What are surface and interfacial tensions?
In short; surface tension is the property of the liquid in contact with gas phase (usually air). Interfacial tension, on the other hand, is the property between any two substances. It could be liquid-liquid, liquid-solid or solid-air.
What is interfacial tension Slideshare?
Interfacial tension is defined as the force per unit length parallel to the interface to counter balance the net inward pull.
How is surface tension and interfacial tension measured?
Interfacial measurements can be done through the optical tensiometer by pendant drop shape analysis. The shape of the drop hanging on the needle is determined by a balance of forces, which include the surface tension of the liquid. Interfacial tension can also be measured by a force tensiometer.
What is the importance of surface tension and interfacial phenomena in pharmacy?
SURFACE TENSION Interfacial phenomena affect drug delivery systems. For example, solubilization and dispersion of drugs, suspension or emulsion stability, and adsorption of drugs on different substrates are all affected by the interfacial properties of drugs and their environment.
What is used for surface and interfacial tension?
Surface tension is the excess energy per unit area (force per unit length; SI unit is Nm-1). Typically mN/m (which is equivalent to dynes/ cm) is used as the unit for surface and interfacial tension.
Why is interfacial tension less than surface tension?
The interfacial tension decreases as pressure increases reaching a plateau at around 120 bars. The surface tension is reduced as some of the water molecules are replaced by the surfactant molecules and interaction forces between surfactant and water is less than between two water molecules.
What is interfacial phenomenon?
Interfacial phenomena are behaviors that occur at the interface or boundary surface between a suspended particle and the continuous phase material in which it is suspended. For this reason, interfacial phenomena are almost always associated with disperse systems.
Why is interfacial tension important?
The interfacial tension plays an important role in many processes and phenomena where different phases touch one another: Emulsions and emulsifiability: The interfacial tension affects the emulsifiability and the tendency for the phases to separate.
Why is surface tension important in real life?
The effects of surface tension are of central importance in many everyday phenomena: it causes small droplets of rain to stick to your windows, creates bubbles when you add detergent in your sink, and propels water-striding insects on the surface of ponds.
What are interfacial effects?
What is surface tension used for?
Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to float on a water surface without becoming even partly submerged.
What are the factors affecting the surface tension?
Factors Affecting Surface Tension in Physics – Surface Tension Surface tension of a liquid decreases with increase in temperature and becomes zero at critical temperature. At boiling point, surface tension of a liquid becomes zero and becomes maximum at freezing point. Surface tension decreases when partially soluble impurities such as soap, detergent, dettol, phenol etc are added in water.
What is the cause for surface tension?
“Surface tension is the tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimise surface area”.
What exactly is surface tension?
Surface tension is defined to a single liquid surface, whereas the interfacial tension is defined to the interface of two immiscible liquids. Surface tension is actually a derivation of interfacial tension where force from the second surface is negligible or zero.
What factors affect surface Tention?
Surface tension of a liquid decreases with increase in temperature and becomes zero at critical temperature.