Micro-Cavity Plate Shearing for Layered Material Exfoliation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid-phase shearing devices are limited by rotational speed and shear gap, failing to achieve effective interlaminar exfoliation of layered materials for large-scale production of quasi-two-dimensional materials.
Innovation Solution
A micro-cavity liquid-phase shearing device with a movable and fixed plate system, driven gear system, and external circulation system, utilizing high-speed rotation and adjustable micro-gaps to ensure near-laminar fluid motion and precise shearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high rotational speed (10000 rpm) and micro-gap (40 μm) are used to improve shear force for effective interlaminar exfoliation, then manufacturing precision and productivity are improved, but device complexity increases due to the need for precision differential screw devices and capacitance micro-ranging devices to control the micro-gap
Solution Approach 1:
The patent replaces complex mechanical micro-gap control mechanisms with a liquid-phase shearing system that uses fluid dynamics and pressure control to achieve and maintain the required micro-gap (40 μm) between plates. The liquid medium itself acts as a spacer and lubricant, eliminating the need for precision mechanical adjustment devices while achieving the same gap control effect.
Solution Approach 2:
The patent changes the control parameter from mechanical gap adjustment to liquid pressure and flow rate control. By adjusting the liquid phase parameters (pressure, flow rate, viscosity), the system achieves stable micro-gap conditions and high shear force without complex mechanical structures. The liquid pressure directly controls the gap between plates, providing simple yet precise control.
2Productivity
If high rotational speed is used to increase velocity gradient and shear force, then productivity and manufacturing precision are improved, but the structural stability and reliability worsen due to centrifugal forces and vibration
Solution Approach 1:
The patent uses liquid-phase hydraulics to transmit power and control the shearing process. The liquid medium provides damping and cushioning effects that reduce vibration and stabilize the system at high rotational speeds. The liquid pressure distribution automatically balances centrifugal forces, allowing stable operation at 10000 rpm without compromising structural reliability.
Solution Approach 2:
The patent employs a composite structure where solid plates are combined with liquid medium to form a unified shearing system. The liquid-solid interaction provides both the necessary shear force for exfoliation and the damping effect for vibration reduction. This composite approach allows the system to operate at high speeds while maintaining stability through the viscoelastic properties of the liquid medium.
3Ease of manufacture
If sand mill with eccentric disc and grinding media is used for material dispersion, then ease of manufacture is improved, but the shear effect and refinement capability worsen due to limited rotational speed (less than 3000 rpm)
Solution Approach 1:
The patent replaces the traditional sand mill mechanical grinding system with a liquid-phase shearing system. Instead of using solid grinding media and eccentric discs, the system uses liquid pressure and high-speed plate rotation to generate shear forces. This substitution achieves much finer particle refinement (nanometer scale) while maintaining ease of manufacture through simpler plate and drive mechanisms.
4Manufacturing precision
If colloid mill with helical tooth structure is used to increase velocity gradient, then manufacturing precision is improved, but the rotational speed is limited (not more than 4000 rpm) due to dynamic balance constraints
Solution Approach 1:
The patent divides the shearing action into multiple zones within the liquid phase, creating progressive refinement stages. The liquid medium distributes shear forces uniformly across multiple regions, allowing the system to operate at high speeds without the dynamic balance problems that limit single-point shear mechanisms like helical teeth. This segmented approach enables speeds exceeding 10000 rpm while maintaining refinement quality.
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
Enables high-efficiency shearing of layered materials into quasi-two-dimensional materials with controlled temperature and improved shear efficiency, achieving graphene-like morphologies with high yield.
Implementation Method 1
the shear force in the liquid phase is related to the velocity gradient, which is expressed by a formula of τ=η(dv/dy), wherein τ represents the shear force, η represents viscosity coefficient of multi-phase fluid, dv/dy is velocity gradient of solid-phase material relative surfaces
Implementation Method 2
According to the boundary layer theory, the movement of multi-phase fluid comes from the rotation of the mixing shaft of the sand mill or the actuator of the glue mill. The higher the rotational speed, the more likely it is to produce a large velocity gradient.
Data Source
AI summary
A micro-cavity liquid-phase shearing device for preparing quasi-two-dimensional materials includes a movable plate system, a fixed plate system, a feed liquid external circulation system, a driven gear system and a charging barrel. The movable plate system includes a movable plate unit and a driving gear. The fixed plate system includes a fixed plate unit and a support. A tank of the movable plate unit has a primary shear cavity, an annular micro-gap between a movable plate of the movable plate unit and a fixed plate of the fixed plate unit is defined as a secondary shear micro-cavity. The feed liquid, which flows outside the feed pipe through the liquid discharge port thereof, is primarily sheared in the primary shear cavity by the movable plate system, and then is secondarily sheared in the secondary shear micro-cavity by the movable plate and the fixed plate, and then returns to the charging barrel.