Solid-state polymer adsorption for surface modification: The role of molecular weight

Wenyang Xu*, Karl Mihhels, Nikolay Kotov, Sakari Lepikko, Robin H.A. Ras, C. Magnus Johnson, Torbjörn Pettersson*, Eero Kontturi*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

43 Downloads (Pure)

Abstract

Hypothesis: Solid-state polymer adsorption offers a distinct approach for surface modification. These ultrathin, so-called Guiselin layers can easily be obtained by placing a polymer melt in contact with an interface, followed by a removal of the non-adsorbed layer with a good solvent. While the mechanism of formation has been well established for Guiselin layers, their stability, crucial from the perspective of materials applications, is not. The stability is a trade-off in the entropic penalty between cooperative detachment of the number of segments directly adsorbed on the substrate and consecutively pinned monomers. 

Experiments: Experimental model systems of Guiselin layers of polystyrene (PS) on silicon wafers with native oxide layer on top were employed. The stability of the adsorbed layers was studied as a function of PS molecular weight and polydispersibility by various microscopic and spectroscopic tools as well as quasi-static contact angle measurements. 

Findings: Adsorbed layers from low molecular weight PS were disrupted with typical spinodal decomposition patterns whereas high molecular weight (>500 kDa) PS resulted in stable, continuous layers. Moreover, we show that Guiselin layers offer an enticing way to modify a surface, as demonstrated by adsorbed PS that imparts a hydrophobic character to initially hydrophilic silicon wafers.

Original languageEnglish
Pages (from-to)441-450
Number of pages10
JournalJournal of Colloid and Interface Science
Volume605
Early online date21 Jul 2021
DOIs
Publication statusPublished - Jan 2022
MoE publication typeA1 Journal article-refereed

Keywords

  • Contact angle
  • Dewetting
  • Polymer adsorption
  • Polystyrene
  • Silicon wafers
  • Surface modification

Fingerprint

Dive into the research topics of 'Solid-state polymer adsorption for surface modification: The role of molecular weight'. Together they form a unique fingerprint.

Cite this