Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria, Australia.
Ultrason Sonochem. 2014 Jan;21(1):60-8. doi: 10.1016/j.ultsonch.2013.07.005. Epub 2013 Jul 22.
Ultrasound is known to promote nucleation of crystals and produce a narrower size distribution in a controlled and reproducible manner for the crystallisation process. Although there are various theories that suggest cavitation bubbles are responsible for sonocrystallisation, most studies use power ultrasonic horns that generate both intense shear and cavitation and this can mask the role that cavitation bubbles play. High frequency ultrasound from a plate transducer can be used to examine the effect of cavitation bubbles without the intense shear effect. This study reports the crystal size and morphology with various mixing speeds and ultrasound frequencies. The results show high frequency ultrasound produced sodium chloride crystals of similar size distribution as an ultrasonic horn. In addition, ultrasound generated sodium chloride crystals having a more symmetrical cubic structure compared to crystals produced by a high shear mixer.
超声被认为可以促进晶体成核，并以可控和可重复的方式产生更窄的晶体尺寸分布，从而促进结晶过程。虽然有各种理论表明空化气泡是超声结晶的原因，但大多数研究使用的功率超声变幅杆会同时产生强烈的剪切和空化作用，这可能会掩盖空化气泡的作用。来自板换能器的高频超声可用于检查空化气泡的影响，而不会产生强烈的剪切作用。本研究报告了不同混合速度和超声频率下的晶体尺寸和形态。结果表明，高频超声产生的氯化钠晶体的尺寸分布与超声变幅杆相似。此外，与高剪切混合器产生的晶体相比，超声产生的氯化钠晶体具有更对称的立方结构。
