Graphene Sheet Production via Dry Rubbing Delamination
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Solution Overview
Problem
Current methods for obtaining sheets of graphene, boron nitride, molybdenum disulfide, or tungsten disulfide often require solvents and complex processes, making them costly and inefficient.
Innovation Solution
A method involving rubbing powder of these materials between two substrates under ambient conditions to form sheets or coatings without using solvents, reducing production costs and time, and enabling the creation of flexible electronic devices and transparent electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solvent-based delamination methods are used to obtain graphene sheets, then graphene layers can be separated, but the process becomes costly and complex requiring additional equipment and chemical reagents
Solution Approach 1:
The invention extracts and eliminates the solvent step from the traditional delamination process. By directly rubbing graphite powder between two substrates, the method obtains graphene sheets without requiring solvent immersion or ultrasonic treatment, thus simplifying the process while maintaining effective layer separation
Solution Approach 2:
The invention replaces the chemical-mechanical system (solvent + ultrasonic vibration) with a purely mechanical system (direct rubbing). The mechanical friction and pressure applied during rubbing between substrates are sufficient to delaminate graphene layers without needing chemical solvents or complex ultrasonic equipment
2Reliability
If mechanical ablation of pencil leads is used to obtain graphene sheets, then layers can be separated, but the sheets obtained have small size (mean size of 2 μm) and require solvent treatment
Solution Approach 1:
The invention performs preliminary action by directly placing graphite powder between substrates before any separation process. The rubbing action itself simultaneously achieves both delamination and deposition of graphene sheets onto substrates, eliminating subsequent solvent treatment and sonication steps required in traditional methods
Solution Approach 2:
The invention merges the delamination and deposition steps into a single rubbing operation. While traditional methods separate these steps (first delaminate in solvent, then deposit), this method combines both functions into one mechanical rubbing process between substrates, reducing production time and eliminating solvent usage
3Reliability
If graphite powder is sonicated with acacia gum to obtain few-layer graphene sheets, then sheets can be obtained, but the process requires solvents and additional materials
Solution Approach 1:
The invention extracts and removes the acacia gum binder and solvent components from the sonication process. By using direct mechanical rubbing of graphite powder between substrates, the method achieves few-layer graphene formation without requiring any organic binders or solvent media, simplifying the manufacturing process
Solution Approach 2:
The invention enables the graphite powder to serve itself as both the source material and the lubricant during rubbing. The natural layered structure of graphite allows easy delamination through friction alone, without needing external lubricants or binders like acacia gum, making the process self-sufficient and simpler
4Ease of manufacture
If multilayer graphenes are laminated directly on surfaces to obtain coating, then coating can be applied, but the multilayer graphenes consist of aggregation of many layers with thickness ranging from 0.34 to 10 nm
Solution Approach 1:
The invention applies local quality by controlling the rubbing pressure and duration to achieve different layer thicknesses in different areas or on different substrates. By adjusting local rubbing parameters, one can obtain monolayer, few-layer, or multilayer graphene coatings precisely where needed, rather than uniform thick aggregates
Solution Approach 2:
The invention uses parameter changes (rubbing pressure, number of rubbing cycles, substrate material) to precisely control the number of graphene layers deposited. By varying these parameters, the method achieves precise thickness control from single layers to few layers, overcoming the uncontrolled aggregation (0.34-10 nm) in traditional lamination methods
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 effectively produces sheets with monoatomic or monomolecular thickness, reducing production costs and time, and allows for the development of applications such as flexible electronic devices and transparent electrodes without the need for solvents or complex equipment.
Implementation Method 1
A method involving rubbing powder of these materials between two substrates under ambient conditions to form sheets or coatings
Data Source
AI summary
The invention relates to a method for obtaining sheets of graphene, hexagonal boron nitride, molybdenum disulfide, tungsten disulfide or mixtures thereof from the powder of said materials. Said sheets consist of a set of strips, wherein said strips consist of between one and five layers. Said layers are layers of graphene, hexagonal boron nitride, molybdenum disulfide or tungsten disulfide having a monoatomic or monomolecular thickness. The invention also relates to a method for coating a surface with sheets of graphene, hexagonal boron nitride, molybdenum disulfide, tungsten disulfide or sheets of mixtures thereof.