DOI: 10.5061/dryad.jsxksn0jv
title: Photo-responsive Diels–Alder-based azobenzene-functionalized main-chain liquid crystal networks

description: Light-responsive liquid crystal elastomer networks (LCNs) have received
 significant interest due to their potential application in soft robotics
 and shape-morphing devices. Here, we present a systematic examination of
 light-responsive LCNs prepared using a catalyst-free Diels–Alder
 cycloaddition and a new azobenzene functionalized monomer for main-chain
 incorporation. The networks have robust mechanical stiffness that can be
 reversibly modulated by 1 GPa by turning the UV light on and off. This
 study highlights the contribution of photothermal softening to reversibly
 control the rheological properties of the newly developed LCNs and
 demonstrates the ability to tune the modulus on demand. We believe this
 work will guide future developments of light-responsive LCNs based on the
 newly developed Diels–Alder cycloaddition.
description: # Photo-responsive Diels–Alder-based azobenzene-functionalized main-chain
 liquid crystal networks
 [https://doi.org/10.5061/dryad.jsxksn0jv](https://doi.org/10.5061/dryad.jsxksn0jv) ## Description of the data and file structure ## FIGURE 2B Tip deflection (nm) as a function of time (s) of a polydomain azobenzene sample ## FIGURE 2C Tip deflection (nm) as a function of time (s) of a monodomain azobenzene sample ## FIGURE 3A I) Absorbance as a function of time (min) at 365 nm II) Absorbance as a function of time at nm 470 ## FIGURE 3B I) Absorbance as a function of time (min) II) Temperature (degree Celsius) as a function of time (min) ## FIGURE 3C Heat flow of the physically aged, metastable 1, and metastable 2 as a function of temperature ## FIGURE 4A Storage and loss modulus (Pa) as a function of time (min) ## FIGURE 4B Temperature (degree Celsius) as a function of time (min) ## FIGURE 4C Storage modulus as a function of time at different conditions ## FIGURE S1 1H-NMR of azobenzene-furan liquid crystal ## FIGURE S2 13C-NMR of azobenzene-furan liquid crystal ## FIGURE S3 I) Heat flow as a function of the temperature of the evaporated and annealed sample II) intensity as a function of the angle of a small angle x-ray scattering of the evaporated and the annealed sample--- ## FIGURE S9 Heat flow as a function of the temperature of AzoLCN after several cycles ## FIGURE S10 Intensity of the small angle X-ray scattering before and after UV exposure ## FIGURE S13 Storage modulus as a function of time under different conditions ## FIGURE S14 I) Storage modulus (Pa) as a function of time (min) at a crosslink loading of 0% II) Storage modulus (Pa) as a function of time (min) at a crosslink loading of 2% III) Storage modulus (Pa) as a function of time (min) at a crosslink loading of 10% IV) Storage modulus (Pa) as a function of time (min) and angular frequency (0.1 Hz) at a crosslink loading of 2% V) Storage modulus (Pa) as a function of time (min) and angular frequency (10 Hz) at a crosslink loading of 2% VI) Storage modulus (Pa) as a function of time (min) and angular frequency (0.1 Hz) at a crosslink loading of 4% VII) Storage modulus (Pa) as a function of time (min) and angular frequency (10 Hz) at a crosslink loading of 4% VIII) Storage modulus (Pa) as a function of time (min) and angular frequency (0.1 Hz) at a crosslink loading of 10% IX) Storage modulus (Pa) as a function of time (min) and angular frequency (10 Hz) at a crosslink loading of 10% X) Intensity as a function of angle at a crosslink loading of 0% XI) Intensity as a function of angle at a crosslink loading of 2% XII) Intensity as a function of angle at a crosslink loading of 10%