Preparation And Catalytic Degradation Performance Of Fiber Composites Of Zirconium-Based Metal-Organic Frameworks

Metal-organic frameworks(MOFs)are a class of crystalline porous materials composed of metal ions or metal ion clusters and organic linkers,which have excellent porosity,high specific surface area,structural and functional diversity.MOFs have been studied for a large number of potential applications including,but not limited to in chemical separation,catalysis,sensing,removal of toxic substances,and the degradation and detoxification of chemical warfare agents(CWAs).The crystal form of MOF powder limits its application in real life.To expand the application of MOFs in the field of separation and catalysis,it is necessary to adopt simple methods to retain their crystallinity,adsorption and reactive functionality and integrate them into textiles.In this thesis,polypropylene(PP)meltblown non-woven fabric with wide application prospects in biochemical protective clothing is used as the base material.Based on the polyphenol biomimetic modification technology,the polypropylene(PP)non-woven material is modified with a polyphenol hybrid network coating that exhibits excellent adhesion to a variety of substrates,with the help of the carboxyl and hydroxyl functional groups in the adhesion layer formed on the surface of the material,Zr-MOFs are bonded to PP non-woven fabrics using supramolecular assembly and in-situ growth methods to construct zirconium-based metal-organic framework fiber-based composites that quickly capture and self-purify chemical warfare agents.It mainly carried out the following three aspects of research:(1)The polypropylene meltblown non-woven fabric was used as the substrate,and the fiber surface was coated with a hybrid coating of tannic acid(TA)and 3-aminopropyltriethoxysilane(APTES)by solution dipping,Ui O-66-NH₂ particles were assembled on the surface of PP@TA-APTES using supramolecules formed by?-cyclodextrin and cetyltrimethylammonium bromide to obtain Ui O-66-NH₂@PP@TA-APTES(UPTA)fiber composite material.The surface morphology,composition and structure of the as-prepared composite material were characterized by scanning electron microscope(SEM),Fourier infrared spectroscopy(FTIR),X-ray diffraction spectroscopy(XRD),thermogravimetric analyzer(TG),X-ray photoelectron spectroscopy(XPS),the mass loading of MOFs in the composite material was characterized by inductively coupled plasma luminescence spectrometer(ICP).The catalytic degradation effect of the chemical warfare agent simulant DMNP was tested by an ultraviolet-visible spectrophotometer.The results show that the Ui O-66-NH₂ loading in the prepared UPTA composite material is 14.64%,which has a catalytic degradation effect on the chemical warfare agent simulant DMNP,and its degradation half-life is 17 minutes.(2)Using polypropylene meltblown non-woven fabric as the substrate,the surface was coated with tannic acid(TA)or gallic acid(GA)and 3-aminopropyltriethoxysilane(APTES)hybrid coating by solution dipping.Zirconium tetrachloride and 2-aminoterephthalic acid were used as raw materials to grow Ui O-66-NH₂ on the surface of the modified polypropylene non-woven fabric by in-situ growth method.Prepared polypropylene non-woven composite materials loaded with Ui O-66-NH₂,PP@TA-APTES@Ui O-66-NH₂(PTAU)and PP@GA-APTES@Ui O-66-NH₂(PGAU).The surface morphology,composition and structure of as-prepared PTAU and PGAU were characterized by SEM,FTIR,XRD,TG,XPS and other tests.The mass loading of MOFs in the composite material was characterized by ICP,and the static water contact angle test(WCA)was used to show the change in wettability before and after modification of the composite material.Compared the effects of tannic acid and gallic acid with3-aminopropyltriethoxysilane on the loading of Ui O-66-NH₂ and the catalytic degradation of DMNP.The results indicate that the content of Ui O-66-NH₂ in the prepared PTAU was 20.96%,the half-life of catalytic degradation of DMNP was 4.8 min;while the mass loading of Ui O-66-NH₂ in PGAU was 21.14%,and the half-life of catalytic reduction of DMNP was 12.4 min.(3)The polypropylene melt-blown nonwoven fabric was coated with tannic acid(TA)and3-aminopropyltriethoxysilane(APTES)hybrid coating by solution impregnation method.Using zirconium tetrachloride and trimesic acid as raw materials,MOF-808 was grown on the surface of modified polypropylene non-woven fabric by in-situ growth method.The PP@TA-APTES@MOF-808(PTAM)composite material was prepared.The surface morphology,composition and structure were characterized by SEM,FTIR,XRD,TG,XPS and fully automatic specific surface area and porosity analyzer(BET),and the mass loading of MOFs in the composite material was characterized by ICP.The catalytic degradation and reusability of functionalized PP nonwoven fabric for chemical warfare agent simulant DMNP were monitored by UV-Vis spectroscopy.The results showed that the MOF-808 content in the PTAM composite was 23.44%,and the half-life of catalytic degradation of DMNP was 1.3 min.It had excellent catalytic degradation performance,and can completely degrade DMNP in three repeated degradations.