5 years ago

Critical Role of the Atmosphere in Dip-Coating Process

Critical Role of the Atmosphere in Dip-Coating Process
David Grosso, Marco Faustini, Guillaume Naudin, Cédric Boissière, Elisa Bindini
Dip-coating is a common liquid deposition technique employed in research, and also for industrial production, to obtain polymer, hybrid, and inorganic thin layers of controlled thickness. During liquid deposition, the substrate withdrawal speed allows, in principle, an easy tuning of deposited film thickness (first modeled by Landau and Levich). Yet, experimentally, unexplained thickness irreproducibility or strong fluctuations of the sol–gel films are often observed when coating large substrates, which is a critical issue for optical coatings such as anti-reflective/reflective coatings. In this study, we point out for the first time that uncontrolled solvent relative pressure gradients (coming from solvent evaporation) are responsible for these thickness fluctuation issues. We investigated and quantified their impact for various solutions (of sol–gel or polymer) and pointed out that the solvent evaporation rate is not constant but strongly depends on the geometric configuration of the dip-coating experiment. From this understanding, we demonstrated how an accurate tuning of processing atmosphere can provide a very good control on layer thickness in the practical case of the deposition of anti-reflective water repellent coating. In a second example, we used this phenomenon for developing a very easy synthesis strategy leading to giant and controlled thickness gradient profiles.

Publisher URL: http://dx.doi.org/10.1021/acs.jpcc.7b02530

DOI: 10.1021/acs.jpcc.7b02530

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.