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We use experiments and theory to elucidate the size effect in capillary breakup rheometry, where prestretching in the viscocapillary stage causes the apparent relaxation time to be consistently smaller than the actual value. We propose a method accounting for both the experimental size and the finite extensibility of polymers to extract the actual relaxation time. A phase diagram characterizes the expected measurement variability and delineates scaling law conditions. The results refine capillary breakup rheometry for viscoelastic fluids and advance the understanding of breakup dynamics across scales.
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http://dx.doi.org/10.1103/2jz7-4w4k | DOI Listing |
Phys Rev Lett
July 2025
Princeton University, Department of Mechanical and Aerospace Engineering, Princeton, New Jersey 08544, USA.
We use experiments and theory to elucidate the size effect in capillary breakup rheometry, where prestretching in the viscocapillary stage causes the apparent relaxation time to be consistently smaller than the actual value. We propose a method accounting for both the experimental size and the finite extensibility of polymers to extract the actual relaxation time. A phase diagram characterizes the expected measurement variability and delineates scaling law conditions.
View Article and Find Full Text PDFLangmuir
July 2025
Faculty of Mechanics, Beijing University of Technology, Beijing 100124, China.
The dynamic mechanisms of double emulsions transporting through a microfluidic Y-junction are experimentally studied. Typical flow patterns are categorized according to the interfacial characteristics. Transition rules under the influence of different parameters, including the normalized droplet lengths and the capillary number, are discussed.
View Article and Find Full Text PDFLab Chip
June 2025
State Key Laboratory of Precision Measuring Technology & Instruments, Tianjin University, Tianjin 300072, China.
Benefiting from localization, targeting and rapid response, inhaled drug delivery has become an indispensable method for treating lung diseases. However, the efficacy of drug delivery is often compromised by the physical characteristics of the aerosol produced by current nebulization methods, , large droplet size distributions, which are deposited in the upper airways. In this study, a portable, low-energy, and low-cost approach to nebulize drugs with appropriate size distribution is introduced using capillary wave breakup induced by gigahertz (GHz) acoustic waves.
View Article and Find Full Text PDFPhys Rev Lett
June 2025
King Abdullah University of Science and Technology, Mechanical Engineering, Physical Science and Engineering, (KAUST), Thuwal 23955, Saudi Arabia.
When a column of water drains from a vertical tube, it often leaves behind a trailing film that forms intricate, axisymmetric liquid structures. Using high-speed imaging and first-principles modeling, we investigate the formation and breakup of these fluted films and demonstrate that their diverse morphologies arise from the evolving balance of inertia, surface tension, gravity, and viscous forces. By analyzing the characteristic timescales for film emergence, retraction, and rupture, we classify the observed behaviors into distinct regimes and predict the transitions between them.
View Article and Find Full Text PDFJ Phys Chem B
April 2025
Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada.
Numerous analytical workflows involve electrospray ionization (ESI), a process that converts solution species into gaseous ions for detection by mass spectrometry (MS). Upon exposure of a solution-filled emitter capillary to an electric field, ESI proceeds via a liquid jet that forms at the apex of a Taylor cone. Breakup of this jet generates charged droplets that ultimately release analyte ions into the gas phase.
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