Liquid Temperature On Sonoluminescence Intensity

Ultrasonic is a Mechanical Wave, which can transfer power and has good directivity, better penetrating power and little attenuation. At Present, Ultrasonic has been extensively applied in many fields. Such as ultrasonic cleaning, ultrasonic welding, ultrasonic machining, ultrasonic extraction, ultrasonic testing and ultrasonic medical, etc. Acoustic cavitation is the origin of sonoluminescence. Ultrasonic cavitation induces all kinds of physical, chemical and biologic effects during these applications. Ultrasonic cavitation induces sonoluminescence, which becomes the focus of the scientific community.In ultrasound field, highly energy concentrated in cavitation bubbles will induce luminescence with changing of acoustic field, which phenomenon is called sonoluminescence. In the sonoluminescence, the movement of the bubbles converts low-energy of sound to high-energy of luminous. Sonoluminescence has two types, which is single-bubble and multiple-bubble sonoluminescence according to the amount of bubble.Sonoluminescence has wide application prospects in the areas of physics, chemistry, biology, medicine, etc. As it has special origin of physics and chemistry. The study showed that high temperature and high pressure produced by instant collapse of cavitation bubbles is the main causes of sonoluminescence. The high temperature and high pressure is related to ultrasonic pressure, frequency, liquid temperature and the content of gas. The light intensity will change when theses changed. At present, the report of sonoluminescence is mainly about its application. About the relation between the light intensity and ultrasonic pressure, frequency, liquid temperature and the content of gas is little, temperature is especially less, and some about report is only in foreign.The temperature effect of sonoluminescence has been studied by this paper at theory and experiment. The main contents have follows.1. The theory of sonoluminescence has been studied .The study showed that acoustic cavitation is the origin of sonoluminescence.2. The two kinds chemical reagent (Luminol and Lucigenin) that can enhance sonoluminescence have been studied .Experiments showed that Lucigenin is better than Luminol.3. The relation of acoustic pressure and luminous intensity has been studied. Ultrasonic pressure of maximum intensity at every ultrasonic frequency has been found.4. The relation of luminous intensity and temperature at the same acoustic pressure and frequency has been studied. The study showed that temperature has great influences to the luminous intensity. This experiment showed that luminous intensity increases with increasing of temperature about 30～35℃, but this changes is very slowly. Luminous intensity decreases as temperature increase at about 30～35℃. This change is very quick at about 50℃. The production of light is very difficult at about 60℃. There nearly has no luminous when liquid temperature above about 65℃.About the reason of sonoluminescence, temperature effect is mainly ultrasonic cavitation. Temperature has more Influence on ultrasonic cavitation. Liquid's temperature increasing, one side, liquid surface tension and viscosity coefficient will decreasing, these are more liable to cavitation. But the vapor compression will increase, which are not liable to ultrasonic cavitation. On the other side, the increasing of temperature, the dissolved gas content will decrease. The number of cavitation nuclear will decline, sonochemistry yield will decrease. The cause of relation of luminous intensity and temperature will need further study.