Abstract:
Remote, rapid, and ink-free printing/erasure on
fabrics has great potential to revolutionize specialized clothing
in numerous applications including fashion/aesthetic and
security fields, but the construction of such smart fabrics has
not been realized due to underlying obstacles in obtaining
suitable photoreversible color-switching systems (PCSS). To
address this problem, we have prepared TiO 2−x nanorods as
photocatalytic and photothermal component. With redox dyes
as reversible color indicators and hydroxyethyl cellulose
(HEC) as polymer matrix, TiO 2−x /dye/HEC-based PCSS is
coated on poly(dimethylsiloxane)-treated cotton fabric. Under
365 nm light irradiation, discoloration occurs in 180 s,
resulting from the efficient photocatalytic reduction of the dye. On the contrary, when the colorless fabric is irradiated by 808
nm light, recoloration occurs in a very short time (∼100 s), far lower than the traditional heating mode (30−8 min at 90−150
°C). This rapid recoloration should be attributed to the localized high temperature (164.3−184.5 °C) induced by photothermal
effect of TiO 2−x . Particularly, when TiO 2−x /dye/HEC-based PCSS is extended to coat commercial clothes (such as T-shirts),
red/green/blue figures/letters can be rapidly and remotely printed by UV-light pen and then erased by near-infrared light, with
high cycle stability. Therefore, such rewritable smart fabric represents an attractive alternative to regular clothes in meeting the
increasing aesthetic or camouflage needs.
