Water-continuous spread

The added emulsifiers not only influence stability but also reduce interfacial tension and influence drop-size distribution, hence influencing the creaminess of the product [29]. They can also modify the extent and type of fat crystallization [50]. Mixed gels have also been used [50]. fl-Carotene is often added to produce a yellow colour and provide vitamin A. By varying the amounts of components such as vegetable oils, animal fats and milk fat, a wide range of variations have come into use. Some examples of these spreadable fats include butter, margarine, low-fat spread, vegetable-fat spread, butterfat spread, low-calorie spread, yellow-fat spread, water-continuous spread and so on [50]. The reduced-fat and low-fat spreads tend to have fat contents of 10-79%. Flack [50] provides an illustration of a process plant layout for the manufacture of spreadable fats. 

Chronakis, I.S., Kasapis, S. (1995). Preparation and analysis of water-continuous very low fat spreads. Lebensmittel-Wissenschaft und-Technologie, 28,488 194. 

Fatty acids spread spontaneously on water to form a monomolecular film. A benzene solution containing 0.10 mm3 of stearic acid is dropped into a tray full of water. The acid is insoluble in water, but spreads on the surface to form a continuous film covering an area of 400 cm2 after all of the benzene has evaporated. What is the average film thickness in (a) nanometers and (b) angstroms ... 

Low-fat spreads with 40% fat content and containing protein usually have a shelf life of 8-10 weeks and water-based low-fat spreads of about 4 months based on storage at temperatures below 10°C (50°F) (90) (see Section 5.1). Very low fat spreads with fat contents below 20% and with a water continuous emulsion character require low pH, ultra high temperature processing, and possibly aseptic filling procedures to allow closed shelf lives comparable to conventional low-fat spreads (91). 

Table 3 illustrates low-fat spreads available with fat contents ranging from 60% to as little as 5%. Below about 20% fat content products of a water continuous emulsion character are prevalent (91). 

You have a so-called low-fat spread, i.e., a system containing about equal volumes of triglycerides and an aqueous phase. The system is not a liquid, but it is spreadable. Can you think of a very simple way to find out whether it is oil or water continuous ... 

Sheet flood (also sheetflood) 1)A broad expanse of moving, often storm-generated, water that spreads as a shallow, continuous uniform film over a large area. 2) A flow or the process of water movement in which the fluid is not concentrated in a discrete channel or defined river banks. 

Hydrophobic Surfaces Made Hydrophilic. Greenhouses are often covered with transparent plastic sheets. Morning dew condensing into fine droplets on the plastic scatters the light and robs flowers and plants of much needed sunlight. It is desirable to find a way to force water to spread into a continuous film, in other words, to Svet the material. There are plasma treatments that can create hydrophilic groups on the surface of the plastic, thereby lowering 7c-... 

The cosmetics and transdermal drug delivery fields are also expected to further benefit from the formulation of microemulsions from mild sugarbased surfactants. Lehmann et al. have studied the effect of such a microemulsion on dermal and corneal irritation, and hydrocortisone incorporation [105]. A microemulsion containing commercially available sucrose esters, isopropyl myristate, and propylene glycol and water was prepared as a water continuous system, and 16.5% hydrocortisone was loaded into the anhydrous base mixture. The formulation spread well on the skin due to the low surface tension of the system at 26 mN/m. While the microemulsion provided greater drug penetration, it also resulted in irritation and barrier compromise. The authors make the point that the formulation may be better suited to drugs that do not induce an irritation themselves. 

In a 500 ml. bolt-head flask, provided with a mechanical stirrer, place 70 ml. of oleum (20 per cent. SO3) and heat it in an oil bath to 70°. By means of a separatory funnel, supported so that the stem is just above the surface of the acid, introduce 41 g. (34 ml.) of nitrobenzene slowly and at such a rate that the temperature of the well-stirred mixture does not rise above 100-105°. When all the nitrobenzene has been introduced, continue the heating at 110-115° for 30 minutes. Remove a test portion and add it to the excess of water. If the odour of nitrobenzene is still apparent, add a further 10 ml. of fuming sulphuric acid, and heat at 110-115° for 15 minutes the reaction mixture should then be free from nitrobenzene. Allow the mixture to cool and pour it with good mechanical stirring on to 200 g. of finely-crushed ice contained in a beaker. AU the nitrobenzenesulphonic acid passes into solution if a little sulphone is present, remove this by filtration. Stir the solution mechanically and add 70 g. of sodium chloride in small portions the sodium salt of m-nitro-benzenesulphonic acid separates as a pasty mass. Continue the stirring for about 30 minutes, allow to stand overnight, filter and press the cake well. The latter will retain sufficient acid to render unnecessary the addition of acid in the subsequent reduction with iron. Spread upon filter paper to dry partially. 

After dewatering the cmmb it is fed to the drying process which is usually carried out in a continuous tunnel dryer. The cmmb is spread on a perforated stainless steel bed through which hot air is passed to evaporate the remaining water. Typically, in the first portion of the dryer, air at 110—140°C is used, with lower temperatures being used as the product approaches dryness. A typical target for final moisture content is 0.5% or less. At the exit of the dryer the product is cooled and conveyed to a baler which shapes it into bales for packaging and shipment. 

PDMS based siloxane polymers wet and spread easily on most surfaces as their surface tensions are less than the critical surface tensions of most substrates. This thermodynamically driven property ensures that surface irregularities and pores are filled with adhesive, giving an interfacial phase that is continuous and without voids. The gas permeability of the silicone will allow any gases trapped at the interface to be displaced. Thus, maximum van der Waals and London dispersion intermolecular interactions are obtained at the silicone-substrate interface. It must be noted that suitable liquids reaching the adhesive-substrate interface would immediately interfere with these intermolecular interactions and displace the adhesive from the surface. For example, a study that involved curing a one-part alkoxy terminated silicone adhesive against a wafer of alumina, has shown that water will theoretically displace the cured silicone from the surface of the wafer if physisorption was the sole interaction between the surfaces [38]. Moreover, all these low energy bonds would be thermally sensitive and reversible. 

Platinised-titanium installations have now been in use for 30 years for jetties, ships and submarines and for internal protection, particularly of cooling-water systems . For the protection of heat exchangers an extruded anode of approximately 6 mm in diameter (copper-cored titanium-platinum) has shown a reduction in current requirement (together with improved longitudinal current spread) over cantilever anodes of some 30% . This continuous or coaxial anode is usually fitted around the water box periphery a few centimetres away from the tubeplate. 

The diffusion of one liquid into another also demonstrates molecular motion. Figure 2 shows that if a drop of ink is added to a beaker of still water, the color slowly but surely spreads throughout the water. The water molecules and the molecules that give ink its color move continuously. As they slide by one another, the ink molecules eventually become distributed uniformly throughout the volume of liquid. 

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