Application Of Raman Spectroscopy In Compatibility Study Of Reactive Dyes

In the actual printing and dyeing process,the color provided by a single dye can no longer meet the current people’s demand for clothing color.It often requires two or more single dyes to mix to obtain a specific color.With the application of color matching dyes becoming more and more common,the research and control of color matching dyes in the dyeing process have also begun to be valued.The monitoring of the change of dye concentration in each component during the dyeing process is the key to further study the principle of color matching dyeing and promote the dyeing technology.At present,our research group has explored a method of quantitative analysis model constructed by Raman spectroscopy combined with PLS to analyze the concentration of each component of mixed reactive dyes containing monochloro-s-triazine and vinyl sulfone double active groups.However,the applicability of this method to reactive dyes containing different types of chemical active groups in the actual dyeing process remains to be further explored.Therefore,this paper uses this method to further detect and analyze the three primary color matching dyeing process of reactive dyes with different parent structures and active groups.The main research results are as follows:Firstly,the Raman spectra of reactive dyes with different concentrations can be obtained by Raman spectrometer.Then,according to the linear relationship between the characteristic peak intensity of Raman spectrum and the dye concentration,the detection limit of the component to be tested was determined,and the applicable concentration range of the quantitative component was determined.Then,a multi-component quantitative analysis model is constructed by Raman spectroscopy combined with PLS,which can detect the concentration of each component in multi-component dyeing solution quickly and accurately.The accuracy of the model is improved by two spectral preprocessing methods:band range selection,first derivative and first derivative plus smoothing.The corresponding quantitative analysis models of RR195/RY145,RR195/RB194,RY145/RB194,RR243/RO70,RO70/RB171,RR243/RB171,RR4/RY4,RY4/RB5,RR4/RB5 two-component color matching system and RR195/RY145/RB194,RR243/RO70/RB171,RR4/RY4/RB5 three-component color matching system were constructed.The RMSEP value of the model was less than 0.2,and the correlation coefficient(R~2)between the prediction set and the calibration set of each component in the multi-component quantitative analysis model of the mixed dye solution was above 0.99,indicating that the established model was accurate..Finally,this model was used to quantitatively analyze the mixed dyeing process of reactive dyes with different active groups.In the mixed system of RR195,RY145 and RB194,RR195and RB194 inhibited the dyeing of RY145 on cotton fabric.The dyeing of RB194 was less affected by RY145 and RR195.RY145 promoted the dyeing of RR195.The effect of RB194 on RR195 was affected by the concentration ratio.A small amount of RB194 inhibited the dyeing of RR195.When the concentration ratio of RB194 exceeded 60%,it promoted the dyeing of RR195.In the two-component mixed system with lower concentrations of RR243,RO70 and RB171,RO70 promotes the dyeing of RR243 and RB171,and the force of RR243 on RO70 is affected by the concentration ratio.When the proportion of RO70 exceeds 60%,RR243promotes the dyeing of RO70,while in the three-component mixed system,the force between dyes changes;in the mixed system of RR4,RY4 and RB5,under the low dye dosage,RR4 and RY4 have competitive effect in the dyeing process of the three dyes,and the other two components have good overall compatibility.After the dye dosage increases,the force between the dyes changes,and the dye uptake percentage curve of the three components is difficult to achieve consistency.