The specific surface area and high porosity percentage of silica aerogels due to the presence of nanometer holes can be important in creating new and desirable properties in textiles, however, their high brittleness leads to the phenomenon of separation of the aerogel from the fibers and the release of the dust of aerogels, are serious limitations in the application and commercialization of these materials. In the present research, in order to resolve the problem of aerogel dust and improve the dyeability, and increase the dyeing depth of the polyester fibers, the feasibility of producing nanocomposite yarns of polyethylene terephthalate containing silica aerogel using the melt spinning method was studied. In this regard, firstly, with the help of a twin-screw extruder, silica aerogel/polyethylene terephthalate nanocomposite masterbatches containing 0.4,1 and 2 percent silica aerogel was produced. Then, using these masterbatches and a melt spinning process, POY nanocomposite polyester yarns containing different amounts of the silica aerogel were obtained. The presence and amount of the silica aerogel in the produced yarns were confirmed by the density of the yarns, and also by the results of the corresponding FTIR, EDX, and TGA spectra. The results of the measured physical-mechanical properties of the POY yarns, even in a high concentration of the silica aerogel, were acceptable and comparable to those obtained by the traditional semi-opaque yarn containing TiO2 particles. The microscopic images of the fibers indicated the uniformity of the structure of the produced yarns and they also confirmed that the aerogel dust problem was resolved. The XRD results showed a decrease in the percentage of crystallinity from 27.5 to 17.13 for the PET pure and fiber containing 2% silica aerogel, respectively. In the next step, the POY yarns were processed into DTY yarns by using a texturizing machine, and the corresponding fabrics were prepared by a knitting machine. Washing, heat-setting, and relaxation operations were performed on the fabrics and, then, the alkaline hydrolysis processes were carried out on the fabrics. The resulting fabric containing silica aerogel showed an increase in thickness, a decrease in air permeability, an increase in the percentage of moisture absorption, as well as an increase in the percentage of weight loss. The SEM images showed continuous and interwind pits on the surface of the hydrolyzed fibers containing the silica aerogel. These pits were different from the pits created by the alkaline hydrolyzation of the fibers containing TiO2 particles. In the third step, the effect of silica aerogel nanostructure on changing the dyeability and dyeing depth of the dyed fabrics with C.I. Disperse Blue56 and Disperse Black SBRN dyes were eva‎luated. It was observed that there is a direct relationship between the improvement of dyeability & dyeing depth of fabrics with the increase of the silica aerogel content in the fibers. These observations were related to the structural changes and the changes in the morphology of the fibers. In other words, these observations, especially those for the hydrolyzed fibers, were associated with the decrease in the fiber crystallinity and/or the effect of a destructive interference phenomenon, due to the created surface roughness, in the fibers containing silica aerogel.

اكبر خدامي، حسين ايزدان

محمدعلي الشريف، محمدرضا نعيمي راد

محمد كريمي، هاله خليلي، زهرا طالبي مزرعه شاهي