Formation and Mechanism of Superhydrophobic/Hydrophobic Surfaces Made from Amphiphiles through Droplet-Mediated Evaporation-Induced Self-Assembly
- 9 April 2015
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry B
- Vol. 119 (16), 5321-5327
- https://doi.org/10.1021/acs.jpcb.5b00011
Abstract
Superhydrophobic/hydrophobic surfaces have attracted wide attention because of their broad applications in various regions, including coating, textile, packaging, electronic devices, and bioengineering. Many studies have been focused on the fabrication of superhydrophobic/hydrophobic surfaces using natural materials. In this paper, superhydrophobic/hydrophobic surfaces were formed by an amphiphilic natural protein, zein, using electrospinning. Water contact angle (WCA) and scanning electron microscopy (SEM) were used to characterize the hydrophobicity and surface morphology of the electrospun structures. The highest WCA of the zein electrospun surfaces could reach 155.5 ± 1.4°. To further understand the mechanism of superhydrophobic surface formation from amphiphiles using electrospinning, a synthetic amphiphilic polymer was selected, and also, a method similar to electrospinning, spray drying, was tried. The electrospun amphiphilic polymer surface showed a high hydrophobicity with a WCA of 141.4 ± 0.7°. WCA of the spray-dried zein surface could reach 125.3 ± 2.1°. The secondary structures of the zein in the electrospun film and cast-dried film were studied using ATR-FTIR, showing that α-helix to β-sheet transformation happened during the solvent evaporation in the cast drying process but not in the electrospinning process. A formation mechanism was proposed on the basis of the orientation of the amphiphiles during the solvent evaporation of different fabrication methods. The droplet-based or jet-based evaporation during electrospinning and spray drying led to the formation of the superhydrophobic/hydrophobic surface by the accumulation of the hydrophobic groups of the amphiphiles on the surface, while the surface-based evaporation during cast drying led to the formation of the hydrophilic surface by the accumulation of the hydrophilic groups of the amphiphiles on the surface.Keywords
Funding Information
- National Natural Science Foundation of China (51303153)
- Hong Kong Polytechnic University (1-ZVA9, 5-ZDAJ, G-UC07, G-YK99)
This publication has 28 references indexed in Scilit:
- Electrospinning of Prolamin Proteins in Acetic Acid: The Effects of Protein Conformation and Aggregation in SolutionMacromolecular Materials and Engineering, 2012
- Nanoscale Characterization of Zein Self-AssemblyLangmuir, 2012
- Controlled Delivery of Gentamicin Antibiotic from Bioactive Electrospun Polylactide‐Based Ultrathin FibersAdvanced Engineering Materials, 2011
- Production of hydrophobic surfaces in biodegradable and biocompatible polymers using polymer solution electrospinningJournal of Applied Polymer Science, 2010
- Formation of Zein Microphases in Ethanol−WaterLangmuir, 2010
- Structural Properties and Antibacterial Effects of Hydrophobic and Oleophobic Sol−Gel Coatings for Cotton FabricsLangmuir, 2009
- Electrospinning: Applications in drug delivery and tissue engineeringBiomaterials, 2008
- Production of superhydrophobic polymer fibers with embedded particles using the electrospinning techniquePolymer International, 2007
- Preparation of superhydrophobic polystyrene membranes by electrospinningColloids and Surfaces A: Physicochemical and Engineering Aspects, 2007
- Three-dimensional structure of maize α-zein proteins studied by small-angle X-ray scatteringBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1997