Immobilization Of Metal Organic Frameworks Onto Textiles By Irradiation Induced Grafting Method

With the improvement of living standards, functional textiles, which have somespecial physical or chemical properties besides the general ones, have shown broadprospect in recent years. The vigorous development of nanotechnology also provides anew route for the preparation of functional textiles. Among various kinds ofnanomaterials, metal organic frameworks (MOFs) materials formed by the link ofcenter metal ions and organic ligands containing abundant nanopores are good carriersof functional nanoparticals. In the present work, MIL-101(Cr) type MOFs material(denoted as MIL-101) was immobilized onto nylon fabrics by co-grafting withhydroxyl ethyl acrylate (HEA) initiated by gamma irradiation.The research of the irradiation effects of MOFs is rarely reported. In the presentwork, electron spin resonance spectroscopy (ESR) was used to investigate the speciesof the free radicals of MIL-101initiated by irradiation. The kinetics of the decay of thefree radicals was also studied. The results showed that after the irradiation of MIL-101,benzoyl free radicals generate and reduce with the increasing of time. The study of theradiolysis reaction between MIL-101and tetrahydropyran (THP) showed that thebenzoyl free radicals of MIL-101can be coupled with the radicals of THP underirradiation and the polar groups can be introduced onto the surface of MIL-101. Theproducts of the radiolysis reaction were characterized by infrared spectrum (FT-IR),thermogravimetric (TG) analysis, X-ray diffraction spectrum (XRD), X-rayphotoelectron spectroscopy (XPS), scanning electron microscopy (SEM), specificsurface area and contact angle tests. HEA was grafted onto the MIL-101surface, andthe results demonstrated that the benzoyl free radicals initiated can initiate the graftpolymerization of HEA.MIL-101particles and HEA were grafted onto the nylon fabrics via irradiationinduced graft polymerization. The kinetics of the graft polymerization, such as theeffect of ratio of MOFs and HEA, the HEA concentration and absorbed dose on thedegree of grafting (DG) were studied. The results showed that the DGs of MIL-101have a linear relationship to adding quantity of MIL-101, while the grafting kinetics of HEA was the same as those of the conventional organic monomers. The chemicalstructure, thermal stability, surface morphology and thermo durability of the modifiednylon fabric were characterized, and the results showed that MIL-101nanoparticleswere successfully immobilized onto the nylon fabrics. Dry-cleaning tests showed thatthe binding force between MIL-101particles and the nylon fabrics is quite strong. XRDtest showed that the nanopore structure of MIL-101still exists after irradiation grafting.BET tests showed that immobilization of MIL-101particles significantly increased thespecial surface area of nylon fabrics. Ethyl butyrate and D-limonene were used asmodel compounds to investigate the fragrance sustained release property of themodified nylon fabrics and the results showed that the fragrance sustained releaseproperty of the modified nylon fabrics is much better than that of the pristine nylonfabrics.From this study, a new route to the covalently immobilization of MIL-101particlesonto the surface of textiles was established. The modified textiles containing abundantnanopores have application prospect in fragrance sustained release. The abundantnanopores on the surface of the modified textiles can be used as the carriers of variousfunctional nanoparticals which provide new route for the preparation of compositefunctional textiles in the future.