Nanoparticle Separation Using Porous Electrodes and Ultrasonic Redistribution

The patent replaces the mechanical precipitation and redistribution process with an electrophoretic separation system. The electrophoresis apparatus uses electric fields to separate nanoparticles from impurities, eliminating the need for iterative precipitation and redistribution that consumes large amounts of organic solvent. This substitution of mechanical/chemical methods with an electrical field-based method resolves both the solvent waste issue and the consistency problem by providing a controlled, repeatable separation process.

The patent changes the separation parameter from chemical precipitation (requiring solvent addition and iterative processing) to electrophoretic mobility (controlled by electric field strength, voltage, and particle charge). By changing the fundamental separation parameter, the process achieves consistent results independent of worker variability while eliminating the need for massive solvent usage associated with traditional precipitation methods.

The patent incorporates porous electrodes in the electrophoresis apparatus. The porous structure increases the surface area of the electrodes, enhancing the electrophoretic separation efficiency. The porous material allows for better interaction between the electric field and nanoparticles, improving both the efficiency and completeness of separation. The high surface area-to-volume ratio of porous electrodes enables more effective particle attachment and detachment cycles, achieving wholesale separation of nanoparticles from impurities.

The patent employs periodic application of voltage to the electrophoretic system, with cycles of attachment and detachment. This periodic action allows nanoparticles to be repeatedly attached to the porous electrodes and then detached into the target solvent, ensuring complete separation from impurities. The cyclic process maximizes separation efficiency by multiple passes through the electrophoretic field, addressing the incompleteness issue of single-pass methods.

The patent uses porous electrodes that provide high specific surface area without requiring miniaturization of the electrode cross-section. The porous structure internally increases the active surface area while maintaining robust external dimensions, avoiding the manufacturing difficulties and mechanical fragility associated with down-sized electrodes. This approach achieves high separation efficiency through increased surface area while preserving mechanical durability and ease of manufacturing.

The patent transitions from increasing surface area by reducing cross-sectional dimensions (one-dimensional approach) to increasing surface area through porous internal structure (three-dimensional approach). This dimensional transformation allows the electrode to maintain adequate mechanical strength and ease of manufacturing while achieving high specific surface area through the porous network, resolving the contradiction between efficiency and durability.

The patent uses porous electrodes that provide high surface area within a compact volume. This allows the electrophoresis apparatus to process large amounts of nanoparticles efficiently without requiring long channel lengths, enabling equipment downsizing while maintaining high processing capacity. The porous structure concentrates the separation action in a compact space, eliminating the need for extended processing paths.

The patent employs periodic attachment and detachment cycles that amplify the processing capacity within a compact apparatus. By repeatedly cycling nanoparticles through the electrophoretic field in short intervals, the system achieves high throughput without requiring long channel lengths. This temporal multiplication of processing action allows compact equipment design while maintaining ability to process massive amounts of nanoparticles.