{"title":"瞬态效应及润湿在微泡产生中的作用","authors":"Pratik D. Desai , William B. Zimmerman","doi":"10.1016/j.cocis.2023.101722","DOIUrl":null,"url":null,"abstract":"<div><p>Microbubble dispersions are now commonly deployed in industrial applications ranging from bioprocesses to chemical reaction engineering, at full scale. There are five major classes of microbubble generation devices that are scalable. In recent years, some of these approaches have been explicitly studied for the influence of wetting properties on microbubble performance, for which the major proxy is the bubble-size distribution. In this piece, the methodologies for inferring bubble-size distribution are explored, with several recent advances as well as their potential pitfalls. Subsequently, studies where microbubble generation has been under investigation for wetting effects are assessed and in some cases, those that were not allowed the deduction that wetting is a significant factor. Two particular studies are highlighted: (i) systematic variation of wetting effects within a venturi with removable walls substituted with coated walls of known contact angle with hydrodynamic cavitation induced microbubbles and (ii) variation of ionic liquids with staged fluidic oscillation before steady flow. The first study shows that even in scenarios where high inertial effects would be expected to dominate, wetting influences are significant. The second study shows that transient effects are strongly influenced by both imbibition into pores and surface wetting but that viscous resistance is always a key factor. From the exploration of these recent studies, specific recommendations are made about how to assess the influence of wetting in those mechanisms/devices where it has not been explicitly studied, via deduction from those mechanisms/devices where the effects are demonstrably significant and indeed in some cases, controlling. In study (ii), which is the first to blow micro/bubbles into ionic liquids, wetting and transient effects are reasonable for between 25% and 50% reduction in average bubble size, although up to 70% reduction is observable when viscous effects are dominant, relative to the control of steady flow with the same pressure drop. Indeed, staging transient operations shows both bubble-size reduction and increased volumetric throughput are simultaneously possible.</p></div>","PeriodicalId":293,"journal":{"name":"Current Opinion in Colloid & Interface Science","volume":null,"pages":null},"PeriodicalIF":7.9000,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S135902942300047X/pdfft?md5=40606af57423dde648fb33c261c361be&pid=1-s2.0-S135902942300047X-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Transient effects and the role of wetting in microbubble generation\",\"authors\":\"Pratik D. Desai , William B. Zimmerman\",\"doi\":\"10.1016/j.cocis.2023.101722\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Microbubble dispersions are now commonly deployed in industrial applications ranging from bioprocesses to chemical reaction engineering, at full scale. There are five major classes of microbubble generation devices that are scalable. In recent years, some of these approaches have been explicitly studied for the influence of wetting properties on microbubble performance, for which the major proxy is the bubble-size distribution. In this piece, the methodologies for inferring bubble-size distribution are explored, with several recent advances as well as their potential pitfalls. Subsequently, studies where microbubble generation has been under investigation for wetting effects are assessed and in some cases, those that were not allowed the deduction that wetting is a significant factor. Two particular studies are highlighted: (i) systematic variation of wetting effects within a venturi with removable walls substituted with coated walls of known contact angle with hydrodynamic cavitation induced microbubbles and (ii) variation of ionic liquids with staged fluidic oscillation before steady flow. The first study shows that even in scenarios where high inertial effects would be expected to dominate, wetting influences are significant. The second study shows that transient effects are strongly influenced by both imbibition into pores and surface wetting but that viscous resistance is always a key factor. From the exploration of these recent studies, specific recommendations are made about how to assess the influence of wetting in those mechanisms/devices where it has not been explicitly studied, via deduction from those mechanisms/devices where the effects are demonstrably significant and indeed in some cases, controlling. In study (ii), which is the first to blow micro/bubbles into ionic liquids, wetting and transient effects are reasonable for between 25% and 50% reduction in average bubble size, although up to 70% reduction is observable when viscous effects are dominant, relative to the control of steady flow with the same pressure drop. Indeed, staging transient operations shows both bubble-size reduction and increased volumetric throughput are simultaneously possible.</p></div>\",\"PeriodicalId\":293,\"journal\":{\"name\":\"Current Opinion in Colloid & Interface Science\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":7.9000,\"publicationDate\":\"2023-10-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S135902942300047X/pdfft?md5=40606af57423dde648fb33c261c361be&pid=1-s2.0-S135902942300047X-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Current Opinion in Colloid & Interface Science\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S135902942300047X\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Current Opinion in Colloid & Interface Science","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S135902942300047X","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Transient effects and the role of wetting in microbubble generation
Microbubble dispersions are now commonly deployed in industrial applications ranging from bioprocesses to chemical reaction engineering, at full scale. There are five major classes of microbubble generation devices that are scalable. In recent years, some of these approaches have been explicitly studied for the influence of wetting properties on microbubble performance, for which the major proxy is the bubble-size distribution. In this piece, the methodologies for inferring bubble-size distribution are explored, with several recent advances as well as their potential pitfalls. Subsequently, studies where microbubble generation has been under investigation for wetting effects are assessed and in some cases, those that were not allowed the deduction that wetting is a significant factor. Two particular studies are highlighted: (i) systematic variation of wetting effects within a venturi with removable walls substituted with coated walls of known contact angle with hydrodynamic cavitation induced microbubbles and (ii) variation of ionic liquids with staged fluidic oscillation before steady flow. The first study shows that even in scenarios where high inertial effects would be expected to dominate, wetting influences are significant. The second study shows that transient effects are strongly influenced by both imbibition into pores and surface wetting but that viscous resistance is always a key factor. From the exploration of these recent studies, specific recommendations are made about how to assess the influence of wetting in those mechanisms/devices where it has not been explicitly studied, via deduction from those mechanisms/devices where the effects are demonstrably significant and indeed in some cases, controlling. In study (ii), which is the first to blow micro/bubbles into ionic liquids, wetting and transient effects are reasonable for between 25% and 50% reduction in average bubble size, although up to 70% reduction is observable when viscous effects are dominant, relative to the control of steady flow with the same pressure drop. Indeed, staging transient operations shows both bubble-size reduction and increased volumetric throughput are simultaneously possible.
期刊介绍:
Current Opinion in Colloid and Interface Science (COCIS) is an international journal that focuses on the molecular and nanoscopic aspects of colloidal systems and interfaces in various scientific and technological fields. These include materials science, biologically-relevant systems, energy and environmental technologies, and industrial applications.
Unlike primary journals, COCIS primarily serves as a guide for researchers, helping them navigate through the vast landscape of recently published literature. It critically analyzes the state of the art, identifies bottlenecks and unsolved issues, and proposes future developments.
Moreover, COCIS emphasizes certain areas and papers that are considered particularly interesting and significant by the Editors and Section Editors. Its goal is to provide valuable insights and updates to the research community in these specialized areas.