Natrual Packing Industrial Limited / 2022-07-05
=== Base Info ===
=== Description ===
Introduction:
Ultrasonic Sonochemistry is the cross-penetration of acoustics and physical chemistry, and it is also a branch of physical chemistry. Ultrasonic can accelerate conventional chemical reactions, accelerate the decomposition and synthesis of substances in organic solvents, and strengthen chemical units (ultrasonic cleaning, ultrasonic extraction, ultrasonic crystallization, ultrasonic emulsification, ultrasonic flocculation, ultrasonic adsorption and ultrasonic membrane separation, etc.). These applications are called sonochemistry. Sonochemical technology is an emerging, multidisciplinary and fringe science developed in the 20th century.
The cavitation effect of ultrasonic energy Irradiate the solution with a certain sound intensity. When the sound intensity increases to 0.5 ~ 0.7 W / cm *, if you put a hydrophone in the solution, you can hear the strong noise in the solution. . This noise occurs with the phase of the sound field and occurs once in one or more cycles. It has been found that this noise essentially bends when the sound field is in the expanding phase, and the trace gas dissolved in the solution accumulates into small bubbles (also known as cavitation nuclei). After the sound field becomes a compression phase, the radius meets- Conditioned gas pools are rapidly compressed and inward condensation occurs. In this way, the liquid wall around the bubble produces a strong paddle sound when it shrinks rapidly. This process is usually extremely momentary and only occurs between a few nanoseconds and a few microseconds. For the gas in the bubble, the temperature rises sharply after being compressed. This temperature is usually astonishingly high, reaching a maximum of more than 10,000 degrees Celsius, and at a few thousand degrees when it is low. This physical process is called cavitation effect, and the accompanying noise is called cavitation noise. This temperature is related to the green strength, the initial radius of the bubble, the radius at which the compression ends, and the specific heat capacity of the gas. Therefore, as the dissolved gas in the solution is different, the temperature at which the cavitation region terminates after cavitation occurs is not the same, and the volume of the solution in which the rare gas is dissolved often has a higher cavitation termination temperature. The local high temperature in the solution caused by the cavitation effect is the determinant of the chemical reaction.
Cavitation effect and sonochemical reaction Because the temperature of the cavitation region is extremely quotient, this region is generally called a hot spot ", which is the local quotient temperature point in the solution. The high temperature of the hot spot causes the interface between bubbles and liquid to be several hundred nanometers thick In the city being poured, the liquid molecules are cracked into free radicals. Due to the rapid contraction of the liquid wall when cavitation occurs, these: free radicals are projected into the solution at high speed at the same time as these are generated, and these highly talkative free radicals will be mixed with ficus Free radical reactions of molecules in the liquid, which trigger a series of chemical reactions
• Cell disrupter (extraction of plant substances, disinfecting, enzyme deactivation)
• Therapeutic ultrasound, i.e. induction of thermolysis in tissues (cancer treatment)
• Decrease of reaction time and/or increase of yield
• Use of less forcing conditions e.g. lower reaction temperature
• Possible switching of reaction pathway
• Use of less or avoidance of phase transfer catalysts
• Degassing forces reactions with gaseous products
• Use of crude or technical reagents
• Activation of metals and solids
• Reduction of any induction period
• Enhancement of the reactivity of reagents or catalysts
• Generation of useful reactive species
New product
Hot product
2022-06-23
2022-06-23
2022-06-23
2022-06-23
2022-06-23
2022-06-23
2022-06-23
2022-06-23
2022-06-23
2022-06-23