Ultrahigh-sensitivity thermochromic smart fabrics and flexible temperature sensors based on intramolecular proton-coupled electron transfer

Preparation of a Cellulose Film Based on a Binary Thermoreversible Color-Changing System with Long-Chain Color Developers for Information Storage

“…This causes a red shift in its absorption spectrum, presenting the complementary color of the absorbed light to the human eye. 12 This opening and closing of the ring can be observed in the IR absorption spectrum. In the IR absorption curve of the colored FD/PCU mixture, a characteristic peak of C�O appears at 1744.80 cm −1 , and the characteristic absorption corresponding to the PCU phenolic hydroxyl group at 3358.15 cm −1 disappears, indicating that FD has combined with PCU, the five-membered ring in the FD molecule has opened, forming a carboxyl group; in the IR absorption curve of the decolored FD/PCU mixture, the characteristic absorption of C�O shifts to 1763.75 cm −1 , existing as an ester group, indicating that FD and PCU have separated, and the five-membered ring in the FD molecule has closed.…”

“…In the FD molecule structure, the five-membered lactone ring is induced to open by the PCU phenolic hydroxyl group, while the nitrogen atom connected to the benzene ring promotes a large π-bond-conjugated structure in the FD molecule through conjugation. This causes a red shift in its absorption spectrum, presenting the complementary color of the absorbed light to the human eye . This opening and closing of the ring can be observed in the IR absorption spectrum.…”

“…In recent years, thermochromic information storage carriers − have become one of the research hotspots in the field of reversible color change due to their advantages of having a wide range of energy sources, broad application scope, and long service life. As early as the 1950s, patents described the use of crystal violet lactone (CVL) as the dye, Lewis acid as the color developer, and an organic solvent as the temperature-regulating agent in a ternary thermochromic system, achieving a preliminary thermally reversible information storage function .…”

A fully printed sensor with optical readout for real-time flow monitoring

“…Most common categories are smectic, nematic, cholesteric, and nonsterol-based crystals (chiral-nematic). Advanced systems can accurately represent different temperature levels with different colors, providing irreversible [37] and even reversible effect in color change [38,39] with high limits. More complex systems incorporate a heater beneath the TC layer to exploit or control the pattern presented on the sensor; mechanical strain can be represented with color changes [40], and pressure as well [41].…”

A manufacturing method of the flexible copper sensor for protection of hydro generators and transformers

“…Recently, copper film temperature sensors are widely utilized for the measurement of temperature in industry instead of platinum one because the design of the sensor based on PCB technology allow cost-efficient fabrication, easy handling, and simple retrofitting and replacement [2] . And then many kinds of flexible temperature sensor are developed by different sensing principles [27][28][29][30] and several sensing materials [31,32] But, the defects in flexible temperature sensor are usually being on the substrates, and decline the performance of the sensor like stability [18][19][20][21][22][23][24][25][26] . The lethal defect can be divided into two types, and one is disconnection and other is fall [3][4] .…”