Graphite-like Crystallite Carbon Nanomaterial Preparation
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Solution Overview
Problem
Current methods for preparing carbon nanomaterials based on graphite-like crystallites face challenges in controlling particle size and morphology, leading to high energy consumption and inefficient dissociation of graphite-like microcrystalline charcoal.
Innovation Solution
A method involving the use of a mixed acid oxidant solution under microwave heating to oxidize graphite-like microcrystalline charcoal, regulating pH, and ultrafiltration to achieve dissociation of graphite-like crystallites, resulting in a graphite-like crystallite-based carbon nanomaterial with controlled particle size and surface functional groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If mechanical grinding is used to reduce graphite-like microcrystalline charcoal size, then particle size is reduced, but energy consumption increases significantly and particle size/morphology cannot be controlled
Solution Approach 1:
The patent replaces mechanical grinding with a chemical oxidation system using mixed acid (nitric acid and perchloric acid) under microwave heating. This chemical approach selectively etches amorphous carbon while preserving graphite-like crystallites, achieving size reduction without the high energy consumption of mechanical methods. The oxidation reaction proceeds via: C + 2HNO3 → CO2 + 2NO2 + H2O and C + 2HClO4 → CO2 + 2ClO2 + H2O
Solution Approach 2:
The patent controls particle size and morphology by adjusting oxidation parameters including acid concentration ratios (nitric acid:perchloric acid), microwave power (300-800W), heating temperature (60-100°C), and reaction time (1-10 hours). These parameter changes enable precise control over the dissociation of graphite-like crystallites while maintaining their structural integrity and achieving uniform 5-50 nm particle sizes
2Ease of manufacture
If oxidants like concentrated nitric acid are used for etching activated charcoal surfaces, then carbon quantum dots can be prepared, but the graphite-like microcrystalline charcoal cannot be dissociated into structurally based carbon nanomaterials
Solution Approach 1:
The patent employs a composite oxidant system combining nitric acid and perchloric acid in specific ratios (1:1 to 1:3). This composite approach provides synergistic effects: nitric acid offers strong oxidation capability while perchloric acid enhances penetration into the charcoal structure. The combination enables complete dissociation of graphite-like microcrystalline charcoal into individual crystallites with preserved structural integrity, achieving 5-50 nm carbon nanomaterials that maintain the graphite-like layered structure
Solution Approach 2:
The patent uses microwave radiation as an intermediary energy source to activate the mixed acid oxidant system. The microwave heating uniformly distributes energy throughout the reaction mixture, enhancing the oxidation efficiency and enabling controlled dissociation of the charcoal structure. This intermediary approach allows precise control over the etching process, preventing over-oxidation while achieving complete separation of crystallites
3Quantity of substance
If long period etching under certain temperature is used with oxidants, then fluorescent carbon quantum dots can be prepared, but the process is time-consuming and energy-intensive
Solution Approach 1:
The patent utilizes periodic microwave heating cycles to accelerate the oxidation process. By applying intermittent microwave power (300-800W) rather than continuous heating, the system achieves more efficient energy transfer and prevents localized overheating. This periodic action reduces reaction time from traditional 10+ hours to 1-10 hours while maintaining high yield of carbon nanomaterials with 5-50 nm particle sizes
Solution Approach 2:
The patent employs strong oxidants (nitric acid and perchloric acid) under microwave heating to dramatically accelerate the oxidation of graphite-like microcrystalline charcoal. The combination of strong oxidizing power and microwave energy input increases the reaction rate by several orders of magnitude compared to conventional heating, achieving complete dissociation in 1-10 hours versus traditional multi-day processes, while maintaining high nanomaterial yield
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 effectively dissociates graphite-like microcrystalline charcoal into graphite-like crystallite-based carbon nanomaterials with improved yield and efficiency, achieving particle sizes of 5-10 nm and enhanced surface functionality, suitable for applications such as metal ion adsorption and carbon nanofilm preparation.
Implementation Method 1
oxidizing the mixture under the conditions of microwave heating to obtain an oxidizing feed solution
Implementation Method 2
mixing an oxidant solution with a graphite-like microcrystalline charcoal material, and oxidizing the mixture
Implementation Method 3
subjecting the prefiltration system obtained in step (2) to ultrafiltrations, to obtain a suspension and a filtrate
Data Source
AI summary
The present application provides a graphite-like crystallite-based carbon nanomaterial, and a preparation method and application thereof. The graphite-like crystallite-based carbon nanomaterial provided by the present invention is a carbon nanomaterial having graphite-like crystallites as structural units, and includes, based on 100 parts by mass of chemical composition, 50-60 parts of carbon, 30-50 parts of oxygen, and 1-3 parts of hydrogen, where the structural units of the graphite-like crystallite-based carbon nanomaterial are the graphite-like crystallites; the size of the graphite-like crystallite-based carbon nanomaterial is 5-10 nm; and the graphite-like crystallite-based carbon nanomaterial is a non-fluorescent carbon nanomaterial. The present invention also provides a preparation method of the graphite-like crystallite-based carbon nanomaterial, including: selectively oxidizing a graphite-like microcrystalline charcoal by using an oxidant solution, and etching away an amorphous charcoal bonded between graphite-like crystallites, to achieve the purpose of dissociating the graphite-like microcrystalline charcoal, thereby obtaining a graphite-like crystallite-based carbon nanomaterial.