期刊
ACS CENTRAL SCIENCE
卷 3, 期 1, 页码 58-65出版社
AMER CHEMICAL SOC
DOI: 10.1021/acscentsci.6b00331
关键词
-
资金
- Camille and Henry Dreyfus Foundation
- Army Research Office for a Multidisciplinary University Research Initiatives (MURI) [W911NF-15-1-0447, W911NF-15-1-0189]
- National Science Foundation
- National Institutes of Health/National Institute of General Medical Sciences under NSF Award [DMR-1332208]
- NSF [DMR-1120296, DGE-1144153]
- National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health [F32EB021859]
- International Institute of Nanotechnology
- National Defense Science and Engineering Graduate Fellowship
- U.S. Department of Energy [DE-AC05-76RL01830]
- Div Of Civil, Mechanical, & Manufact Inn
- Directorate For Engineering [1334012] Funding Source: National Science Foundation
Covalent organic frameworks (COFs) are two- or three-dimensional (2D or 3D) polymer networks with designed topology and chemical functionality, permanent porosity, and high surface areas. These features are potentially useful for a broad range of applications, including catalysis, optoelectronics, and energy storage devices. But current COF syntheses offer poor control over the material's morphology and final form, generally providing insoluble and unprocess-able microcrystalline powder aggregates. COF polymerizations are often performed under conditions in which the monomers are only partially soluble in the reaction solvent, and this heterogeneity has hindered understanding of their polymerization or crystallization processes. Here we report homogeneous polymerization conditions for boronate ester-linked, 2D COFs that inhibit crystallite precipitation, resulting in stable colloidal suspensions of 2D COF nanoparticles. The hexagonal, layered structures of the colloids are confirmed by small-angle and wide-angle X-ray scattering, and kinetic characterization provides insight into the growth process. The colloid size is modulated by solvent conditions, and the technique is demonstrated for four 2D boronate ester-linked COFs. The diameter of individual COF nanoparticles in solution is monitored and quantified during COF growth and stabilization at elevated temperature using in situ variable-temperature liquid cell transmission electron microscopy imaging, a new characterization technique that complements conventional bulk scattering techniques. Solution casting of the colloids yields a free-standing transparent COF film with retained crystallinity and porosity, as well as preferential crystallite orientation. Collectively this structural control provides new opportunities for understanding COF formation and designing morphologies for device applications.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据