Dispersion Performance of Methanol-Diesel Emulsified Fuel Prepared by High Gravity Technology

A new continuous process for preparing methanol-diesel emulsified fuel with an Impinging Stream-Rotating Packed Bed is proposed. The droplet size of dispersed phase(methanol) of the emulsified fuel has a significant effect on the combustion of methanol-diesel emulsified fuel. In this paper, the methanol-diesel emulsified fuel uses diesel as the continuous phase and methanol as the dispersed phase. The Sauter mean diameter of the dispersed phase of methanol-diesel emulsified fuel was characterized with microphotography and arithmetic method. The experimental result showed that the Sauter mean diameter of the dispersed phase, which was decreased with the augmentation of the high gravity factor, liquid flow rate and emulsifier dosage, was inversely proportional to the methanol content. The Sauter mean diameter of the dispersed phase can be controlled and adjusted in the range of 12—40 μm through the change of operating conditions. The correlative expressions of the Sauter mean diameter of emulsified fuel were obtained and the calculated values agreed well with the experimental values.

Preparation and Lubricating Properties of A New Antibacterial Emulsion Containing Nano-TiO_2 for Cold Rolling Strips

A new kind of emulsion containing nano TiO_2 was developed through the dispersion experiment. A commercial emulsion and a prepared by our lab emulsion without nano particles were chosen as controls to test the tribological and antibacterial properties of this new emulsion. The load carrying capacity, friction coefficient and average diameter of wear scars were tested by a four-ball machine and the comprehensive antifriction parameter ω was calculated. The wetting angle was also tested using a JC200C1 wetting angle tester. The micro surface and roughness of rolled strips were analyzed to investigate the tribological performance of the recommended new emulsion in strip production. It is shown that the new nano-emulsion possesses a higher load carrying capacity and wetting ability. Therefore the abrasive/plowing wear is reduced more efficiently with the addition of nano particles, and the micro surface is improved. The density of bacteria in the emulsions was tested after the cold rolling experiment. The emulsion breaking ratio and bacteria density were also tested in different time intervals after the cold rolling experiment. The final p H values and bacteria density of different layers of emulsions were measured and the sediment was analyzed by TEM to evaluate the antibacterial behavior of this new emulsion. It is shown that the density of microbial colonies which led to a corruption of emulsions was decreased about 90% and the effective antibacterial period was prolonged.

Influence of Suspended Emulsion Polymerization Conditions on Particle Characteristics of Polyvinyl Chloride Resin

Suspended emulsion polymerization of vinyl chloride was carried out in a 5 L autoclave. The influence of agitation, polymerization conversion, dispersant and surfactant on the average particle size (PS) and particle size distribution (PSD), particle morphology and porosity of polyvinyl chloride (PVC) resin was investigated. It showed that the agitator had great influence on the smooth operation of polymerization, PS and PSD. The PS increased and PSD became narrow as polymerization conversion became high. The porosity decreased with the increase of conversion. A convenient choice of additives, both dispersants and non-ionic surfactants, allows one to adjust PS and PSD. The PS decreased with the addition of polyvinyl alcohol or hydroxypropyl methylcellulose dispersants,and increased with the addition of Span surfactants. The addition of dispersants or surfactants also affected the morphology and porosity of resin, and PVC resin with looser agglomeration and homogeneous distribution of primary particles was prepared.

NEW METHOD FOR EFFECTIVE VISCOSITY OF COLLOIDAL DISPERSIONS WITH PERIODIC MICROSTRUCTURES

One of the central theoretical problems in the colloid field is to determine the rheological relation between the macroscopic properties of colloidal suspensions and the microstructures of the systems. In this work, the authors develop a method of transformation field by which one call calculate the effective viscosity of an incompressible: viscous fluid containing colloidal particles (either solid particles: or liquid drops) fixed at the points of a periodic lattice. The effective viscosity of a colloidal dispersion of spherical particles is calculated. The predictions of the theory are in good agreement with the Einstein's formula for suspensions and the Taylor's formula for emulsions at low particle concentrations. At higher particle concentrations, the theory reproduces the results of Nunan and Keller. The method is also applicable to the viscosity of colloidal systems with non-spherical particles.

A THEORETICAL RESEARCH TO EFFECTIVE VISCOSITY OF COLLOIDAL DISPERSIONS

Colloidal dispersions are common in nature with wide industrial applications. One of the central theoretical problems in the field is to determine the rheological properties of the colloidal dispersion from the microstructures of the systems. Because of the difficulties associated with the boundary-value problems of the many-particle system, existing theories for colloidal suspensions are limited to low particle concentrations. In this work, a method of transformation field is developed by which one can calculate the effective viscosity of an incompressible viscous fluid containing colloidal particles ( either solid particles or liquid drops). The predictions of the theory are in goad agreement with the Einstein's formula for suspensions and the Taylor's formula for emulsions at low particle concentrations. At higher particle concentrations, the results of Nunan and Keller are produced. The method is also applicable to the viscosity of colloidal systems with non-spherical particles.

Preparation of Composite Particles by Forming Pickering Emulsion Followed by Drying-In-Liquid and Effect of Stepwise Addition of Solid Powder on Structure of Composite Particles

It was tried to prepare composite particles made of polymer and two kinds of solid powders by forming Pickeringemulsion followed by the drying-in-liquid method and to investigate how the stepwise addition of solid powders affected the contained ratio and adhesion ratio of solid powders and the structure of composite particles. Limonene oil dissolving expanded polystyrene and ethylene glycol were adopted as the dispersed phase and the continuous phase, respectively. Magnetite and titanium dioxide were used as solid powders. Magnetite was added before or after formation of the (O/W) dispersion. Titanium dioxide was added at the various elapsed times from addition of magnetite. Titanium dioxide adhered only on the surface of composite particles irrespective of addition time. At the earlier addition of both solid powders, the surface-covering type composite particles were prepared. At the latter addition of titanium dioxide, a part of magnetite adhered on the surface and the remainder was dispersed into composite particle.

Preparation of Microcapsules Containing Aqueous Solution of Azur B with Melting Dispersion Cooling Method and Application to DNA Amplification Detector

Microcapsules containing the aqueous solution of Azur B of a water soluble dye were prepared with the melting dispersion cooling method and applied to the amplification detector of plant DNA. Paraffin wax with melting temperature of 75°C was used as the shell material. In the experiment, the aqueous solution (W) of Azur B as the core material was dispersed in the melted paraffin wax (O) to form the (W/O) emulsion and then, the (W/O) emulsion was dispersed in the silicon oil (O’) as the continuous phase to form the (W/O)/O’ emulsion at 85°C. After formation of the (W/O)/O’ emulsion, the microcapsules were prepared by cooling the (W/O)/O’ emulsion to 50°C. The microcapsules were prepared by changing the concentration of oil soluble surfactant in the (W/O) emulsion and the volume of the (W/O) emulsion in the (W/O)/O’ emulsion. The microencapsulation efficiency increased with the concentration of oil soluble surfactant and finally became 100% under the optimum conditions. Furthermore, the microcapsules were melted down at temperature of 85°C to reveal the sharp thermal responsibility and to release the aqueous solution of Azur B. As a result, it was found that the microcapsules were able to be applied to the amplification detector of plant DNA by utilizing the reaction between DNA and Azur B.

Cellulose Nanocrystals-Coated Polylactide(PLA) Microspheres Obtained via a Pickering Emulsion Approach

In order to prepare cellulose nanocrystals( CNCs)-coated polylactide( PLA) microspheres for the use of drug delivery and tissue engineering,a Pickering emulsion route was applied. The stable Pickering emulsions were prepared using CNCs as efficient stabilizers without any additional surfactant. The microspheres were successfully fabricated after volatilization of the solvent. What's more,the size of microspheres could be controlled by fabrication parameters.

Extraction of Neodymium by Emulsion-Liquid-Membrane within Hollow-Fiber-contactor and Its Mass Transfer Properties

A non-dispersive extraction technique, using an emulsion liquid membrane within a hollow-fiber-contactor for the extraction and enrichment of Nd^3＋ from the dilute feed aqueous, was applied. The emulsion system is consisted of span80 [ sorbitian monooleate], paraffin oil, D2EHPA [ 2-（ 2-ethylhexyl- phosphonic acid）], kerosene as well as HCl solution. The extraction under various conditions such as the span80 concentrations, the flow rate of aqueous, the extraction time and HCl concentrations in receiving phase were studied. Results show that the lower the flow rates of aqueous are, the higher the extraction percentage and enrichment-fold are, and the extraction percentage increases with the increasing of HCl concentrations. When the initial Nd^3＋ concentration in feed is maintained at 1000 mg· L^-1 and the emulsion is recycled with 70 times by a counter-flow,

复合型水性丙烯酸树脂乳液的制备和性能

采用低玻璃化转变温度、高分子量的丙烯酸树脂乳液与高玻璃化转变温度、低分子量的丙烯酸树脂分散体混合的方式,制备了无交联剂水性丙烯酸树脂复合乳液,用于彩印包装纸与塑料薄膜的热复合。以丙烯酸、丙烯酸丁酯、苯乙烯、丙烯酸羟乙酯等为原料,采用种子乳液聚合法制备了相对分子质量(1.48~1.84)×10^(5)、玻璃化转变温度(T_(g))﹣20~﹣40℃的丙烯酸酯乳液。以丙烯酸、丙烯酸丁酯、苯乙烯、α-甲基苯乙烯、马来酸单酯等为原料,采用本体聚合法制备了相对分子质量(1.34~1.65)×10^(4)、T_(g) 20~45℃、软化点80~105℃的固体树脂,进一步采用自乳化方法将固体树脂制备成树脂水分散体。考察了不同Tg的丙烯酸酯乳液与水分散体以不同比例混配后的乳液混合体的性能。研究结果表明,T_(g)为﹣27.6℃的丙烯酸酯乳液与Tg为28.2℃固体树脂的分散体以质量比8:2混合后,用于PET膜-黑色印刷纸的热复合,剥离强度达到5.6 N/25 mm,持粘性达270 h,可以充分满足覆膜材料的附着力和耐压纹等性能要求。

阳离子分散松香胶/AKD乳液/壳聚糖联合提高麻浆与烟梗浆配抄滤嘴棒用纸的疏水疏油性能

以麻浆和烟梗浆为原料,抄造滤嘴棒用纸。通过浆内添加施胶剂〔阳离子分散松香胶和烷基烯酮二聚体(AKD)乳液〕和表面涂布壳聚糖的方法,提高滤嘴棒用纸的疏水疏油性能。探究施胶剂添加量和壳聚糖涂布量对滤嘴棒用纸防水性能、防油等级和物理性能的影响。研究结果表明:当浆内阳离子分散松香胶和AKD乳液添加量均为2%(相对绝干浆)时,滤嘴棒用纸的接触角为128.8°,60 s时滤嘴棒用纸的可勃值为24.30 g/m^(2);当壳聚糖涂布量为20 g/m^(2)时,滤嘴棒用纸的防油等级为12级。

DISPERSED PHASE HOLDUP AND DROP SIZE DISTRIBUTION IN A ROTATING PERFORATED DISK CONTACTOR

Hydrodynamic characteristics of rotating perforated disk contactor(RPDC)were studied with emulsionwater system.The emulsion was dispcrsed in water and its holdup was measured.The effects of columndimensions and operating conditions on holdup and characteristic velocity were studied.By using the methodof dimensional analysis,the authors obtained two experimental correlations for estimating holdup and characteristic velocity respectively.Drop size distribution was studied photographically.The experimental results showedthat drop size distribuiion could be described by upper-limit log-normal distribution.

THE SWELLING BEHAVIOR OF (W/O)/W LIQUID SURFACTANT MEMBRANE (Ⅰ) ADSORPTION OF SURFACTANT AT THE INTERFACE AND THE SWELLING CAUSED BY EMULSIFICATION

The concept of effective concentration of surfaetant in membrane phase has been proposed,considering the high ad-sorption density of the surfactant at the droplet interfaces in LSM system.The effective concentration of surfactant,C2,can be estimated by Eq.（7）—（9）.The swelling caused by emulsification during the initial dispersion process was investigated.The swelling rate wasmeasured by a density method.A model for estimating the"Emulsification" swelling rate,Fse,has been proposed,basedon a mechanism of swelling due to the entrainment of water resulted from the interracial turbulence and emulsification inthe initial dispersion process.It has been found that Eq.（26）gives excellent fit to the experimental data of Fujinawa,etal.and of the authors.

基于Pickering乳液的油基钻井液

Pickering乳液通过颗粒在油水界面吸附,形成稳定界面膜防止水滴聚并,能够提高油基钻井液的稳定性。然而,关于Pickering乳液油基钻井液的研究,忽略了油相中水滴和无机亲水颗粒间相互作用,均未考虑配浆时加入的氢氧化钙、加重剂以及地层中进入的劣质固相等无机颗粒对乳液中水滴存在形式的影响。因此,向W/O型Pickering乳液中加入氢氧化钙、重晶石和不同水化程度高岭土颗粒,通过宏观沉降实验和显微镜图像证明水滴与颗粒结合,以结合水形式存在,导致颗粒聚集;通过激光共聚焦显微镜和低温差示扫描量热对结合水进行表征。通过添加分散剂可以促进结合水颗粒的分散,提高钻井液体系的稳定性。基于W/O型Pickering乳液的油基钻井液不是油包水乳液,而是结合水颗粒在油相中适度分散的体系。此外,配制低密度油基钻井液模型体系,并调控体系的流变性能,实现低温恒流变。

乳化型沥青质分散抑制剂的研制

为解决重油开采过程中的沥青质沉积问题,对塔河油田井筒沉积物进行了物性分析,研制了一种低毒环保的乳化型分散抑制剂,考察了分散抑制剂的作用机理。结果表明,当乳化体系中的油相分散剂为RJY200,抑制剂为十二烷基苯酚时,抑制率在90%以上;当十二烷基苯磺酸∶S20为7∶3时,乳液体系在常温下静置7 d仍保持稳定。添加沥青质分散抑制剂前后的X射线衍射及扫描电镜表明,沥青质分散抑制剂的作用机理主要是通过氢键、π-π堆积作用等,吸附、嵌入到沥青质分子层间,使沥青质分子的极性减弱,平面堆砌的聚集结构被分散,抑制沥青质沉积物产生。

反应溶剂对聚合过程的影响

分散体系中不同的聚合过程能够制备出具有不同功能特性的纳米凝胶,这些聚合物可广泛应用在生物医学、靶向药物输送和其他领域。综述了反应溶剂对聚合过程的调控,重点介绍了乳液聚合和分散聚合,通过调节溶剂组成引发乳液聚合与分散聚合的转化。探讨了溶剂极性、溶解度参数和聚合反应的临界链长等参数对聚合方式的影响。

纳米石蜡乳液在钻井液处理剂作用下的稳定性研究

由于页岩存在微细的裂缝网络和纳米至微米尺度的孔隙度,因此使用含纳米粒子的钻井液体系对页岩裂缝进行封堵是必不可少的。本文通过粒径测试、沉降稳定性以及离心稳定性实验,研究了传统钻井液处理剂对纳米石蜡乳液性质的调控效果。实验结果表明,纳米石蜡乳液在水性介质中具有良好的稳定性,其平均粒径在60-70 nm之间,并遵循正态分布。在不同钻井液处理剂作用下,乳液的粒径和稳定性表现出显著差异。其中BPT-507抑制剂使乳液平均粒径显著增至465.97 nm,而HV-CMC增黏剂几乎不影响乳液的粒径,稳定在71 nm左右。此外,高光透过率(HV-CMC处理剂为90.7%)表明了处理剂在防止颗粒聚集方面的显著效果,进而提高了乳液的稳定性。此研究对页岩密封技术和钻井液处理剂的应用提供了理论支撑和实际指导。

单组分聚合物乳液防水涂料吸水率的影响因素研究

介绍了一种低吸水率的单组分聚合物乳液防水涂料的制备方法。实验表明,在单组分聚合物乳液建筑防水涂料的制备过程中,按照纯丙树脂乳液添加量48%(质量分数,后同)、去离子水为3%、400目重钙为16%、800目重钙为15%、1 250目沉淀硫酸钡为17%、消泡剂为0.3%、杀菌剂为0.2%、增稠剂1为0.3%、铵盐分散剂2为0.3%制备涂料,控制涂膜厚度为1.5mm,制备的涂膜吸水率最低,可达到7.6%,可满足标准≤10%的要求。

PVC糊树脂乳化剂精准入料控制的研究及应用

重点研究了微悬浮法生产PVC糊树脂过程中水乳液、分散液的制备工艺控制条件,探索了乳化剂精准入料控制对PVC糊树脂聚合生产过程和质量稳定性的影响。

FRACTIONAL RESEARCH OF POLYDISPERSED MICROCRYSTALS OF SILVER IODOBROMIDE EMULSION

Ⅰ. INTRODUCTION It is well known that iodide plays an important role in making photographic emulsion of high sensitivity. It is recognized that incorporation of iodide ions into silver bromide changes the grain size distribution, increases the crystal defect of silver halid microcrystals, promotes the latent image formation and produces traps of vacan-