Zeta potential of microfluidic substrates: 2. Data for polymers.

Area of Science:

• Materials Science
• Surface Chemistry
• Analytical Chemistry

Background:

• Polymeric materials are increasingly used in microfluidic devices for separations.
• Understanding zeta potential is critical for optimizing electroosmotic flow in microfluidics.
• Limited data exists for zeta potential on these novel polymeric substrates.

Purpose of the Study:

• To propose and evaluate pC normalization for zeta potential data on polymer microfluidic substrates.
• To facilitate consistent comparison of zeta potential measurements across different studies.
• To improve the prediction of electroosmotic flow performance in microfluidic devices.

Main Methods:

• Review of existing zeta potential data for various polymeric microfluidic substrates.
• Application of pC (negative logarithm of counterion concentration) as a normalization factor.
• Analysis of zeta potential versus pH curves under different ionic conditions.

Main Results:

• Normalization of zeta potential by pC collapses data onto a single zeta/pC vs. pH curve for univalent counterions.
• The normalization method shows consistency with double layer and adsorption theory.
• Repeatable zeta potential data was observed for most polymer substrates, except PMMA.

Conclusions:

• pC normalization is a promising method for standardizing zeta potential data in polymer microfluidics.
• This approach enhances the comparability of electroosmotic flow performance across studies.
• Improved prediction and comparison of zeta potential behavior on microfluidic substrates are achievable.