Stimuli-responsive films

Surface Rearrangement of Diblock Copolymer Brushes—Stimuli Responsive Films... 

The field of stimuli-responsive films has grown enormously in the past few years. This review will principally concentrate on work from the primary... 

Chen JK, Chang CJ. Fabrications and applications of stimulus-responsive polymer films and patterns on surfaces a review. Materials 2014 7(2) 805—75. 

Electrical stimulation has been shown to enhance nerve cell regeneration [124,125], the mechanisms for this effect are, however, unclear. One hypothesis is that an electrical stimulus alters the local electrical fields of extracellular matrix molecules, changing protein adsorption [126]. As early as 1994, studies into the suitability of ICPs such as PPy as neuronal scaffolds provided positive proof that these electroactive stimulus response polymers indeed have a role to play. Shastri et al. [127] showed that neurite extension of PC 12 cells was more pronounced on PPy surfaces as compared to tissue culture polystyrene. The authors also showed that the application of an electrical stimulus to the cell culture on the PPy film significantly increased the expression of neurites in the cells compared to the controls. In addition, they demonstrated through tissue compatibility and transected sciatic nerve regeneration studies in rat models that the PPy films invoke little negative response and support nerve regeneration. 

Webber, G. B. Wanless, E. J. Butun, V. Armes, S. P Biggs, S. Self-organized monolayer films of stimulus-responsive micelles. Nano Lett. 2002, 2,1307-1313. 

Vasani, R. B. Mclnnes, S. J. R Cole, M. A. Jani, A. M. M. Ellis, A. V. Voelcker, N. H. Stimulus-responsiveness and drag release from porons sUicon films ATRP-grafted with poly(iV-isopropylacrylamide). Langmuir 2011, 27, 7843-7853. 

Vasani RB, Mclnnes SJP, Cole MA, Jani AMM, EUis AV, Voelcker NH (2011) Stimulus-responsiveness and drug release from porous sihcon films ATRP-grafted with poly(-V-isopropylacrylamide). Langmuir 27 7843... 

Wei, J.J., Ren, L.X., Tang, C.B., Su, Z.H., 2014. Electric-stimulus-responsive multilayer films based on a cobaltocenium-containing polymer. Polym. Chem. 5 (22), 6480-6488. 

Figure 2.11 Change in strain (a) and temperature (b) of SWNT-LCE nanocomposite films under IR stimulus, (a) The strain responses to an IR stimulus in five different SWNT-LCE nanocomposite films 0.2 wt% SWNT-LCE nanocomposite films subjected to 16 min of curing and different percentages of hot-drawing (I. 160%, II. 130%, and III. 70%) and 0.1 wt% SWNT-LCE nanocomposite films subjected to 200% hot-drawing and different curing times (IV. 16 min, and V. 20 min), (b) The temperature responses to an IR stimulus in SWNT-LCE nanocomposite films with 0.1 and 0.2 wt% PPE-SWNT loading levels. Reprinted by permission from Wiley-VCH Verlag GmbH Co. KGaA. ...

Furthermore, these block copolymers may be designed to contain stimuli-responsive components such that the assembly process may be triggered through the application of a stimulus. With unique properties and a host of potential applications, stimuli-responsive assemblies such as micelles, vesicles, bioconjugates, films, networks, and patterned surfaces have been prepared from block copolymers synthesized via controlled polymerization methods (Fig. 3.5) [1, 42]. 

Nemat-Nasser S, Wu Y (2003) Comparative experimental study of ionic polymer-metal composites with different backbone ionomeis and in various cation forms. J Appl Phys 93 5255-5267 Nemat-Nasser S, Zamani S (2006) Modeling of electrochemomechanical response of ionic polymer-metal composites with various solvents. J Appl Phys 100 064310 Oguro K, Kawami Y, Takenaka H (1992) Bending of an ion-conducting polymer film-electrode composite by an electric stimulus at low voltage. J Micromach Soc 5 27-30 Palmre V, Lust E, Janes A et al (2011) Electroactive polymer actuators with carbon aerogel electrodes. J Mater Chem 21 2577-2583... 

This subchapter will describe how to prepare thin silicone elastomeric films for DBAs and includes a brief survey of present cross-linking strategies, how backbones can be modified with substituents other than methyl, and which composites have been developed to improve material performance. Cross-linking is required to obtain attractive elastic properties, while modification with polar substituents and the creation of composites aim at increasing the permittivity and therefore serve to increase the response of the material to an external electrical stimulus. 

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