Acoustic processing uses audible sound waves from 20 Hz to 20 KHZ, and ultrasonic processing uses ultrasonic waves with frequencies higher than 20 KHZ, both of which are based on the acoustic cavitation effect. The sound wave propagates in the liquid medium, forming a high and low pressure region, forming bubbles in the low pressure region, collapsing bubbles in the high pressure region, generating local high temperature, high pressure, shock wave and high-speed microjet, achieving the destruction of cell structure, the dispersion of aggregates and the improvement of mass transfer efficiency.
In terms of chemical synthesis, ultrasonic treatment accelerates the chemical reaction, promotes the uniform nucleation and growth of nanoparticles, improves the yield, enhances the interaction between metal ions and organic ligands, syntheses high-quality metal-organic skeleton compound materials, and also breaks solid reactants to improve their solubility. In the extraction process, ultrasonic assisted extraction technology can achieve efficient extraction of bioactive substances such as polyphenols, flavonoids and essential oils by destroying plant cell walls and enhancing mass transfer. The extraction rate of this technology is higher, the time is shorter, and the solvent consumption is less.
In the process of cell lysis, ultrasonic shock wave can destroy the cell membrane of bacteria, yeast and mammalian cells, release intracellular substances, and serve the work of protein purification, DNA extraction and enzyme separation. With the help of ultrasound and contrast agents or microbubbles, the acoustic hole effect forms temporary micropores on the cell membrane to achieve the delivery of drugs, genes and nanoparticles to the cell, which has great potential in gene therapy and targeted drug delivery.
In the preparation of nanomaterials, acoustic and ultrasonic treatment can control the size and shape of the nanoparticles, prevent the agglomeration of gold nanoparticles, and also peel graphite to prepare graphene nanosheets. In the process of composite preparation, the sound treatment can break the aggregate of carbon nanotubes and other fillers, so that they are uniformly dispersed in the polymer matrix, and improve the mechanical properties and electrical conductivity of the composite.
In the future, acoustic treatment and ultrasonic treatment technology is expected to be used in the field of environmental science for sewage treatment and pollutant degradation, in the food industry to help food processing and preservation, through the combination of artificial intelligence and machine learning technology, but also to achieve accurate control of ultrasonic treatment process, expand the scope of application.
