1 research outputs found
An in-depth evaluation of sample and measurement induced influences on static contact angle measurements
Static contact angle measurements are one of the most popular methods to analyze the wetting
behavior of materials of any kind. Although this method is readily applicable without the need
of sophisticated machinery, the results obtained for the very same material may vary strongly.
The sensitivity of the measurement against environmental conditions, sample preparation
and measurement conduction is a main factor for inconsistent results. Since often no detailed
measurement protocols exist alongside published data, contact angle values as well as elaborated
wetting studies do not allow for any comparison. This paper therefore aims to discuss possible
infuences on static contact angle measurements and to experimentally demonstrate the extent of
these efects. Sample storage conditions, cleaning procedures, droplet volume, water grade and
droplet application as well as the infuence of evaporation on the static contact angle are investigated
in detail. Especially sample storage led to diferences in the contact angle up to 60%. Depending
on the wetting state, evaporation can reduce the contact angle by 30–50% within 10 min in dry
atmospheres. Therefore, this paper reviews an existing approach for a climate chamber and introduces
a new measuring setup based on these results. It allows for the observation of the wetting behavior for
several minutes by successfully suppressing evaporation without negatively afecting the surface prior
to measurement by exposure to high humidity environments