Light-Induced Actuation of Poly(dimethylsiloxane) Filled with Graphene Oxide Grafted with Poly(2-(trimethylsilyloxy)ethyl Methacrylate)

Abstract

This study serves to combine two approaches into one single step, to achieve a significant improvement of the light-induced actuation capabilities. Graphene oxide (GO) is an inert material, from the electrical and thermal conductivity point of view, and is incompatible with the usually-used poly(dimethylsiloxane) (PDMS) matrix. During surface-modification by surface-initiated atom transfer radical polymerization, the GO was transformed into a conducting and compatible material with the PDMS showing enormous light-induced actuation capability. The GO surface-modification with poly(2-(trimethylsilyloxy)ethyl methacrylate) (PHEMATMS) chains was confirmed by transmission electron microscopy and thermogravimetric analysis, with an on-line monitoring of gasses using FTIR. The improved compatibility was elucidated using contact angle and dielectric properties measurements. The PHEMATMS shell was investigated using gel permeation chromatography and nuclear magnetic resonance. The improved electric conductivity was measured using the four-point probe method and by Raman spectroscopy. The very important mechanical properties were elucidated using dynamic mechanical analysis, and with the help of thermo-mechanic analysis for the light-induced actuation. The excellent actuation capabilities observed, with changes in the length of around 0.8% at 10% pre-strain, are very promising from the point of view of applications.

Smart Non-Woven Fiber Mats with Light-Induced Sensing Capability

“…The second region is from 185 °C to 260 °C and corresponds to oxygen-containing groups. For the GO-PBMA hybrid particles, there is significantly lower adsorbed water due to the substantial polymer coating and region corresponding to oxygen containing groups is shifted to lower temperatures, which is a common phenomenon already published elsewhere [19]. The presence of PBMA coating is visible in the region from 250 °C to 350 °C when the decomposition occurs.…”

“…The filler absorbs the light of certain wavelength while the matrix exhibits appropriate elasticity. The majority of the fillers are based on carbon (carbon nanotubes [15,16] (CNTs) or graphene particles [17] and more specifically based on graphene oxide [18,19] (GO)). There are also some other substances with photo-active capability such as azobenzene-based molecules [20,21] that are utilized as well.…”

Light-Responsive Hybrids Based on Carbon Nanotubes with Covalently Attached PHEMA-g-PCL Brushes

“…To show that the hybrid material acts as a photomechanical actuator, 68 the typical change in the length of the sample (ΔL) was investigated using a 627 nm wavelength diode as a light source, similar to the process employed in previous works based on composites with graphene oxide 69−71 or CNTs 35,36 (Figure 12). It should be mentioned that the neat PHEMA-g-PCL copolymer shows a ΔL of 10 μm (Figure 13a), which is a typical value for neat elastic matrices used in photo-mechanical actuation applications (7 μm for neat polydimethylsiloxane (PDMS) 69 or 12 μm for neat Vista- maxx 35 ). The performance of the MWCNTs-PHEMA-g-PCL sample under an intensity of light of 6 mW cm −2 showed a length change of nearly 50 μm in a 10 s light-on regime and a fully reversible process to the starting length after a 25 s lightoff regime (Figure 13b).…”

Effect of Structure of Polymers Grafted from Graphene Oxide on the Compatibility of Particles with a Silicone-Based Environment and the Stimuli-Responsive Capabilities of Their Composites

“…The actuation response has been enhanced by the addition of azo-moieties, that are however highly toxic, into polymer structures [19,20]. Compared to previously mentioned matrix materials, poly(dimethyl siloxane) is easy to process, is nontoxic and provides the ability for sufficient photo-actuation [14,[21][22][23].…”

“…Similarly, the studies of poly(dimethyl silioxane) (PDMS) filled with graphene oxide polymer hybrids (GO-g-polymer) photo-actuators also revealed that through surfaced modification we were able to improve the affinity GO-g-polymer particles to a PDMS matrix. SI-ATRP enables one to finely tune the properties of the chemical cross-linking network in terms of decreasing the activation energy of glass transition (systems possess enhanced flexibility of the PDMS network) that finally improves the ability for photo-actuation [21,22,27].…”