(More literature on contact angle measurement)
Contact angle, θ, is a quantitative measure of wetting of a solid by a liquid. It is defined geometrically as the angle formed by a liquid at the three-phase boundary where a liquid, gas and solid intersect. The well-known Young equation describes the balance at the three-phase contact of solid-liquid and gas:
where
YSL equals to interfacial tension between the liquid and the surface
YS equals to interfacial tension between the surface and the vapor
YL equals to interfacial tension between the liquid and its vapor.
The interfacial tensions, YSL, YS and YL, form the equilibrium contact angle of wetting, referred as Young contact angle, θ.
From the figure below, it can be seen that the low contact angle values indicate that the liquid spreads on the surface while high contact angle values show poor spreading. If the contact angle is less than 90° it is said that the liquid wets the surface, zero contact angle representing complete wetting. If contact angle is greater than 90°, the surface is said to be non-wetting with that liquid.
Supported Range of Measurements
- Static and dynamic contact angles measurement
- Surface free energy
- Roughness corrected contact angle
- Interfacial tension
- Interfacial rheology (viscoelasticity)
- High temperature measurements - up to 250 degree
Specifications
- Contact angle range：0...180º
- Contact angle resolution: ± 0.1º
- Surface/Interface tension range：0.01...1000 mN/m
- Surface/Interface tension resolution: ± 0.01 mN/m
- Maximum sample size with stage: 95mm x 180mm (max)
- High speed camera: 138-3009 fps.
- Includes zoom lens with 1 – 4 magnification.
- Sample Stage Motorized movement ranges:
- X = 180 mm, Y = 60 mm and Z = 30 mm.
- Automatic single liquid dispenser: 300µl
- Liquid dispenser:
- Motorized syringe pump for four 1 ml syringes.
- Dispensing resolution: 0.1µl.
- Needle/capillary diameter: 0.4 mm.
- Tilting cradle from 0-90º, resolution 0.01º, not to use with x- or y-axis.
