MINDO/3 molecular orbital theory has been used to study the thermal rearrangements of HNCRCR'CO.The results obtained show that the activation energy of this rearrangement depends on the migrating group R and the g...MINDO/3 molecular orbital theory has been used to study the thermal rearrangements of HNCRCR'CO.The results obtained show that the activation energy of this rearrangement depends on the migrating group R and the group R'.展开更多
Objective The distribution characteristics and formation mechanism of rearranged hopanes in hydrocarbon source rocks are affected by various geological conditions.Among these geological conditions,thermal action has a...Objective The distribution characteristics and formation mechanism of rearranged hopanes in hydrocarbon source rocks are affected by various geological conditions.Among these geological conditions,thermal action has an important influence on the formation of rearranged hopanes,which has been however little documented previously.展开更多
Solid polymer electrolytes have demonstrated high promise to solve the safety problems caused by conventional liquid electrolytes in lithium ion batteries.However,the inherent flammability of most polymer electrolyte ...Solid polymer electrolytes have demonstrated high promise to solve the safety problems caused by conventional liquid electrolytes in lithium ion batteries.However,the inherent flammability of most polymer electrolyte materials remains unresolved,hence hindering their further industrial application.Addressing this challenge,we designed and constructed a thermal-responsive imide-linked covalent organic framework(COF)bearing ortho-positioned hydroxy groups as precursors,which can conduct a thermal rearrangement to transform into a highly crystalline and robust benzoxazole-linked COF upon heating.Benefiting from the release of carbon dioxide through thermal rearrangement reaction,this COF platform exhibited excellent flame retardant properties.By contrast,classic COFs(e.g.,boronate ester,imine,olefin,imide linked)were all flammable.Moreover,incorpo-rating polyethylene glycol and Li salt into the COF channels can produce solid polymer electrolytes with outstanding flame retardancy,high ionic conductivity(6.42×10^(-4) S cm^(-1))and a high lithium-ion transference number of 0.95.This thermal rearrangement strategy not only opens a new route for the fabrication of ultrastable COFs,but also provides promising perspectives to designing flame-retardant materials for energy-related applications.展开更多
基金Project supported by the Natural Science Foundation of Jiangxi Province,China.
文摘MINDO/3 molecular orbital theory has been used to study the thermal rearrangements of HNCRCR'CO.The results obtained show that the activation energy of this rearrangement depends on the migrating group R and the group R'.
基金supported by the National Natural Science Foundation of China (grant No.41272170)the National Oil and Gas Major Project (grant No.2016ZX05007-001)
文摘Objective The distribution characteristics and formation mechanism of rearranged hopanes in hydrocarbon source rocks are affected by various geological conditions.Among these geological conditions,thermal action has an important influence on the formation of rearranged hopanes,which has been however little documented previously.
基金supported by Tianjin Natural Science Foundation(20JCJQJC00170)National Natural Science Foundation of China(22001131 and 22175099)+2 种基金Frontiers Science Center for New Organic Matter of Nankai University(63181206)111 Project(B12015)Postdoctoral Science Foundation of China(2019M660974).
文摘Solid polymer electrolytes have demonstrated high promise to solve the safety problems caused by conventional liquid electrolytes in lithium ion batteries.However,the inherent flammability of most polymer electrolyte materials remains unresolved,hence hindering their further industrial application.Addressing this challenge,we designed and constructed a thermal-responsive imide-linked covalent organic framework(COF)bearing ortho-positioned hydroxy groups as precursors,which can conduct a thermal rearrangement to transform into a highly crystalline and robust benzoxazole-linked COF upon heating.Benefiting from the release of carbon dioxide through thermal rearrangement reaction,this COF platform exhibited excellent flame retardant properties.By contrast,classic COFs(e.g.,boronate ester,imine,olefin,imide linked)were all flammable.Moreover,incorpo-rating polyethylene glycol and Li salt into the COF channels can produce solid polymer electrolytes with outstanding flame retardancy,high ionic conductivity(6.42×10^(-4) S cm^(-1))and a high lithium-ion transference number of 0.95.This thermal rearrangement strategy not only opens a new route for the fabrication of ultrastable COFs,but also provides promising perspectives to designing flame-retardant materials for energy-related applications.
