Controllable Preparation And Performance Of Fiber /MOFs Functional Crystalline Composites

Metal-organic frameworks?MOFs?are highly crystallized three-dimensional reticular crystalline materials with metal ions,metal clusters as nodes and self-assembled with organic ligands by coordination bonds,hydrogen bonds,or intermolecular forces.Most of the MOFs are bulk crystals,the properties are excellent,but fragile crystal morphology is not conducive to practical application.Fiber,as an important class of flexible substrates,will MOFs and fiber composite,not only can achieve functional composite but also can meet the macro-use morphology,is an effective method to prepare MOFs practical functional materials.This paper uses three kinds of fiber products,such as Juncus effusus?JE?fibers,active carbon fiber felt and silk fabric as substrates,synthesizing micro-nano MOFs hybrids by self-assembly layer by layer,hydrothermal method and biomimetic mineralization method on the substrates.Three studies have been carried out on:?1?Application of Juncus effusus?JE?fibers/MOFs crystalline composites for formaldehyde adsorption.Based on Juncus effusus?JE?fibers as the substrate,the bovine serum protein?BSA?into the reaction system can be introduced by the synthetic method of bionic mineralization,and the zeolitic imidazolate framework-8?ZIF-8?nanocrystals can be attached to the JE fibers quickly.The morphological structure representation was demonstrated using tests such as FESEM,XRD,FTIR,TG,and BET,and its adsorption effect under high concentrations?100 mg/m³?and low concentrations?10 mg/m³?were also explored.The results show that the bionic mineralization method can quickly synthesize ZIF-8-BSA/JE fiber composite materials in three seconds,has obvious adsorption effect on formaldehyde,the adsorption efficiency of formaldehyde can reach more than 99% under high concentration conditions,and the full adsorption of formaldehyde under low concentration conditions is only 17 min.The composite material uses a wide range of plant fibers,which can reduce the cost of adsorbents.?2?Application of active carbon fiber felt/MOFs crystalline composites for formaldehyde adsorption.Based on active carbon fiber felt,TiO₂ was modified by atomic layer deposition?ALD?and then synthesized on its surface by hydrothermal reaction.the as-prepared ZIF-8@ALD-ACF composite was characterized by morphology structure using FESEM,XRD,FTIR,and BET,while also exploring its adsorption removal efficiency at high concentration?100 mg/m³?and low concentration?10 mg/m³?formaldehyde.The results showed that ALD-modified TiO₂ provided abundant active sites for carbon fiber felt,which was beneficial to the synthetic attachment of ZIF-8,and the ZIF-8@ALD-ACF composite could effectively adsorb formaldehyde at both high and low concentrations.In addition,formaldehyde can be decomposed into water and carbon dioxide by titanium dioxide under ultraviolet light,which can avoid the secondary pollution caused by formaldehyde slow release.?3?Application of silk fabric/MOFs crystalline composites for temperature detection.Based on silk fabric,TiO₂ was modified by atomic layer deposition?ALD?and then the rare metal-organic framework material?Ln-MOFs?was constructed under hydrothermal reaction,and ALD-TiO₂-Eu-MOFs silk fabric was prepared.The morphological structure characterization was carried out by FESEM,TEM,XRD,and other tests,and its temperature detection performance under different pH conditions was further tested.The results show that ALD-modified TiO₂ provides a rich active site for silk fabrics,which is beneficial to the controlled construction of Eu-MOFs,and the functional silk fabrics show different fluorescence detection effects on temperature under different acid and alkaline conditions where the hydrothermal reaction is different.Under medium and alkaline conditions,with the increase of temperature,the fluorescence intensity of functional silk fabric I_Euis reduced linearly,which can achieve temperature detection in the high temperature?25¹50 ??and low temperature?77³00 K?region.