Article
Multidisciplinary Sciences
Hossein Zargartalebi, S. Hossein Hejazi, Amir Sanati-Nezhad
Summary: The authors introduce a passive protocol to suppress the coffee-ring effect and form uniform films at micro- and nanoscales by combining superhydrophilic substrate with a neutral-wetting low-roughness mold. This method has broad applications in fabricating ordered coatings, producing nanofilters, and creating functionalized nanosensors.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Yi-Ting Cheng, Heng-Kwong Tsao, Yu-Jane Sheng
Summary: In this study, it was demonstrated that various ordered structures of adsorbed nanorods on smooth substrates can be achieved simply by non-affinity adsorption through dissipative particle dynamics simulations. The structures of interfacial assembly depend on nanorod concentration and solvent size, with the arrangement changing from nematic-like to smectic as the concentration increases. The assembly process is driven by entropy and results in a two-dimensional layer-by-layer growth.
Article
Thermodynamics
Pu Zhang, Zhikun Xu, Tianyou Wang, Zhizhao Che
Summary: A novel method to measure the vapor concentration field during the impact of volatile droplets on solid surfaces was proposed in this study, using modified background oriented Schlieren, inverse Radon transform, high-speed imaging, and image processing techniques. The results demonstrated a significant difference in vapor distribution from the diffusion-limited model due to strong convection during the impact process. The complex structure of the vapor cloud was attributed to the interplay among fluid inertia, fluid evaporation, vapor diffusion, vapor convection, and droplet shape evolution.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Environmental Sciences
Jiaqi Li, Bing Gao
Summary: This study reconstructed the Epan at meteorological stations in China from 1985 to 2017 using the PenPan model, and compared the differences in Epan between urban and adjacent rural stations. The results showed that urbanization increased the annual Epan at urban stations by approximately 50-200 mm compared with rural stations. Urbanization also tended to enhance the trend in Epan during the rapid urbanization period. The increase in vapor pressure deficit and air temperature caused by urbanization was the main reason for the differences in Epan between urban and rural stations.
Article
Thermodynamics
Jiazheng Liu, Jialing Yu, Xuemei Chen, Zhenhai Pan
Summary: Understanding droplet evaporation is important for science and industry. In this study, numerical simulations were used to investigate the evaporation of vertical and pendant ethanol droplets. A comprehensive model that incorporates multiple mechanisms was developed and showed excellent accuracy. The study found that vertical droplets have higher evaporation intensity and internal convection, while pendant and sessile droplets are similar.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Energy & Fuels
Yuan-Qing Lin, Chun-Mei Wu, You-Rong Li
Summary: This study investigates the influence of vapor environment on the thermal patterns induced by water droplet evaporation through a series of experiments. The results show that the thermal patterns transition from gear-like distribution to Bénard-Marangoni cell in ethanol vapor, while the transition is from central warmer region to shifting multi-cells in nitrogen environment. The initial pressure reduction enhances the thermocapillary instabilities and brings the critical time for pattern transition forward. The tangential and normal temperature gradients determine the internal flow and the evolution of thermal patterns. The solutal-Marangoni convection is induced in ethanol vapor to suppress the buoyancy flow.
Article
Thermodynamics
Ankita Pujahari, Sunando Dasgupta, Anandaroop Bhattacharya
Summary: This study focuses on the performance of thin film evaporation using micropillar arrays in an ultra-thin vapor chamber. A numerical model was developed to analyze the fluid flow and phase change heat transfer, considering the capillary pumping action. The results show that the geometry and arrangement of the micropillars strongly influence the pumping action, liquid vapor interface shape, pressure field, and dry-out heat flux within the vapor chamber.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Mechanics
Robin Pham, Sheng Wang, Heng-Chieh Chien, Chung-Lung Chen
Summary: The impact of topology on capillary action in heat pipes and vapor chambers was studied to optimize thermal performance. Different planar topologies of thermal ground were evaluated for their ability to facilitate liquid transportation, with tightly packed structures shown to draw the most liquid in the same amount of time. It was found that sufficient clearance between structures and freedom of mobility are two core constraints that need to be met for efficient capillary performance.
Article
Chemistry, Physical
Yang Liu, Yangbin Zhu, Hailong Hu, Tailiang Guo, Fushan Li
Summary: In this study, it was found that physically confined space can affect the flow and self-assembly process of droplets in inkjet printing techniques, without the need for additional modification of quantum dots or solvents. Additionally, the research results provide important guidance for inkjet-printed patterning applications.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Thermodynamics
Hongbo Guo, Qingyang Meng, Yong Xu, Huangwei Zhang
Summary: The autoignition of n-heptane droplet/vapor/air mixtures behind an oblique shock wave was studied using the Eulerian-Lagrangian method and a skeletal chemical mechanism. The study investigated the effects of gas/liquid equivalence ratio, droplet diameter, flight altitude, and Mach number on ignition transient and chemical timescales. The results showed that the ratio of chemical excitation time to ignition delay time can predict the oblique detonation wave transition mode. The study provided insights into spray oblique detonation wave initiation.
COMBUSTION AND FLAME
(2023)
Article
Chemistry, Multidisciplinary
Chang Li, Yafeng Yu, Huizeng Li, Haisong Lin, Huanqing Cui, Yi Pan, Ruotong Zhang, Yanlin Song, Ho Cheung Shum
Summary: The heterogeneous self-assembly of a single type of nanoparticle is achieved by quickly evaporating a colloid-poly(ethylene glycol) (PEG) droplet, facilitated by the spatial confinement induced by a skin layer. This approach allows for the formation of face-centered-cubic (FCC) lattices with different plane orientations, generating binary bandgaps and structural colors. The self-assembly of nanoparticles can be regulated by adjusting the PEG concentration, and the method is applicable to various droplet shapes, substrates, and nanoparticle types.
Article
Construction & Building Technology
Menghui Liao, Rong Luo
Summary: In this study, the three main factors influencing blistering in pavement were investigated, along with the deformation characteristics and growth mechanisms of blisters. The results showed that temperature had the greatest influence on blistering growth, while the initial debonding area had the least influence. Blistering growth reached its limit within 30 to 90 minutes during the curing period, and blister deformation was rapid when the ambient temperature exceeded 30 degrees C. The ability of epoxy asphalt mixtures to resist deformation positively correlated with curing time.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Thermodynamics
Arnov Paul, Purbarun Dhar
Summary: This article experimentally investigates the vapor-mediated interaction behavior between evaporating pendant and sessile droplets in an interacting droplet system. The study reveals that the mass transfer rate from both droplets is reduced due to the interaction of their evaporative fluxes, hindering the diffusion and impeding the evaporation rate. A theoretical model is proposed to characterize the vapor diffusion domain and the relationship between the effective external vapor concentration and the separation distance between the droplets. The experimental observations are found to be in good agreement with the predictions from the theoretical model.
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Chemical
Christian Lieber, Stefanos Melekidis, Rainer Koch, Hans-Joerg Bauer
Summary: Understanding the transmission of SARS-CoV-2 through virus-laden droplets and aerosols is crucial for controlling the COVID-19 pandemic. This study focuses on the evaporation characteristics of saliva droplets, finding that the final droplet diameter correlates with 20% of the initial diameter.
JOURNAL OF AEROSOL SCIENCE
(2021)
Article
Chemistry, Physical
M. Mohib Ur Rehman, Gyoko Nagayama
Summary: In this study, it was found that the presence of micro/nanostructured surfaces significantly affects the evaporation rate of droplets, with the wettability and volume of the droplets further influencing this effect. Theoretical and experimental results showed agreement when the scale of the solid-liquid-vapor interface (slv) was negligible. For microstructured surfaces, the scale of the slv interface could reach 253-940 μm, and the evaporation rate at the slv interface accounted for 16-48% of the total evaporation rate. The scale and rate of the slv interface increased with a decrease in the initial contact angle or an increase in the droplet volume. These findings are important for practical engineering and medical applications involving droplet evaporation on micro/nanostructured surfaces.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Physics, Applied
Lalit Bansal, Pranjal Seth, Bhubesh Murugappan, Saptarshi Basu
APPLIED PHYSICS LETTERS
(2018)
Article
Chemistry, Physical
Angkur Jyoti Dipanka Shaikeea, Saptarshi Basu, Lalit Bansal
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2018)
Article
Chemistry, Multidisciplinary
Lalit Bansal, Apratim Sanyal, Prasenjit Kabi, Binita Pathak, Saptarshi Basu
Article
Chemistry, Physical
Sandeep Hatte, Riju Dhar, Lalit Bansal, Suman Chakraborty, Saptarshi Basu
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2019)
Article
Mechanics
Sandeep Hatte, Keshav Pandey, Khushboo Pandey, Suman Chakraborty, Saptarshi Basu
JOURNAL OF FLUID MECHANICS
(2019)
Article
Chemistry, Multidisciplinary
S. Hatte, R. Pitchumani
Article
Chemistry, Physical
Gannena K. S. Raghuram, Lalit Bansal, Saptarshi Basu, Aloke Kumar
Summary: This study experimentally investigates the concentration and molecular weight dependence of deposit patterns of polymer droplets on hydrophobic surfaces. The results show a transition from ring to non-ring patterns with increasing concentration, while decreasing the polymer molecular weight does not suppress the coffee ring formation. The findings provide insights for applications like inkjet printing, surface coatings, and biotechnology assays where tuning polymer deposit patterns is important.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Thermodynamics
S. Hatte, R. Pitchumani
Summary: An analytical model is developed in this study for structured non-wetting surfaces, which provides optimal design maps for maximizing convective heat transfer and thermal-hydraulic performance in fluid flow over cylinder surfaces. It is found that structured non-wetting surfaces are most effective for low Reynolds numbers and small cylinder radii.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Environmental
S. Hatte, R. Pitchumani
Summary: This article explores multiscale rough superhydrophobic or slippery liquid infused porous surfaces and develops analytical models for convection heat transfer. It shows that multiscale non-wetting surfaces are most effective in the range of lower Reynolds number and small cylinder radius for achieving the best convective heat transfer. Contrary to prevailing notion, it also demonstrates that superhydrophobicity does not always lead to the maximum convective heat transfer performance.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Thermodynamics
S. Hatte, R. Stoddard, R. Pitchumani
Summary: This study systematically analyzes the dynamic flow fouling of calcium carbonate and calcium sulfate on smooth, superhydrophobic, and liquid-infused surfaces. The fouling characteristics are examined through microstructural analysis and quantified using fouling resistance and threshold time. The study presents closed-form analytical relationships for fouling resistance and threshold time based on the Reynolds number, fouling agent concentration, and infused liquid viscosity. The results accurately predict the fouling characteristics and provide contour maps for optimal surface designs to minimize fouling resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Chemical
Sandeep Hatte, Ranga Pitchumani
Summary: This paper compares the temperature-dependent mineral fouling deposition on smooth surfaces and nonwetting superhydrophobic and lubricant-infused surfaces under dynamic flow conditions. The study develops an empirical relationship for the asymptotic fouling resistance in terms of Reynolds number, foulant concentration, temperature, and surface type. The results provide insight into the temperature-dependent fouling of surfaces and a rational design of fouling-resistant nonwetting surfaces.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Thermodynamics
S. Hatte, R. Stoddard, R. Pitchumani
Summary: In this article, we introduce a novel nonwetting solid-infused surface that is easily fabricated using industrially widely adopted methods and exhibits sustained dropwise condensation performance better than superhydrophobic and lubricant-infused surfaces.
APPLIED THERMAL ENGINEERING
(2023)
Article
Chemistry, Physical
S. Hatte, R. Pitchumani
Summary: This paper develops an analytical model for evaluating effective slip and drag reduction on liquid-infused structured non-wetting surfaces, eliminating empirical fitting in previous studies. It also presents design maps for achieving desired drag reduction and validates the model across experimental and computational data.
Article
Physics, Fluids & Plasmas
Khushboo Pandey, Sandeep Hatte, Keshav Pandey, Suman Chakraborty, Saptarshi Basu