Related Experiment Video
Updated: Jan 2, 2026
16:24
Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
19.2K
Chain conformation: A key parameter driving clustering or dispersion in polyelectrolyte - Colloid systems.
I Grillo1, I Morfin2, J Combet3
1Institut Laue Langevin, Large Scale Structures, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France.
Journal of Colloid and Interface Science
|December 2, 2019
Summary
Hyaluronic acid and salt concentration influence Pluronic F127 micellar solutions. Increasing ionic strength or hyaluronic acid concentration promotes micellar clustering and liquid crystalline phase formation.
Area of Science:
- Polymer science
- Materials science
- Physical chemistry
Background:
- Pluronic F127 forms micelles in aqueous solutions.
- Hyaluronic acid is a biopolymer with significant effects on solution properties.
- Understanding their interactions is crucial for various applications.
Purpose of the Study:
- Characterize Pluronic F127 micellar solutions with hyaluronic acid.
- Investigate the impact of salt concentration and type on these systems.
- Determine the phase behavior and aggregation mechanisms.
Main Methods:
- Differential scanning calorimetry (DSC) for thermal analysis.
- Small-angle neutron scattering (SANS) for structural characterization.
- Systematic variation of salt concentration, type, and hyaluronic acid parameters.
Main Results:
- Hyaluronic acid lowers the critical micellar temperature, similar to increased ionic strength.
- Micelle size and shape remain unaffected by hyaluronic acid, but dispersion changes with salt.
- Increased ionic strength induces micellar clustering and formation of a face-centered cubic liquid crystalline phase.
- Divalent cations (e.g., Ca2+) strongly promote micellar aggregation and crystallization.
- Hyaluronic acid concentration and molecular weight enhance these aggregation behaviors.
Conclusions:
- Salt-induced changes in hyaluronic acid conformation (from stretched to coil) drive micellar aggregation via depletion interactions.
- The observed phase transitions are tunable by adjusting salt and hyaluronic acid properties.
- These findings offer insights into designing advanced functional materials based on polymer self-assembly.
Related Concept Videos
01:26Polymer Classification: Stereospecificity
3.1K
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
3.1K
01:14Polymer Classification: Architecture
3.6K
Polymers are classified as linear or branched on the basis of their chain architecture. The polymer chains in linear polymers have a long chain-like structure with minimal to no branching at all. Even if a polymer features large substituent groups on the monomer, which appear as branches to the skeleton, it is not considered a branched polymer. A branched polymer contains secondary polymer chains that arise from the main polymer chain. The branching occurs when the polymer growth shifts from...
3.6K
01:19Complexation Equilibria: The Chelate Effect
1.1K
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
1.1K
01:21Polymer Classification: Crystallinity
3.7K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
3.7K
01:09Colloidal precipitates
4.6K
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
4.6K
00:57Cationic Chain-Growth Polymerization: Mechanism
2.7K
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the...
2.7K