Surface structures and properties of polystyrene/poly(methyl methacrylate) blends and copolymers

Area of Science:

• Polymer science
• Surface chemistry
• Spectroscopy

Background:

• Understanding polymer surface behavior is crucial for material applications.
• Polystyrene (PS) and poly(methyl methacrylate) (PMMA) are common polymers with distinct surface properties.
• Investigating blends and copolymers provides insights into structure-property relationships.

Purpose of the Study:

• To investigate the molecular surface structures of PS/PMMA blends and PS-co-PMMA.
• To determine the effect of annealing on surface segregation and morphology.
• To examine how different polymer surfaces influence fibrinogen adsorption.

Main Methods:

• Sum frequency generation (SFG) vibrational spectroscopy to probe molecular surface structures.
• Atomic force microscopy (AFM) for surface morphology analysis.
• Contact angle goniometry to assess surface wettability.

Main Results:

• Both PS and PMMA segregated to the surface of the blend and copolymer before annealing.
• Annealing induced significant PS surface segregation in the PS/PMMA blend, but not in the copolymer.
• AFM revealed a rougher surface with domains for the annealed blend compared to the flat copolymer surface.
• Fibrinogen adsorption differed significantly between the blend and copolymer interfaces over time.

Conclusions:

• Annealing-induced surface restructuring of PS/PMMA blends alters their interaction with proteins.
• The molecular architecture (blend vs. copolymer) dictates surface behavior and protein adsorption.
• SFG spectroscopy is a powerful tool for characterizing polymer surface dynamics and interfacial interactions.