Knowledge of the thermodynamic potential in terms of the independent variables allows to characterize the macroscopic state of the system. However, in practice, it is difficult to access this potential experimentally due to irreversible transitions that occur between equilibrium states. A showcase example of sudden transitions between (meta)stable equilibrium states is observed for soft porous crystals possessing a network with long-range structural order, which can transform between various states upon external stimuli such as pressure, temperature and guest adsorption. Such phase transformations are typically characterized by large volume changes and may be followed experimentally by monitoring the volume change in terms of certain external triggers. Herein, we present a generalized thermodynamic approach to construct the underlying Helmholtz free energy as a function of the state variables that governs the observed behaviour based on microscopic simulations. This concept allows a unique identification of the conditions under which a material becomes flexible.
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http://dx.doi.org/10.1038/s41467-017-02666-y | DOI Listing |
Langmuir
January 2025
College of Transportation, Ludong University, No.186, Middle Hongqi Road, Zhifu District, Yantai 264025, Shandong, China.
In recent years, flexible pressure sensors have played an increasingly important role in human health monitoring. Inspired by traditional papermaking techniques, we have developed a highly flexible, low-cost, and ecofriendly flexible pressure sensor using shredded paper fibers as the substrate. By combining the properties of laser-induced graphene with the structure of paper fibers, we have improved the internal structure of pressure-sensitive paper and designed a conical surface microstructure, providing new insights into nanomaterial engineering.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Center for Electron Microscopy, South China University of Technology, Guangzhou 511436, China.
Adsorption behaviors are typically examined through adsorption isotherms, which measure the average adsorption amount as a function of partial pressure or time. However, this method is incapable of identifying inhomogeneities across the adsorbent, which may occur in the presence of strong intermolecular interactions of the adsorbate. In this study, we visualize the adsorption of molecular iodine (I) in the metal-organic framework material MFM-300(Sc) using high-resolution scanning transmission electron microscopy (STEM).
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Graduate School of Energy Convergence, Institute of Integrated Technology, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea.
Zeolitic imidazolate framework-8 (ZIF-8) has been extensively studied as a precursor for nitrogen-doped carbon (NC) materials due to its high surface area, tunable porosity, and adjustable nitrogen content. However, the intrinsic microporous structure of the ZIF-8 limits mass transport and accessibility of reactants to active sites, reducing its effectiveness in electrochemical applications. In this study, a soft templating approach using a triblock copolymer was used to prepare mesoporous ZIF-8-derived NC (Meso-ZIF-NC) samples.
View Article and Find Full Text PDFACS Sens
January 2025
Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
It is crucial yet challenging to sensitively quantify low-abundance biomarkers in blood for early screening and diagnosis of various diseases. Herein, an analytical model of intra-mesopore immunoassay (IMIA) was proposed, which was competent to examine various biomarkers at the femtomolar level. The success is rooted in the design of an innovative superparamagnetic core-shell structure with FeO nanoparticles (NPs) at the core and hierarchically porous zeolitic imidazolate frameworks as a shell (FeO@HPZIF-8), achieved through a soft-template directed self-assembly coupled with confinement growth mechanism.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, Central Tribal University of Andhra Pradesh (CTUAP), Andhra Pradesh, 535003, India.
Hydrogen is a zero-emissive fuel and has immense potential to replace carbon-emitting fuels in the future. The development of efficient H sensors is essential for preventing hazardous situations and facilitating the widespread usage of hydrogen. Chemiresistors are popular gas sensors owing to their attractive properties such as fast response, miniaturization, simple integration with electronics and low cost.
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