Insight into the crystallization of amorphous imine-linked polymer networks to 2D covalent organic frameworks

2016 ◽  
Vol 52 (18) ◽  
pp. 3690-3693 ◽  
Author(s):  
Brian J. Smith ◽  
Anna C. Overholts ◽  
Nicky Hwang ◽  
William R. Dichtel
Keyword(s):  
Growth Mechanism ◽  
Amorphous Polymer ◽  
Polymer Networks ◽  
Covalent Organic Frameworks ◽  
Rapid Formation ◽  
Insight Into

The growth mechanism of 2D imine-linked COF involves the rapid formation of an amorphous polymer, which subsequently crystallizes.

scholarly journals Conversion of amorphous polymer networks to covalent organic frameworks under ionothermal conditions: a facile synthesis route for covalent triazine frameworks

2015 ◽  
Vol 3 (48) ◽  
pp. 24422-24427 ◽  
Author(s):  
Sophie Kuecken ◽  
Johannes Schmidt ◽  
Linjie Zhi ◽  
Arne Thomas
Keyword(s):  
Amorphous Polymer ◽  
Polymer Networks ◽  
Porous Polymer ◽  
Covalent Organic Frameworks ◽  
Facile Synthesis ◽  
Synthesis Route

Covalent triazine frameworks (CTFs) are prepared from amorphous, non-porous polymer networks using a facile and scalable procedure.

Design and Synthesis of Two-Dimensional Covalent Organic Frameworks with Four-Arm Cores: Prediction of Remarkable Ambipolar Charge-Transport Properties

2019 ◽  
Author(s):  
Simil Thomas ◽  
Hong Li ◽  
Raghunath R. Dasari ◽  
Austin Evans ◽  
William Dichtel ◽  
...  
Keyword(s):  
Charge Transport ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Polymer Networks ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
Zinc Porphyrin ◽  
Design And Synthesis ◽  
Predicted Values

<p>We have considered three two-dimensional (2D) π-conjugated polymer networks (i.e., covalent organic frameworks, COFs) materials based on pyrene, porphyrin, and zinc-porphyrin cores connected <i>via</i> diacetylenic linkers. Their electronic structures, investigated at the density functional theory global-hybrid level, are indicative of valence and conduction bands that have large widths, ranging between 1 and 2 eV. Using a molecular approach to derive the electronic couplings between adjacent core units and the electron-vibration couplings, the three π-conjugated 2D COFs are predicted to have ambipolar charge-transport characteristics with electron and hole mobilities in the range of 65-95 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>. Such predicted values rank these 2D COFs among the highest-mobility organic semiconductors. In addition, we have synthesized the zinc-porphyrin based 2D COF and carried out structural characterization via powder X-ray diffraction and surface area analysis, which demonstrates the feasability of these electroactive networks.</p>

Insight into CH4 formation and chain growth mechanism of Fischer−Tropsch synthesis on θ-Fe3C(0 3 1)

2017 ◽  
Vol 682 ◽  
pp. 115-121 ◽  
Author(s):  
Yifan Wang ◽  
Ying Li ◽  
Shouying Huang ◽  
Jian Wang ◽  
Hongyu Wang ◽  
...  
Keyword(s):  
Growth Mechanism ◽  
Tropsch Synthesis ◽  
Chain Growth ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Insight Into

Insight into volatile iodine uptake properties of covalent organic frameworks with different conjugated structures

2019 ◽  
Vol 279 ◽  
pp. 120979 ◽  
Author(s):  
Yuling Yang ◽  
Xiaohong Xiong ◽  
Yaling Fan ◽  
Zhenqin Lai ◽  
Zhenzhen Xu ◽  
...  
Keyword(s):  
Iodine Uptake ◽  
Covalent Organic Frameworks ◽  
Insight Into

Real-time insight into nanostructure evolution during the rapid formation of ultra-thin gold layers on polymers

2021 ◽  
Author(s):  
Matthias Schwartzkopf ◽  
Sven-Jannik Wöhnert ◽  
Vivian Waclawek ◽  
Niko Carstens ◽  
André Rothkirch ◽  
...  
Keyword(s):  
Polymer Matrix ◽  
Hybrid Material ◽  
Time Resolved ◽  
X Ray ◽  
Polymer Hybrid ◽  
X Ray Scattering ◽  
Rapid Formation ◽  
Metal Polymer ◽  
Insight Into

At the nascence of a metal–polymer hybrid material primarily vertical Au dimers and free adatoms diffuse on and into the polymer matrix revealed in situ by sub-millisecond time-resolved surface-sensitive X-ray scattering (GISAXS).

Formation of Lithium Titanate Hydrate Nanosheets: Insight into a Two-Dimension Growth Mechanism by in Situ Raman

2016 ◽  
Vol 16 (7) ◽  
pp. 3898-3904 ◽  
Author(s):  
Hsien-Chieh Chiu ◽  
Xia Lu ◽  
Samir Elouatik ◽  
Karim Zaghib ◽  
George P. Demopoulos
Keyword(s):  
Growth Mechanism ◽  
Lithium Titanate ◽  
Two Dimension ◽  
In Situ Raman ◽  
Insight Into

Ability to Control the Glass Transition Temperature of Amorphous Shape-Memory Polyesterurethane Networks by Varying Prepolymers in Molecular Mass as well as in Type and Content of Incorporated Comonomers

2009 ◽  
Vol 1190 ◽  
Author(s):  
Joerg Zotzmann ◽  
Steffen Kelch ◽  
Armin Alteheld ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Glass Transition ◽  
Minimally Invasive Surgery ◽  
Shape Memory ◽  
Molecular Mass ◽  
Amorphous Polymer ◽  
Polymer Networks ◽  
Precise Control ◽  
Low Weight ◽  
Switching Temperature ◽  
Selection Of

AbstractThe need of intelligent implant materials for applications in the area of minimally invasive surgery leads to tremendous attention for polymers which combine degradability and shape-memory capability. Application of heat, and thereby exceeding a certain switching temperature Tsw, causes the device to changes its shape. The precise control of Tsw is particularly challenging. It was investigated in how far Tg, that can be used as Tsw, of amorphous polymer networks from star-shaped polyester macrotetrols crosslinked with a low-weight linker can be controlled systematically by incorporation of different comonomers into poly(rac-lactide) prepolymers. The molecular mass of the prepolymers as well as type and content of the comonomers was varied. The Tg could be adjusted by selection of comonomer type and ratio without affecting the advantageous elastic properties of the polymer networks.

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