Light-fueled self-oscillation of liquid crystal polymer network: Effect of photostabilizers

The quest for harnessing light-induced oscillatory motion, inspired by natural oscillations, has become a focus of scientific attention. Researchers are exploring the use of liquid crystal network (LCN) polymers and their integration with compatible materials as soft actuators. Of particular interest is the utilization of photostabilizers, which play a pivotal role in preserving the polymer against photodegradation. For this, three distinct derivatives of Tinuvin were chosen to explore their influence on the light-fueled oscillatory motion of LCN polymers when exposed to polarized light to examine the impact of molecular orientation on the resultant motion. The research includes a comprehensive analysis of morphology, FT-IR spectra, and elastic modulus assessments. The findings indicate that the Tinuvin derivatives along with light polarization have an impact on the resulting oscillatory characteristics. The findings include oscillation frequencies spanning from 8.95 to 14.96 Hz and oscillation amplitudes ranging from 0.47 to 1.73 mm. The dipole moment of Tinuvin types influences the oscillation frequency by altering the elastic modulus of the LCN, while its impact on surface roughness and structural configuration affects the resulting oscillation amplitude. Notably, the highest oscillation frequency is observed when all oriented molecules within the LCN respond to 45 degrees polarized light. Investigating the impact of utilized photostabilizers on the polymer structural configuration was although possible through the examination of related FT-IR specra.