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Your search keyword '"Liang, Rong-Ran"' showing total 23 results
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23 results on '"Liang, Rong-Ran"'

14. Regulating the topology of 2D covalent organic frameworks by the rational introduction of substituents† †Electronic supplementary information (ESI) available: Procedure for the preparation of the COFs, IR spectra, solid-state 13C NMR, SEM images, TGA traces, PXRD profiles and simulations, fractional atomic coordinates, and BET plots. See DOI: 10.1039/c6sc05673c Click here for additional data file

Author

Pang, Zhong-Fu, Zhou, Tian-You, Liang, Rong-Ran, Qi, Qiao-Yan, and Zhao, Xin

Subjects
Chemistry
Abstract

Regulating the topology of 2D COFs has been achieved by introducing alkyl substituents into the skeleton of a parent monomer, which led to the formation of a dual-pore COF or single-pore COFs, depending on the sizes of the substituents., The topology of a covalent organic framework (COF) is generally believed to be dictated by the symmetries of the monomers used for the condensation reaction. In this context, the use of monomers with different symmetries is usually required to afford COFs with different topologies. Herein, we report a conceptual strategy to regulate the topology of 2D COFs by introducing alkyl substituents into the skeleton of a parent monomer. The resulting monomers, sharing the same C 2 symmetry, were assembled with a D 2h symmetric tetraamine to generate a dual-pore COF or single-pore COFs, depending on the sizes of the substituents, which were evidenced using PXRD studies and pore size distribution analyses. These results demonstrate that the substituent is able to exert a significant influence on the topology of COFs, which is crucial for their application.

Published
2017

21. Fabricating Organic Nanotubes through Selective Disassembly of Two-Dimensional Covalent Organic Frameworks

Author

Liang, Rong-Ran, A, Ru-Han, Xu, Shun-Qi, Qi, Qiao-Yan, and Zhao, Xin

Abstract

Covalent organic frameworks (COFs) are an emerging class of crystalline porous organic polymers with potential for innovative applications. Here we report the use of COFs as precursors for the fabrication of well-defined tubular nanomaterials. A proof-of-concept study is presented for the controllable fabrication of organic nanotubes through selective disassembly of two-dimensional heteropore COFs. Two dual-pore COFs are constructed based on orthogonal reactions. Each COF possesses two different kinds of pores, which are formed by linking all-hydrzaone-bonded nanopores with boroxines. Selectively hydrolyzing boroxine rings in the COFs while keeping hydrazone linkages untouched gives rise to organic nanotubes with diameters and shapes corresponding to the nanochannels of the COFs.

Published
2020
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23. Boosting Hydrostability and Carbon Dioxide Capture of Boroxine-Linked Covalent Organic Frameworks by One-Pot Oligoamine Modification.

Author

Jia C, Liang RR, Gan SX, Jiang SY, Qi QY, and Zhao X

Abstract

Boron-based covalent organic frameworks (COFs) are susceptible to nucleophilic attack by water at the electron-deficient boron sites and even slightly humid air could destroy the integrity of their porous frameworks within hours. Such instability is a major limitation to the practical applications of boron-based COFs. Herein we report a significant enhancement of hydrostability of boroxine-linked COFs (COF-1 as representative) by modification with an oligoamine (tetraethylenepentamine, TEPA), which leads to survival of the modified COF in water and long-time stability under humid atmosphere. Meanwhile, the TEPA modification also results in a considerable increase in CO 2 adsorption capacity up to 13 times and a dramatic improvement in CO 2 /N 2 selectivity in low pressure region, which make the modified COF suitable for capturing CO 2 from flue gas. This work provides a facile, efficient, and scalable method to greatly improve hydrostability of boroxine-linked COFs and reshape them into high-performance CO 2 adsorbents., (© 2023 Wiley-VCH GmbH.)

Published
2023
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