摘要:

The mechanism of emulsifier blending of different hydrophile-lipophile balance has been studied by the measurements of 1) the phase inversion temperature ( PIT) in emulsions, 2) the size distribution of droplets and the stability of emulsions, and 3) the cloud points of aqueous solutions. The PIT was slowly depressed with the replacement of lipophilic emulsifier at first and then suddenly and discontinuously dropped when the difference in HLB of two emulsifiers is too large. These results imply 1) the HLB number of emulsifier blend markedly deviates from weight average of two emulsifiers and 2) the PIT of certain temperature range, i. e., HLB of certain range cannot be prepared by blending, provided the difference in HLB (or PIT) of two emulsifiers is too large. The emulsion droplets were smaller and the emulsion was more stable when the difference of HLB of emulsifiers to be blended is smaller in the mixture of Tween and Span type emulsifiers. There was, however, an optimum difference in HLB in the blends of polyoxyethylene nonylphenylethers. It is clear that the blending of extreme two emulsifiers yields less stable emulsions and additional emulsifier of medium HLB is necessary. In other words, an emulsifier whose solubility behavior towards water and oil is medium is necessary as well as highly water and oil soluble emulsifiers in order to prepare stable emulsions over the wide HLB range required

ISSN:0193-2691    

DOI:10.1080/01932698008962158

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0193-2691    

DOI:10.1080/01932698008962159

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Phase diagrams developed for methyl methacrylate containing microemulsions show that the effect of 0.01 M persulfate on the size of the phase stability region is negligible. At higher concentrations ( 0.1 M) the persulfate showed an influence to be expected from an electrolyte; reduced water solubilization at low surfactant/ alcohol ratios and increased solubilization at the highest ratios Molecular weight dependencies on initiator concentration for both water and organic soluble initiators are shown to follow solution behavior. Added chain transfer agents follow the Mayo equation, however the chain transfer constant for n-C10SH is about 10 times lower than expected, possibly due to incorporation of the thiol group within the micellar interior. Solvent chain transfer alone, being 10 times lower for MMA than for MA, does not give sufficient lowering of molecular weight to give useful comparisons by GPC technique. Comparisons of structure based kinetic differences between emulsions and microemulsions explain solution type behavior observed for microemulsions

ISSN:0193-2691    

DOI:10.1080/01932698008962160

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A unified theory is proposed to explain the ultra-low inter-facial tension minimum observed in dilute petroleum sulfonate solution/ oil systems encountered in tertiary oil recovery process. The relative distribution of the surfactant in oil and aqueous phase was determined using UV spectrophotometry as well as the monolayer technique. The critical micelle concentration ( CMC) of the aqueous phase equilibrated with oil was measured using surface tension, osmotic pressure and light scattering measurements. For three major variables namely, the surfactant concentration, the chain length of oil and the salinity of brine, the interfacial tension minimum was found to occur whenever the equilibrated aqueous phase was at CMC. This minimum in interfacial tension also coincided with partition coefficient of unity for surfactant distribution in oil and brine. The increase of the interfacial tension after reaching a minimum was attributed to the decrease in the onomer concentration in the aqueous phase. Three possible causes of the decrease in monomer concentration are (1) he incorporation of oil soluble fraction into mixed micelles in the aqueous phase, or (2) the decrease of the effective CMC in the equilibrated aqueous phase due to solubilization of oil or (3) the transfer of surfactant from aqueous to oil phase upon increasing the salinity. The decrease in surface concentration of surfactant at the oil-brine interface after the interfacial tension minimum is reached was confirmed by the electrophoretic mobility measurements

ISSN:0193-2691    

DOI:10.1080/01932698008962161

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The relevance and meaning of particle size characterization is discussed. Attention is drawn to the difficulty of providing adequate information to characterize dispersions containing particles with “ diameters” around and below 1 μ m although technically this region is of considerable interest. Methods of characterization are briefly reviewed, with emphasis on those methods which are of actual or potential use for the dispersions that contain smaller particles

ISSN:0193-2691    

DOI:10.1080/01932698008962162

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0193-2691    

DOI:10.1080/01932698008962163

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0193-2691    

DOI:10.1080/01932698008962157

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor