Solubilization of phenols in surfactant/polyelectrolyte systems

Area of Science:

• Supramolecular Chemistry
• Polymer Science
• Physical Chemistry

Background:

• Microheterogeneous systems formed by surfactants and polymers are crucial in various applications.
• Cetyltrimethylammonium bromide (CTAB) is a common cationic surfactant.
• Alternating copolymers of maleic acid and styrene (MAS) and their derivatives offer tunable properties.

Purpose of the Study:

• To investigate the properties of microheterogeneous systems formed by CTAB and MAS/MAS-n copolymers.
• To characterize the hydrophobicity and solubilization abilities of these polymer/CTAB aggregates.
• To understand the influence of phenol structure and alkyl chain length on solubilization.

Main Methods:

• Fluorescence spectroscopy using pyrene as a probe to determine aggregate polarity.
• Solubilization studies using a series of p-alkyl substituted phenols.
• Determination of distribution constants (K(S)) and free energy of transfer (Deltamicro(0)(t)) using the pseudo-phase model.

Main Results:

• Polymer/CTAB aggregates exhibit higher hydrophobicity compared to conventional CTAB micelles.
• The solubilization of phenols is primarily governed by the phenol's molecular structure.
• A linear free energy relationship exists between the free energy of transfer and phenol structure.
• Alkyl chain length in phenols has no significant impact on the solubilization free energy.

Conclusions:

• The investigated MAS-n/CTAB systems form hydrophobic microheterogeneous aggregates.
• Phenol structure is the dominant factor in determining solubilization within these aggregates.
• The findings provide insights into the design and application of novel polymer-surfactant systems.