Surface-Initiated Polymerizations Mediated by Novel Germanium-Based Photoinitiators

Matthias Müller, Manfred Drusgala, Roland C. Fischer, Ana Torvisco, Wolfgang Kern, Michael Haas, Christine Bandl

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Since surface-initiated photopolymerization techniques have gained increasing interest within the last decades, the coupling of photoinitiators to surfaces and particles has become an important research topic in material and surface sciences. In terms of surface modification and functionalization, covalently coupled photoinitiators and subsequent photopolymerizations are employed to provide a huge variety of surface properties, such as wettability, stimulus responsive features, antifouling behavior, protein binding, friction control, drug delivery, and many more. For this purpose, numerous type I and type II photoinitiators or other photosensitive moieties have been attached to different substrates so far. In our studies, a convenient and straightforward synthetic protocol to prepare a novel germanium-based photoinitiator (bromo-tris(2,4,6-trimethylbenzoyl)germane) in good yields was developed. The immobilization of this photoinitiator at the surface of silicon wafers and quartz plates was evidenced by X-ray photoelectron spectroscopy (XPS). Employing visible-light-triggered surface-initiated polymerization of different functional monomers, including acrylamide, perfluorodecyl acrylate, and fluorescein-o-acrylate, surfaces with various features such as hydrophilic/hydrophobic and fluorescent properties were prepared. This was also achieved in a spatially resolved manner. The polymer layers were characterized by contact angle measurements, UV–vis/fluorescence spectroscopy, spectroscopic ellipsometry, and XPS. The thicknesses of the surface grafted polymer layers ranged between 10 and 126 nm.
Original languageEnglish
Pages (from-to)31836-31848
Number of pages13
JournalACS Applied Materials and Interfaces
Volume15.2023
Issue number26
DOIs
Publication statusPublished - 23 Jun 2023

Bibliographical note

Publisher Copyright: © 2023 The Authors. Published by American Chemical Society.

Keywords

  • acylgermanes
  • grafting from reaction
  • photoinitiator immobilization
  • photopolymerization
  • surface modification
  • surface-initiated polymerization

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