Fabric color change

Li, K., Zhang, Q., Wang, H., Li, Y, 2014. Red, green, blue (RGB) electrochromic fibers for the new smart color change fabrics. ACS Appl. Mater. Interfaces 6,13043-13050. 

There can be many uses for these fibers. Weaving them into fabric, for example, could create color-changing camouflage uniforms... 

No attempt was made to apply the Arrhenius equation to the color change data because of the relatively large ( 1 AE unit) variation of the color uniformity ("evenness") of the original uncoated silk fabric. At the lower temperatures, 70°C and 80°C, the measured color changes were close to the uncertainty in the color of the unexposed silk fabric itself and therefore too few temperature data points were available for meaningful calculations. 

The effect of humidity variation on the color change of uncoated silk fabric at constant temperature (90°C) for a fixed exposure time (17 days) is shown in Figure 8. The rate of change in color increases with relative humidity above 50 % for both coated and uncoated fabric. This is the same humidity level above which the change in the tensile property degradation rates also increases. 

In contrast to the color changes that occurred in modern, uncoated silk after exposure to heat, the light-induced color change was not indicative of the tensile properties of the fabric. Loss in tensile properties with irradiation continued while the color remained static. 

Several inks111 112 have been developed for paints and labels of security masks. Furyl fulgide was spun into fibers and woven into a fabric that was used to manufacture photochromic labels. In 1995, the Color Change Corporation (U.S.) exhibited several different color photochromic fabrics as commercial products at the third international symposium on the chemistry of functional dyes. 

Rice has suggested that in order to conserve historic colorants, it is necessary to know what constitutes the color, what chemicals affect it and how, and what factors cause it to fade or change (16), The specific objectives of this investigation were two-fold to discover dye types and characteristics in the voile fabric to discover if and how the fabric color changes in response to selected conditions it could have encountered in its wear life. This information could indicate possible factors to explain the types of discolorations on the dress. Experimental procedures and results for both objectives followed separate courses and therefore will be discussed separately. Results from the investigation of the first objective in part determined testing procedures for the second. 

For every colorfastness test conducted, the color change of tested specimen was evaluated by comparing it with the remnant fabric color using the Gray Scale for Color Change. In addition, the color of the resulting specimen for each test was analyzed and assigned a Munsell color number. Results are in Table III. 

Represent Class on a 1 to 5 scale. Highest number indicates less color change on fiber and therefore less color transfer from fabric dyes. Lower number indicates greater color change and consequently greater color transfer. 

Tested specimens in the preceding test series exhibited certain color changes in response to the isolated conditions, yet none of the conditions tested produced a specimen that became darker or yellower in hue. In instances where some sort of color change did occur, the opposite reaction occurred—fabric became redder, corroborating with Giles report that certain dyes redden upon losing color (5). 

Colorfastness to Acids and Alkalis. In wear, the garment probably would have come in contact with atmospheric contaminants and with dust. A.A.T.C.C. Test Method 6-1975, Colorfastness to Acids and Alkalis, is designed to test a fabric s color reaction to acid fumes, applied alkaline or acid sizings, alkaline cleansing agents, and alkaline street dirt. All of these factors have been noted earlier as possible contributors to color change. 

The degree of color change as compared with the original fabric and the Munsell color of the tested specimens were evaluated in the MacBeth SpectraLight, following previously explained procedures. Results are recorded in Tables VI and VII. 

This series of tests indicates that a color change similar to that seen on the dress fabric is reproducible. The only method by which it was produced in this study was with a pretreating solution that contained sulfur and potassium, both elements shown in the x-ray analysis to be increased in the dress fabric. 

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