4. Conclusions
A clean and catalytical fixation of disperse reactive dye on cotton substrate via a heterogeneous and phase transfer catalytic reactionin a liquid-supercritical-solid triphase systemwas demonstrated atthe first time, by employing a perfluor compound of FC-134 as phase transfer agent to transfer hydroxyl/carbonate ions from the liquid phase in a home-built reactor. The dye fixation efficiency was significantly improved in the presence of the phase transfer catalyst of FC-134 and the reaction accelerant of sodium carbonate, and a maximum result was obtained with the dosage of the aqueous
solution at 16.0 g involving a mass fraction of 10% the mixture of sodium carbonate with the FC-134 in a mole ratio of 3:1, at a reaction time of 60 min under a optimized process. FT-IR analysis, C1s,O1s XPS spectra and SEM analysis further confirm that the hydroxyl/carbonate anions, as well as the phase transfer catalyst itself, could be phase transferred from the aqueous phase to the supercritical fluid, and then accessed to the solid substrate for enhancing the catalytic fixation reaction to fix the disperse reactive dye molecules on the cellulosic polymer with covalent ether bonds.