Article
Chemistry, Multidisciplinary
Yang Liu, Hui Zhang, Yijun Zhu, Jiawei Chen, Pu Wang, Songjie Dai, Xing Li, Guangneng Dong
Summary: Inspired by the jaws of tiny insects, researchers have developed a surface with novel jaw-like microstructures as micro one-way valves, enabling self-driven unidirectional spreading of liquid. These microstructures, which are almost two-dimensional, are simple and easy to fabricate. Surfaces with such micro one-way valves exhibit remarkable rapid and long-distance water droplet spreading behaviors, with a maximum forward-backward distance ratio of about 14.5, nearly double that of previous research. The capillary attraction at the location of the jaws and the pinning effect brought by the sharp edge of the jaws are identified as the main mechanisms.
Article
Multidisciplinary Sciences
Dieter A. Baumgartner, Samira Shiri, Shayandev Sinha, Stefan Karpitschka, Nate J. Cira
Summary: This study explores the rich dynamics of fully miscible, three-component droplets composed of water, ethanol, and propylene glycol on completely wetting glass substrates. The research finds that evaporation changes the composition and shape of the droplet, altering its spreading behavior. This research has practical significance in the collection, aggregation, and removal of contaminants.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Thermodynamics
Song Yang, Yu Hou, Dongdong Zhou, Xiufang Liu, Xin Zhong
Summary: We investigated the impact of liquid properties and surface supercooling on the spreading dynamics of a droplet consisting of binary ethylene-glycol and ethanol. The maximum spreading factor is determined by both surface supercooling and solution concentration. The relationship between maximum spreading factor and surface supercooling depends on the concentration of ethylene-glycol. We proposed a new model for the maximum spreading factor, considering the effect of surface cooling in viscous dissipation, which improves the prediction accuracy for droplet spreading on surfaces with different supercooling degrees.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Haixiang Zhang, Xiwen Zhang, Xian Yi, Feng He, Fenglei Niu, Pengfei Hao
Summary: The experimental study demonstrates the significant influence of surface wettability on the spreading and splashing of water droplets, with surface wettability contributing to the lift of the lamella and promoting spreading speed. The spreading velocity of water droplets on superhydrophobic surfaces is much higher than on other surfaces, and splashing behavior is dominated by the force from the surrounding air.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2021)
Article
Chemistry, Physical
Qier An, Jinshu Wang, Feng Zhao, Peiliu Li, Lei Wang
Summary: The study focuses on a titanium dioxide-based hydrophilic channel with anisotropic superhydrophobic barriers inspired by creatures with unique structures on their skins. This channel demonstrates unidirectional water transporting properties, with design parameters such as angle and radius playing key roles in achieving optimal performance. Overall, this research is expected to have significant implications in the field of water transportation.
Article
Thermodynamics
Yue Ma, Huang Zhang, Qianfeng Liu
Summary: This study experimentally investigates the spreading and splashing behavior of continuous droplets impinging on a heated wall under different conditions. The spreading parameters of the droplets and the relationship between splashing parameters, droplet Weber numbers, and Jacob numbers are analyzed and mathematically fitted.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
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
Chemistry, Physical
Yi Ding, Li Jia, Liaofei Yin, Chao Dang, Xinyuan Liu, Jinzhu Xu
Summary: The anisotropic wetting characteristics of droplets on micro-grooved surfaces were studied through experiments and simulations. The results showed that gravity played an important role in affecting droplet wetting behavior without inducing collapse of the Cassie-Baxter state. The spreading stage of the deposited droplets was dominantly influenced by capillary forces, and anisotropic wetting characteristics were evident with differences in droplet base length and contact angle in different directions.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Chemistry, Physical
Y. T. Aksoy, P. Eneren, E. Koos, M. R. Vetrano
Summary: This study found that even a small fraction of nanoparticles in fluids can affect the splashing behavior of a droplet upon impact on a smooth surface, promoting splashing at low Reynolds numbers. Through experiments and analysis, an empirical correlation describing the dependency of splashing threshold on nanoparticle concentration was proposed for the first time.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Engineering, Environmental
Zexin Cai, Faze Chen, Yanling Tian, Dawei Zhang, Zhongxu Lian, Moyuan Cao
Summary: This study presents a tridirectionally anisotropic slippery surface (TASS) with periodic step-like micro grooves for programmable droplet transport. The surface exhibits ultra-slipperiness along the grooves and bidirectionally anisotropic sliding perpendicular to the grooves caused by the pinning effect of the step edge. The TASS enables droplet transport under periodic vertical vibration on both horizontally and tilted surfaces.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Peiliu Li, Fei Zhan, Lei Wang
Summary: This study investigates the motion of droplets on anisotropic surfaces through experiments, theoretical models, and energy balance analysis. The research finds that the direction of droplet rebound on an anisotropic surface can be switched by designing the initial impacting velocity, and the motion of the droplet changes with an increase in impacting height.
Article
Multidisciplinary Sciences
Youchuang Chao, Olinka Ramirez-Soto, Christian Bahr, Stefan Karpitschka
Summary: The research investigates the coupling between liquid-liquid phase separation and the spreading motion of three-phase contact lines, finding that the classical Cox-Voinov law is no longer applicable and observing spreading beginning well before any visible nucleation of microdroplets. The study suggests that evaporation-induced enrichment, together with surface forces, causes an earlier nucleation in the wetting precursor film, initiating the observed wetting transition.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Chemistry, Physical
Amir Azimi Yancheshme, Giuseppe R. Palmese, Nicolas J. Alvarez
Summary: This work presents a generalized solution for the spontaneous spreading dynamics of droplets, taking into account the influence of interfacial tension and gravity. The authors validate and modify a dynamic contact angle model to accurately describe the dependency of contact angle on the contact line velocity. This model is then implemented into a computational fluid dynamics (CFD) model, which is validated using experimental results.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Engineering, Chemical
Masaki Ueda, Tomonori Fukasawa, Toru Ishigami, Kunihiro Fukui
Summary: Surface wettability has a significant impact on the coalescence of oil droplets and pressure drop within a fibrous filter. Low surface wettability promotes droplet coalescence through closely attached fibers, while high surface wettability enhances coalescence through small interfiber spacing and increases pressure drop.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Multidisciplinary Sciences
Fang Wang, Meijin Liu, Cong Liu, Chao Huang, Lidong Zhang, Anyang Cui, Zhigao Hu, Xuemin Du
Summary: Photo-induced charged superamphiphobic surfaces enable flexible and reliable droplet manipulation for droplet robots and bio-applications. The development of a new superamphiphobic material with the capability of photo-induced charge generation provides a novel approach for light control of droplets. The photo-induced charged surface (PICS) allows for controllable droplet motion with high velocity, unlimited distance, and multi-mode motions. This technology has potential applications in various fields, including robotics, biosensing, and biomedical applications.
NATIONAL SCIENCE REVIEW
(2023)
Article
Chemistry, Multidisciplinary
Cong Liu, Irina Legchenkova, Libao Han, Wenna Ge, Cunjing Lv, Shile Feng, Edward Bormashenko, Yahua Liu
Summary: The research reported experimental studies on the impact of droplets on superhydrophobic circular groove arrays, resulting in directional droplet transport. The influence of factors such as Weber number, ridge height, and deviation distance on lateral offset distance of bouncing drops was further explored. The study confirmed the suggested theoretical analysis, showing the importance of wetting transition and dynamic pressure in directional droplet transport.
Article
Multidisciplinary Sciences
Shile Feng, Pingan Zhu, Huanxi Zheng, Haiyang Zhan, Chen Chen, Jiaqian Li, Liqiu Wang, Xi Yao, Yahua Liu, Zuankai Wang
Summary: By designing 3D capillary ratchets, the spreading direction of liquids with different surface tensions can be tailored, achieving directional steering. This method also allows for self-propulsion and high flow velocity, which are preferred in liquid transport.
Article
Chemistry, Multidisciplinary
Wenna Ge, Fusheng Zhang, Dongdong Wang, Quanmao Wei, Qiongya Li, Zhixin Feng, Shile Feng, Xingya Xue, Guangyan Qing, Yahua Liu
Summary: The authors report a facile and robust strategy to create a composite material by combining poly(ethylene glycol) dimethacrylate with cellulose nanocrystals, resulting in a material with toughness, strength, and multiple responses. The composite exhibits impressive properties such as strength, stretchability, toughness, and solvent resistance, and responds to mechanical stimuli with stretchable color variation. It also shows sensitive actuation and complex 3D deformation behaviors in response to spraying moisture.
Article
Materials Science, Paper & Wood
Wenna Ge, Quanmao Wei, Fusheng Zhang, Zhixin Feng, Xiangge Bai, Shile Feng, Guangyan Qing, Yahua Liu
Summary: Cellulose nanocrystals (CNCs) exhibit sensitive chemoselectivity and precise structure modulation, providing insights into various practical applications.
Review
Green & Sustainable Science & Technology
Kuanfu Chen, Yujie Tao, Weiwei Shi
Summary: Water is essential for life, but water scarcity is becoming a severe global issue. This review summarizes recent technologies in water harvesting, based on different forms of water resources, aiming to improve water harvesting systems.
Article
Multidisciplinary Sciences
Huanxi Zheng, Jing Li, Yongsen Zhou, Chao Zhang, Wanghuai Xu, Yajun Deng, Jiaqian Li, Shile Feng, Zhiran Yi, Xiaofeng Zhou, Xianglin Ji, Peng Shi, Zuankai Wang
Summary: Researchers have reported an underwater capillary adhesive that can be strengthened by the combination of inner water bridge and outer air shell, and switched by a small direct current voltage. This study is important for the development of underwater adhesives with rapid and reversible adhesion in wet conditions.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Haiyang Zhan, Yuhang Xia, Yihe Liu, Haojie Sun, Wenna Ge, Shile Feng, Yahua Liu
Summary: Designing an intelligent slippery surface that can manipulate droplets is crucial for various applications. However, the sustainability of the lubricant layer poses a significant challenge. In this study, an ultrafast lubricant self-mediating photothermal slippery surface was designed using a porous structure and photothermal expansion of the material. The surface allows for sustainable transport of droplets under near infrared light even when the lubricant layer is completely wiped clean. Additionally, the surface enables arbitrary splitting of droplets by controlling the irradiation route of the near infrared light.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Review
Chemistry, Physical
Quanmao Wei, Wenna Ge, Zichao Yuan, Shixu Wang, Chenguang Lu, Shile Feng, Lei Zhao, Yahua Liu
Summary: With the increasing concern of energy crisis and global warming, there is an urgent need for the development of clean energy from renewable sources. Moisture electricity generation is an emerging technology which converts low-grade energy from moisture into electricity through hygroscopic films. Recent research on moisture electricity generators (MEGs) has led to the creation of self-powered sensors and potential replacements for conventional batteries. This review summarizes the mechanisms, different types, advances, and applications of MEGs, and highlights the remaining challenges and future perspectives.
Article
Nanoscience & Nanotechnology
Liang Zhang, Haiyang Zhan, Yuhang Xia, Renwei Zhang, Juncheng Xue, Jiahao Yong, Lei Zhao, Yahua Liu, Shile Feng
Summary: Surfaces with efficient passive daytime radiative cooling (PDRC) that maximize solar reflection and thermal radiation to the outer space have practical challenges due to complicated fabrication processes, contamination and damage, and high costs. In this study, a hierarchically designed passive daytime radiative cooling film (HPRF) made of cost-effective Al2O3 particles and PDMS was fabricated using a simple phase separation method. The HPRF film showed high solar spectrum reflectance and mid-infrared emittance, leading to a subambient cooling effect under direct solar irradiation. The film's excellent PDRC is attributed to the efficient Mie scattering and molecular vibrations of PDMS and the phonon polariton resonance of Al2O3 particles. Furthermore, the HPRF film has robust durability with self-cleaning, flexibility, and anti-ultraviolet radiation properties, making it promising for thermal management in electronic devices and wearable products.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Yihe Liu, Haiyang Zhan, Xixing He, Mengfan Zhang, Juncheng Xue, Tianhao Ouyang, Lei Zhao, Yahua Liu, Shile Feng
Summary: A tilted-sector arrayed tube is proposed for excellent liquid unidirectional transport, which applies to a vast width domain of liquid surface tension and injecting velocity. The transport direction is abnormally against the tilted direction of structure, in stark contrast to the traditional understanding. This excellent and unique liquid unidirectional transport is caused by synergistic effects of tilted sectors and tube structures, which induce a unique 3D liquid propagation mode as well as a large Laplace pressure asymmetry between the front and rear sides of the liquid.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Multidisciplinary Sciences
Zichao Yuan, Chenguang Lu, Cong Liu, Xiangge Bai, Lei Zhao, Shile Feng, Yahua Liu
Summary: This study proposes a droplet ultrasonic tweezer (DUT) based on phased array for versatile droplet manipulation. By changing the position of the focal point, the DUT can generate a twin trap ultrasonic field for trapping and maneuvering the droplet, enabling highly flexible and precise programmable control. The findings provide a satisfactory paradigm for robust contactless droplet manipulation in various practical settings.
Article
Engineering, Multidisciplinary
Xixing He, Yihe Liu, Haiyang Zhan, Yahua Liu, Lei Zhao, Shile Feng
Summary: A bionic flounder two-tier structural surface (BFTSS) inspired by flounder ctenoid scales can significantly reduce skin friction drag in both forward and backward directions. This bidirectional drag reduction is achieved through the synergistic effects of the two-tier structures, which distort the boundary layer flow and mitigate viscous shear, as well as promote flow separation to relieve the pressure gradient in the viscous sublayer. The BFTSS technology has potential applications in reducing energy consumption in ships, underwater vessels, and pipeline transport.
Article
Materials Science, Multidisciplinary
Chenguang Lu, Cong Liu, Zichao Yuan, Haiyang Zhan, Danyang Zhao, Lei Zhao, Shile Feng, Yahua Liu
Summary: Preventing frost formation on surfaces is crucial for anti-icing applications. This study demonstrates that using a macro-ridged surface can prevent ice formation by changing the distribution of water vapor, leading to the formation of a frost-free zone.
COMMUNICATIONS MATERIALS
(2022)
Article
Engineering, Multidisciplinary
Yahua Liu, Zhixin Feng, Haiyang Zhan, Wenna Ge, Yuhang Xia, Junqiu Zhang, Shile Feng
Summary: Hot-water repellency on traditional superhydrophobic surfaces is challenging due to the formation of liquid bridges between tiny droplets and the substrate. In this study, a facile and fluorine-free vapor-deposition method was proposed to fabricate excellent hot-water-repellent surfaces. The surfaces showed outstanding repellency to hot water droplets and other normal-temperature droplets with high surface tension, and also demonstrated excellent self-cleaning performance in specific environments.
Article
Chemistry, Multidisciplinary
Yahua Liu, Peng Xu, Wenna Ge, Chenguang Lu, Yunlai Li, Shichao Niu, Junqiu Zhang, Shile Feng
Summary: The study proposed a method for synchronous oil/water separation and wastewater treatment on mesh surfaces coated with copper-oxide particles. The superwetting and catalytic properties of copper oxide were utilized to achieve selective oil/water separation and water purification. Adjusting the content of copper oxide on the mesh surfaces could result in high efficiencies for both oil/water separation and catalytic degradation of organic pollutants.
