CONTACT ANGLE MEASUREMENT
The contact angle is the angle between solid-liquid interaction at interface or two vapors or two liquids.It is based on the classical liquid-solid-vapor interaction model (Figure 1). The theoretical basis of the contact angle is based on the Young's equation. The contact angle is measured by using an apparatus known as contact angle goniometer.
(1) Clean the sample ultrasonically with acetone/ethanol as medium (2) Clean the syringe and fill it with the required liquid with which the test is to be conducted (3) Place the sample on the sample stage (4) Turn - on the Illumination lamp and CCD camera (5) Make sure the sample stage is properly labelled (6) Open the syringe knob to allow a liquid drop to come out and let it fall on the sample.Drop acquires the shape (7) Click on the software which measures the contact angle at both the ends (θC1 and θC2) (8) Repeat the experiment at least 5 times at different positions of the sample (9) Take the arithmetic mean of the θC1 and θC2 to obtain the contact angle