Langmuir, Vol.11, No.10, 4153-4158, 1995
Static Electrification by Nonwetting Liquids - Contact Charging and Contact Angles
A glass slide hydrophobized with dimethyldichlorosilane appears to be electrostatically charged when a nonwetting liquid recedes from its surface. The surface charge has negative polarity. The density of the charge which arises on retraction from water is 10(-4) C/m(2). The half-life of the charge on the surface in air is 0.5 h. The charging effect is observed with different liquids and solutions for which contact angle and surface tension are high. A correlation of the value of the charge with the conductivity and double layer parameters is not pronounced. The electrification leads to a long range attraction between the plate and the liquid and influences the wetting of the substrate.