Structure Formation of Ultrathin PEO Films at Solid Interfaces—Complex Pattern Formation by Dewetting and...

Area of Science:

• Materials Science
• Polymer Physics
• Surface Science

Background:

• Ultrathin polymer films on solid substrates are prone to rupture via dewetting.
• Crystallizable polymers like polyethyleneoxide (PEO) can exhibit molecular self-assembly.
• Pattern formation in thin films can arise from multiple competing physical processes.

Purpose of the Study:

• To investigate pattern formation in ultrathin polyethyleneoxide (PEO) films.
• To understand the interplay between dewetting and molecular self-assembly in PEO.
• To examine the self-organization of hydrophobic n-alkylterminated PEO oligomers in thin films.

Main Methods:

• Fabrication and characterization of ultrathin PEO films (< 10 nm thickness).
• Analysis of morphological features resulting from dewetting and lamella growth.
• Comparative study of hydrophilic PEO and hydrophobic n-alkylterminated PEO oligomers.

Main Results:

• Morphological features in ultrathin PEO films are a result of dewetting and diffusion-limited lamella growth.
• Ordered lamella structures form within dewetted areas, contributing to pattern complexity.
• The presence of n-alkyl groups in PEO oligomers did not significantly alter the characteristic morphological features of pure PEO.

Conclusions:

• Dewetting and molecular self-assembly are key drivers of pattern formation in ultrathin PEO films.
• Hydrophobic modifications of PEO do not fundamentally change its thin-film morphology.
• The study provides insights into the complex morphological evolution of ultrathin polymer films.