Tunable Hydrophilic or Amphiphilic Coatings: A "Reactive Layer Stack" Approach

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Science

Background:

• Tunable thin films are crucial for advanced functional coatings.
• Existing methods often lack control over film properties and self-assembly.
• Applications include anti-icing and easy-to-clean surfaces.

Purpose of the Study:

• To develop a novel "reactive layer stack" approach for creating covalently grafted polymer multilayers.
• To investigate the self-cross-linking behavior of poly(glycidyl methacrylate)/poly(tert-butyl acrylate) diblock copolymers.
• To prepare and characterize amphiphilic films with tunable wettability using triblock terpolymers.

Main Methods:

• Reactive layer stack approach for polymer grafting.
• Ellipsometry for determining coating thickness.
• Infrared reflection absorbance spectroscopy (IRRAS) for mechanism investigation.
• Atomic force microscopy (AFM) and contact angle measurements for surface analysis.

Main Results:

• Ellipsometrically determined coating thickness showed a linear dependence on the number of applied layers.
• Hydrophilic multilayers were successfully created via self-cross-linking after tert-butyl group removal.
• Amphiphilic and switchable terpolymer layers exhibited tunable wettability.
• The acidolysis mechanism of tert-butyl acrylate blocks was sensitive to the acidic reagent.

Conclusions:

• The "reactive layer stack" approach enables the creation of covalently grafted polymer multilayers with tunable properties.
• The diblock copolymers exhibit self-cross-linking capabilities, leading to stable hydrophilic films.
• Triblock terpolymers allow for the preparation of amphiphilic films with switchable wettability.
• This method offers a versatile platform for developing advanced functional coatings.