Plasma treatment of PDMS

Plasma treatment of PDMS followed by adsorption of self-assembled silane monolayers has enabled us to controllably modify the surface energy of elastomer surfaces as described in the section on the Johnson, Kendall, and Roberts approach to deriving the surface free energy of solids. A similar treatment of silicon substrates has produced a useful, low—hysteresis model substrate for contact angle study. There are three types of PDMS contact angle substrates usually studied fluids baked or otherwise chemisorbed on solids such as glass or metals cross-linked coatings on flexible substrates, such as paper or plastic film PDMS elastomer surfaces. 

Fig. 4 shows the influence of oxygen-plasma treatment of PDMS surface on the measured friction vs. load plots (m = 0.0025 m/s). The friction forces and error bars represent the average kinetic fiiction forces and standard deviations from the fiiction vs. time (or number of rotation) plots for each measurement. A few characteristics are observed. Firstly, the sliding contact of untreated PDMS... 

The second method involves plasma treatment of the surface. For example, when two plasma oxidized PDMS surfaces are brought into conformal contact, an irreversible seal forms between them. This technique can be used to bond two PDMS layers [15,16]. Oxygen plasma treatment of PDMS also enables the bonding of PDMS to other materials such as glass [17]. Plasma oxidation of a PDMS surface makes it more hydrophilic from its native hydrophobic state [15,16]. 

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