Inkjet printing of mechanochromic fluorenylidene-acridane

Abstract

In mechanochromic material research, a serious problem is that mechanical treatment cannot be applied to the materials because of their responsiveness to stimuli. Inkjet printing is a useful solution deposition method for electronics, but materials must be processed to be suitable for an inkjet printer. Fluorenylidene-acridane (FA) exhibits ground-state mechanochromism with visual color changes and responds not only to mechanical pressure but also to alcohol. Alcohol inhibits the color change induced by mechanical stimulation because the mechanochromism of FA is based on a conformational change in its molecular structure. This phenomenon suggests that the mechanochromism of FA can be controlled using alcohol. For use in inkjet printing, minute particles of FA obtained by bead milling in ethanol were investigated for uniformity and size by scanning electron microscopy and gas adsorption measurement. Also, ink containing FA particles was prepared and examined for physical properties such as viscosity and surface tension. It was confirmed that the inkjet-printed pattern demonstrated visual color changes between yellow and green in response to mechanical pressure and alcohol. This report describing the control of mechanochromism and its specific application is expected to contribute to broadening the mechanochromic materials research field.

Color-Changing Paper: Cellulose Nanofiber Films Incorporating Mechanochromic Fluorenylidene-Acridane

“…Additionally, by harnessing the control of mechanochromism, we have developed a mechanochromic resin and demonstrated its application in inkjet printing technology. 19 In this paper, we focus on the cellulose nanofiber (CNF), which has numerous hydroxyl groups. CNF is garnering research attention because it is a biomass material derived from dietary fiber, potentially contributing to a sustainable environment and a decarbonized society.…”

“…Theoretical calculations suggested that this phenomenon is related to the interplay between aggregation/disaggregation and changes in the molecular conformation. Additionally, by harnessing the control of mechanochromism, we have developed a mechanochromic resin and demonstrated its application in inkjet printing technology …”