When the solid has a high affinity for water - in which case it is called hydrophilic (high energy e.g. glass)- water spreads. In the opposite case of hydrophobic (low energy e.g. teflon) surfaces, water does not spread but, instead, forms at equilibrium a spherical cap resting on the substrate with a 'contact angle'.
Infections such as trichomoniasis, gonorrhea, and Chlamydia (all STDs); and yeast infection can all cause vaginal discharge. Vaginal discharge can be associated with other symptoms such as burning or itching. Antibiotics are given for infections that cause vaginal discharge.
1 Trichomoniasis: Trichomoniasis is an infection that can cause yellow-green vaginal discharge and pain with sex or when emptying the bladder. 2  It can increase the risk of having a preterm baby. 3  Rarely, the new baby can get the infection during delivery and have a vaginal discharge after birth.