Fig. S3.

Peel adhesion test indicates good adhesion strength between the PEMA/POSS layer and the polyurethane elastomer. A strip of tape (3M 371 Carton Sealing Tape) is applied to a PEMA/POSS-coated polyurethane elastomer with finger pressure. The tape is peeled from the sample at a 180° angle. After the peel adhesion test, no apparent change is observed on the coated surface, implying good adhesion between the PEMA/POSS layer and the underlying polyurethane elastomer. PEMA acts as a compatiblizing layer between the POSS and the polyurethane surface that enhances the adhesion of hydrophobic fluorodecyl POSS molecules to the polyurethane elastomer. The low-energy POSS molecules reside preferentially at the free surface, whereas the PEMA chains interact with the polyurethane elastomer, creating a strong interface. Therefore, the interfacial tension between the PEMA/POSS layer and the PU elastomer is estimated to be ${\gamma }_{12}={\gamma }_1+{\gamma }_2-2{\left({\gamma }_1{\gamma }_2\right)}^{1/2}=0.3\hspace{0.5em}\mathrm{mN}/\mathrm{m}$, where ${\gamma }_1=40\mathrm{\pm }5\hspace{0.5em}\mathrm{mN}/\mathrm{m}$ is the surface energy of a typical poly(ether-urethane) (33) and ${\gamma }_2=34\mathrm{\pm }5\hspace{0.5em}\mathrm{mN}/\mathrm{m}$ is the surface energy of PEMA (33).