涂料树脂的乳化

叙述了SAD和油/水比在乳化中的作用。     

碱-助表面活性剂-聚合物体系相性质的研究

本文综述了采用乳化筛选试验法制作活性图,对碱-助表面活性剂-聚合物(APS)驱油体系相性质所作的研究。讨论了活性剂、碱对体系相性质的影响及相性质与界面张力、驱油效率之间的关系。在碱-原油体系中加入低浓度表面活性剂可使活性区加宽,体系最佳含盐量提高。过量碱在体系中起电解质作用。一价阳离子对相性质的影响次序为 K~ >Na~ >NH_4~ 。最佳体系的界面张力可达到很低值。     

Hydrolyzed wheat gluten suppresses transglutaminase-mediated gelation but improves emulsification of pork myofibrillar protein

The influence of 15-h chymotrypsin-hydrolyzed wheat gluten (GH) on microbial transglutaminase (MTGase)-mediated interaction, gelation and emulsification of pork myofibrillar protein isolate (MPI) was investigated at two ionic strengths (0 M and 0.6 M NaCl) and pH 6.5. MTGase treatments in 0 M NaCl solution decreased the size of myosin heavy chain through deamidation, but this was inhibited by GH or in 0.6 M NaCl where myosin polymerization dominated. Stabilization of MPI (thermal transitions) by the MTGase treatment was also diminished (P < 0.05) by the presence of GH at both ionic strengths. These GH-induced MPI physicochemical changes greatly weakened the ability of MTGase to promote MPI thermal gelation (gel storage modulus, P < 0.05), especially at 0.6 M NaCl, which was shown to result from reduced protein aggregation. However, GH improved (P < 0.05) emulsifying properties of MPI, regardless of MTGase treatment.     

汽车用LF－5W型水乳化防锈蜡的研究和应用

简述了近年来国外汽车防锈蜡的概况，技术路线的选择，乳化剂及其它助剂对产品性能的影响。与进口同类产品比较，该产品具有同等的防锈性及工艺性能，较优良的干燥性。     

硅酸钠在金属脱脂剂中的作用

硅酸钠是金属脱脂剂配方中常用的主要原料之一。它对各类油脂及污物有良好的乳化作用，对各类金属材料都有缓蚀作用，利用硅酸钠在清洗冷轧镀锡原板时在钢板表面形成的一层SiO2吸附膜，可防止带钢在进行罩式炉退火时粘结。     

Emulsifying effect of dimethyldioctadecylammonium-hectorite in polystyrene/poly(ethyl methacrylate) blends

An organically modified clay, dimethyldioctadecylammonium-hectorite (DMDO-Hect.), was used as an emulsifier for the immiscible polystyrene/poly(ethyl methacrylate) (PS/PEMA) pair of polymers. The organoclay in this blend adsorbs selectively the PEMA chains and creates PEMA/DMDO-Hect. intercalated structures within which the PS chains are shaped into separate domains. The size of these domains decreases as the concentration of the inorganic DMDO-Hect. partner increases giving a typical emulsification curve that testifies the emulsifying action of the organoclay. SEM and TEM micrographs reveal efficient mixing of the polymers in the presence of the organoclay. The emulsifying action of the organoclay is also reflected by the presence of only one T_g in the DSC thermograms when the organoclay concentration reaches the equilibrium value in the emulsifying curve.     

Efficiency of graft copolymers as compatibilizers for immiscible polymer blends

This work was aimed at studying the emulsification efficiency of graft copolymers and the effect of feeding mode on the emulsification efficiency using the emulsification curve approach. The blends were composed of polystyrene (PS) and polyamide 6 (PA6). PS was always the matrix and PA6 the dispersed phase. A series of graft copolymers of PS and PA6, denoted as PS-g-PA6, with different molecular structures were used as emulsifiers. Feeding mode had a very significant effect on the size of the dispersed phase domains at short mixing time and its effect decreased or became negligible at long mixing time. This indicates that feeding mode affected mostly the time necessary for the PS-g-PA6 emulsifier to reach and emulsify the PS/PA6 interfaces. The molecular structure of the PS-g-PA6 graft copolymer also had a profound effect on its emulsification efficiency. The longer the PA6 grafts (from 1.7 to 5.1 kg/mol), the higher the emulsification efficiency. On the other hand, the number of PA6 grafts had little effect on the emulsification efficiency when the PA6 grafts were short (1.6-1.7 kg/mol). The effect of the blend composition was also investigated.     

Effect of mixing protocol on formation of fine emulsions

Emulsions are usually stabilised with a mixture of surfactants with different hydrophilicity. The initial partitioning of surfactants between the dispersed phase and continuous phase, and how these phases are brought into contact, can significantly affect the emulsification processes. Dynamic-phase behaviour maps were prepared to allow for a systematic investigation of the effects of emulsification routes on emulsion properties. Six semibatch modes of additions with constant surfactant concentration across the routes were selected. For a target cyclohexane-in-water emulsion using a pair of polyoxyethylene nonylphenyl ether surfactants with a specified HLB and water volume fraction, fine droplets could form only if water dissolving the water-soluble surfactant was added to the oil dissolving the oil-soluble surfactant. This route allowed the transitional inversion to occur and as a result fine droplets were formed due to an ultra-low interfacial tension. The addition of water dissolving the water-soluble surfactant to oil dissolving the oil-soluble surfactant, direct emulsification method, produced by far large droplets because of a rather high interfacial tension. In a series of experiment, the semibatch direct and phase-inversion emulsification method, were assimilated in situ. The impeller location was used as a variable that controls which phase is added as the dispersed phase. The location of impeller in relation to the interface did not affect the emulsion drop size at a high agitation rate, but it did at a low agitation rate. Under low agitation speed and when the impeller was placed in the oil phase, the oil layer progressively, but slowly, dragged the water phase and eventually inverted to an oil-in-water emulsion, indicating that transitional-phase inversion has locally occurred in the oil layer. At a high agitation speed the mechanical energy provided by the impeller homogenised the emulsion instantaneously and did not allow the optimum formulation and the associated ultra-low interfacial tension to be reached regardless of location of the impeller. A high impeller speed increased drop size by transforming the transition inversion mechanism to a catastrophic mechanism under which the size of drops is mainly determined by the mechanical energy provided. This paper aims to show how some of the complexities involved in emulsification processes can be explained by consulting with dynamic-phase maps.     

The fuel properties of three-phase emulsions as an alternative fuel for diesel engines

Diesel engines are employed as the major propulsion power for in-land and marine transportation vehicles primarily because of their rigid structure, low breakdown rate, high thermal efficiency and high fuel economy. It is expected that diesel engines will be widely used in the foreseeable future. However, the pollutants emitted from diesel engines (in particular nitrogen oxides and particulate matter) are detrimental to the health of living beings and ecological environment have been recognized as the major air pollution source in metropolitan areas and have thus attracted much research interest. Although diesel oil emulsion has been considered as a possible approach to reduce diesel engine pollutants, previous relevant applications were restricted to two-phase emulsions. Three-phase emulsions such as oil-in-water-in-oil briefly denoted as O/W/O emulsions and water-in-oil-in-water, denoted as W/O/W, have not been used as an alternative fuel for any combustion equipment. Studies on the properties of three-phase emulsion as fuel have not been found in the literatures. The emulsification properties of an O/W/O three-phase diesel fuel emulsion were investigated in this experimental study. The results show that the mean drop size of the O/W/O emulsion was reduced significantly with increasing homogenizing machine revolution speed. An increase in inner phase proportion of the O/W/O emulsion resulted in increasing the emulsion viscosity. The viscosity of O/W/O emulsion is greater than that for water-in-oil (denoted briefly as W/O emulsion) for the same water content. More stable emulsion turbidity appeared for three-phase O/W/O diesel emulsions added with emulsifier with HLB values ranging from 6 to 8. In addition, three-phase O/W/O emulsions with greater water content will form a larger number of liquid droplets, leading to a faster formation rate and greater emulsion turbidity at the beginning but a faster descending rate of emulsion turbidity afterwards. The potential for using O/W/O emulsions as an alternative fuel for diesel engines was also evaluated.     

柴油乳化技术的研究

介绍新研制的乳化装置和拟订的乳化工艺。在大量试验的基础上对乳化柴油的物理特性、节油机理以及乳化油对柴油机排放特性的影响进行了探讨。新研制的乳化装置简易可行;配制的乳化油成本低,稳定性可满足要求。通过柴油机台架和实际运行试验,表明可节油6—8％以上。