Article
Mechanics
Minghuan Xu, Xiran Li, Andrew Riseman, John M. Frostad
Summary: A novel approach for quantifying the retention efficiency of agricultural sprays using polymer additives was presented in this study. Results indicated that increasing the extensional rheology of the spray solution can significantly improve retention efficiency, with potential to achieve over 95% total efficiency.
Review
Chemistry, Physical
Xingjian Yu, Yu Zhang, Run Hu, Xiaobing Luo
Summary: The dynamics of water droplet bouncing is highly dependent on liquid properties, surface characteristics, and ambient pressure. Achieving no droplet/surface contact, which is crucial for droplet bouncing, can be realized through various methods such as lowering the Weber number of droplet, designing hydrophobic surfaces, actively maintaining the air/vapor film, vibrating the liquid bath, and applying electric/magnetic/pressure fields.
Article
Mechanics
Lijuan Qian, Benjie Huo, Zhongli Chen, Erqiang Li, Hang Ding
Summary: This study investigates the bouncing behavior of droplets on a moving superhydrophobic groove surface and focuses on the influence of the normal and tangential Weber numbers. Experimental results show that the rebound behavior of droplets varies greatly with the substrate velocity at the same normal Weber number. Moreover, an increase in the superhydrophobic substrate velocity leads to an increase in the maximum spreading diameter and a non-monotonic change in the dimensionless contact time, before eventually stabilizing. Additionally, proposed scaling laws for predicting the maximum spreading diameter and velocity recovery coefficients are validated using experimental data.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Chemistry, Physical
Run Liu, Yi-Bo Wang, Shu-Wei Yang, Han-Wu Liu, Yan-Ru Yang, Xiao-Dong Wang, Duu-Jong Lee
Summary: Through molecular dynamics (MD) simulations, the study investigates the bouncing dynamics of nanodroplets impacting a hydrophobic surface under electric fields with various field strengths and directions. The impacts of the electric fields on the bouncing dynamics of nanodroplets are significant, especially when the field strength exceeds 0.08 V A-1 and the field direction is altered.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Chemistry, Multidisciplinary
Chenyang Wu, Xuezhi Qin, Huanxi Zheng, Zhenyu Xu, Yuxin Song, Yuankai Jin, Huanhuan Zhang, Jiaying Mo, Wanbo Li, Jian Lu, Zuankai Wang
Summary: This study introduces a dual gradient surface design that enables adaptive droplet bouncing, reducing contact time significantly across a range of impacting velocities and spatial locations. This design provides new insights for liquid-repellent surface engineering and offers opportunities for various applications.
Review
Chemistry, Multidisciplinary
Xing Han, Jiaqian Li, Xin Tang, Wei Li, Haibo Zhao, Ling Yang, Liqiu Wang
Summary: Droplet impact is a common phenomenon in nature, daily life, and industrial processes, and it is crucial to control the outcomes for different applications. Droplet bouncing, as a special outcome, preserves the droplet shape and minimizes energy loss, making it beneficial in various applications. This review provides a comprehensive understanding of millimeter-sized droplet bouncing on solid surfaces and liquid pools, summarizing regulation methods, current applications, and proposing potential directions for future research.
Article
Chemistry, Multidisciplinary
Samir Kumar, Kyoko Namura, Motofumi Suzuki, Jitendra P. Singh
Summary: The study reports a hydrophobic Si nanospring surface that effectively suppresses wetting by repelling water droplets. The morphology of the nanostructures influences the impact dynamics, with Si nanosprings showing higher rebound time and coefficient of restitution compared to vertical Si columns. The study suggests that the nanosprings' restoring force may be responsible for the water-droplet rebound, and the bouncing phenomena could be helpful in designing self-cleaning surfaces and studying wetting behavior on nanostructures.
NANOSCALE ADVANCES
(2021)
Article
Chemistry, Physical
Jianqiang Hou, Jianying Gong, Xin Wu, Qiwang Huang, Yu Li
Summary: In this study, the numerical investigation on fast droplet bouncing on concave superhydrophobic surfaces (SHSs) with trapezoidal cross-section revealed asymmetric spreading behavior and the influence of structure parameters and impact velocity on the droplet contact time. The presence of tangential momentum can enhance droplet spreading, but may not always reduce contact time. An optimal concave SHS structure with certain width and inclination angle is expected to reduce droplet contact time by 40 to 45%.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Thermodynamics
Chuchen Yue, Qingwen Dai, Wei Huang, Xiaolei Wang
Summary: This study reports on droplets bouncing on curved surfaces with elevated temperatures, confirming the bouncing and depositing phenomena of different lubricant droplets. The influence of initial diameter, tangential velocity, and surface roughness on the impact dynamics of silicone oil droplets on wetted curved surfaces is investigated, with emphasis on the temperature dependence of the bouncing phenomenon. Bouncing and depositing thresholds under various conditions are summarized, with surface roughness having the most significant negative effect on the bounceable velocity range, followed by initial diameter and tangential velocity. A theoretical model and force analysis are established to explain the bouncing mechanism, while modified Bond numbers and Ohnesorge numbers are introduced to predict the bouncing thresholds. This work provides sufficient experimental and theoretical insights into manipulating droplets bouncing on wetted and curved surfaces with elevated temperatures.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Multidisciplinary Sciences
M. A. Quetzeri-Santiago, J. R. Castrejon-Pita, A. A. Castrejon-Pita
Summary: Dielectrowetting can actively control the dynamics of droplet impact to prevent bouncing and suppress splashing. The strength of the electric potential can regulate the dynamic contact angle and affect the spreading, splashing, and receding dynamics.
SCIENTIFIC REPORTS
(2021)
Article
Mechanics
Yaolin Tai, Yang Zhao, Xinyu Guo, Linan Li, Shibin Wang, Zhenyan Xia
Summary: The bouncing dynamics of microdroplets with varying viscosities on a superhydrophobic surface were investigated through numerical simulations. It was found that the contact time of the droplets remains constant over a wide Weber number range in the low-viscosity regime, but increases with impact velocity in the high-viscosity regime. New scaling parameters were proposed to describe the viscosity effect and characterize the contact time in different viscosity regimes. The study also revealed that viscous dissipation is significant even for relatively low-viscosity fluids, providing valuable insights for understanding and controlling microdroplet dynamics.
Article
Physics, Applied
Lei Liu, Chunfang Guo, Rui Yang, Jiangtao Lu, Senyun Liu
Summary: The dynamics of droplets on superhydrophobic surfaces were thoroughly studied, revealing a previously unreported phenomenon of vertical elongation and re-contact with the surface after pancake bouncing. Scale analysis showed that the critical Weber number for the jet splash phenomenon decreased with post spacing and edge length. This study provides valuable insights for understanding and applying the pancake bouncing effect.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Applied
Yannick Meeus, Frederik Janssen, Arno G. B. Wouters, Jan A. Delcour, Paula Moldenaers
Summary: This study investigated the hydrolysis of arabinoxylan (AX) in wheat and mixed cereal doughs by xylanases, finding that low dosages of enzyme did not significantly alter rheological properties while high dosages led to a considerable decrease in linear extensional viscosity. This decrease was attributed to changes in dough water distribution resulting from extensive hydrolysis of AX.
FOOD HYDROCOLLOIDS
(2021)
Article
Engineering, Chemical
Akapong Kongjaroen, Pawadee Methacanon, Chaiwut Gamonpilas
Summary: Rheological properties of thickened liquids from various commercial gum-based thickening powders were studied, showing that xanthan gum-based samples exhibited higher zero shear viscosity and longer relaxation time, behaving as weak gels with superior cohesiveness compared to guar gum and tara gum-based samples. The breakup time of these samples in extensional rheology was xanthan gum > guar gum > tara gum, indicating the superior cohesiveness of xanthan gum-based samples.
JOURNAL OF FOOD ENGINEERING
(2022)
Review
Polymer Science
Shuang Liu, Qian Huang, Quan Chen, Xian-bo Huang
Summary: This review summarizes the methods of measuring extensional rheology for polymer melts and solutions. Different types of extensional rheometers and measurement modes are introduced, along with suggestions for minimizing experimental errors and pushing the experimental limits. The importance of combining extensional rheology with other techniques in revealing more dynamic features of polymeric materials under extensional flow is highlighted.
ACTA POLYMERICA SINICA
(2023)
Article
Mechanics
Nan Xue, Min Y. Pack, Howard A. Stone
JOURNAL OF FLUID MECHANICS
(2020)
Article
Multidisciplinary Sciences
Boyang Qin, Chenyi Fei, Andrew A. Bridges, Ameya A. Mashruwala, Howard A. Stone, Ned S. Wingreen, Bonnie L. Bassler
Article
Multidisciplinary Sciences
Boyang Qin, Chenyi Fei, Bruce Wang, Howard A. Stone, Ned S. Wingreen, Bonnie L. Bassler
Summary: Bacterial cells can self-organize into structured communities at fluid-fluid interfaces, forming pellicles - soft living materials composed of cells and extracellular matrix. The time evolution of pellicle formation depends on the initial heterogeneity of the film microstructure, with different starting bacterial seeding densities producing variations in morphogenic stages. Despite global architectural transitions, individual microcolonies remain spatially segregated, maintaining spatial and genetic heterogeneity within the community.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Multidisciplinary
Ziwen He, Huy Tran, Min Y. Pack
Summary: Experimental results and observations reveal the dynamics of drops contacting thin films and the factors that influence the process. Within specific thickness and drop size ratio ranges, the possibility of drop contact bouncing is established.
Article
Chemistry, Multidisciplinary
Huy Tran, Ziwen He, Jordan Sakakeeny, Yue Ling, Min Y. Pack
Summary: This study reports the oscillation dynamics of drops on thin liquid films and finds that increasing the viscosity of the underlying oil film can increase the oscillation time and affect the natural frequency of the oscillation.
Article
Multidisciplinary Sciences
Ranjiangshang Ran, Quentin Brosseau, Brendan C. Blackwell, Boyang Qin, Rebecca L. Winter, Paulo E. Arratia
Summary: Bacterial activity affects fluid stretching and chaoticity, influencing the transport process; Bacterial activity hinders the transport of scalar variance across scales, increasing the size and lifetime of structures; At small scales, bacterial activity seems to enhance local mixing.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Mechanics
Ziwen He, Huy Tran, Min Y. Pack
Summary: Recent studies have focused on the air-cushioning effect of droplet impact on different surfaces. This study specifically explored the air entrainment dynamics of aqueous polymeric droplets and found that the viscoelastic properties of the droplets significantly influenced the air film thickness gradients.
Article
Multidisciplinary Sciences
Boyang Qin, Bonnie L. Bassler
Summary: Bacterial cells at fluid interfaces can self-assemble into soft living materials, called pellicles. Using Vibrio cholerae as a model system, researchers identified matrix proteins and a key quorum-sensing regulator that drive mechanical instabilities underlying pellicle morphogenesis, resulting in fractal patterning. Manipulation of these components could enable precise engineering of biomaterial morphologies.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Boyang Qin, Paulo E. Arratia
Summary: This study investigates the transport of microorganisms in complex unsteady flows using simulations and experiments. The results reveal that the dispersion dynamics of swimming bacteria are controlled by the pathlength of the flow and the swimmer speed. The study demonstrates the nontrivial chaotic transport that can occur in simple unsteady flows and suggests a potentially optimal dispersal strategy for microswimmers in nature.
Article
Chemistry, Physical
Angela Yang, Brian E. McKenzie, Yingqi Yi, Aditya S. Khair, Stephen Garoff, Robert D. Tilton
Summary: Polymer/surfactant complexation significantly enhances diffusiophoretic transport of colloids. Low concentration P123/SDS complexes prolong the existence of concentration gradients and drive colloid diffusion migration.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Huy Tran, Ziwen He, Pooria Pirdavari, Min Y. Pack
Summary: In order to improve the efficiency of Dynamic Wetting Condensation (DWC), researchers have been studying the distribution of droplets on the condensing surface. This study investigates the relationship between droplet shedding mechanisms and surface wettability patterning. By varying the area fraction and width of the DWC region, the study reveals changes in droplet shedding mechanisms. The results show that the sliding drop radii decrease with increasing DWC region width, while the jumping drop radii remain unchanged.
Article
Chemistry, Physical
Boyang Qin, Ranjiangshang Ran, Paul F. Salipante, Steven D. Hudson, Paulo E. Arratia