Here, the formation of responsive polymeric materials with tunable response time is reported. These structures are fabricated by chemically modifying poly(vinylmethyl siloxane) (PVMS) networks with alkanethiols bearing a hydrophilic end‐group (COOH or OH). The response time is facilitated by the liquid nature of the PVMS backbone and increases with increase in length of the methylene spacer (CH2)n in the alkanethiol pendent group. While for n = 2 and 6, the surface reconstructs almost instantaneously, specimens with n = 11 resist reconstruction because of strong van der Waals forces, leading to the formation of semi‐crystalline regions. It is demonstrated that the responsive nature of PVMSS(CH2)11OH can be fine‐tuned by varying the temperature; it possesses a faster response at temperatures above the melting point of the S(CH2)11OH moiety.

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Dielectric, calorimetric, and dynamic mechanical measurements were performed to delineate the types and dynamic rates of molecular scale motion in modified poly(vinylmethyl siloxane) (PVMS) stimuli-responsive networks, where pendent groups of the formS -(CH 2) n-OH were chemically attached to the vinyl moiety of PVMS. The glass transition temperature (T g) for the unsubstituted PVMS network matches that previously reported for linear PVMS indicating that the flexibility of the polymer chains is unaffected by the network cross-linking. In contrast, T g increases with the introduction of pendent groups of the typeS -(CH 2) n-CH 3 or-S-(CH 2) n-OH, where n is 2, 6, or 11, as the different groups constrain the siloxane backbone to differing degrees. The macroscopic response time and amplitude, as previously measured by dynamic contact angle, are correlated with the observed glass transition temperatures. One conclusion is that the flexibility of the network and the interactions between pendent groups affect responsiveness.

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