A thermochromic wood that can change colour at 24–40 ℃ and collect heat for heating flooring

Thermochromic woods ( TW ) were prepared by directly filling our thermochromic dye ( TD ) into the wood samples. TD and TW all are temperature-induced phase-changing materials between solid phase and liquid phase, and whose phase-changing temperature directly corresponds to the color-changing temperature. TW can undergo a colour change from light red to dark red at from 24 to 40 ℃ for 3 min, whose peak of colour change is at ~32 ℃, and can recover to light red below 22 ℃ after about 4 h. According to the relationship between thermochromic phenomenon and temperature, the thermochromic performance of TW can indicate warm sense for users when TW used as heating flooring. To compare with the original wood (radial bending strength: 67.281 MPa, radial hardness: 2.33 kN), the radial bending strength (114.83 MPa) and radial hardness (3.98 kN) of TW all had obvious improvement. After heat treatment at 60 ℃ for 30 min, the temperature of TW was 4 ℃ higher than the temperature of original wood in 40 min, so the heat-collecting property of TW has obvious improvement to compare with the original wood. • Thermochromic wood ( TW ) was prepared by filling thermochromic dye into poplar. • TW can undergo a colour change from light red to dark red at 24–40 ℃ for 3 min. • TW can indicate warm sense for users when used as heating flooring. • TW with better radial bending strength and radial hardness than the original wood. • TW with better heat storage than the original wood.