What is viscosity of emulsion?
Viscosity of emulsions. Emulsion viscosity can be substantially greater than the viscosity of either the oil or the water because emulsions show non-Newtonian behavior. This behavior is a result of droplet crowding or structural viscosity.
What determines the viscosity of the emulsion?
The viscosity of an emulsion depends on the initial viscosity of the bulk phase, η 0 and the volume fraction of the drops, φ. Many equations are used to describe this dependence and three are shown here.
What increases the viscosity of emulsion?
The viscosity of the continuous phase is increased by solution of stabilizers in the continuous phase of oil-in-water (o/w) emulsions. Mobility of the droplets and their collision frequency decreases. Thus, stabilizers can improve the stability of emulsions by hydrodynamic effects.
How does viscosity affect emulsion stability?
Viscosity is not the only factor that affects the stability of an emulsion, but it does have an effect none the less. If for two products the only difference lay in the zero shear viscosity and all other factors were the same, then the product with the higher zero shear viscosity would be the most stable long term.
What is emulsion example?
In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, homogenized milk, liquid biomolecular condensates, and some cutting fluids for metal working. Two liquids can form different types of emulsions.
How can the viscosity of emulsion be reduced?
The simplest way to achieve a viscosity reduction is to heat the product because most liquids become less viscous when they heated. The viscosity decrease is usually accompanied by a decrease in the interfacial tension, more readily making a good emulsion form.
Do surfactants increase viscosity?
Like dish washing detergent, the main composition is anionic surfactants! It increases the viscosity. Obviously, anionic surfactant will increase the viscosity. In addition to that, if anionic & cationic surfactants are both added to water at the same time the viscosity increases.
Which one is more stable emulsion high viscosity or low viscosity?
The results shows that viscosity decreases as temperature and shear rate increase. In contrast, viscosity becomes higher when water cut is lower. The droplet sizes become smaller when high shear rate is applied and emulsion becomes more stable.
Why emulsion is thermodynamically unstable?
Emulsion, from a thermodynamics point of view, is considered unstable because there is a natural tendency for a liquid or a liquid system to separate and reduce its interfacial area and, hence, its interfacial energy.
What are the three types of emulsions?
There are three kinds of emulsions: temporary, semi-permanent, and permanent. An example of a temporary emulsion is a simple vinaigrette while mayonnaise is a permanent emulsion. An emulsion can be hot or cold and take on any flavor from sweet to savory; it can be smooth or have a bit of texture.
What are the three examples of emulsion?
How does viscosity affect the stability of an emulsion?
As seen in fig.1 there can be a vast difference (orders of magnitude) in zero shear viscosity for seemingly similar products. Viscosity is not the only factor that affects the stability of an emulsion, but it does have an effect none the less.
When to use an emulsion instead of an extract?
Best answer: you should choose an emulsion when you’re concerned about the flavor baking out of a recipe. Because they are water-based, bakery emulsions don’t evaporate as quickly as extracts, resulting in stronger aromas and tastes.
Which is a sign of failure of an emulsion formulation?
Let us know how we can help Creaming, sedimentation, flocculation and coalescence: four clear signs that spell failure for a formulation.
How does zero shear viscosity affect the movement of droplets?
In simple terms: if the zero shear viscosity is high it is more difficult for the droplets to coalesce as movement through the continuous phase is hindered. If the zero shear viscosity is low the opposite is true, the low viscosity means droplets move around and come together more easily.