Atomic force microscopy nanoindentation kinetics and subsurface visualization of soft inhomogeneous polymer

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Atomic force microscopy (AFM) enables high-resolution surface topography and mechanical property mapping.
• Understanding soft, heterogeneous materials requires advanced analysis beyond standard indentation methods.

Purpose of the Study:

• To investigate the surface and subsurface structure of phase-separated polymers using AFM nanoindentation.
• To analyze the interaction dynamics between the AFM tip and soft polymer surfaces.
• To estimate the elastic moduli of different polymer phases.

Main Methods:

• Nanoindentation using Atomic Force Microscopy (AFM).
• Analysis of AFM tip-material interaction rates.
• Mapping of topography and physical-mechanical properties.

Main Results:

• Identified reversible inelastic surface changes during indentation.
• Revealed a transition from a soft nanofilm to a fibrillar heterogeneous structure.
• Determined the point of stable mechanical contact and estimated elastic moduli of soft and hard polymer blocks.

Conclusions:

• AFM nanoindentation provides detailed insights into soft heterogeneous material structures.
• The study demonstrates a method for characterizing complex polymer morphologies and mechanical properties.
• This approach is applicable to a broad range of soft, phase-separated materials.