Water is the most abundant molecule found on the earth’s surface and is a key factor in multiscale rock destruction.However,given the fine-grained nature of rock and the complexity of its internal structure,the micro...Water is the most abundant molecule found on the earth’s surface and is a key factor in multiscale rock destruction.However,given the fine-grained nature of rock and the complexity of its internal structure,the microstructural evolution of rock under the action of water has not yet been elucidated in detail,and little is understood about the relationship between the rock structure and solideliquid unit.A variety of techniques were used in this study to track the mechanical properties,pore and crack characteristics,and mineral structure degradation characteristics of sandstone at different stages under the action of deionized water,and the evolution mechanisms of the microstructure were analyzed at the molecular scale.The results showed that during the watererock interaction process,water was adsorbed onto the surface of dolomite minerals and the hydrophilic surface of clay minerals,forming a high-density hydrogen bond network.However,different mineral surface structures had different water adsorption structures,resulting in the strain of the dense clay mineral aggregates under expansion action.Stress concentrated at crack tips under the capillary force of dolomite minerals(very weak dolomite dissolution).These effects resulted in a substantial increase in the number of small pores and enhancements in poreecrack connectivity,and the rock strength exhibited varying degrees of decline at different stages of wet-dry cycles.In general,the results of this paper will help to further elucidate the internal connections between molecular-scale and macroscale processes in rock science.展开更多
Stretchable conjugated polymer films are pivotal in flexible and wearable electronics.Despite significant advancements in film stretchability through molecular engineering and multicomponent blending,these conjugated ...Stretchable conjugated polymer films are pivotal in flexible and wearable electronics.Despite significant advancements in film stretchability through molecular engineering and multicomponent blending,these conjugated polymer films often exhibit limited elastic ranges and reduced carrier mobi-lities under large strain or after cyclic stretching.These limitations hinder their application in wearable electronics.Therefore,it is imperative to reveal the mechanical fatigue mechanisms and incorporate multiple strain energy dissipation strategies to enhance elastic deformation and electrical perform-ance of stretched conjugated polymer films.In this review,we begin by introducing the typical mechanical behaviors of conjugated polymer films.Subsequently,we discuss the multiscale structural evolution under various stretching conditions based on both in-situ and ex-situ characterizations.This analysis is further related to the diverse strain energy dissipation mechanisms.We next establish the correlation between strain-induced microstructure and the electrical performance of stretched conjugated polymer films.After that,we propose to develop highly elastic conjugated polymer films by constructing stable crosslinks and promoting polymer dynamics in low-crystalline polymer films.Finally,we highlight the future opportunities for high-performance and mechanically stable devices based on stretchable conjugated polymer films.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.41922055 and 42090054)Zhejiang Huadong Construction Engineering Co.,Ltd.(Grant No.KY2019-HDJS-07).
文摘Water is the most abundant molecule found on the earth’s surface and is a key factor in multiscale rock destruction.However,given the fine-grained nature of rock and the complexity of its internal structure,the microstructural evolution of rock under the action of water has not yet been elucidated in detail,and little is understood about the relationship between the rock structure and solideliquid unit.A variety of techniques were used in this study to track the mechanical properties,pore and crack characteristics,and mineral structure degradation characteristics of sandstone at different stages under the action of deionized water,and the evolution mechanisms of the microstructure were analyzed at the molecular scale.The results showed that during the watererock interaction process,water was adsorbed onto the surface of dolomite minerals and the hydrophilic surface of clay minerals,forming a high-density hydrogen bond network.However,different mineral surface structures had different water adsorption structures,resulting in the strain of the dense clay mineral aggregates under expansion action.Stress concentrated at crack tips under the capillary force of dolomite minerals(very weak dolomite dissolution).These effects resulted in a substantial increase in the number of small pores and enhancements in poreecrack connectivity,and the rock strength exhibited varying degrees of decline at different stages of wet-dry cycles.In general,the results of this paper will help to further elucidate the internal connections between molecular-scale and macroscale processes in rock science.
基金support from the National Natural Science Foundation of China(51933010,52433009)the Fundamental Research Funds for the Central Universities(GK202309019).
文摘Stretchable conjugated polymer films are pivotal in flexible and wearable electronics.Despite significant advancements in film stretchability through molecular engineering and multicomponent blending,these conjugated polymer films often exhibit limited elastic ranges and reduced carrier mobi-lities under large strain or after cyclic stretching.These limitations hinder their application in wearable electronics.Therefore,it is imperative to reveal the mechanical fatigue mechanisms and incorporate multiple strain energy dissipation strategies to enhance elastic deformation and electrical perform-ance of stretched conjugated polymer films.In this review,we begin by introducing the typical mechanical behaviors of conjugated polymer films.Subsequently,we discuss the multiscale structural evolution under various stretching conditions based on both in-situ and ex-situ characterizations.This analysis is further related to the diverse strain energy dissipation mechanisms.We next establish the correlation between strain-induced microstructure and the electrical performance of stretched conjugated polymer films.After that,we propose to develop highly elastic conjugated polymer films by constructing stable crosslinks and promoting polymer dynamics in low-crystalline polymer films.Finally,we highlight the future opportunities for high-performance and mechanically stable devices based on stretchable conjugated polymer films.
