Time-temperature paper indicator from polydiacetylene

Abstract

The polydiacetylene-based (PDA-based) time-temperature indicators (TTIs) are successfully prepared from commercially available diacetylene (DA) monomers i.e. 10, 12-pentacosadiynoic acid (PCDA) and 10, 12-tricosadiynoic acid (TCDA). The indicators are fabricated on filter paper strips by dip-coating technique followed by UV irradiation at 254 nm under controlled temperature at 278 ± 1 K. The color transition of the indicators at 300 ± 1 K is monitored by a webcam. The color images are converted to RGB values and the color transition time is determined by intersection point of %R and %B curves in their plots against time. The blue PDAs themselves do not change their color at room temperature. In the presence of 1-dodecanol, the blue-to-red color transition at the tested temperature is observed without time dependence. With the addition of cationic surfactant such as DTAB, TTAB or HTAB, the DA/1-dodecanol/surfactant three-component TTIs show desirable time dependent color transition. The color transition time can be tuned in the range of 1.5-6.5 days by the amount and selection of the cationic surfactant.