PING, C.C.W. ... et al, 2009. Spreading behaviour of aqueous trisiloxane solutions over hydrophobic polymer substrates. Colloid Journal, 71 (3) pp. 391–396.
The kinetics of spreading of aqueous trisiloxane solutions over different
solid hydrophobic substrates has been investigated experimentally. Two pure
trisiloxane surfactants with 6 and 8 polyoxyethylene groups at concentrations
closed to the critical aggregation concentration (CAC) and the critical wetting
concentration (CWC) were used in the spreading experiments. The following
three hydrophobic substrates (Teflon AF, Parafilm, and Polystyrene) having
different surface properties were used. It was found that the spreading behaviour
depends on the hydrophobic/roughness properties of substrates. The rapid
spreading and complete wetting were observed for both trisiloxane surfactant
solutions at the CWC on a substrate with a moderate hydrophobicity. For both
highly hydrophobic Teflon AF and Parafilm substrates only partial wetting was
found. The experiments have shown that the spreading behaviour over all substrates proceeds at two stages. At the CAC for both trisiloxanes on all
substrates the time lag of the spreading was detected.