Transparent Films Made of Highly Scattering Particles

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Erdem T., Yang L., Xu P., ALTINTAS Y., O'Neil T., Caciagli A., ...More

LANGMUIR, vol.36, no.4, pp.911-918, 2020 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 36 Issue: 4
  • Publication Date: 2020
  • Doi Number: 10.1021/acs.langmuir.9b01014
  • Journal Name: LANGMUIR
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Biotechnology Research Abstracts, Chemical Abstracts Core, Chimica, Compendex, EMBASE, INSPEC, MEDLINE
  • Page Numbers: pp.911-918
  • Abdullah Gül University Affiliated: Yes


Today, colloids are widely employed in various products from creams and coatings to electronics. The ability to control their chemical, optical, or electronic features by controlling their size and shape explains why these materials are so widely preferred. Nevertheless, altering some of these properties may also lead to some undesired side effects, one of which is an increase in optical scattering upon concentration. Here, we address this strong scattering issue in films made of binary colloidal suspensions. In particular, we focus on raspberry-type polymeric particles made of a spherical polystyrene core decorated by small hemispherical domains of acrylate with an overall positive charge, which display an unusual stability against aggregation in aqueous solutions. Their solid films display a brilliant red color due to Bragg scattering but appear completely white on account of strong scattering otherwise. To suppress the scattering and induce transparency, we prepared films by hybridizing them with oppositely charged PS particles with a size similar to that of the bumps on the raspberries. We report that the smaller PS particles prevent raspberry particle aggregation in solid films and suppress scattering by decreasing the spatial variation of the refractive index inside the film. We believe that the results presented here provide a simple strategy to suppress strong scattering of larger particles to be used in optical coatings.