2.1.8 Water salinity. The salinity of the water is a measure of the tоtal dissolved solids in the water phase. As salinity of the water increases, the density of the water increases, which in turn increases the differential density between the water and the оil. The increase in differential density аids in sepаration of the water and oil phases. Small amount of salt or other dissolved solids, in the water phаse will appreciably lower the interfacial tension and thus will decrease the difficulty of separating the two phases [14]. 2.1.9 Temperature. Temperаture affects the stability of the emulsion as follows: by increasing the temperature decreases the stability of the emulsion, since the mechanical strength of adsorption membranes, particulаrly …show more content…
However, when the interfacial film between the droplets has thinned to below some critical thickness, it ruptures, and the capillary pressure difference causes the droplets to rapidly fuse into one droplet. Hence, the properties of the thin film are of uttermost importance for the separation. If the droplets deform, the area of the interface increases and consequently the drainage path in the film also increases, resulting in lower drainage rates [16]. Electrical double layer repulsion, or steric stabilization by polymers and surfactants with protruding molecular chains, may prevent the droplets to come into contact with each other. Polymer, surfactants or adsorbed particles can create a mechanically strong and elastic interfacial film that act as a barrier against aggregation and coalescence. A film of close packed particles has considerable mechanical strength, and the most stable emulsions occur when the contact angle is close to 90˚C, so that the particles will collect at the interface. Solide particles diffuse to the o/w interface, forming rigid structures that can sterically inhibit droplet coalescence. Particles, which are oil-wet, tend to stabilize w/o emulsions. In order to stabilise the emulsions the particles should be least one order of magnitude smaller in size than the emulsion droplets and in sufficient high concentration. The indigenous crude oil components contribute to the formation of a viscoelastic film on the crude o/w interface, and the dominating mechanism whereby crude oil emulsions are stabilised is through the formation of a viscoelastic, physically cross-linked network of asphaltene aggregates at the o/w interface. The ability of asphalthenes and resins to form elastic crude o/w interfaces is an important factor regarding emulsion stability. Other factors that usually favour emulsion stability, is low interfacial tension, high
An emulsion is the forcing of substances that would not normally mix. In this experiment, multiple oil-in-water emulsions were performed. An oil-in-water emulsion is when there are little droplets of oil dispersed throughout water. The most common type of emulsion includes fats and water. A temporary emulsion was formed from this experiment. A temporary emulsion has to be shaken or mixed in some form to stay together (later on it will separate). This similar idea is used with salad dressings.
is reached between the surfactant monomers at the interface and those in the bulk, surfactants
Demulsification is defined as a process of breaking emulsions with intention to separate water from oil. This emulsion breaking is necessary in many practical applications as the petroleum industry and waste water treatment in environmental technology. The emulsion stability results from the presence of interfacial barrier preventing coalescence of the
... of films on liquids” (12). What things are larger than 1 Angstrom? A few are bacteria, viruses, organic matters and small planktonic organisms but we will get into this later (1). When the membranes separate two water types, water molecules pass from the less concentrated zone into the more concentrated zone in order to balance ionic forces. To reverse the natural flow of water through the membrane, pressure greater than osmotic pressure has to be applied on the concentrated solution. Providing pressures from 70 to 84 bars, 40 to 60% of seawater or brackish water is converted into fresh water by reverse osmosis. The influent saline solution is divided into two phases. Permeate is the first which is the fresh water free of particulates and dissolved impurities and the second is the concentrate stream which is brine enriched with suspended and dissolved solids (1).
The Biological Importance of Water as a Solvent and as a Medium for Living Organisms
The general properties of fluids are density, specific weight, viscosity and relative density. The values under specific conditions (temperature, pressure, etc) can be readily found in many reference books. But in this experiment, we want to measure the fluid properties by using instruments and compare the measured values with the theoretical values. In this evaluation of fluid properties experiment, we will measure two fluid properties, which are, density and viscosity. Selected fluids were used in this experiment as samples for both experiments. Samples of fluid that we used are hydraulic oil, cooking oil, syrup and honey. All of the samples have different physical and chemical properties.
The new technology uses water-repellent ferrous nanoparticles. Once these particles are combined in with the oil, they join to the oil an...
Therefore, oil and water do not mix. This is why Oil does not dissolve when you run water over it. How does the oil wash off your hands if the water isn¡¦t soluble with the oil? This is where soap comes in. While soaps head is attracted to water its tail is attracted to non-polar substances such as oil. When oil and grease etc. mix with oil it creates a slightly polar substance because of the head group. This makes the oil soluble with water allowing you to wash off your hands with water and rinse the grease off.
The Effects of Temperature on the Rate of Clotting Milk and Rennet Introduction ------------ The following experiment investigates the effects of different temperatures on a mixture of rennet and whole milk. On having the choice between testing the mixtures reactions at various temperatures, or testing the mixture with various amounts of concentration of rennet, my partner and I decided upon the first option. We made this decision as we felt it would be valuable to our scientific knowledge if we had a better understanding of how different temperatures can effect the behaviour of an enzyme, such as Rennin, which is also known as Chymosin. Our scientific knowledge tells us that enzymes work most efficiently at specific temperatures, and this experiment helps us to discover exactly which temperatures they are.
Living in an industrialized country people hardly think about the consumption of water. People go about their day without ever knowing or thinking about whether their body is receiving the proper amount of water to function properly. They do not realize that they are constantly losing water! Every breath uses water, sweating forces water out of the water as well as urine and excretion (Erickson, 2013). Two-thrids of the body is made of water therefore the water supply must be replenished frequently (Erickson, 2013). Water serves many functions that promote good health and bodily functions. Water lubricates joints, aids in digestion, kidney function, maintains body temperature and helps the body’s metabolism (Erickson, 2013). All of these functions are important for maintaining a healthy body.
In the most basic sense, as described in Fennema’s Food Chemistry, an emulsion is a “dispersion of one liquid into another.” The properties of these mixtures are defined by the type of emulsion (oil in water or water in oil), droplet size, volume fraction of the dispersed phase, composition of the surface layer and composition of the continuous phase. Droplet size is important to emulsions in that a finer droplet size, typically 1 um, generally yields a more stable emulsion (Srinivasan and others, 2008). The volume fraction is imp...
Incompactibity between the components of formulation will be aggravated due to being in contact with the solvent(2).
Water for Life is a poignant title. It symbolizes not just that no one can survive without safe drinking-water.
Slightly lower than fresh water, its density is slightly higher, its electrical conductivity is much higher, and it is slightly basic. we cannot used brine water for domestic purpose. So it is needed to convert it into soft water. In this paper we observe the techniques of softening water. Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of approximately 3.5%, or 35 parts per thousand. This means that for every 1 litre (1000 mL) of seawater there are 35 grams of salts (mostly, but not entirely, sodium chloride) dissolved in it.
...and their molecules goes and stick to the bulk molecules; as a result of which the average droplet size of the emulsions shift to larger value.