Cellulose nanocrystals as template for improving the crystallinity of two-dimensional covalent organic framework films
| Autor: | Xudong Chen, Wei Liu, Ruilian Chen, Zhaowei Ou, Jing Yang, Yue Li, Baokun Liang, Wei Hong, Liangwei Du, Haoyuan Qi, Zhikun Zheng, Ute Kaiser |
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| Přispěvatelé: | European Union (EU), Horizon 2020 |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
DDC 540 / Chemistry & allied sciences
Materials science Polymers and Plastics Diffuse reflectance infrared fourier transform Scanning electron microscope Organic chemistry 010402 general chemistry 01 natural sciences Article symbols.namesake Crystallinity QD241-441 X-ray photoelectron spectroscopy Fourier transform infrared spectroscopy Film 010405 organic chemistry Cellulose nanocrystals General Chemistry 0104 chemical sciences Covalent organic framework Chemical engineering ddc:540 symbols Selected area diffraction Raman spectroscopy Crystallization |
| Zdroj: | Polymers, Vol 13, Iss 1561, p 1561 (2021) Polymers Volume 13 Issue 10 |
| Popis: | Despite the rapid development of two-dimensional covalent organic frameworks (2D COFs) in recent years, it remains a great challenge to synthesize highly crystalline COF materials. Here, a CNC-assisted approach was adopted to synthesize high crystallinity COF materials. A series of 2D COF films were synthesized at the air���water interface by using cellulose nanocrystals (CNCs) as the template. The occurrence of Schiff reactions based on the imine bond was demonstrated by Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) exhibited the appearances of 2D COF films were flower-like. When CNCs were added to a certain extent, the size of a single petal in the flowers gradually increased with the amount of CNCs. The film with large petals was characterized by Ultraviolet���Visible diffuse reflectance spectroscopy (UV���Vis DRS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). In UV���Vis DRS curves, the S-band of COF-366 film was red-shifted by 24 nm compared with that of 5,10,15,20-tetrakis(4-aminophenyl)-21H,23H-porphyrin (TAPP), confirming the existence of extended conjugation in COF-366 film. XPS was used to identify the surface composition of the sample. The N1s signal of the film indicated that each TAPP formed four imine bonds with 2,5-dihydroxyterephthalaldehyde (DHTA) in COF-366 film. TEM images showed that CNCs had an influence on the crystal size. It was observed from SAED that the crystallinity of the film with CNCs was higher than the film without CNCs. This work provided a new template for improving the crystallinity of 2D COF films. publishedVersion |
| Databáze: | OpenAIRE |
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