Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
6.7
4.6
Journals
Molecules
Special Issues
Superhydrophobic and Superoleophobic Materials
molecules-logo
Submit to Molecules Review for Molecules Propose a Special Issue

Journal Menu

► Journal Menu

Journal Browser

► Journal Browser
share announcement

Superhydrophobic and Superoleophobic Materials

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Materials Chemistry".

Deadline for manuscript submissions: closed (31 March 2023) | Viewed by 10015

Special Issue Editor

Dr. Jiale Yong

E-Mail Website
Guest Editor
Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230027, China
Interests: femtosecond laser microfabrication; controlling the wettability of solid surfaces; bio-inspired superwettability-based applications
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Wettability is one of the most basic properties of solid surfaces, mainly depending on surface chemical composition and structures. Particularly, materials showing superwettability are most captivating for their significance in bionics, fundamental research, and practical applications. After billions of years of evolution, creatures in nature have nearly perfect structure and function, and many organisms have evolved special surface wettability. For example, the lotus leaf has a self-cleaning function; water striders can walk on water surfaces; butterflies can shake off raindrops and fly in the rain; the eyes of mosquito can repel fog; fish scales cannot be polluted by oil in water; and desert beetles, cacti, and spider silk have the capacity of harvesting water in dry air. Inspired by superwettability in nature, a large number of superhydrophobic and superoleophobic materials have been developed by the combination of designing special surface microstructures and appropriate chemical composition in the past two decades. Artificial superhydrophobic or superoleophobic materials have attracted much attention because of their broad applications in liquid repellence, self-cleaning coatings, anti-fog/ice/snow, anti-corrosion for metals, underwater drag reduction, cell engineering, oil/water separation, liquid/droplet manipulation, microfluidics, lab on a chip, buoyancy enhancement, liquid patterning, etc. Studies related to extreme surface wettability is still a current research focus. This issue presents recent developments of superhydrophobic/superoleophobic surfaces, mainly focusing on their design principles, fabrication methods, colorful properties, and novel applications.

Dr. Jiale Yong
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • surface wettability
  • superhydrophobicity
  • superoleophobicity
  • micro/nanostructures
  • liquid repellence
  • self-cleaning

Published Papers (5 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

11 pages, 6715 KiB  
Article
Molecular Simulation Study on the Wettability of a Surface Texturized with Hierarchical Pillars
by Kiduk Kim, Seyong Choi, Zhengqing Zhang and Joonkyung Jang
Molecules 2023, 28(11), 4513; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules28114513 - 02 Jun 2023
Cited by 1 | Viewed by 1096
Abstract
By using molecular dynamics simulation, we investigate the wettability of a surface texturized with a periodic array of hierarchical pillars. By varying the height and spacing of the minor pillars on top of major pillars, we investigate the wetting transition from the Cassie–Baxter [...] Read more.
By using molecular dynamics simulation, we investigate the wettability of a surface texturized with a periodic array of hierarchical pillars. By varying the height and spacing of the minor pillars on top of major pillars, we investigate the wetting transition from the Cassie–Baxter (CB) to Wenzel (WZ) states. We uncover the molecular structures and free energies of the transition and meta-stable states existing between the CB and WZ states. The relatively tall and dense minor pillars greatly enhance the hydrophobicity of a pillared surface, in that, the CB-to-WZ transition requires an increased activation energy and the contact angle of a water droplet on such a surface is significantly larger. Full article
(This article belongs to the Special Issue Superhydrophobic and Superoleophobic Materials)
►▼ Show Figures

Graphical abstract

13 pages, 3751 KiB  
Article
Effect of Oxyfluorination of PFA-Coated Metal Mesh with Superhydrophobic Properties on the Filtration Performance of SiO2 Microparticles
by Kyung-Soo Kim, Cheol-Hwan Kwak, Seong-Min Ha, Jae-Chun Ryu and Young-Seak Lee
Molecules 2023, 28(7), 3110; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules28073110 - 30 Mar 2023
Cited by 1 | Viewed by 1426
Abstract
Recently, semiconductor wastewater treatment has received much attention due to the emergence of environmental issues. Acid-resistant coatings are essential for metal prefilters used in semiconductor wastewater treatment. Perfluoroalkoxy alkane is mainly used as an acid-resistant coating agent, since PFA has inherent superhydrophobicity, water [...] Read more.
Recently, semiconductor wastewater treatment has received much attention due to the emergence of environmental issues. Acid-resistant coatings are essential for metal prefilters used in semiconductor wastewater treatment. Perfluoroalkoxy alkane is mainly used as an acid-resistant coating agent, since PFA has inherent superhydrophobicity, water permeability is lowered. To solve this problem, the surface of the PFA-coated metal mesh was treated via an oxyfluorination method in which an injected mixed gas of fluorine and oxygen reacted with the surface functional groups. Surface analysis, water contact angle measurement, and water permeability tests were performed on the surface-treated PFA-coated mesh. Consequently, the superhydrophobic surface was effectively converted to a hydrophobic surface as the PFA coating layer was surface-modified with C-O-OH functional groups via the oxyfluorination reaction. As a result of using simulation solutions that float silica particles of various sizes, the permeability and particle removal rate of the surface-modified PFA-coated stainless-steel mesh were improved compared to those before surface modification. Therefore, the oxyfluorination treatment used in this study was suitable for improving the filtration performance of SiO2 microparticles in the PFA-coated stainless-steel mesh. Full article
(This article belongs to the Special Issue Superhydrophobic and Superoleophobic Materials)
►▼ Show Figures

Graphical abstract

17 pages, 12556 KiB  
Article
Eco-Friendly Fluorine Functionalized Superhydrophobic/Superoleophilic Zeolitic Imidazolate Frameworks–Based Composite for Continuous Oil–Water Separation
by Wenlong Xiang, Siyu Gong and Jiabin Zhu
Molecules 2023, 28(6), 2843; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules28062843 - 21 Mar 2023
Cited by 2 | Viewed by 1550
Abstract
Superhydrophobic metal−organic framework (MOF)-based sponges have received increasing attention in terms of treating oil−water mixtures. However, highly fluorinated substances, commonly used as modifiers to improve the hydrophobicity of MOFs, have aroused much environmental concern. Developing a green hydrophobic modification is crucial in order [...] Read more.
Superhydrophobic metal−organic framework (MOF)-based sponges have received increasing attention in terms of treating oil−water mixtures. However, highly fluorinated substances, commonly used as modifiers to improve the hydrophobicity of MOFs, have aroused much environmental concern. Developing a green hydrophobic modification is crucial in order to prepare superhydrophobic MOF-sponge composites. Herein, we report the preparation of a porous composite sponge via a polydopamine (PDA)-assisted growth of zeolitic imidazolate frameworks (ZIF-90) and eco-friendly hydrophobic short-chain fluorinated substances (trifluoroethylamine) on a melamine formaldehyde (MF) sponge. The composite sponge (F-ZIF-90@PDA-MF) exhibited superhydrophobicity (water contact angle, 153°) and superoleophilicity (oil contact angle, 0°), which is likely due to the combination of the low surface energy brought on by the grafted CF3 groups, as well as the rough surface structures that were derived from the in situ growth of ZIF-90 nanoparticles. F-ZIF-90@PDA-MF showed an excellent adsorption capacity of 39.4–130.4 g g−1 for the different organic compounds. The adsorbed organic compounds were easily recovered by physical squeezing. Continuous and selective separation for the different oil−water mixtures was realized by employing the composite sponge as an absorbent or a filter. The separation efficiency and flux reached above 99.5% and went up to 7.1 ×105 L m−2 h−1, respectively. The results illustrate that the superhydrophobic and superoleophilic F-ZIF-90@PDA-MF sponge has potential in the field of water−oil separation, especially for the purposes of large-scale oil recovery in a water environment. Full article
(This article belongs to the Special Issue Superhydrophobic and Superoleophobic Materials)
►▼ Show Figures

Graphical abstract

19 pages, 4816 KiB  
Article
Superhydrophobic Aluminium Surface to Enhance Corrosion Resistance and Obtain Self-Cleaning and Anti-Icing Ability
by Peter Rodič, Barbara Kapun and Ingrid Milošev
Molecules 2022, 27(3), 1099; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules27031099 - 07 Feb 2022
Cited by 12 | Viewed by 2817
Abstract
A facile environmentally acceptable surface roughening method using chemical etching in HCl/H2O2 followed by grafting with n-octyltrimethoxysilane (AS-8) and 1H,1H,2H,2H-perfluorooctyltrimethoxysilane (FAS-8) was studied to fabricate a (super)hydrophobic aluminium surface. The ground aluminium surface after selected etching times (before and after [...] Read more.
A facile environmentally acceptable surface roughening method using chemical etching in HCl/H2O2 followed by grafting with n-octyltrimethoxysilane (AS-8) and 1H,1H,2H,2H-perfluorooctyltrimethoxysilane (FAS-8) was studied to fabricate a (super)hydrophobic aluminium surface. The ground aluminium surface after selected etching times (before and after grafting), was characterised using a contact profilometer, optical tensiometer, scanning electron microscope coupled with an energy-dispersive spectroscope and X-ray photoelectron spectroscope to evaluate surface roughness, wettability, surface morphology and composition. The durability of the grafted surface was tested using thermal and UV resistance tests. The corrosion properties were evaluated using potentiodynamic measurements and standard salts spray testing, ASTM B117-19. Finally, the self-cleaning and anti-icing abilities were assessed. The grafted aluminium surface with octyl- or perfluorooctyl silane reflected the highly hydrophobic (AS-8) and superhydrophobic behaviour (FAS-8). Moreover, the different behaviour of the octyl- or perfluorooctyl chain in the silane molecule on modified surface properties was also noticed because durability tests confirmed greater thermal, UV stability and corrosion resistance of FAS-8 compared to AS-8. The aluminium etched for 2 min and grafted with FAS-8 also demonstrated an excellent self-cleaning and anti-icing performance. Full article
(This article belongs to the Special Issue Superhydrophobic and Superoleophobic Materials)
►▼ Show Figures

Graphical abstract

13 pages, 4560 KiB  
Article
Application of Nano-Hydroxyapatite Derived from Oyster Shell in Fabricating Superhydrophobic Sponge for Efficient Oil/Water Separation
by Chao Liu, Su-Hua Chen, Chi-Hao Yang-Zhou, Qiu-Gen Zhang and Ruby N. Michael
Molecules 2021, 26(12), 3703; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules26123703 - 17 Jun 2021
Cited by 8 | Viewed by 2468
Abstract
The exploration of nonhazardous nanoparticles to fabricate a template-driven superhydrophobic surface is of great ecological importance for oil/water separation in practice. In this work, nano-hydroxyapatite (nano-HAp) with good biocompatibility was easily developed from discarded oyster shells and well incorporated with polydimethylsiloxane (PDMS) to [...] Read more.
The exploration of nonhazardous nanoparticles to fabricate a template-driven superhydrophobic surface is of great ecological importance for oil/water separation in practice. In this work, nano-hydroxyapatite (nano-HAp) with good biocompatibility was easily developed from discarded oyster shells and well incorporated with polydimethylsiloxane (PDMS) to create a superhydrophobic surface on a polyurethane (PU) sponge using a facile solution–immersion method. The obtained nano-HAp coated PU (nano-HAp/PU) sponge exhibited both excellent oil/water selectivity with water contact angles of over 150° and higher absorption capacity for various organic solvents and oils than the original PU sponge, which can be assigned to the nano-HAp coating surface with rough microstructures. Moreover, the superhydrophobic nano-HAp/PU sponge was found to be mechanically stable with no obvious decrease of oil recovery capacity from water in 10 cycles. This work presented that the oyster shell could be a promising alternative to superhydrophobic coatings, which was not only beneficial to oil-containing wastewater treatment, but also favorable for sustainable aquaculture. Full article
(This article belongs to the Special Issue Superhydrophobic and Superoleophobic Materials)
►▼ Show Figures

Graphical abstract

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-5
Back to TopTop