Durable, reversible color changing polyester fabrics were successfully fabricated using thermochromic leuco dye-loaded silica nanocapsules via dyeing.

Design and fabrication of smart surfaces for separation of oily water have been developed rapidly. Nevertheless, construction of these smart surface materials by using green and sustainable paths for intelligent separation of oily water still faces huge challenges. The aim of this study was to develop a facile, sustainable, and energy-efficient approach for the fabrication of smart coatings with pH-responsive switchable wettability. The coating was formed on the textiles from UV-cured fluoride-free pH-responsive polyurethane (pH-PU). The wettability of obtained textiles could switch reversibly between superhydrophobicity and underwater superoleophobicity due to the protonation and deprotonation of the pH-PU under different pH conditions, which was used to successfully separate either oil or water from oily water with high separation efficiencies. More importantly, oil-in-water and water-in-oil emulsions could all be selectively separated with high water flux and oil purity by as-fabricated textiles, and these pH-PU-functionalized textiles or sponges effectively performed for oil collection of oil spilled on water. Our work provided a fast, economical, and sustainable pathway to prepare smart coatings with switchable wettability for both environmental protection and energy-saving merits.

The novel functionalized poly(silanization alcoholamine diacetylene)/silica nanoparticles (poly(SiDGADA)/SiO 2 nanoparticles) have been achieved for reversible thermochromism. The silanized alcoholamine diacetylenic monomer (SiDGADA) is condensed with the hydroxyl group of SiO 2 nanoparticle via hydrolysis of the SiDGADA siloxy group, followed by fixation after being polymerized upon UV light stimulation. The maximum thermal decomposition rate of the SiDGADA/SiO 2 nanoparticles is 0.65%/ C at 460 C, while the maximum thermal decomposition rate of the SiDGADA is 1.92%/ C at 400 C. Poly(SiDGADA)/SiO 2 nanoparticles appears a blue phase after photo polymerization and exhibits a distinctive red phase at the discoloration temperature of 65 C, which is 5 C higher than that of the pure poly(SiDGADA). It shows excellent reversible thermochromic properties, undergoing stable reciprocal blue-to-red conversion from 25 to 65 C, and returning to bluish violet after cooling. The extension of the SiDGADA alkyl chain length with formation of the covalent bond, to promote the interaction between the alkyl chains of polydiacetylene (PDA). This work provides a strategy to effectively improve the reversibility of thermochromic PDA.

A reversible, adjustable thermochromic colorant with bichromatic conversion from dark red (cool state) to yellow (heat state) was prepared using bromocresol purple (BCP) as colour former. The thermochromic behaviour of this colorant was investigated during the heating‐cooling cycle, including the colour depth, colour difference and switching temperature. The mechanism of thermochromic colorant switching between dark red and yellow originated from the transformation of the conjugated structures of BCP, which was confirmed by infrared spectrometry. The switching temperature can be flexibility adjusted between 13–46 °C by mixing solvents according to Schröder's equation, which was demonstrated by differential scanning calorimetry measurement. The thermochromic colorant presented good reversible thermochromic performance with stable changes in colour parameters for 50 heating‐cooling cycles. This sultone‐based reversible dark red‐yellow conversion thermochromic colorant is suitable for application as thermal‐indicating material under various conditions.