Diblock Polymer Brush (PHEAA- b-PFMA): Microphase Separation Behavior and Anti-Protein Adsorption Performance

Area of Science:

• Polymer Chemistry
• Surface Science
• Biomaterials

Background:

• Surface modification is crucial for controlling biomaterial interactions.
• Amphiphilic block copolymers offer tunable surface properties.
• Fluorinated polymers are known for their low surface energy and potential antifouling characteristics.

Purpose of the Study:

• To synthesize and characterize amphiphilic diblock polymers (PHEAA-b-PFMA) grafted onto silicon wafers.
• To investigate the conditions for microphase separation and nanostructure formation.
• To evaluate the protein adsorption resistance of the modified surfaces.

Main Methods:

• Surface-initiated atom transfer radical polymerization (SI-ATRP) for polymer grafting.
• Contact angle goniometry and X-ray photoelectron spectroscopy (XPS) for surface characterization.
• Gel permeation chromatography (GPC) for polymer molecular weight determination.
• Atomic force microscopy (AFM) for topography and microphase separation analysis.

Main Results:

• Controlled grafting density and thickness of PHEAA brush, along with specific PFMA/PHEAA ratios, induced diblock copolymer phase separation into nanostructures.
• Modified surfaces showed reduced adsorption of Bovine Serum Albumin (BSA), fibrinogen, and lysozyme compared to bare silicon wafers.
• PHEAA-b-PFMA surfaces with microphase segregation exhibited superior antifibrinogen adsorption compared to PHEAA-only surfaces.

Conclusions:

• Surface composition and microphase segregation of fluorinated moieties in block copolymer brushes significantly influence protein adsorption.
• The study provides a pathway for designing surfaces with enhanced antifouling properties through controlled polymer architecture and phase separation.
• These findings are relevant for developing advanced biomaterials with improved biocompatibility.