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

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:605

Article

Xu, Wenyang^1,2  Mihhels, Karl¹  Kotov, Nikolay³  Lepikko, Sakari⁴  Ras, Robin H. A.^1,4  Johnson, C. Magnus³  Pettersson, Torbjorn^2,5  Kontturi, Eero¹ 

[1] Aalto Univ, Sch Chem Engn, Dept Bioprod & Biosyst, POB 16300, FI-00076 Aalto, Finland

[2] KTH Royal Inst Technol, Dept Fibre & Polymer Technol, Tekn Ringen 56, S-10044 Stockholm, Sweden

[3] KTH Royal Inst Technol, Dept Chem, Drottning Kristinas Vag 51, SE-10044 Stockholm, Sweden

[4] Aalto Univ, Sch Sci, Dept Appl Phys, Espoo, Finland

[5] KTH Royal Inst Technol, Wallenberg Wood Sci Ctr, Dept Fibre & Polymer Technol, Tekn Ringen 56, S-10044 Stockholm, Sweden

关键词: Contact angle;    Dewetting;    Polymer adsorption;    Polystyrene;    Silicon wafers;    Surface modification;   

DOI  :  10.1016/j.jcis.2021.07.062

来源: Elsevier

【 摘 要 】

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. (c) 2021 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

【 授权许可】

Free