Thepossibility of Poly (ethylene terephthalate) surface modification viaimidazolium- based ionic liquids was investigated due to the benefits of thesechemicals reagent. Owing to thesensitivity caused by environmental issues, Ionic liquids (ILs) with theirspecial characteristics such as low melting point, high thermal stability,electrical conductivity and unnoticeable vapour pressure are widely used as newgreen solvents for a large range of material and catalysts in different chamicalreactions. The substrate surface modification was carried out under differentconditions such as treatment temperature,catalysis and concentration of ionic liquids. Also the difference between twoimidazolium-based ionic liquids with different anions and the possibility of reuse of solutions containing ionic liquidswas investigated. Moreover the effect of the modification on dyeing ofpolyester with disperse dye with measuring of K/S was studied. To evaluate thestructural changes occurred on the samples by ionic liquids, the electronmicroscopy images, fourier transform infrared spectroscopy and the absorptionof methylne blue dye were examine. SEM images show corrosionon the surface of fibers due to the polymer chain failure, these changes causeincreasing of the functional groups like carboxylic acid and hydroxyl which areconfirmed by FTIR Spectrum. The creation of carboxylic acid group is also confirmedby increasing in absorption of methylene blue. Wettability of the surface weretested by some experiments such as vertical wicking height, water absorptiontime, moisture absorption and drop contact angle. The electrical surfaceresistivity of the samples were also calculated. To survey mechanical changesoccurred on samples the bending and strength properties were also tested. Theresults indicated that wettability properties of the treated fabric with ionicliquids were improved without noticeable strength loss of the samples. The resultsof color difference and color strength at the wavelength of maximum absorption for the modified samples with disperse dye showed moredye absorption than the sample dyed without carrier in 100 ? c.
