Quantitative analysis of bending hysteresis by real-time monitoring of curvature in flexible polymeric films.

Flexibility, viscoelasticity and stress-strain relation in bending polymeric films are key factors in designing mechanically durable flexible electronic devices and soft robots. However, bending hysteresis, which appears as a precursor phenomenon of fracture and fatigue, remains unclear; no one quantitatively evaluated a bending curvature causing hysteresis. Herein, we report the bending hysteresis of polymeric films used as common substrates in flexible electronics by precisely monitoring bending curvatures.

Synthesis of fluorescent polycarbonates with highly twisted ,-bis(dialkylamino)anthracene AIE luminogens in the main chain.

A synthetic route to embed aggregation-induced-emission-(AIE)-active luminophores in polycarbonates (PCs) in various ratios is reported. The AIE-active monomer is based on the structure of 9,10-bis(piperidyl)anthracene. The obtained PCs display good film-forming properties, similar to those observed in poly(bisphenol A carbonate) (Ba-PC).