We developed a nano-gold incorporated liquid crystalline elastomer nanocomposite which demonstrated significant photo actuation and nonlinear optic properties, and thus is potential in the application of smart devices and laser technologies.

For the first time, an ultrasonics sonochemistry method is developed to promote the one‐pot hydrosilylation polyaddition polymerization and crosslinking reaction in the preparation of polysiloxane main‐chain liquid‐crystalline elastomers (MC‐LCEs). Due to the extraordinary effect of acoustic cavitation, the polyaddition polymerization and crosslinking reaction can be successfully carried out in an ordinary laboratory ultrasonic cleaner at room temperature, and generates the LCE matrix network in about 30 min. The prepared MC‐LCEs demonstrate good quality, good properties, and stimuli‐actuation performances. Compared to the traditional thermal processing methods for preparing polysiloxane MC‐LCEs, this method exhibits superior properties rapidly, with high convenience and efficiency, and can be a path for batch fabrication at low cost. The work also demonstrates that the ultrasonics sonochemistry method is effective in generating linear main‐chain liquid crystal polymers through hydrosilylation polyaddition and polysiloxane side‐chain LCE matrix through hydrosilylation crosslinking reaction, thus confirming the high availability of ultrasonics sonochemistry in the processes of hydrosilylation polymerization, crosslinking reactions, or synchronous polymerization and crosslinking reactions.