Solvent-Free COF Synthesis for High Crystallinity at Scale
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Solution Overview
Problem
Current methods for synthesizing covalent organic framework (COF) materials are time-consuming, environmentally unfriendly, and limited to small-scale production due to the use of solvothermal reactions and toxic solvents.
Innovation Solution
A novel, solvent-free, and green solid-phase synthesis method is developed for COF materials, using a catalyst to facilitate a condensation reaction between organic monomers under non-solvent conditions, allowing for large-scale production and easy functionalization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If solvothermal preparation method is used, then COF materials can be synthesized with good crystallinity, but the process is time-consuming and environmentally unfriendly due to special organic solvents and catalysts
Solution Approach 1:
The patent uses mechanical energy (grinding) as an intermediary to activate the reaction between monomers, replacing the traditional solvothermal method that requires organic solvents and catalysts. The high-energy grinding process directly activates the monomers to form COF structures with good crystallinity without needing lengthy solvothermal reactions.
Solution Approach 2:
The patent replaces the thermal-mechanical solvothermal system with a purely mechanical grinding system. The mechanical energy from the grinder directly drives the condensation reaction, eliminating the need for prolonged heating in solvents and significantly reducing synthesis time while maintaining crystallinity.
2Manufacturing precision
If solvothermal preparation method is used, then COF materials can be synthesized, but it requires special organic solvents and catalysts making the process environmentally unfriendly
Solution Approach 1:
The patent extracts and removes the harmful organic solvents and catalysts from the synthesis system. By using mechanical grinding alone to activate the monomers, the method eliminates the need for special organic solvents and catalysts, making the process environmentally friendly while still producing COFs with good crystallinity.
Solution Approach 2:
The patent converts the mechanical grinding process, which could be seen as a simple or crude method, into a beneficial alternative that eliminates harmful solvents and catalysts. The mechanical energy directly activates the monomers in a clean, environmentally friendly manner while achieving the desired crystalline structures.
3Manufacturing precision
If solvothermal reaction is performed in closed glass tube or closed vessel under high-temperature and high-pressure conditions, then COF materials can be synthesized, but it severely hinders large-scale production
Solution Approach 1:
The patent replaces the high-temperature and high-pressure thermal-mechanical system with a mechanical grinding system operating at ambient conditions. This substitution eliminates the need for closed vessels and extreme conditions, enabling easy scaling to large production while maintaining crystallinity.
Solution Approach 2:
The patent changes the reaction parameters from high-temperature and high-pressure conditions to ambient temperature and pressure, using mechanical grinding energy instead. This parameter change makes the process suitable for large-scale production while still achieving good crystallinity in the COF materials.
4Ease of manufacture
If environmental-friendly methods such as ionic liquid synthesis, microwave-assisted synthesis and mechanical-chemical synthesis are used, then synthesis can be simplified, but these methods are confined and can only realize synthesis of individual COFs without wide universality
Solution Approach 1:
The patent creates a universal mechanical grinding method that can synthesize multiple types of COFs with different linkages (imine, boroxine, triazine, hydrazone, etc.). The same grinding apparatus and general procedure work for various monomer combinations, making the method highly versatile while maintaining simplicity.
Solution Approach 2:
The patent segments the synthesis approach into a simple mechanical grinding step followed by standard characterization and analysis. This segmentation makes the core synthesis method universally applicable to different COF types while keeping the process simple and easy to implement across various laboratories.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables the production of high-crystallinity COF materials with uniform pore sizes and high specific surface areas, suitable for various applications such as gas adsorption separation and catalysis, while reducing environmental impact and production costs.
Implementation Method 1
using a catalyst to facilitate a condensation reaction between organic monomers under non-solvent conditions
Implementation Method 2
a condensation reaction under a solvent-free condition aided by a catalyst
Data Source
AI summary
The present invention relates to a novel method for synthesizing olefin covalent organic framework foams, and polyimide, imine, hydrazone or Ketoenamine covalent organic frameworks (COFs). The method is a green synthetic strategy, including: under non-solvent condition, performing condensation reaction of a methyl-containing monomer and an aldehyde monomer with participation of acid anhydride or carboxylic acid compound to prepare olefin COFs; performing condensation reaction of a multihead acid anhydride or a multihead carboxylic acid monomer and an amino monomer with participation of acid anhydride or carboxylic acid compound to prepare amide COFs; and performing condensation reaction of the aldehyde monomer and the amino monomer with participation of acid anhydride, imidazole or carboxylic acid compound to prepare imine COFs. The COFs obtained by using the method have large specific surface area, regular and adjustable porous structure, and high crystallinity. The method effectively avoids use of organic solvent and risk of high pressure in the reaction process, and is suitable for large-scale preparation of COF materials.