Wettability or wetting is the actual process when a liquid spreads on a solid substrate or material. Wettability can be estimated by determining the contact angle or calculating the spreading coefficient. Wetting or spreading of a liquid on a solid surface or material depends on the solid surface properties as well as the liquid used. Therefore, by manipulating the properties of surfaces one can optimize the function or performance of a solid surface or material for the purpose of interest. Likewise, if modifying the solid surface properties is not an option, one can manipulate the properties of the liquid of interest to achieve the desired wetting conditions.
Examples of applications where solid surface wettability plays a crucial role are body implants, contact lenses, biomaterials, offset printing processes, packaging, semiconductor wafers, electronic products, biofilm growth, fabrics, superhydrophobic surfaces, self-cleaning and non-sticky surfaces. In addition, as with wetting properties of macroscopic surfaces, the wettability of smaller objects like fibers, micro- and nanoparticles plays an important role in stabilization and performance of many products, such as composites, paints & coatings, inks, cosmetics, pharmaceuticals and food products.
Contact angle is the primary parameter for determining wettability and suitable instruments from Attension for this are the Theta, Theta Lite and Sigma701/700 tensiometers.