Design rules for reversible thermochromic mixtures

Formation of a leuco Spirolactone from 4‐(2‐Carboxyphenyl)‐7‐diethylamino‐4′‐dimethylamino‐1‐benzopyrylium: Design of a Phase‐Change Thermochromic System Based on a Flavylium Dye

“…Addition of the EDIPA base is thus a necessary requirement and this component plays the role of a developer. [31,33] The formation of the colored species from the lactone occurs upon the phase transition of the solvent. This implies that the protonated amine is less stabilized in the solid structure, which is a predicted effect taking into account that the solvation entropy increases in the liquid state favoring the deprotonation of the carboxylic moiety.…”

“…These molecules comprise spiroheterocyclic compounds, [11,[17][18][19] salicylSchiff bases, [20][21][22][23] overcrowded ethylenes [24][25][26] and phasechange thermochromic materials (PCTM, organic thermochromic mixtures) that include crystal violet lactone and related compounds. [27][28][29][30][31] Thermochromism involving the present flavylium compound is a PCTM sample and was achieved by using EDIPA as a color developer, and different solvents, namely acetonitrile and n-pentadecanonitrile ( Figure 5). …”

Flexible Reflective Color Displays using Thermochromic Pigments

“…The accurate chemical compositions of the thermochromic pigments obtained from H.W. Sands Corp. are unknown (proprietary information), but are presumably similar to other formulations reported in the literature [16,17]. The thermochromic material used in the study is believed to be vinyl acrylate terpolymer-type with an additive, where the additive reversibly interacts with the polymer with temperature to result in change in color.…”

Core-Shell Nanofibers: Nano Channel and Capsule by Coaxial Electrospinning

“…They used the phase change thermochromic materials (PCTMs) to make an improvement to PCMs. Displaying in Figure 14, PCTM system of crystal violet lactone (CVL) as dye and bisphenol A as developer mix in fatty alcohol or fatty acid was chosen (Burkinshaw, et al, 1998;Hirata, et al, 2006;MacLaren, et al, 2005). As a traditional PCTM, it has a simple component and stable thermochromic property, and the thermochromic temperature can be adjusted by changing fatty alcohol or fatty acid filling.…”