 min. De-emulsification experiment in the seam indicated that oil droplet sizes in O/W emulsion became larger after de-emulsification. The main de-emulsification mechanism in RHCD was the coalescence of oil droplets in oil-wet narrow channels. With increase of the rotation speed, oil droplets dispersed better in the aqueous phase. However, de-emulsification effect enhanced due to the increase of the coalescence rate at a bit higher rotation speed. In addition, internal circulation made those O/W emulsions to be broken repeatedly, consequently de-emulsification ratio increased. Repeated de-emulsification through internal circulation might make continuous extraction of ethanol come true at a low rotation speed.     

Preparation of microcapsules of W/O/W emulsions containing a polysaccharide in the outer aqueous phase by spray‐drying

A water‐in‐oil‐in‐water (W/O/W) multiple emulsion containing a hydrophilic substance, 1,3,6,8‐pyrenetetrasulfonic acid tetrasodium salt (PTSA), and a wall material in its inner and outer aqueous phases, respectively, was prepared by a two‐step emulsification using a rotor/stator homogenizer, and was further homogenized with a high‐pressure homogenizer. Maltodextrin or gum arabic were used as wall materials, and olive oil was used as the oily phase. The high encapsulation efficiency for PTSA (>0.9) was realized. The emulsion was spray‐dried to produce microcapsules of W/O/W type. The efficiencies of the microcapsules prepared with maltodextrin and gum arabic were 0.82 and 0.67, respectively. Stability of the microcapsules was examined at 37 °C and 12%, 33% and 75% relative humidity. Microcapsules prepared with maltodextrin were more stable than those prepared with gum arabic.     

Effects of addition of diacylglycerols on fat crystallization in oil‐in‐water emulsion

The effects of addition of diacylglycerols (DAGs) on the crystallization behavior of n‐hexadecane dispersed in oil‐in‐water emulsion (oil 20% and water 80%, v/v) were studied by differential scanning calorimetry (DSC) and ultrasonic velocity measurement. In an attempt to modify the crystallization rate of n‐hexadecane, five DAGs having the fatty acid moieties of behenic (DAB), stearic (DAS), palmitic (DAP), lauric (DAL) and oleic acid (DAO) were added to n‐hexadecane, which was mixed with water and Tween 20 for emulsification. The DSC study showed that the addition of DAB, DAS or DAP (1.0 wt‐% with respect to n‐hexadecane) increased the crystallization temperature (Tc) of a n‐hexadecane/water emulsion from 3 °C (without DAG) to 8 °C, whereas the addition of DAL and DAO showed no effect. The ultrasonic velocity measurement also revealed that the addition of DAGs resulted in increasing the Tc of n‐hexadecane in O/W emulsion. These effects were discussed by taking into account the formation of molecular aggregates at the interface due to the addition of DAGs, which act as a template for crystallization of n‐hexadecane. The template‐assisted crystallization depends on the structure of the fatty acid chains present in the DAG: the longer the fatty acid moiety of DAG , the more is the crystallization of n‐hexadecane in O/W emulsion accelerated.     

毒死蜱农药的进展和剂型加工

毒死蜱是一种高效、广谱、低残留并有中等毒性的杀虫剂,可用于农业上粮食、蔬菜、水果及经济作物,防治50余种害虫,正成为替代甲胺磷等高毒农药的主要农药品种。本文论述毒死蜱农药国内外进展和剂型加工情况,指出改进毒死蜱乳油的方法以及研发毒死蜱水包油乳液剂型是替代毒死蜱乳油的方向。     

Complex formation in a ternary system composed of lauroamphoglycinate, oleic acid, and water

The formation of a complex, composed of lauroamphoglycinate (LG), oleic acid (OA) and water, was investigated, and this system was applied to emulsification. The complex was formed in the water-rich area (more than 90% in this system) at a molar ratio of OA to LG from 1 to 3, where two-phase systems of water and the complex existed. The interaction between LG and OA, both in the aqueous solution and at the interface of liquid paraffin dissolving the OA and LG solution, was studied by pH measurements and interfacial tension measurements, respectively. The results implied that LG and OA were linked stoichiometrically, both in aqueous solution and at the interface, and formed complexes. X-ray diffraction patterns and the strong hydrophobicity showed that the equimolar complex composed of LG, OA, and water was a liquid crystal with a reversed hexagonal structure. The reversed hexagonal liquid crystal was capable of solubilizing a certain amount of liquid paraffin in its alkyl group parts while maintaining its hexagonal structure. These results suggest the possibility to prepare a W/O-type emulsion by using the liquid crystal formed by LG, OA, partial liquid paraffin, and water as the continuous phase. The authors could obtain a stable W/O emulsion without coalescence of the water droplets that contained a substantial amount of water (approximately 90%). Furthermore, various types of emulsions, O/W, W/O, W/O/W, could be prepared by changing the ratio of LG and OA.     

稳定悬浮亚毫米级油滴设计高SPF值水性低粘度喷雾产品研究

采用新颖的油滴悬浮的方法设计,研究了以多种防晒功效物为主要成分的低粘度、高SPF指数、水性喷雾产品体系,通过密度仪、流变仪、激光粒度分析仪等手段以及理论计算,筛选优化出合适的防晒剂溶解分散剂、油水密度平衡配比、乳化和增稠等承载体系,得到一款稳定、轻薄不油腻、易喷出、方便实用的低粘高弹配方体系。结果表明,该体系可以较大幅度地提升防晒能力和效率,SPF值为30.0,可运用于油脂含量较低的透明悬浮体系。     

Effects of hydrophobic emulsifier additives on crystallization behavior of palm mid fraction in oil-in-water emulsion

Ultrasonic velocity measurements and X-ray diffraction were employed to monitor the crystallization behavior of palm mid fraction (PMF) in oil-in-water emulsions (20 vol%). Three hydrophobic emulsifiers—sucrose oligoesters (SOE) containing palmitic acid (P-170) and stearic acid (S-170) moieties and a polyglycerine ester (DAS-750) containing a stearic acid moiety—were added to PMF in an attempt to increase the rate and extent of crystallization of PMF, which are otherwise suppressed owing to emulsification of the oil phase into many droplets. The results revealed that the hydrophobic emulsifiers accelerate the nucleation of PMF in the emulsion system, while retarding the rate of crystal growth. As a results, the crystallization temperature (T _c) of PMF increased with increasing concentrations of the hydrophobic emulsifiers. The effects of the three additives were different; in particular the addition of DAS-750 remarkably enhanced crystallization at low concentrations. By adding the emulsifiers at higher concentrations, the polymorphic behavior of PMF crystallization was also modified to different degrees, depending on the type of emulsifier. With addition of SOE, PMF crystallized predominantly in the β′ form; with addition of DAS-750, the extent of β′ nucleation was reduced by comparison with that observed with SOE. The results were explained in terms of adsorption of the hydrophobic emulsifier additives at the oil-water interface, which provides a template for acceleration of surface heterogeneous nucleation of PMF in the emulsion system.     

低粘度高固含量醋酸乙烯-丙烯酸酯共聚乳液胶粘剂的研制

介绍了一种低粘度、高固体含量的醋酸乙烯-丙烯酸丁酯-丙烯酸异辛酯共聚乳液胶粘剂的合成工艺及性能。该乳液粘度低于2500mPa.s,固体含量≥52%,较低的玻璃化温度和良好的耐水性能,应用于卷烟和防水涂料的生产。     

水性聚氨酯/聚甲基丙烯酸甲酯杂化乳液的合成

用异佛尔酮二异氰酸酯(IPDI)、聚丙二醇(PPG)和二羟甲丙酸(DMPA)合成了水性聚氨酯分散体(WPU),讨论了PPG摩尔质量,NCO/OH及PPG/DMPA比例对WPU乳液和涂膜性能的影响。以WPU为种子与甲基丙烯酸甲酯进行乳液聚合制备杂化乳液,研究了不同PU/PMMA物质的量比例对杂化乳液及涂膜性能的影响,并采用TEM对WPU及杂化乳液粒子进行了表征。结果表明,在以PPG1000为原料,NCO与OH物质的量比为1.4∶1,PPG与DMPA物质的量比为1∶0.8条件下制备的WPU杂化乳液,随着PMMA比例增加,杂化乳液的稳定性和成膜性变差,聚合物膜断裂伸长率降低,但铅笔硬度、耐水性及耐乙醇性均得到了改善。     

复合可聚合乳化剂制备高固含量低黏度聚丙烯酸酯乳液

以DNS-86和F-6为复合可聚合乳化剂APS为引发剂,MMA、BA为单体采用半连续法制备20%固含量种子乳液,以种子乳液为介质,选用4种不同类型乳化剂:非离子可聚合乳化剂F-6,阴离子可聚合乳化剂DNS-86、常规非离子乳化剂OP-10、常规阴离子乳化剂SDS进行不同组合,同时滴加预乳化液、引发剂、缓冲剂直接二次成核制备62%固含量二元粒径分布乳液。重点研究了乳化剂复合方式、用量及配比、反应温度等对聚合稳定性、乳液流变性等的影响。,     

The effect of process parameters on the size and morphology of poly(D,L‐lactide‐co‐glycolide) micro/nanoparticles prepared by an oil in oil emulsion/solvent evaporation technique

For the past few decades, there has been a considerable research interest in the area of biodegradable polymeric micro‐ and nanoparticles for tissue engineering, regenerative medicine, implants, stents, medical devices, and drug delivery systems. Poly(D,L ‐lactide‐co‐glycolide) (PLGA) is well‐known by its safety in biomedical preparations which has been approved for human use by the FDA. The goal of this study was to evaluate the influence of process parameters on size characteristics of PLGA microparticles prepared by oil in oil (o/o) solvent evaporation technique. This method has been introduced as one of the most appropriate methods for hydrophilic agents. Scanning electron microscopy showed that prepared particles were spherical with smooth surface without aggregation. Particle size varied from 570 nm to 29 μm in different experimental conditions. Stirring speed, polymer concentration, impeller type, and dropping size had a significant effect on the particle size. The polydispersity index of particles showed a strong relationship with the surfactant concentration, impeller type, and dropping size. It was concluded that increasing in temperature up to 50°C or changing in dropping rate has a little effect on reducing the size of PLGA particles. The residual solvent content in the final suspension was less than 0.1 ppm that is in appropriate range for biomedical application. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of emulsion polymerized mixed matrix aluminum silicate/poly(2,6‐dimethyl 1,4‐phenylene oxide) films

A series of poly (2,6‐dimethyl‐1,4‐phenylene oxide) (PPO)‐based organic/inorganic films for the potential application in membrane gas separation were prepared by employing a method in which aluminum hydroxonitrate contained in a stable water‐in‐oil (W/O) emulsion, the oil phase being a solution of PPO in trichloroethylene, was mixed with a homogeneous solution of PPO in trichloroethylene containing tetraethyl orthosilicate (TEOS). Inorganic polymerization occurred in or at the surface of the aqueous droplets of the W/O emulsion. Subsequently, thin films were prepared by a spin coating technique, and they were referred to as emulsion polymerized mixed matrix (EPMM) films. Scanning electron micrographs taken from a film cross section indicated the presence of particles in the PPO matrix, and energy dispersive X‐ray measurements showed that the embedded particles contained Al and Si elements. Differential scanning calorimetry analysis showed a decrease in the glass transition of the EPMM films with increase of TEOS loading. The compatibility between aluminum silicate nanoparticles and PPO in the EPMM films was confirmed by air separation tests. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008