Liquid-Crystalline Elastomers with Gold Nanoparticle Cross-Linkers

Embedding nanoparticles in a responsive polymer matrix is a formidable way to fabricate hybrid materials with predesigned properties and prospective applications in actuators, mechanically tunable optical elements, and electroclinic films. However, achieving chemical compatibility between nanoparticles and organic matter is not trivial and often results in disordered structures. Herein, it is shown that using nanoparticles as exclusive cross-linkers in the preparation of liquid-crystalline polymers can yield long-range-ordered liquid-crystalline elastomers with high loadings of well-dispersed nanoparticles, as confirmed by small-angle XRD measurements. Moreover, the strategy of incorporating NPs as cross-linking units does not result in disruption of mechanical properties of the polymer, and this phenomenon was explained by the means of all-atom molecular dynamics simulations. Such materials can exhibit switchable behavior under thermal stimulus with stability spanning over multiple heating/cooling cycles. The presented strategy has proven to be a promising approach for the preparation of new types of hybrid liquid-crystalline elastomers that can be of value for future photonic applications.