Functionalized Graphene via Supercritical Fluid Deoxygenation
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Solution Overview
Problem
Current methods for preparing graphene suffer from high-risk, inefficient, and non-uniform introduction of functional groups, leading to impurities and reduced conductivity, making it difficult to achieve high-quality functionalized graphene with excellent dispersibility and conductivity.
Innovation Solution
A method involving a mixture of graphite oxide, water, and thiourea is pre-heated and reacted under subcritical or supercritical conditions to form functionalized graphene, introducing sulfur atoms into the basal plane and edges, allowing for simultaneous deoxygenation and functionalization, resulting in high-quality graphene with improved dispersibility and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If chemical oxidation and reduction method is used to prepare graphene, then mass production and economical feasibility are achieved, but the prepared graphene includes impurities and has reduced electrical conductivity
Solution Approach 1:
The patent changes the chemical parameters of the reduction process by using hydrazine monohydrate under controlled temperature and time conditions, optimizing the balance between removing oxygen groups (to improve conductivity) and avoiding excessive reduction that would create impurities. This parameter optimization enables mass production while maintaining high electrical conductivity.
2Manufacturing precision
If reducing agents such as hydrazine are used for deoxygenation reaction, then oxygen groups are removed, but the reducing agents are dangerous due to high corrosiveness, explosiveness, and human toxicity
Solution Approach 1:
The patent uses hydrazine monohydrate as an intermediary reducing agent that can be precisely controlled and neutralized. The controlled addition and subsequent washing steps act as intermediary processes that enable effective deoxygenation while managing the harmful properties of the reducing agent through systematic treatment and removal.
Solution Approach 2:
The patent optimizes the concentration and reaction time parameters of hydrazine monohydrate to achieve maximum deoxygenation efficiency with minimum exposure and risk. By controlling these parameters, the harmful effects are minimized while maintaining the beneficial reducing action.
3Ease of operation
If separate reactions in various stages using general batch typed reactors are processed to introduce functional groups, then functional groups are introduced to improve dispersibility, but it is difficult for the functional group to be uniformly distributed and the amount to be introduced is difficult to adjust
Solution Approach 1:
The patent combines multiple reaction stages into a single integrated continuous flow reactor system. The functionalization reaction is performed in one continuous process rather than separate batch stages, ensuring uniform distribution of functional groups throughout the graphene material and enabling precise control of the amount introduced through flow rate and residence time parameters.
Solution Approach 2:
The patent employs a dynamic continuous flow system that allows real-time adjustment of reaction parameters (flow rate, temperature, reagent concentration) to optimize functional group distribution and amount. This dynamic control enables precise tuning of the functionalization process that cannot be achieved with static batch reactors.
4Stability of the object's composition
If materials such as metal are intercalated between layered structure for preventing restacking phenomenon, then restacking is prevented, but size and distribution of particles to be intercalated are not uniform, making it difficult to prepare high quality graphene
Solution Approach 1:
The patent uses small molecule compounds (such as organic molecules or ions) instead of large metal particles for intercalation. These small molecules can uniformly penetrate and distribute between graphene layers, preventing restacking while maintaining uniform size and distribution. The small molecules can also be easily removed or remain as uniform dopants without the aggregation problems of metal particles.
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 approach enables the production of functionalized graphene with high exfoliation properties and uniform functional group distribution, enhancing its electrical conductivity and dispersibility, while being economically and environmentally safer, suitable for various industrial applications.
Implementation Method 1
reacting the mixture under a subcritical condition of the solvent
Implementation Method 2
reacting the mixture under a subcritical condition or a supercritical condition
Data Source
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AI summary
There are provided a method and an apparatus for preparing a functionalized graphene, and a functionalized graphene, and more specifically, a method and an apparatus for preparing a functionalized graphene having excellent electrical and thermal conductivity properties, and a barrier property, using a fluid in a subcritical condition or a supercritical condition and a functional compound, and a functionalized graphene.