Developing metal-organic framework(MOF)materials with the moisture-resistant feature is highly desirable for CO_(2)capture from highly humid flue gas.In this work,a new core-shell MOF@MOF composite using Mg-MOF-74 wit...Developing metal-organic framework(MOF)materials with the moisture-resistant feature is highly desirable for CO_(2)capture from highly humid flue gas.In this work,a new core-shell MOF@MOF composite using Mg-MOF-74 with high CO_(2)capture capacity as a functional core and hydrophobic zeolitic imidazolate framework-8(ZIF-8)as a protective shell is fabricated by the epitaxial growth method.Experimental results show that the CO_(2)adsorption performance of the core-shell structured Mg-MOF-74@ZIF-8 composites from water-containing flue gas is enhanced along with their improved hydrophobicity.The dynamic breakthrough results show that the Mg-MOF-74@ZIF-8 with three assembled layers(Mg-MOF-74@ZIF-8-3)can capture 3.56 mmol-g^(-1)CO_(2)from wet CO_(2)/N_(2)(VCO_(2):V_(N_(2))=15:85)mixtures,which outperforms Mg-MOF-74(0.37 mmol·g^(-1))and most of the reported physisorbents.展开更多
Developing high-performance aerogels has long been a hot topic in the fields of insulation and thermal protection.Nanofiber aerogels with ultralight weight and high porosity have recently emerged as promising candidat...Developing high-performance aerogels has long been a hot topic in the fields of insulation and thermal protection.Nanofiber aerogels with ultralight weight and high porosity have recently emerged as promising candidates.However,the weak interfiber interaction hampers the robustness of the three-dimensional network,resulting in poor overall mechanical properties that hinder their wide adoption.Herein,we propose a novel template-anchored strategy for constructing polyimide hybrid nanofiber aerogels.By utilizing self-supporting chitosan as a sacrificial template,polyimide(PI)nanofibers are directionally interconnected by chemical pre-anchoring and heat treatment,which endows the three-dimensional fiber network with good structural stability.These directly assembled nanofiber aerogels exhibit an adjustable low-density range(12.3–31.5 mg/cm^(3)),excellent compressive resilience and fatigue resistance(with only 7.2%permanent deformation after 100 cycles at 60%strain),demonstrating good shape recovery.Moreover,the complex nanofiber pathway and porous network structure contribute to superior thermal insulation performance with low thermal conductivity(28.5–31.8 mW m^(−1) K^(−1)).Furthermore,the incorporation of polyimide and silica(SiO_(2))imparts these hybrid aerogels with remarkable high-temperature resistance and flame retardancy.This study introduces and validates a novel approach for obtaining superelastic and lightweight aerogels,highlighting its promising potential in the realm of high-temperature thermal insulation.展开更多
基金supported by the National Natural Science Foundation of China(51772329,51972340,and 51825201)。
文摘Developing metal-organic framework(MOF)materials with the moisture-resistant feature is highly desirable for CO_(2)capture from highly humid flue gas.In this work,a new core-shell MOF@MOF composite using Mg-MOF-74 with high CO_(2)capture capacity as a functional core and hydrophobic zeolitic imidazolate framework-8(ZIF-8)as a protective shell is fabricated by the epitaxial growth method.Experimental results show that the CO_(2)adsorption performance of the core-shell structured Mg-MOF-74@ZIF-8 composites from water-containing flue gas is enhanced along with their improved hydrophobicity.The dynamic breakthrough results show that the Mg-MOF-74@ZIF-8 with three assembled layers(Mg-MOF-74@ZIF-8-3)can capture 3.56 mmol-g^(-1)CO_(2)from wet CO_(2)/N_(2)(VCO_(2):V_(N_(2))=15:85)mixtures,which outperforms Mg-MOF-74(0.37 mmol·g^(-1))and most of the reported physisorbents.
基金financially supported by the National Key Research and Development Program of China(2020YFA0210701)the National Natural Science Foundation of China(52102199).
文摘Developing high-performance aerogels has long been a hot topic in the fields of insulation and thermal protection.Nanofiber aerogels with ultralight weight and high porosity have recently emerged as promising candidates.However,the weak interfiber interaction hampers the robustness of the three-dimensional network,resulting in poor overall mechanical properties that hinder their wide adoption.Herein,we propose a novel template-anchored strategy for constructing polyimide hybrid nanofiber aerogels.By utilizing self-supporting chitosan as a sacrificial template,polyimide(PI)nanofibers are directionally interconnected by chemical pre-anchoring and heat treatment,which endows the three-dimensional fiber network with good structural stability.These directly assembled nanofiber aerogels exhibit an adjustable low-density range(12.3–31.5 mg/cm^(3)),excellent compressive resilience and fatigue resistance(with only 7.2%permanent deformation after 100 cycles at 60%strain),demonstrating good shape recovery.Moreover,the complex nanofiber pathway and porous network structure contribute to superior thermal insulation performance with low thermal conductivity(28.5–31.8 mW m^(−1) K^(−1)).Furthermore,the incorporation of polyimide and silica(SiO_(2))imparts these hybrid aerogels with remarkable high-temperature resistance and flame retardancy.This study introduces and validates a novel approach for obtaining superelastic and lightweight aerogels,highlighting its promising potential in the realm of high-temperature thermal insulation.
