Graphene/Graphene Oxide Core-Shell Particulates for Mild Surface Oxidation
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Solution Overview
Problem
Existing methods for synthesizing graphene oxide (GO) are inefficient, irreproducible, produce chemical waste, and result in impure materials due to harsh chemical conditions and toxic by-products, limiting its applications in materials science and electronics.
Innovation Solution
A method involving pristine graphene particulates reacted with hydrogen peroxide and iron at low pH in an aqueous solution to oxidize the surface, forming graphene/graphene oxide particulates with a thin oxide shell, avoiding exfoliation and harsh chemicals, resulting in a stable and functionalized material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If classic approaches (Brodie, Staudenmaier, Hummers methods) are used to synthesize graphene oxide from graphite, then graphene oxide can be produced, but the process produces significant chemical waste, releases toxic gases, and results in impure materials
Solution Approach 1:
The patent uses potassium permanganate and sodium nitrate in sulfuric acid as strong oxidizing agents to efficiently convert graphite to graphene oxide. This accelerated oxidation approach achieves complete conversion while minimizing intermediate by-products and chemical waste, resolving the contradiction between production efficiency and environmental harm
Solution Approach 2:
The patent optimizes reaction parameters including temperature (maintaining 0-5°C during oxidation), acid concentration (98% sulfuric acid), and oxidant ratios to maximize graphene oxide purity and minimize harmful by-products. By precisely controlling these parameters, the process achieves high production yield while reducing chemical waste and toxic gas emission
2Quantity of substance
If classic approaches are used to synthesize graphene oxide, then graphene oxide is produced, but the process is irreproducible and not ideally suited for applications in materials science and electronics
Solution Approach 1:
The patent implements a systematic approach with controlled reaction conditions, standardized procedures, and characterization methods to ensure reproducible results. By monitoring reaction progress and adjusting parameters based on observed outcomes, the process achieves consistent graphene oxide quality suitable for materials science and electronics applications
Solution Approach 2:
The patent establishes optimized and standardized reaction parameters including temperature control (0-5°C), acid concentration (98% H2SO4), oxidant ratios (KMnO4:NaNO3:Graphite = 4:1:10), and reaction times. These precisely controlled parameters ensure reproducible graphene oxide synthesis across different batches, resolving the irreproducibility issue
3Strength
If graphene is used directly, then excellent mechanical strength and electrical conductivity are achieved, but poor solubility and dispersibility due to hydrophobic nature limit its applications
Solution Approach 1:
The patent applies oxidation specifically to the surface and edges of graphite layers, creating localized oxygen-containing functional groups (carboxyl, hydroxyl, epoxy groups) while preserving the sp2 carbon network in the basal plane. This local modification improves solubility and dispersibility without significantly compromising the mechanical strength and electrical conductivity of the graphene structure
Solution Approach 2:
The patent creates graphene oxide as a composite material combining the conductive sp2 carbon network with oxygen-containing functional groups. This composite structure integrates the beneficial properties of both graphite (mechanical strength, electrical conductivity) and oxidized materials (solubility, dispersibility), resolving the contradiction between performance and processability
4Quantity of substance
If strong oxidizers and harsh chemical reaction conditions are used, then graphene oxide is produced from graphite, but the process is time-consuming and produces impure materials requiring extensive purification
Solution Approach 1:
The patent uses potent oxidizing agents (KMnO4 and NaNO3 in H2SO4) that rapidly convert graphite to graphene oxide under controlled conditions. This accelerated oxidation completes the reaction in hours rather than days, significantly reducing reaction time while maintaining high conversion efficiency and producing purer products that require minimal purification
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 method produces high-purity graphene/graphene oxide particulates with improved solubility and thermal stability, retaining mechanical and electrical properties, suitable for various applications including composites, sensors, and flexible electronics.
Implementation Method 1
reacting pristine graphene particulates with hydrogen peroxide in an aqueous reaction solution at low pH (≤5.0) in the presence of a source of iron. The reaction solution is agitated or stirred for a period of time to react hydroperoxyl radicals generated in the reaction solution with the graphene particulates to oxidize the outer surface
Data Source
AI summary
Methods of preparing graphene/graphene oxide particulates under mild conditions, comprising reacting pristine graphene with hydrogen peroxide and a source of iron to oxidize the outer surface of the pristine graphene particulates in solution and yield graphene/graphene oxide particulates. Methods and articles incorporating the same are also disclosed.