5 years ago

Fabrication of Liquid Crystalline Polyurethane Networks with a Pendant Azobenzene Group to Access Thermal/Photoresponsive Shape-Memory Effects

Fabrication of Liquid Crystalline Polyurethane Networks with a Pendant Azobenzene Group to Access Thermal/Photoresponsive Shape-Memory Effects
Ren-Fan Shao, Chen-Hui Zhu, Rayshan Visvanathan, Dan Liu, Yu-Zhong Wang, Xiao-Yang Li, Ke-Ke Yang, Zhi-Bin Wen, Noel A. Clark
Herein, we report a novel thermal/photoresponsive shape-memory polyurethane network with a pendant azobenzene group by utilizing its anisotropic–isotropic phase transitions and photoresponsive feature concurrently. To achieve this goal, the side-chain liquid crystalline polyurethane networks based on the pendant azobenzene group [SCLCPU(AZO)-Ns] were developed in a well-defined architecture. The smectic C nature of an LC phase in the polyurethane networks was confirmed by differential scanning calorimetry, polarized optical microscopy, and one-dimensional and two-dimensional wide-angle X-ray diffraction. The well-defined architecture-made SCLCPU(AZO)-N displays two distinct transition temperatures (Ttrans) (Tg and Tcl), with a difference of about 40 °C. Consequently, the excellent triple-shape-memory effect in this network was demonstrated by cyclic thermomechanical analysis. By making full use of the trans–cis photoisomerization of azobenzene, the reversible bending and unbending behaviors were realized under the light irradiation with wavelengths of 450 and 550 nm, respectively.

Publisher URL: http://dx.doi.org/10.1021/acsami.7b05280

DOI: 10.1021/acsami.7b05280

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.