5 years ago

Grafting of Ring-Opened Cyclopropylamine Thin Films on Silicon (100) Hydride via UV Photoionization

Grafting of Ring-Opened Cyclopropylamine Thin Films on Silicon (100) Hydride via UV Photoionization
L. S. Tew, Y. L. Khung, J. Tung, Y. M. Ng, J. Y. Ching
The grafting of cyclopropylamine onto a silicon (100) hydride (Si–H) surface via a ring-opening mechanism using UV photoionization is described here. In brief, radicals generated from the Si–H surface upon UV irradiation were found to behave in classical hydrogen abstraction theory manner by which the distal amine group was first hydrogen abstracted and the radical propagated down to the cyclopropane moiety. This subsequently liberated the strained bonds of the cyclopropane group and initiated the surface grafting process, producing a thin film approximately 10–15 nm in height. Contact angle measurements also showed that such photoionization irradiation had yielded an extremely hydrophilic surface (∼21.3°) and X-ray photoelectron spectroscopy also confirmed the coupling was through the Si−C linkage. However, when the surface underwent high-temperature hydrosilylation (>160 °C), the reaction proceeded predominantly through the nucleophilic NH2 group to form a Si–N linkage to the surface. This rendered the surface hydrophobic and hence suggested that the Si–H homolysis model may not be the main process. To the best of our knowledge, this was the first attempt reported in the literature to use photoionization to directly graft cyclopropylamine onto a silicon surface and in due course generate a highly rich NH-terminated surface that was found to be highly bioactive in promoting cell viability on the basis of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide studies.

Publisher URL: http://dx.doi.org/10.1021/acsami.7b08343

DOI: 10.1021/acsami.7b08343

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.