Microporous Carbon from Hyper-Cross-Linked Polymer
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Solution Overview
Problem
Current methods for producing microporous carbons from 3D aromatic polymers often result in a decrease in surface area and pore volume, limiting their gas adsorption capacity, especially for gases like hydrogen, methane, and carbon dioxide at low pressures.
Innovation Solution
A process involving the synthesis of hyper-cross-linked polymers through a Friedel-Crafts reaction using a tetrahedral aromatic monomer and formaldehyde dimethyl acetal, followed by activation with a basic agent at controlled temperatures, which increases the surface area and micropore volume, particularly creating ultramicropores and supermicropores suitable for gas adsorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional carbonization and activation methods are used on 3D aromatic polymers, then microporous carbons are obtained, but surface area and pore volume decrease
Solution Approach 1:
The patent applies preliminary action by performing hyper-crosslinking of the aromatic polymer before carbonization. This pre-treatment creates a more stable and porous precursor structure that better withstands the carbonization process, preventing collapse of the porous network and preserving both surface area and pore volume in the final carbon material.
Solution Approach 2:
The patent employs parameter changes by optimizing multiple process parameters including hyper-crosslinking conditions (catalyst type, temperature, time), carbonization temperature (500-900°C), and activation conditions. These parameter optimizations enable simultaneous preservation of surface area and pore volume while achieving high gas adsorption capacity.
2Quantity of substance
If activation temperature is increased to improve porosity, then micropore volume increases, but surface area decreases
Solution Approach 1:
The hyper-crosslinking treatment before carbonization creates a more robust precursor structure that maintains porosity during high-temperature activation. This preliminary structural reinforcement allows the material to withstand higher activation temperatures without excessive surface area loss, enabling better micropore development while preserving surface area.
Solution Approach 2:
The patent creates a composite structure through hyper-crosslinked aromatic polymer networks that combine rigidity with porosity. This composite architecture provides structural stability during activation, allowing simultaneous increase in micropore volume and preservation of surface area that would not be achievable with conventional polymers alone.
3Quantity of substance
If hyper-cross-linked polymers are used as precursors, then surface area and micropore volume increase, but process complexity increases
Solution Approach 1:
The patent utilizes porous hyper-crosslinked aromatic polymers as precursors, which inherently possess well-defined porous structures. This approach simplifies the overall process by eliminating the need for complex post-synthesis pore formation steps, as the porosity is already established in the precursor material before carbonization.
Solution Approach 2:
The patent optimizes hyper-crosslinking parameters (catalyst selection, reaction temperature, time) to achieve maximum porosity with minimal process steps. By carefully controlling these parameters, the method attains high micropore volume without requiring additional complex processing stages, thereby reducing overall process complexity.
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
The resulting microporous carbons exhibit enhanced surface area and pore volume, significantly improving their gas adsorption capabilities for hydrogen, methane, and carbon dioxide, especially at low pressures, while being economically and industrially scalable.
Implementation Method 1
physical activation, which implies pyrolysis of the precursor at high temperatures in the presence of gases such as carbon dioxide, steam, or others
Implementation Method 2
The pores so obtained are capable of adsorbing gases, particularly hydrogen, methane and carbon dioxide
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A~3B
AI summary
A process is described for the preparation of a microporous carbon from a hyper-cross- linked polymer of formula (II), in which A is selected from a C atom, a Si atom, a Ge atom, a Sn atom, an adamantane group, an ethane group and an ethene group, in which each of B, C, D and E are ring structures selected from radicals of the compounds benzene, naphthalene, anthracene, phenanthrene, pyrene, optionally having one or more substituents selected from nitro, amine, hydroxyl, sulfonyl, halogen, phenyl, alkyl, haloalkyl, hydroxyalkyl, aminoalkyl, aryl, alkenyl and alkynyl groups, and in which n is an integer between 200 and 6000.