Article
Chemistry, Multidisciplinary
Meng Li, Yelena Kan, Hang Su, Ulrich Poschl, Sapun H. Parekh, Mischa Bonn, Yafang Cheng
Summary: Acidity is crucial for atmospheric aerosol formation and its impacts on air quality, climate, and the ecosystem. This study directly measures the pH distribution in NaH2PO4-Na2HPO4 microdroplets and finds that the pH values of the microdroplets are similar to the parent bulk solutions and remain constant across the microdroplets. Similar results are observed for acidic NaHSO4 microdroplets.
Article
Mechanics
Haojie Xu, Junfeng Wang, Kai Yu, Bin Li, Wei Zhang, Lei Zuo, Hyoung-Bum Kim
Summary: This study investigated the effects of an electric field on droplet impact behavior and dynamic mechanisms. It was found that different impact phenomena occur in different thermal regimes due to the competition between electrostatic and capillary pressures.
Article
Chemistry, Multidisciplinary
Alexander M. Prophet, Kritanjan Polley, Gary J. Van Berkel, David T. Limmer, Kevin R. Wilson
Summary: The oxidation kinetics of iodide by ozone at the air-water interface is studied in single microdroplets. Molecular simulations and kinetic modeling are used to understand the underlying multiphase mechanism.
Article
Chemistry, Physical
Xiong Wang, Xiao Yan, Jiayu Du, Bingqiang Ji, Mohammad Jalal Inanlu, Qi Min, Nenad Miljkovic
Summary: The spreading behavior of microdroplets differs from larger droplets due to the influence of size and surface tension. Experiments showed that the initial spreading of smaller droplets is shorter with reduced oscillation damping compared to millimeter-scale droplets. The coupling between spreading velocity and dynamic contact angle may have applications in microscale heat transfer, advanced manufacturing, and aerosol transmission studies.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Environmental Sciences
Pierre Zeiger, Frederic Frappart, Jose Darrozes, Catherine Prigent, Carlos Jimenez
Summary: The monitoring of flood and wetland dynamics at global scale is limited by data availability and resolution, but using CYGNSS can provide high temporal resolution monitoring of flood and wetland dynamics with good agreement with static inundation maps and dynamic estimations.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Chemistry, Multidisciplinary
Pallab Basuri, Amrita Chakraborty, Tripti Ahuja, Biswajit Mondal, Jenifer Shantha Kumar, Thalappil Pradeep
Summary: Imprinted charged aqueous droplets of micrometer dimensions containing spherical gold and silver nanoparticles, gold nanorods, proteins and simple molecules were visualized using dark-field and transmission electron microscopies. With such studies, we hoped to understand the unusual chemistry exhibited by microdroplets.
Article
Chemistry, Physical
Changyang Li, Yong Chen, Peng Wang, Guoqing Wang, Qingli Cheng, Junfei Ou, Dun Zhang
Summary: The study designed ZnO-nanoneedle array, investigated the growth and merging process of SHS surface droplets under simulated condensation conditions, established the correlation between surface microstructure and jumping behavior, and analyzed the self-propelling mechanism from an energy perspective, providing a new pathway for future atmospheric corrosion protection.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Chemistry, Multidisciplinary
Yanglimin Ji, Yiyang Lin, Yan Qiao
Summary: Inspired by plant cell walls, a method was developed to prepare membranized coacervates as protocell models by coating membraneless liquid-like microdroplets with rigid polysaccharides. The membranization enhanced stability, prevented aggregation, facilitated selective biomolecule sequestration, and allowed chemical exchange across the membrane. The polysaccharide wall surrounding the protocells acted as a stimuli-responsive structural barrier for enzyme-triggered membrane lysis and internalization of bacteria, offering a means to mimic cell behavior.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Agustin J. Colussi, Shinichi Enami, Shinnosuke Ishizuka
Summary: It has been found that atmospheric cloud, fog, and aerosol microdroplets are more acidic than previously assumed, with sharp changes in acidity across interfacial layers. Surface-specific experiments show significant differences in protonation of gas-phase molecules at the outermost layer of aqueous microdroplets compared to deeper layers.
ACS EARTH AND SPACE CHEMISTRY
(2021)
Article
Chemistry, Physical
Manuel F. Ruiz-Lopez, Marilia T. C. Martins-Costa
Summary: This study investigates the origin of the unexpected phenomenon of reaction rate acceleration in water microdroplets compared to bulk water. Using a unique and versatile kinetic model, the acceleration factors for atmospheric and synthetic reactions can be broken down into elemental contributions. The microdroplets are divided into surface and interior sub-volumes, acting as interconnected chemical reactors in the fast diffusion regime. The acceleration of reaction rates and its dependence on reaction molecularity and microdroplet dimensions are explained using transition-state theory at thermodynamic equilibrium. Additionally, the study demonstrates that the model, combined with experimental measurements of rate acceleration factors, can be used to obtain chemical kinetics data at the air-water interface, a long-standing challenge for chemists.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Masoud A. Mehrgardi, Mohammad Mofidfar, Richard N. Zare
Summary: Water has the ability to produce hydrogen peroxide when sprayed to form microdroplets, and gas-surface interactions increase the concentration of hydrogen peroxide.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Letter
Chemistry, Physical
Joseph P. Heindel, Hongxia Hao, R. Allen LaCour, Teresa Head-Gordon
Summary: There is growing evidence that chemical reactions in micrometer-sized liquid droplets can occur at significantly accelerated rates. However, the molecular mechanism behind this enhancement is still unclear. In this study, the authors investigate the energy step of hydroxide ions converting to hydroxyl radicals in microdroplets, and find that the ionization energy of partially solvated hydroxide ions is greatly reduced at the droplet's interface.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Multidisciplinary Sciences
Shiquan Lin, Leo N. Y. Cao, Zhen Tang, Zhong Lin Wang
Summary: This study proposes a method for quantifying the amount of charge carried by water microdroplets produced by ultrasonic atomization, and reveals the size-dependent charge transfer between microdroplets. Furthermore, a theoretical model for microdroplets charging is proposed, providing evidence for the contact electrification-induced spontaneous generation of H2O2 in water microdroplets.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Multidisciplinary
Zhexuan Song, Chiyu Liang, Ke Gong, Supin Zhao, Xu Yuan, Xinxing Zhang, Jing Xie
Summary: The application of high external electric fields (EEF) as green and efficient catalysts in synthetic chemistry has gained significant attention. In this study, the EEF was applied to Menshutkin reactions, resulting in accelerated reaction rates and controlled reaction selectivity, showcasing the potential of microdroplet chemistry for green synthesis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Xiaowei Song, Chanbasha Basheer, Richard N. Zare
Summary: Water microdroplets containing ammonia are synthesized in a gas-liquid-solid heterogeneous catalytic system without the need for electric potential or irradiation. The conversion rate reaches 32.9 ± 1.38 nmol s(-1) cm(-2) at room temperature. This eco-friendly and low-cost one-step nitrogen-fixation strategy converts widely available starting materials into a value-added product.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Physics, Applied
Tomo Kurimura, Masatoshi Ichikawa
APPLIED PHYSICS LETTERS
(2016)
Article
Physics, Multidisciplinary
Shunsuke F. Shimobayashi, Masatoshi Ichikawa, Takashi Taniguchi
Article
Chemistry, Physical
S. F. Shimobayashi, M. Hishida, T. Kurimura, M. Ichikawa
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2016)
Article
Physics, Multidisciplinary
Hiroaki Ito, Masahiro Makuta, Yukinori Nishigami, Masatoshi Ichikawa
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2017)
Article
Chemistry, Physical
Kazusa Beppu, Ziane Izri, Jun Gohya, Kanta Eto, Masatoshi Ichikawa, Yusuke T. Maeda
Article
Chemistry, Multidisciplinary
Tomo Kurimura, Yoshiko Takenaka, Satoru Kidoaki, Masatoshi Ichikawa
ADVANCED MATERIALS INTERFACES
(2017)
Article
Multidisciplinary Sciences
Takuya Ohmura, Yukinori Nishigami, Atsushi Taniguchi, Shigenori Nonaka, Junichi Manabe, Takuji Ishikawa, Masatoshi Ichikawa
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2018)
Article
Chemistry, Physical
Yusuke Kashiwagi, Takashi Nishio, Masatoshi Ichikawa, Chwen-Yang Shew, Naoki Umezawa, Tsunehiko Higuchi, Koichiro Sadakane, Yuko Yoshikawa, Kenichi Yoshikawa
COLLOID AND POLYMER SCIENCE
(2019)
Article
Multidisciplinary Sciences
Ryou Kubota, Masahiro Makuta, Ryo Suzuki, Masatoshi Ichikawa, Motomu Tanaka, Itaru Hamachi
NATURE COMMUNICATIONS
(2020)
Article
Physics, Multidisciplinary
Saori Suda, Tomoharu Suda, Takuya Ohmura, Masatoshi Ichikawa
Summary: Through experimental and theoretical analysis, the study investigates the transition of a water-in-oil swimming droplet from straight to curvilinear motion, highlighting the dependence of the motion transition on the droplet's susceptibility to external stimuli as influenced by environmental parameters. The simplicity of the experimental system and model suggests implications for a general class of transitions in self-propelled swimmers.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Analytical
Kohei Okuyama, Yukinori Nishigami, Takuya Ohmura, Masatoshi Ichikawa
Summary: The study investigates the spatial population dynamics of the ciliate Tetrahymena pyriformis through quantitative data analysis, utilizing image processing of 3D micrographs and machine learning to obtain individual cell positional data and examine their statistical properties based on spatio-temporal data. The cells are found to accumulate both on the solid wall at the bottom surface and underneath the air-liquid interface at the top according to their 3D spatial distribution and temporal evolution. A simple behavioral model incorporating quantitative accumulation coefficients was created to quantitatively clarify the difference in accumulation levels between the bulk and the interface, allowing for comparisons under different conditions and between different species.
Article
Multidisciplinary Sciences
Takuya Ohmura, Yukinori Nishigami, Atsushi Taniguchi, Shigenori Nonaka, Takuji Ishikawa, Masatoshi Ichikawa
Summary: Single-celled microorganism Tetrahymena responds autonomously to shear flow through rheotaxis by utilizing cilia-stalling mechanics, enabling it to survive in harsh environments effectively.
Article
Physics, Fluids & Plasmas
Saori Suda, Tomoharu Suda, Takuya Ohmura, Masatoshi Ichikawa
Summary: This study investigates the effect of external perturbations on the motion of microdroplets driven by the Marangoni effect. The results show that the types and properties of external perturbation have a considerable impact on the droplet motion.
Article
Chemistry, Physical
Charlotte de Blois, Vincent Bertin, Saori Suda, Masatoshi Ichikawa, Mathilde Reyssat, Olivier Dauchot
Summary: The behavior of self-propelled water-in-oil droplets in capillaries of different cross-sections was experimentally investigated. It was found that the velocity of the droplet decreases with increasing confinement in straight capillaries, but even very long droplets can still swim at very high confinement. In stretched circular capillaries, the non-uniform thickness of the lubrication layer around the droplet leads to neck formation and eventual spontaneous splitting events for large enough confinement, highlighting the critical role of the droplet's interface activity under confinement.
Article
Physics, Fluids & Plasmas
Mariko Suga, Saori Suda, Masatoshi Ichikawa, Yasuyuki Kimura