Preparation and properties of Fe(II)‐ion‐sensitive colour‐changing fabric

Textile fabrics were dyed with complexometric indicators (ionochromic dyes) to develop Fe(II) ionochromic fabric. Three kinds of ionochromic dye were used to dye silk fabric, and they were evaluated for colour changes triggered by Fe(II) solution. The K/S values and photos of the fabrics were then recorded. It was found that 1,10‐phenanthroline was the most suitable ionochromic dye in these dyes. Colour change from white to red could be clearly seen when 1,10‐phenanthroline‐dyed silk fabric was triggered by Fe(II) solution, but it showed no colour change when triggered by Cu(II), Mg(II), or Ca(II) solution. Moreover, 1,10‐phenanthroline‐dyed nylon, polyester, and cotton fabrics showed no obvious colour changes after triggering by Fe(II) solution. Ion concentration, pH value, and reaction time could affect the colour changes. When triggered by 8 mg l⁻¹ of Fe(II) solution at neutral pH for about 15 min, the ionochromic fabric showed a clear colour change. In addition, three coloured fabrics in green, blue, and yellow were also dyed with 1,10‐phenanthroline. It was found that they could also show clear colour changes when triggered by Fe(II) solution. These ionochromic fabrics may find broad application in many fields, such as Fe(II) detection, magic toys, anticounterfeiting materials, and bionic silk flowers.