Textile applications of photochromic dyes. Part 1: establishment of a methodology for evaluation of photochromic textiles using traditional colour measurement instrumentation

Abstract

Commercial photochromic dyes change rapidly and reversibly from colourless to coloured when activated by ultraviolet irradiation. This paper contributes towards the growing interest in the development of chromic textiles for creative design, functional or smart purposes. The optimisation of a methodology to evaluate the colouristic properties of photochromic textiles using traditional ultraviolet illumination source and colour measurement equipment is described. The experimental factors requiring careful control, including temperature and the time interval between ultraviolet irradiation and measurement, are identified. On the basis of a statistical evaluation of validity, a consistent, reproducible semi‐quantitative methodology is described, which is appropriate for evaluation of the performance of commercial photochromic dyes applied to textiles, a detailed investigation of which will form the basis of subsequent papers in this series.

Substituent effects on absorption spectra of pH indicators: An experimental and computational study of sulfonphthaleine dyes

“…[1,2] Some dyes show chromic properties, meaning that they change colour depending on an external influence. [3] The most exploited chromic types are thermochromism and photochromism, [4,5] but halochromism (pH sensitivity) is also increasingly studied and put into practice. [6][7][8][9][10][11][12] Our main interest lies in the possible application of halochromic dyes in pH-responsive polymers, or more precisely intelligent textiles.…”

Textiles screen‐printed with photochromic ethyl cellulose–spirooxazine composite nanoparticles

“…We found that 1.5 % w/w nanoparticles dispersion having 10 % w/w nanocapsules containing 30 % w/w SO provided intense blue colour, and 4 layers of printing supplied a homogeneous colour coating on cotton. Consequently, the SO concentration of the printing paste was 0.045 % w/w (1.26 x 10 -3 mol L -1 ) which is in the range that was used by Little et al [9][10][11] in their comprehensive studies. As a comparison we also investigated the application of photochromic nanocapsules containing a double amount The prepared photochromic pastes were printed on cotton fabrics using a flat bed screen printing machine, and then thermally polymerized.…”

“…Photochromic textiles have been prepared by conventional dyeing techniques that applied photochromic dyes in dispersed form in exhaust dyeing [4,7,8] and in screen-printing [9][10][11], or by attaching microcapsules containing photochromic dyes onto textile surfaces [12]. Nanomaterials such as particles, fibres, tubes or sheets coated on a substrate may display novel functionalities to the substrate because of the structure and size effect [13].…”

Ultrasound-aided dyeing of cotton fabric with spirooxazines and photochromic properties

“…There have been a number of reports on the use of commercial photochromic materials that contain spirooxazines for treatment on textiles by conventional dyeing and screen printing. Spirooxazines have also been incorporated into polymer matrixes to obtain photochromic fibers [15] and made into microcapsules for attachment onto textiles [16][17][18][19][20][21]. A thin layer of hybrid silica-photochromic dye was coated onto the surface of wool to produce photochromic wool fabrics by using the sol-gel process, and the durability of the photochromic coated layer was improved by introducing epoxy groups into the silica matrix [11].…”