[Characterization of polycyclic aromatic hydrocarbons dissolved in nonionic surfactants]

Area of Science:

• Environmental Chemistry
• Physical Chemistry
• Chemical Engineering

Background:

• Polycyclic Aromatic Hydrocarbons (PAHs) are persistent organic pollutants with low water solubility, posing environmental challenges.
• Nonionic surfactants are widely used in various applications, including pollutant remediation and solubilization.
• Understanding surfactant-micelle interactions is crucial for predicting and enhancing the solubility of hydrophobic compounds.

Purpose of the Study:

• To investigate the solubilization enhancement of four polycyclic aromatic hydrocarbons (PAHs) by three common nonionic surfactants.
• To determine the relationship between surfactant concentration and PAH solubility.
• To explore the correlation between the micelle-aqueous phase partitioning coefficient (K(m)) and the octanol-water partitioning coefficient (Kow) of PAHs.

Main Methods:

• Characterization of PAH solubilization using Tween80, Tween20, and Triton X-100.
• Measurement of PAH solubility at concentrations above the critical micellar concentration (CMC).
• Determination of micelle-aqueous phase partitioning coefficients (K(m)) and octanol-water partitioning coefficients (Kow).

Main Results:

• Nonionic surfactants significantly enhanced PAH solubilization above their CMC.
• PAH solubility exhibited a linear relationship with increasing nonionic surfactant concentration.
• The solubilization enhancement order was Triton X-100 > Tween80 > Tween20.
• A strong linear correlation was found between K(m) and Kow for the studied PAHs in surfactant solutions.

Conclusions:

• Nonionic surfactants are effective agents for increasing the solubility of PAHs.
• The concentration of nonionic surfactants directly influences PAH solubility in a predictable manner.
• The partitioning behavior of PAHs in surfactant micelles is predictable based on their octanol-water partitioning coefficients.