pH-Controlled Electrochemical Deposition of Polyelectrolyte Complex Films

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Polyelectrolyte complex (PEC) films are utilized in drug delivery, separation membranes, and biocompatible coatings.
• Traditional layer-by-layer methods for PEC film fabrication are slow, multistep, and low-throughput, limiting scalability for thicker films.

Purpose of the Study:

• To develop a rapid, one-pot electrochemical deposition method for fabricating thick PEC films.
• To achieve high-throughput production of PEC coatings suitable for various applications.

Main Methods:

• Electrochemical deposition of PEC films using poly(acrylic acid) and poly(allylamine) HCl.
• Exploitation of hydrogen peroxide reduction at mild potentials to trigger pH-responsive self-assembly.
• In situ rheology via electrochemical quartz crystal microbalance to characterize film properties.

Main Results:

• Successfully fabricated 1 μm thick PEC films within 5 minutes using the electrochemical method.
• Quantified the shear modulus-density product (~10^7 Pa g/cm^3) and viscoelastic phase angle (~50°) of the deposited films.
• Demonstrated a rapid, efficient single-step approach for PEC coating development.

Conclusions:

• The developed electrochemical deposition scheme provides a fast and efficient method for producing thick PEC films.
• This technique significantly enhances throughput compared to conventional methods, enabling broader applications for PEC coatings.
• The study advances the development of high-throughput manufacturing processes for functional polymer films.