Techshore Inspection Services-Kochi-official blog of Techshore Kerala: TECHSHORE INSPECTION SERVICES : SURFACE TENSION

Due to molecular attraction, liquid have properties of cohesion and adhesion. Cohesion is due to the force of attraction between molecule of same liquid .otherwise the inter molecular attraction holds the liquid molecule together are known as cohesion. This force is very small. it enable the liquid to withstand a small tensile stress. Surface tension is due to the cohesion between particles at the free surface.
Adhesion is defined as the force of attraction between the molecules of two different liquids or between the molecules of the liquid and molecules of solid boundary surface . surface tension is due to the force of attraction between liquid particles at free surface .liquid molecule at the interior of the liquid are generally free to move within the liquid are generally free to move within the liquid and they move at random, because these molecules are attracted equally in all directions by the other surroundings molecules and they are in random

Because these molecular attractions are equal in all direction by the other surrounding molecules and they are in equilibrium. It is defined as the tensile force required to keep unit length of the surface film in equilibrium. It may also be defined as the tensile force acting on the surface of the liquid when in contact with surface or gas between different immiscible liquids. The surface tension is same everywhere on the surface of its curvature.

Some important real life examples are

Formation of water bubbles
Formation of rain droplets
Collection of dust particles on water surface
A small needle can gently placed on the liquid surface without sinking
Breakup of liquid jets.

Surface tension depends directly upon the intermolecular cohesion and hence the cohesion decreases with temperature rise,the surface tension tension also decreases with rise in temperature.It also depends upon following factors

Nature of liquid
Nature of surrounding liquid
Kinetic energy of liquid

several effects of surface tension can be seen with ordinary water:

Beading of rain water on a waxy surface. Water adheres poorly to wax and strong to itself, so water clusters into drops. Surface tension gives them their near-spherical shape, because a sphere has the smallest possible surface volume to area ratio.
Drops Formation occurs when a mass of liquid is stretched. The animation shows water adhering to the faucet gaining mass when it is stretched to a portion where the surface tension can no longer keep the drop linked to the faucet. It then separates and surface tension will be formed as drop into a sphere. If a stream of water running from the faucet, the stream will break up into drops during its fall. forces arising from surface tension. For example, water striders use surface tension to walk on the surface of a pond
Tears of wine is the formation of rivulets and drops on the glass side containing an alcoholic beverage. Its cause is a complex interaction between the differing surface tensions of water and ethanol; it is produced by a combination of surface tension and modification of water by ethanol together with ethanol evaporating rapidly than water.

Friday, March 17, 2017

TECHSHORE INSPECTION SERVICES : SURFACE TENSION

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