Study On Dyeing Mechanism And Performance Of Sodium Copper Chlorophyllin On Silk Fabric

With the decreasing of oil resources, the growing of people's environmental protection consciousness and improving of the quality of life, the application of the natural dye on textiles has attracted more and more attention. The study about the dyeing performance and mechanism of natural dyes is very important.Sodium Copper Chlorophyllin (SCC) is a natural chlorophyll derivative. Its resource is abundant, it has no enviromental pollution and toxic side effects and has some natritional value and health function. SCC has bright color and is a good food pigment. In this paper, we studied the dyeing performance and mechanism of SCC on silk fabrics, mainly included the following four aspects: (1) optimized the dyeing conditions of SCC dye on silk to obtain vivid green shade, and investigated the uptake of SCC dye and K/S values of SCC dye on silk under the optimized dyeing conditions, (2) studed the adsorption kinetic and thermodynamic of SCC on silk fabrics; (3) the effect of NaCl in dye bath on the adsorption kinetics and thermodynamics of SCC dye on silk; (4) the fastness of dyed fabrics were investigated. According to the poor light fastness of SCC dye on silk fabric, preliminary disucusses the mathods of improving the light fastness of SCC dye on silk fabric.Fundamental studies on the adsorption kinetics and thermodynamics of the dyeing process are important to understand the dyeing mechanics in order to improve the dyeing properties of natural dyes. To obtain most vivid green shade, the optimized dyeing conditins of SCC dye direct dyeing silk fabrics were investigated through the single-factor experiment, the optimized dyeing conditins: pH 8, NaCl concentration of 9 g/L, dyeing temperature of 70℃, initial SCC dye concentration of 0.31 g/L and dyeing time of 100 min.In this paper, the adsorption kinetics of SCC on sillk fabrics was studed and the results indicate the pseudo second-order kinetic model agrees well with the adsorption system of SCC on silk with and without NaCl in dye bath for the dyeing temperatures of 70, 80 and 90℃. Adding NaCl in the dye bath increased the amount of adsorption at equilibrium qe, the diffusion coefficient D and decreased the half dyeing time t1/2. Raising dyeing temperature decreased the amount of adsorption at equilibrium qe, increased diffusion coefficient D and decreased the half dyeing time t1/2.The study of thermodynamics of SCC on sillk fabrics indicated that the Langmuir equation agrees well with the equilibrium isotherm for the dyeing temperatures of 70, 80 and 90℃in the entire SCC dye concentration range (0².91 g/L) with and without NaCl in dye bath. The negative adsorption affinity (Δμ°) and enthalpy change (ΔH°) of SCC dye on silk show that the adsorption process is an exothermic and spontaneous process. Addition of NaCl increases affinity and enthalpy change, indicating that NaCl can increase interactive attraction between SCC dye and silk and therefore increase the adsorption capacity.The fastness of SCC dye on fabrics experiments illustrates that the washing fastness and crock fastness were better than light fastness. Flos Sophorae Immaturus is also a nature dye, has strong ultraviolet absorption and light fastness good ability. Firstly, dyeing silk fabrics with Flos Sophorae Immaturus and SCC dye togetherly in one-dye bath. Secondly, the dyed silk fabrics of SCC dye were processed by ultraviolet absorption agent nano- TiO₂ , the results indicate that Flos Sophorae Immaturus dye and nano- TiO₂ are all improve the light fastness from 2³ grade to 3⁴ or 4 grade.SCC could be a potentially viable natural green dye for protein fibers. It also solved the difficult problems of vegetable dye dyed green color for textiles. A natural green dyestuff, sodium copper chlorophyllin (SCC) was used to dye silk. There are several advantages, including the reasonable utilization of resources, and improving the added value of dyeing silk products, moreover, meeting the requirements of eco-textiles. Therefore, in this paper, study on the performace and mechanism of the green vegetable dye SCC on silk have important significance, provided reference value for its industrialized production.