A surface with superoleophilic-to-superoleophobic wettability gradient.
Guangyu Zhang1, Xin Zhang, Meng Li
1State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China.
ACS Applied Materials & Interfaces
|January 15, 2014
Summary
Researchers created tunable wettability gradient surfaces on aluminum using polyelectrolyte multilayer (PEM) deposition and counterion exchange. This method allows precise control over surface wetting properties, from superoleophilic to superoleophobic, for advanced material applications.
Area of Science:
- Materials Science
- Surface Chemistry
- Nanotechnology
Background:
- Fabricating surfaces with controlled, spatially varying wettability is crucial for advanced applications.
- Existing methods often lack precise control over the wettability gradient or are difficult to tune.
- Aluminum surfaces present unique challenges due to their native oxide layer and reactivity.
Purpose of the Study:
- To develop a novel strategy for creating continuous wettability gradient surfaces on rough aluminum.
- To precisely control the transition from superoleophilic to superoleophobic wetting behaviors.
- To investigate the role of counterion exchange kinetics in tailoring surface chemical composition and wettability.
Main Methods:
- Fabrication of polyelectrolyte multilayer (PEM) films on rough aluminum substrates.
- Utilizing counterion exchange kinetics to induce spatial variation in surface chemical composition.
- Characterization of wettability gradients using water and oil contact angle measurements.
- Analysis of surface chemical composition using X-ray photoelectron spectroscopy (XPS).
Main Results:
- Successfully fabricated aluminum surfaces with continuously tunable wettability gradients.
- Demonstrated that wettability is dependent on the identity and concentration of counterions in the outermost PEM layer.
- Showcased the ability to erase and rewrite wettability gradients by altering counterion exchange conditions.
- Confirmed the spatial gradient in surface chemical composition correlating with wettability variations.
Conclusions:
- The combined approach of PEM deposition and counterion exchange offers a versatile method for creating tunable wettability gradient surfaces.
- This technique provides precise control over surface wetting properties on rough aluminum substrates.
- The developed surfaces have potential applications in areas requiring controlled liquid-surface interactions.
Related Concept Videos
02:57Surface Tension, Capillary Action, and Viscosity
28.6K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
28.6K
01:27Surface Active Agents
158
Surfactants, named for their behavior at interfaces, positively adsorb at the interfaces of two phases, reducing interfacial tension. Their versatility as emulsifiers, detergents, and foaming agents stems from this ability. Surfactants, often termed amphiphiles, share the property of amphipathy, with molecules having both hydrophilic and hydrophobic portions. The hydrophilic part is called the head, and the hydrophobic part, including an elongated alkyl substituent, forms the tail.Surfactants...
158
01:18Surface Membrane Barriers
3.0K
The skin and mucous membranes serve as the primary line of defense against pathogens by providing both physical and chemical protection. These barriers are essential in preventing the entry and establishment of microbes, thereby maintaining the integrity of the host.
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
3.0K
01:13Contact Angle
27.7K
When a solid is dipped inside a liquid, the liquid surface becomes curved near the contact. For some solid–liquid interfaces, the liquid is pulled up along the solid, while for others, the liquid surface is convex or depressed near the solid surface. This phenomenon can be explained using the concept of cohesive and adhesive forces.
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive...
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive...
27.7K
01:16Surface Tension and Surface Energy
3.2K
When a paint brush is immersed in water, the bristles wave freely inside the water. When it is taken out, the bristles stick together. The reason behind this effect is surface tension.
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
3.2K
03:00Solubility
16.9K
Solution, Solubility, and Solubility Equilibrium
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules,...
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules,...
16.9K