Methyl Orange를 이용한 나일론 직물의 염색 및 산성용액 접촉에 따른 색 변화

Strong acids, such as hydrochloric acid and sulfuric acid, are colorless and are not easily detected when leaked. Halochromic dyes can be used for detecting strong acids because they show different colors when exposed to acid liquids. In this study, methyl orange was used as a pH-indicating dye in detecting acid liquids. Nylon 66 woven fabric was dyed with methyl orange, and the dyeing properties were determined, along with the pH-sensing property, colorfastness, and fixing agent effect. Methyl orange in an aqueous solution showed maximum absorption at 464 nm with orange color at a pH of 5-10, whereas the maximum absorption changed to 507 nm showing red color at a pH of 2. Nylon 66 dyed with methyl orange exhibited a good color yield (K/S), and the dyeing property was influenced by the pH and dye concentration. When the dyed sample was immersed in a solution with a pH range of 3.5-4.0, its original orange color was maintained. Then, the color turned to reddish-orange when immersed in a solution of 2.0-3.0 pH and red in a pH 1.5 solution. The acid-sensing property was retained after fixing agent treatment. The wash and water fastness of the dyed fabrics varied from poor to very poor, and the fastness of the staining was improved to a moderate level by fixing agent treatment. The lightfastness indicators before and after the application of fixing agent treatment were moderate and good, respectively.