Surface emulsions

PVP/alpha- styrene emulsion surface-active film formers waterproofing... 

Su, J., Everett D.W. 2003. Adsorption of K-casein onto native milk fat globule, latex particle, and emulsion surfaces Food Hydrocoil. 17, 529-537. 

FIGURE 4 Influence of emulsion surface charges cyclosporin A (CsA) concentrations in ocular surface tissues (cornea and conjunctiva) following one single-dose (50-pL) instillation of positively (cationic) and negatively (anionic) charged CsA-loaded nanosized emulsions into albino rabbit eye. 

The combination of reducing the flow and increasing the turbulence level has been shown by Brown and Pitt (4) to decrease emulsion drop size and, in systems as we have here with a fixed amount of dispersed phase, increase the emulsion surface area. 

The HIT impeller has been shown to generate emulsions with 20% more surface area than did the FBT when compared at the same input power level. This is in line with Brown and Pitt s correlations if the observed flow characteristics for the HIT impeller are used. To increase the emulsion surface area by this amount using the FBT, the power level must be approximately doubled. When the FBT power level is doubled, the improvement in product quality is in line with that obtained with the HIT impeller. This suggests the key role of the impeller in alkylation is to generate emulsion surface area. 

Practical Emulsions (Surface Active Agents), H. Bennett, Chemical Pub. Co., New York. 

The lamellar phases on the surface of the emulsion particles are mainly composed of monoacylglycerides, lyso-phospholipids and ionized fatty acids. When the phases have reached a certain size, they will desorb from the emulsion surface and form multi-lamellar vesicles, which are transformed into uni-lamellar vesicles upon increased incorporation of bile salts (Rigler et al., 1986). Upon further incorporation of bile salts, the ratio of lipid amphiphiles to bile salts will decrease to 1 or lower, whereby the uni-lamellar vesicles are transformed to mixed micelles (Staggers et al., 1990). These events are presented in Figure 4. 

Under certain circumstances vibration may cause direct problems with the product, independent of the pack, i.e. segregation of powders, separation of emulsions, surface dulling of tablets, settling down of product, etc. Vibration will also act in combination with compression forces and thereby possibly accelerate the weakening or distortion of board outers, cartons, etc. It can also lead to the distortion of flexible packs such as strips or sachets. 

Zn(II) l,l2-Dodecanediol-0,0 -diphenyl phosphonic acid L-glutamic acid dioleylester ribitol TRIM toluene 2-ethylhexyl alcohol acetate buffer (pH 3.5) SDS+Mg(N03)2 (for W/O/W emulsion) Surface imprinting by W/O or W/O/W emulsion polymerization for microspheres [119]... 

GrapHsiz. [Akzo] Polyurethane emulsion surface size and treatment for paper water rqpellatt... 

Microinbe. [Hercules] Paraffin wax emulsion surface treatment, lubricant ftvpapen improves water resistance. 

As with emulsion formation, the maximal absorption of proteins has been reported to occur near the isoelectric point [6,18,47], The effects of pH on the properties of proteins at emulsion surfaces, noted previously, probably also apply to the behavior of proteins in films. While foams formed near the isoelectric point of proteins tend to be more stable than those formed at other pH values, it is often possible to obtain higher overruns away from the isoelectric point [48]. The largest effect of pH on foam stability can probably be explained by the more viscoelastic nature of the films formed in this pH region... 

The third kind of variable to be dealt with is the drop size average value and distribution. Since the overall emulsion surface area depends on the square of the drop size, while the internal phase volume depends upon the cube of the drop. size, the surface-to-volume ratio changes as the inverse of the size. In other words, small-drop emulsions exhibit a higher surface area per unit volume than big-drop emulsions. Since the interdrop friction effect is related to the surface area of the drops, an increase in viscosity is expected to be associated to a decrease in drop size. 

Figure 8 Effect of subiiiii,TOii emulsion surface ehuigc on plasntu tontentiaiion of diolabelled cholesieryl oleate following i.v. administration (33).

We have seen above that surface-force measurements provide important information about interactions between solid hydrophobic surfaces coated with surfactants and polymers, and that some of the informa tion obtained is directly relevant for oil-in-water emulsions. However, the details of the interaction pro files are expected to be different for liquid hydrocarbon droplets coated with the same molecules as the model solid surfaces. In particular, the coalescence behavior of the emulsion droplets cannot be modelled. It is even more difficult to make a solid model surface that mimieks the behavior of water-in-oil emulsions. At present, the best one can do is to use a polar surface that attracts the polar part of the emulsifier. In fliis way the orientation of the emulsifier on the model sur face and at the water-in-oil emulsion surface will be the same. This will allow us to draw some eonclusions about how polar solid surfaces coated with emulsifiers interact across oil, but care should be taken when using such results to draw conclusions about water-in-oil emulsions. 

Emulsion droplets cannot only break by coalescing with each other, but they may also break by attaehing to a solid surface. Depending on the application this may be wanted or unwanted. In order to study emulsion-surface interactions a model oil-in-water emulsion was prepared from purified soybean oil (20 wt %) using fractionated egg phosphatides (1.2 wt %) as emulsifier. The major compo-... 

Effect factors Stabilization of emulsion Surface fUm Imerfaeial film Aggregation of asphaltenes... 

ASTM D 7000. 2011. Standard test method for sweep test of bituminous emulsion surface treatment. West Conshohocken, PA ASTM International. 

A technique has been developed for the continuous measurement of emulsion surface tension based on the pressure necessary to form a bubble in liquid. Details of the method may be found in Schork and Ray [24]. With a laboratory prototype of the bubble tensiometer, it has been possible to measure surface tensions continuously to within 1 to 2% [24]. A commercial instrument based on these principles is now available. Figures 5.5 and 5.7 demonstrate the use of the bubble tensiometer to monitor the surface tension of methyl methacrylate emulsion during continuous and batch polymerization. It will be noted that during conversion oscillation the surface tension oscillated as well, in accordance with the discrete initiation mechanism often postulated to explain this phenomenon. 

The dispersion of a liquid into another liquid with which it is immiscible to obtain a sufficiently physically stable product is only possible by emulsifying or solubilising, using surface-active substances (tensides, surfactants). This process is applied in the preparation of creams and solubilisations. In oral emulsions surface-active substances are not used, but instead viscosity enhancers that possess little surface activity. Below the preparation of emulsirMis and solubilisations is briefly discussed. 

Emulsion Surface tension Foaming tendency Stability (dilution, mechanical, shear, freeze-thaw, heat, bacterial) Compatibility (plasticizers, thickeners, pigments, extenders, coalescing agents) Rheological character... 

Dilute bed region In all the models developed above, it was assumed that reaction is restricted to the bubbling bed but the data of Lewis et al. (1962) and Ean et al. (1962) show that an axial distribution of bed density exists. Eurther, it seans most likely that bubbles carry solid particles along with than through the central region of the bed and enter the dilute phase by a process of bursting on the emulsion surface (Miyauchi, 1974 ... 

Gillatt, J. W., 1994. The effect of redox chemistry on the efficacy of biocides in polymer emulsions. Surface Coatings Int. 4, 172-177. Harries, R. C., White, D. B. and McFarlane, R. B., 1970. Mercury compounds reduce photosynthesis by plankton. Science 170, 736-737. Herrick, J., 2001. Gluconoacetobacter liquefaciens, a slow growing acidophilic bacteria isolated from an acidic medium. Paper presented at the Thor Group Technical Conference, Speyer, Germany, April 25th 2001. 

A technique has been developed (1,2,4) for the continuous measurement of emulsion surface tension with an instrument similar to the bubble densitometer. A schematic of the bubble surface tensiometer is shown in Figure 4. The construction of the bubble cell is similar to that for the bubble densitometer, except in this case the two orifices are mounted at equal depths and have different radii. Differential back pressure between the two orifices is measured and filtered as before. In this case, due to the fact that the two orifices are at the same depth, the liquid head terms in the pressure signals from the two orifices cancel when the pressures are differenced by the transducer, leaving a signal which after filtering, is proportional to the orifice radii and to the surface tension of the test fluid. Since the orifice radii are constant, their effect is absorbed into a calibration constant, and the instrument provides a voltage signal proportional to the surface tension of the test fluid. 

Methods have recently been developed for the monitoring of monomer conversion and emulsion surface tension (free surfactant conversion and emulsion surface tension (free surfactant concentration). These methods are continuous, on-line, and compatible with digital data acquisition and control systems. A number of methods have been proposed for the measurement of particle size distribution. Of these, a few seem to offer promise for... 

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