Skip to content
DraconiticResearch
Search Sources API
203,234 studies31 sourcesUpdated 30 min ago
Peer-reviewedCC BY 4.0Molecules

A Durable Hierarchical ZnO/Epoxy Superhydrophobic Coating for Dual-Mode Drag Reduction of Surface and Underwater Vehicles

  • Ruoyu Sun1
  • Yan Huang2
  • Jing Zhao3
  • Jiangpeng Qu3
  1. 1School of Mechanical Engineering, Sichuan University of Science and Engineering, Yibin 644000, China
  2. 2College of Physical Education and Health Science, Yibin University, Yibin 644000, China
  3. 3School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, China
Open at sourceDOICite

Abstract

Superhydrophobic coatings can reduce hydrodynamic drag without external energy input, but their application in marine vehicles is hindered by limited durability and by studies addressing only a single navigation mode. Here, a durable ZnO/epoxy superhydrophobic coating with a hierarchical flower-like micro/nanostructure was fabricated by spray coating followed by chemical immersion, and its wettability, durability, and drag-reduction performance were systematically evaluated by model ship towing tests, steel-ball free-fall tests, interfacial friction measurements, and numerical simulations. The coating showed a water contact angle of 161.8 ± 3.1° and a roll-off angle below 1°, and remained superhydrophobic after 200 cm of sandpaper abrasion, 50 h of underwater immersion, 100 repeated water-entry cycles, and immersion in pH 1–11 solutions. The superhydrophobic model ship achieved drag-reduction efficiencies of up to 31%, while the 20 and 30 mm superhydrophobic steel balls achieved 19% and 28%, respectively. Interfacial friction measurements and numerical simulations revealed that the retained air layer induces wall slip on the water surface, whereas the entrained spindle-shaped cavity delays flow separation underwater, reducing both frictional and pressure drag. These results demonstrate a feasible coating strategy for energy-saving marine vehicles operating at or below the water surface.

Related

  1. Hierarchical Multimodal Large Language Model-Based Interpretation and Aggregation of PDP and ICE Explanations for Battery State-of-Charge Prediction in Electric Vehicles
    Jaeseung Lee, Jehyeok Rew
    BatteriesPeer-reviewedCC BY 4.0Full textElectrochemistry & energyCrossrefDOAJ
  2. Surface‐Selective Pt Enrichment for Stabilizing Ultrathin 2D PtCu Nanosheets Toward Durable Oxygen Reduction
    HyunWoo J. Yang, SangJae Lee, KwangHo Lee +5
    Advanced SciencePeer-reviewedCC BY 4.0Full textElectrochemistry & energyPMC
  3. Hierarchical nature of hydrogen-based direct reduction of iron oxides
    Yan Ma, Isnaldi Souza Filho, Yang Bai +12
    Scripta MaterialiaPeer-reviewedCC BY-NC-ND 4.0Full text162 citedMaterials & polymersCondensed matterHAL
  4. Superhydrophobic Porous Coordination Polymer-Confined Co3O4 Nanoparticles: A Sustainable Strategy for Electrochemical Water Splitting
    Ravula Nagaraju, Litun Kumar Pradhan, J. N. Behera +1
    ACS omegaPeer-reviewedCC BY-NC-NDFull textGeneral chemistryEurope PMC
  5. Superhydrophobic-Like Complete Rebound of Impacting Water Droplets on a Smooth Oleic- Acid-Coated Phenyl-Silica Surface
    Dai Watanabe, Keita Niikura, Youfeng Yue +1
    ChemRxivPreprintCC BYFull textMaterials & polymersChemRxiv

Cite

BibTeXRIS
BibTeX
@article{sun2026durable,
  title = {{A Durable Hierarchical ZnO/Epoxy Superhydrophobic Coating for Dual-Mode Drag Reduction of Surface and Underwater Vehicles}},
  author = {Ruoyu Sun and Yan Huang and Jing Zhao and Jiangpeng Qu},
  journal = {Molecules},
  year = {2026},
  month = oct,
  doi = {10.3390/molecules31213896},
  url = {https://www.mdpi.com/1420-3049/31/21/3896},
  note = {CC BY 4.0},
}
RIS
TY  - JOUR
TI  - A Durable Hierarchical ZnO/Epoxy Superhydrophobic Coating for Dual-Mode Drag Reduction of Surface and Underwater Vehicles
AU  - Ruoyu Sun
AU  - Yan Huang
AU  - Jing Zhao
AU  - Jiangpeng Qu
PY  - 2026
DA  - 2026/10/28
JO  - Molecules
DO  - 10.3390/molecules31213896
UR  - https://www.mdpi.com/1420-3049/31/21/3896
AB  - Superhydrophobic coatings can reduce hydrodynamic drag without external energy input, but their application in marine vehicles is hindered by limited durability and by studies addressing only a single navigation mode. Here, a durable ZnO/epoxy superhydrophobic coating with a hierarchical flower-like micro/nanostructure was fabricated by spray coating followed by chemical immersion, and its wettability, durability, and drag-reduction performance were systematically evaluated by model ship towing tests, steel-ball free-fall tests, interfacial friction measurements, and numerical simulations. The coating showed a water contact angle of 161.8 ± 3.1° and a roll-off angle below 1°, and remained superhydrophobic after 200 cm of sandpaper abrasion, 50 h of underwater immersion, 100 repeated water-entry cycles, and immersion in pH 1–11 solutions. The superhydrophobic model ship achieved drag-reduction efficiencies of up to 31%, while the 20 and 30 mm superhydrophobic steel balls achieved 19% and 28%, respectively. Interfacial friction measurements and numerical simulations revealed that the retained air layer induces wall slip on the water surface, whereas the entrained spindle-shaped cavity delays flow separation underwater, reducing both frictional and pressure drag. These results demonstrate a feasible coating strategy for energy-saving marine vehicles operating at or below the water surface.
SN  - 1420-3049
ER  -