A model for alcohol-enhanced permeation through polydimethylsiloxane membranes

Area of Science:

• Materials Science
• Chemical Engineering
• Polymer Science

Background:

• Polydimethylsiloxane (PDMS) membranes are widely used in separation processes.
• Understanding solute transport through PDMS is crucial for optimizing membrane performance.
• Parabens and alcohols are common industrial chemicals with potential environmental and health implications.

Purpose of the Study:

• To investigate the effect of paraben concentration on flux through PDMS membranes.
• To elucidate the relationship between alcohol sorption, membrane properties, and paraben flux.
• To determine the optimal paraben concentration for maximal flux.

Main Methods:

• Investigated flux of parabens from 1-propanol solutions through PDMS membranes.
• Measured changes in membrane dimensions and partition coefficients due to alcohol sorption.
• Analyzed the influence of paraben concentration on alcohol activity and membrane uptake.
• Examined the impact of different paraben structures (methylparaben) on flux.

Main Results:

• Alcohol sorption by PDMS membranes increased their capacity for parabens (partition coefficient).
• Flux increased 5-30 fold compared to water or polyols, peaking at specific paraben concentrations (1.3-1.4 mmol/g).
• Higher paraben concentrations reduced alcohol uptake, leading to a decline in flux after the peak.
• Flux varied among different parabens, primarily due to differences in diffusivity.

Conclusions:

• Paraben concentration significantly influences flux through PDMS membranes, exhibiting a complex concentration-dependent behavior.
• Alcohol-membrane interactions and partition coefficients are key factors modulating paraben transport.
• Optimizing paraben concentration is essential for maximizing flux in PDMS-based separation systems.