Article
Chemistry, Physical
Ivan U. Vakarelski, Farrukh Kamoliddinov, Sigurdur T. Thoroddsen
Summary: This study investigates the interaction between millimeter-sized bubbles and the seawater-air interface in seawater samples collected from the Red Sea coastal area. It demonstrates that high concentrations of electrolytes and organics in seawater do not affect the mobility of the bubble interfaces during free-rise and bouncing.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Engineering, Environmental
Sandra Orvalho, Petr Stanovsky, Marek C. Ruzicka
Summary: Experimental study on the coalescence of air bubbles in aqueous solutions of electrolytes reveals that the coalescence efficiency decreases with electrolyte concentration and bubble velocity, while the contact time decreases with bubble velocity but increases with electrolyte concentration. The transition from coalescence to noncoalescence proceeds via a minimum in the T(V) graphs, and bubble size affects the extent of the coalescence region.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Acoustics
Tatyana Lyubimova, Konstantin Rybkin, Oscar Fattalov, Michael Kuchinskiy, Lev Filippov
Summary: In this study, the dynamics of vapor-gas bubbles in distilled water under ultrasound on different solid surfaces were experimentally investigated. The surface properties were found to have a significant impact on the behavior of the bubbles, with hydrophobic surfaces leading to stable attachment and linear growth in bubble coverage area. Decreasing gas concentration caused a qualitative change in the time dependence of bubble coverage area.
Article
Chemistry, Analytical
Xiaopeng Shang, Xiaoyang Huang
Summary: This work presents experimental and numerical studies on the dynamics of cavitation bubbles in a nozzle-shaped microfluidic channel with PZT actuations. It is found that a cloud of bubbles can be generated near the center of the microfluidic channel when the actuation voltage is larger than a threshold at 1 kHz. The bubbles oscillate radially with expansion and compression, and translate upstream towards the opening of the nozzle. The bubbles undergo frequent coalescence and breakup, leading to vigorous churning of surrounding liquids. Numerical simulation shows a low-pressure zone inside the microfluidic channel within each cycle of the actuation period, which is responsible for bubble generation observed in the experiments. The method of bubble generation in this study is novel and can be applied for the enhancement of heat and mass transfer in microfluidic operations.
Article
Acoustics
Dui Qin, Qingqin Zou, Shuang Lei, Wei Wang, Zhangyong Li
Summary: The cavitation-mediated bioeffects are mainly related to the dynamic behaviors of bubbles in viscoelastic tissues. The interactions between two interacting cavitation bubbles in such tissues have significant effects on acoustic emissions. Increasing the initial distance between bubbles enhances the nonlinear dynamics of bubbles.
ULTRASONICS SONOCHEMISTRY
(2021)
Article
Mechanics
Yimou Fu, Xiaocheng Hu, Yide Liu, Peng Wang, Shuo Chen, Haofei Zhou, Honghui Yu, Shaoxing Qu, Wei Yang
Summary: This study investigates the impact-induced interactions of bubbles in soft materials through experiments and analysis. A theoretical model containing pressure radiated by bubbles is proposed to predict the deformation and inhibition between bubbles during deformation, as well as the squeeze and coalescence mechanisms of the bubbles. A phase diagram is drawn to predict the critical impact loads for bubble coalescence under different conditions.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Physics, Multidisciplinary
Ilya V. Baimler, Viktor K. Chevokin, Vitaliy A. Podvyaznikov, Sergey V. Gudkov
Summary: The study revealed that optical breakdown plasma flashes in aqueous solutions of Fe nanoparticles under Nd: YAG laser radiation exhibit specific characteristics, with the sizes of plasma flares, plasma glow intensity, and time to reach maximum intensity concentrated around certain values. The movement speed and range of the water-vapor boundary at the initial stage of breakdown process also show distinct numerical features.
FRONTIERS IN PHYSICS
(2021)
Article
Mechanics
Peng Xu, Shuhong Liu, Zhigang Zuo, Zhao Pan
Summary: This paper investigates the onset criteria and dynamics of large cavitation bubbles in a tube, proposing a new cavitation number to describe the maximum bubble length. Both criteria for large cylindrical cavitation bubbles to occur are established, and a Rayleigh-type model for bubble dynamics in a tube is developed. The analytical results are validated through systematic experiments using a modified apparatus.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
S. Cao, G. Wang, O. Coutier-Delgosha, K. Wang
Summary: This study investigates the interaction between fluid dynamics and mechanical response of materials near collapsing bubbles. The research shows that the ratio of longitudinal acoustic impedance of the material compared to that of the ambient fluid plays a significant role in the collapse process and bubble dynamics.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Acoustics
Sergey Lesnik, Atiyeh Aghelmaleki, Robert Mettin, Gunther Brenner
Summary: The acoustic cavitation model proposed in this study is based on the Euler-Lagrange approach with a novel Helmholtz solver and a nonlinear acoustic attenuation model. It is able to depict a polydisperse bubble population, and results show that velocity is strongly influenced by initial void fraction and bubble population type. Additionally, the model successfully reproduces most of the experimentally observed phenomena.
ULTRASONICS SONOCHEMISTRY
(2022)
Article
Mechanics
Silvestre Roberto Gonzalez-Avila, Fabian Denner, Claus-Dieter Ohl
Summary: In this study, acoustic transients emitted during the collapse of laser-induced cavitation bubbles were analyzed systematically for different standoff parameters. Experimental and numerical results were used to investigate the impact of various parameters on the characteristics of the acoustic signals. It was found that the pressure peaks in the acoustic signals and the amplitude ratio of the first to second acoustic transients are related to the bubble nucleation place and the standoff parameter, gamma.
Article
Engineering, Aerospace
O. Fattalov, T. Lyubimova, K. Rybkin, M. Kuchinskiy
Summary: The study found that in liquids containing surfactant, the presence of surfactant inhibits bubble coalescence, resulting in the formation of only small bubbles of around ten microns in size. These small bubbles are unable to rise to the surface due to the dominance of viscous forces over buoyancy.
MICROGRAVITY SCIENCE AND TECHNOLOGY
(2021)
Article
Acoustics
Hossein Haghi, Michael C. Kolios
Summary: This study examines the effect of bubble-bubble interactions on the resonance frequency of MB suspensions. It is found that primary delays cause spreading the resonance frequency of identical MBs within a range, where the closest MB to the acoustic source exhibits the lowest resonance frequency and the furthest MB resonates at the highest frequency. The inclusion of secondary delays also significantly affects the resonance frequency, resulting in an increase when the MBs are situated close to each other.
ULTRASONICS SONOCHEMISTRY
(2022)
Article
Physics, Multidisciplinary
Guillaume Lajoinie, Tim Segers, Michel Versluis
Summary: This study demonstrates that pressure amplification mechanism leads to droplet vaporization phenomenon, and experimental results confirm that acoustic resonance can significantly enhance nucleation rate.
PHYSICAL REVIEW LETTERS
(2021)
Article
Engineering, Mechanical
A. J. Sojahrood, R. Earl, H. Haghi, Q. Li, T. M. Porter, M. C. Kolios, R. Karshafian
Summary: The study explores the nonlinear dynamics of bubbles excited in specific frequency ranges, demonstrating that contrast and signal-to-noise ratio can be improved by introducing 1/2-order subharmonics.
NONLINEAR DYNAMICS
(2021)
Article
Chemistry, Applied
Yue Wu, Wu Li, Enrico Colombo, Gregory J. O. Martin, Muthupandian Ashokkumar
Summary: In this study, the quantitative monitoring of ultrasound-induced inactivation of KTI and BBI was achieved, and its consistency with a traditional assay was verified. The effect of TI concentration, ultrasonic frequency, power density, and pH on the inactivation kinetics of KTI and BBI was explored. The results showed that various factors influenced the inactivation process, including TI concentration, ultrasonic conditions, and pH value.
Article
Chemistry, Applied
Charitha J. Gamlath, Kuan Yen Lo, Thomas S. H. Leong, Muthupandian Ashokkumar, Gregory J. O. Martin
Summary: This study demonstrates the potential of ultrasound emulsification to form whey protein-enriched double emulsions with minimum food-grade emulsifiers to fortify the protein content of cheese and other food products. The encapsulation loading rate of whey proteins within the double emulsion droplets was investigated in relation to ultrasound parameters and formulation loading rates. The results showed that high encapsulation loading rates can be achieved using ultrasound with comparable oil droplet diameters to native milk fat globules.
FOOD HYDROCOLLOIDS
(2023)
Article
Chemistry, Physical
Aissa Dehane, Slimane Merouani, Oualid Hamdaoui, Kyuichi Yasui, Muthupandian Ashokkumar
Summary: In sonochemistry, acoustic bubbles serve as microreactors for producing hydrogen and oxidants. This study developed a novel semi-empirical method using hydrogen sono-production to determine the number density of micro-bubbles during water sonolysis. The results showed that the number density of bubbles ranged from -108 to -1013 L-1 s-1, depending on the experimental conditions, and the calculation method used. The study also found that the number of active bubbles increased with frequency, but decreased when calculated via the total single-bubble yield, especially at higher frequencies and colder liquid temperatures.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Food Science & Technology
Shunyu Yao, Wu Li, Yue Wu, Gregory J. O. Martin, Muthupandian Ashokkumar
Summary: Hempseed protein isolate (HPI) can be improved in functionality, such as solubility, emulsifying, and foaming properties, through ultrasonic-assisted extraction. The enhanced functionality is attributed to the changes in protein structure, including increased hydrophobicity and decreased particle size of protein aggregates. Prolonged high-power ultrasound exposure may negatively affect the functional properties of HPI.
Article
Materials Science, Paper & Wood
Hans Estrella Cainglet, Joanne Tanner, Naghmeh Nasiri, Christine Browne, Gil Garnier, Warren Batchelor
Summary: A new rheological method is described for determining the aspect ratio of cellulose fibres, which is faster and more widely applicable than microscopic methods. It is demonstrated that this method can be used for the production of nanocellulose at industrial scale.
Article
Biochemistry & Molecular Biology
Haiyan Zhu, Sukhvir Kaur Bhangu, Muthupandian Ashokkumar, Francesca Cavalieri
Summary: Ultrasound-based engineering has allowed for the synthesis of carrier-free nanodrugs with anticancer and antimicrobial activities using supramolecular self-assembly. High-frequency sound waves were applied to transform small chemotherapeutic and antibiotic drugs into stable nanodrugs without the need for organic solvents or surfactants. Imaging techniques provided insights into the behavior of the nanodrugs inside cells. The findings suggest the potential for small antibiotic drugs to be transformed into chemotherapeutic nanodrugs with high selectivity against cancer cells.
Article
Acoustics
Juhyeon Park, Ahreum Min, Jayaraman Theerthagiri, Muthupandian Ashokkumar, Myong Yong Choi
Summary: Acoustic levitation is a unique tool for levitating and processing droplets and particles. In this study, gold and silver nanoparticles were synthesized using acoustic levitation and pulsed laser irradiation. The synthesized nanoparticles showed excellent catalytic behavior.
ULTRASONICS SONOCHEMISTRY
(2023)
Article
Acoustics
Yue Wu, Wu Li, Haiyan Zhu, Gregory J. O. Martin, Muthupandian Ashokkumar
Summary: Liquid-liquid interfacial protein adsorption was proposed as a method to inactivate soy trypsin inhibitors. Ultrasound mixing generated the smallest and most uniform emulsion droplets, resulting in the highest adsorption amount and inactivation percentage. The adsorption amount of trypsin inhibitors increased in the presence of vegetable oil and rapidly increased with sonication time. The pathways of interface-induced inactivation differed for different inhibitors. Overall, ultrasound-assisted interfacial adsorption is a rapid and efficient method to inactivate soy trypsin inhibitors.
ULTRASONICS SONOCHEMISTRY
(2023)
Article
Polymer Science
Amrish Kumar Padmakumar, Vianna F. F. Jafari, Nikhil K. K. Singha, Muthupandian Ashokkumar, Greg G. G. Qiao
Summary: This work describes an alternative method (arm-first approach) to efficiently synthesize core-crosslinked star polymers. The star polymers are produced using a two-step, one-pot Sono-RAFT process. By altering the applied power, the reaction time can be decreased by half. A CCS polymer was produced using a triblock arm, and it exhibited a very high arm-to-star conversion.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Engineering, Chemical
Reshma Kaimal, Madappa C. Maridevaru, Aashutosh Dube, Jerry J. Wu, Anandan Sambandam, Muthupandian Ashokkumar
Summary: The study focuses on the development of a sensor for the detection of low levels of As(III) in water. By synthesizing borophene and modifying the glassy carbon electrode with it, high sensitivity detection of As(III) is achieved. The sensor is low-cost, highly selective, and has good repeatability, making it suitable for practical applications.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Physical
Christine Browne, Vikram Singh Raghuwanshi, Gil Garnier, Warren Batchelor
Summary: This study finds that the optical properties of cellulose nanocrystal films are significantly affected by the type, valency and concentration of electrolytes. The addition of electrolytes increases the pitch of the chiral nematic structures, but further concentration leads to aggregation and breakdown of the structures. Univalent species have a stronger influence on the structures compared to divalent species. This research demonstrates the importance of ion valency, concentration and species in controlling the chiral nematic structures of cellulose nanocrystal suspensions.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Polymer Science
Amrish Kumar Padmakumar, Nikhil K. Singha, Muthupandian Ashokkumar, Frank A. Leibfarth, Greg G. Qiao
Summary: Advances in nanomolecular engineering have led to the development of technology using ultrasonic irradiation to initiate polymerization. In this study, ultrasound-assisted reversible addition chain-transfer (Sono-RAFT) polymerization was used to compare batch and continuous flow polymerization methods on monomer conversion, polymer molar mass, and dispersity using different monomer substrates. Results showed that continuous flow polymerization had higher monomer conversion compared to batch reactions under the same conditions. Continuous flow reactors with stainless-steel microreactors provided higher cavitation intensity and lower oxygen contamination, making Sono-RAFT possible at higher monomer concentrations. These findings have implications for mechanochemistry and the practical and sustainable implementation of sonochemically regulated polymerization.
Review
Food Science & Technology
Vitoria Hagemann Cauduro, Jiwei Cui, Erico Marlon Moraes Flores, Muthupandian Ashokkumar
Summary: Ultrasound-assisted encapsulation is an emerging technique that is used to encapsulate phytochemicals into food products. It has the advantages of producing smaller capsules with lower polydispersity index and higher bioavailability. Further studies should focus on incorporating these capsules into model food products to assess their stability and sensory properties.
Article
Chemistry, Multidisciplinary
Devyani Srivastava, Amita Singh, Gabriele Kociok-Koehn, Suresh W. Gosavi, Ratna Chauhan, Muthupandian Ashokkumar, Abhinav Kumar, Mohd. Muddassir
Summary: Three new heteroleptic Co(iii) ferrocene dithiocarbamate complexes with dppe as ligand have been synthesized and characterized. Single crystal X-ray diffraction revealed a distorted octahedral geometry around Co(iii) in the complexes. The compounds were used as photo-sensitizers in dye-sensitized solar cells and exhibited good photovoltaic performance.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Devyani Srivastava, Aparna Kushwaha, Gabriele Kociok-Kohn, Suresh W. Gosavi, Ratna Chauhan, Muthupandian Ashokkumar, Abhinav Kumar, Mohd. Muddassir
Summary: Three new nickel complexes were synthesized and used as sensitizers in dye sensitized solar cells (DSSCs). Among the three sensitizers, the DSSC fabricated using p-NiL exhibited the best photovoltaic performance with an efficiency of 3.40%, strong electronic coupling, and enhanced electron injection.