| Summary: | 碩士 === 國立中興大學 === 化學工程學系所 === 106 === In this research, silica colloidal crystals/aliphatic urethane acrylate (PUA)/ethoxylated trimethylolpropane triacrylate (ETPTA) polymer composites were continuously prepare by a simple, roll-to-roll compatible doctor blade coating technology using three different silica particle sizes (370 nm, 330 nm and 255 nm). After photocuring, the colloidal crystals in the polymer composites are removed by wet chemical etching to obtain the mechanochromic macroporous films. The macroporous structure is three-dimensional and hexagonal close-packed. The films with three different pore sizes can be prepared from three different silica particle sizes, and three macroporous films respectively diffract light by three different photonic band gaps to present different colors. The stretched films can change the lattice spacing and have a mechanism of color change. The 370 nm mechanochromic macroporous film appears red. During the slow stretching, the color gradually changes from red to green from 0 to 50 % elongation. The 330 nm mechanochromic macroporous film appears yellow. From 0 to 50 % elongation, its color gradually changes from yellow to blue. Interestingly, the 255 nm mechanochromic macroporous film exhibits purple. From 0 to 50 % elongation, its color can be gradually changed from purple to colorless. This research has successfully achieved a color-to-colorless effect. Moreover, the color changes of three mechanochromic macroporous films are reversible and can repeat this stretching process at least ten times in the same conditions.
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