Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Micelles01:30

Micelles

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...
Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility02:34

Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility

Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, and solubilities (miscibilities) of substances. Molar mass, molecular shape, and polarity affect the strength of different intermolecular forces, which influence the magnitude of physical properties across a family of molecules.
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Surface Active Agents01:27

Surface 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...
Intermolecular Forces and Physical Properties02:56

Intermolecular Forces and Physical Properties

Phase Diagrams of Ternary Systems01:28

Phase Diagrams of Ternary Systems

Consider a ternary system, which is composed of three components: water (W), ethanoic acid (E), and trichloromethane (T). Here, Ethanoic acid (E) is fully miscible with both water (W) and trichloromethane (T), meaning it can mix entirely with either of them. However, water and trichloromethane have partial miscibility, meaning they can only mix to a certain extent, beyond which two separate phases will form.The phase diagram of a ternary system is represented as an equilateral triangle, where...
Entropy and Solvation02:05

Entropy and Solvation

The process of surrounding a solute with solvent is called solvation. It involves evenly distributing the solute within the solvent. The rule of thumb for determining a solvent for a given compound is that like dissolves like. A good solvent has molecular characteristics similar to those of the compound to be dissolved. For example, polar solutions dissolve polar solutes, and apolar solvents dissolve apolar solutes. A polar solvent is a solvent that has a high dielectric constant (ϵ ≥ 15); an...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Water hyacinth-derived biochars - from invasive biomass to active Pt-free alkaline oxygen reduction reaction catalysts.

Journal of colloid and interface science·2026
Same author

Liposomes and lipid nanoparticles: a tutorial for advanced chemical and structural characterisation.

European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences·2026
Same author

The chaperone DNAJB6b halts amyloid formation through association with transient Aβ oligomers.

Physical chemistry chemical physics : PCCP·2026
Same author

Growth of fatty acid vesicles coupled with amino acid sequences of peptides toward evolvable protocells.

Communications chemistry·2026
Same author

A quantitative approach for high-throughput mapping of collagen fibril orientation using polarization-dependent Second Harmonic Generation.

Acta biomaterialia·2026
Same author

Supramolecular Assembly of Collagen-Mimetic Peptide D-Periodic Fibrils and Nanoassemblies.

Biomacromolecules·2026

Related Experiment Video

Updated: Jul 10, 2026

Lipid Bilayer Experiments with Contact Bubble Bilayers for Patch-Clampers
07:18

Lipid Bilayer Experiments with Contact Bubble Bilayers for Patch-Clampers

Published on: January 16, 2019

Lamellar miscibility gap in a binary catanionic surfactant-water system.

Bruno F B Silva1, Eduardo F Marques, Ulf Olsson

  • 1Centro de Investigação em Química, Department of Chemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto, Portugal.

The Journal of Physical Chemistry. B
|November 13, 2007
PubMed
Summary
This summary is machine-generated.

This study reveals a rare miscibility gap in catanionic surfactant-water systems, showing two coexisting lamellar liquid-crystalline phases. This phenomenon, observed in hexadecyltrimethylammonium octylsulfonate (TASo), is explained by partial dissociation and electrostatic repulsion.

More Related Videos

Self-Assembly of Hybrid Lipid Membranes Doped with Hydrophobic Organic Molecules at the Water/Air Interface
06:28

Self-Assembly of Hybrid Lipid Membranes Doped with Hydrophobic Organic Molecules at the Water/Air Interface

Published on: May 1, 2020

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
06:26

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

Published on: May 15, 2017

Related Experiment Videos

Last Updated: Jul 10, 2026

Lipid Bilayer Experiments with Contact Bubble Bilayers for Patch-Clampers
07:18

Lipid Bilayer Experiments with Contact Bubble Bilayers for Patch-Clampers

Published on: January 16, 2019

Self-Assembly of Hybrid Lipid Membranes Doped with Hydrophobic Organic Molecules at the Water/Air Interface
06:28

Self-Assembly of Hybrid Lipid Membranes Doped with Hydrophobic Organic Molecules at the Water/Air Interface

Published on: May 1, 2020

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
06:26

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

Published on: May 15, 2017

Area of Science:

  • Physical Chemistry
  • Materials Science
  • Surfactant Science

Background:

  • Binary surfactant-water systems rarely exhibit coexistence of two lamellar liquid-crystalline phases in equilibrium.
  • Previous observations involved ionic surfactants, with miscibility gaps attributed to interbilayer force balances.
  • The underlying mechanisms for such phenomena remain largely unexplained.

Purpose of the Study:

  • To report the first observation of a miscibility gap in a catanionic lamellar phase.
  • To characterize the coexisting phases and the immiscibility region.
  • To provide a theoretical explanation for the observed miscibility gap.

Main Methods:

  • Synchrotron small-angle X-ray scattering (SAXS) for structural analysis.
  • Polarizing light microscopy (PLM) for phase identification.
  • 2H Nuclear Magnetic Resonance (NMR) spectroscopy for molecular dynamics.
  • Theoretical modeling using DLVO and short-range repulsive potentials.

Main Results:

  • Demonstrated coexistence of a dilute lamellar phase (Lα') and a concentrated lamellar phase (Lα'') for hexadecyltrimethylammonium octylsulfonate (TASo) in water.
  • Identified the immiscibility region between 15-54 wt % surfactant, with linear swelling in each phase.
  • Observed vesicles in the dilute two-phase region, indicating Lα' dispersed in an isotropic micellar phase.
  • Theoretical model showed good agreement with experimental miscibility gap, attributing it to concentration-dependent electrostatic repulsion from partial surfactant dissociation.

Conclusions:

  • The catanionic surfactant TASo exhibits a miscibility gap, challenging previous assumptions about ionic surfactants being prerequisites.
  • Partial dissociation of TASo leads to residual positive charge and electrostatic repulsion, explaining the observed phase behavior.
  • The theoretical model successfully elucidates the physical basis for the miscibility gap in this net uncharged surfactant system.