Reverse water-in-fluorocarbon microemulsions stabilized by new polyhydroxylated nonionic fluorinated surfactants
Khaled Debbabi1, Frederic Guittard, Julian Eastoe
1Institut de Chimie de Nice FR 3037 CNRS, Laboratoire de Chimie des Matériaux Organiques et Métalliques, CMOM, UFR Sciences, Université de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 02, France.
Langmuir : the ACS Journal of Surfaces and Colloids
|April 7, 2009
Summary
New fluorinated surfactants stabilize water-in-fluorocarbon microemulsions. A semifluorinated alcohol is essential for creating transparent, one-phase systems, as confirmed by scattering techniques.
Area of Science:
- Colloid and Surface Chemistry
- Materials Science
- Fluorocarbon Chemistry
Background:
- Perfluorosurfactants are crucial for stabilizing specialized emulsions.
- Understanding the behavior of water-in-fluorocarbon microemulsions is vital for advanced applications.
- Novel surfactant structures offer opportunities to tune emulsion properties.
Purpose of the Study:
- To synthesize novel polyhydroxylated nonionic perfluorosurfactants.
- To investigate the stabilization of reverse water-in-fluorocarbon microemulsions using these surfactants.
- To characterize the structure and properties of the resulting microemulsions.
Main Methods:
- Synthesis of new polyhydroxylated nonionic perfluorosurfactants.
- Preparation of reverse water-in-fluorocarbon microemulsions using perfluorohexane and a semifluorinated alcohol.
- Structural characterization via dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS).
Main Results:
- Transparent one-phase systems require a sufficient amount of semifluorinated alcohol alongside the perfluorosurfactants.
- Scattering techniques provided detailed insights into the size, shape, and internal structure of the microemulsions.
- The composition of the oil phase significantly impacts the stability and transparency of the microemulsions.
Conclusions:
- The synthesized perfluorosurfactants can stabilize water-in-fluorocarbon microemulsions.
- A minimum concentration of semifluorinated alcohol is critical for achieving stable, transparent microemulsion systems.
- Detailed structural information was obtained, aiding in the design of future fluorinated colloidal systems.
Related Concept Videos
01:27Surface Active Agents
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...
01:30Micelles
Micelle formation is an intricate process that hinges on the properties of amphiphilic or amphipathic molecules and the conditions of the system in which they are found. Amphiphilic molecules, which have both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts, play a critical role in this process.In aqueous environments, these molecules arrange themselves such that their hydrophilic heads are turned towards the water phase, while their hydrophobic tails are oriented away...
03:22Colloids
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles that are visible to the naked eye or can be seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. On the other hand, a solution is a homogeneous mixture in which no settling occurs and in which the dissolved...
01:23Membrane Fluidity
Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are generally able to move about in the plane of the membrane, giving the membrane its flexible nature called fluidity. Two other features of the membrane contribute to membrane fluidity: the chemical structure of the phospholipids and the presence of cholesterol in the membrane.Fatty acids tails of phospholipids can be either saturated or...