EN16.05.08 : Measurement and Modeling of Temperature Rise in Thermochromic Coatings

5:00 PM–7:00 PM Apr 4, 2018 (America - Denver)

PCC North, 300 Level, Exhibit Hall C-E

Danielle Hall1 Alexis Corbett1 John Sinko1

1, St. Cloud State University, St. Cloud, Minnesota, United States

Thermochromic materials are those which change color as a result of a temperature change. A thermochromic coating can passively regulate the temperature of a surface, for example to reduce costs and energy consumption for heating and cooling a building or to hold a component within a desired temperature range. This type of coating enables cross-disciplinary, passive energy savings. The thermochromic pigments used in this research are melamine-microencapsulated leuco dyes based on 7-anilino-3-diethylamino-6-methylfluoran. Three thermochromic samples with transition temperatures at 20, 25, and 30° C were prepared by the suspension of dye powder in acrylic resin. Below the characteristic temperature each thermochromic coating has strong absorption across the visible spectrum, but above this point the pigment becomes transparent. The spectral reflectance above and below the transition temperature was assessed for coated and uncoated substrate materials including aluminum and polyvinylchloride. The temperatures of the coating surface and substrate were measured as a function of time before, during, and after illumination with an incandescent lamp at up to 1000 watts per square meter. The data demonstrates the temperature rise is held lower with a thermochromic coating compared to the uncoated substrate material. An analytical model for temperature rise of the coating and substrate was derived and compared against the experimental data.