Abstract:

On the basis of enhancing photostability of fluorescent dyes for textile, two self-prepared hemicyanine dyes are involved in the research process. After the dyeing process of acrylic fabrics, light fastness of dyed fabrics was explored. Photodegradation tests of aqueous solution of two dyes were also carried out, thus quantitative degradation rate constants were obtained. By density frontier theory study, the optimized geometry parameters and charge distributions of two hemicyanine fluorescent dye cations were obtained. By calculating the frontier molecular orbitals and interactions with various forms of oxygen, this work tried to give explanations for former photofading performance of two dyes. It is proved that hemicyanine dye 1,3,3-trimethyl-trans-2-[p-(N,N-Diethyl)-amino-styryl]-N-methyl indolinium chlorate has better performance in light stability than trans-4-[p-(N,N-Diethyl)-amino-styryl]-N-ethyl pyridinium bromide, which demonstrates good agreement in calculating and experimental results, indicating the mothod can be used as theoretical basis for judgment of similar problems.

Key words: hemicyanine fluorescent dyes, dyeing of acrylic fabrics, photostability, quantum chemistry study, frontier molecular orbital theory