Photochromic Inorganic/Organic Thermoplastic Elastomers

5 years ago

Photochromic Inorganic/Organic Thermoplastic Elastomers

Jiancheng Zhou, Jing Li, Naixu Li, Mengmeng Huo, Jing Jiang, Tuoqi Li, Jiuyang Zhang

Photochromic materials are an important class of “smart materials” and are broadly utilized in technological devices. However, most photochromic materials reported so far are composed of inorganic compounds that are challenging to process and suffer from poor mechanical performance, severely limiting their applications in various markets. In this paper, inorganic photochromic tungsten trioxide (WO3) nanocrystals are conveniently grafted with polymers to hurdle the deficiency in processability and mechanical properties. This new type of photochromic material can be thermally processed into desired geometries like disks and dog-bone specimens. Fully reversible photochromic response under UV light is also achieved for WO3-graft polymers, exhibiting tunable response rate, outperforming the pristine WO3 nanocrystals. Notably, the resulted graft polymers show extraordinary mechanical performance with excellent ductility (≈800% breaking strain) and relatively high breaking strength (≈2 MPa). These discoveries elucidate an effective pathway to design smart inorganic/organic hybrid thermoplastic elastomers endowed with outstanding photochromic and mechanical properties as well as exceptional processability. Inorganic photochromic materials (like WO3) usually have poor processability and mechanical performance, heavily limiting their applications. By grafting engineering polymers from inorganic nanocrystals (WO3), new photochromic thermoplastic elastomers are successfully prepared. Fully reversible photochromic response under UV light is achieved for the WO3-graft polymers, outperforming the original WO3 nanocrystals. These discoveries offer a pathway to design other inorganic/organic hybrid materials.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/marc.201700210