Macromolecules
Macromolecules
4 years ago

Chain Dispersity Effects on Brush Properties of Surface-Grafted Polycaprolactone-Modified Silica Nanoparticles: Unique Scaling Behavior in the Concentrated Polymer Brush Regime

Chain Dispersity Effects on Brush Properties of Surface-Grafted Polycaprolactone-Modified Silica Nanoparticles: Unique Scaling Behavior in the Concentrated Polymer Brush Regime
Kyle C. Bentz, Daniel A. Savin
Silica nanoparticles (Rh = 70 nm) were functionalized with high dispersity (Đ > 2.3) polycaprolactone at various grafting densities, and the brush properties were investigated using dynamic light scattering. Owing to recent advances in controlled polymerization techniques, low dispersity brushes are easily grafted from nanoparticle surfaces, and these systems have been well studied. However, the effect of high dispersity brushes on nanoparticle surfaces is largely unexplored. Here we discuss the brush properties of high dispersity polycaprolactone-grafted silica nanoparticles. Because of the polymerization conditions used, transesterification events are induced during the polymerization to give brushes with increasing dispersity both as brush length increases and as grafting density is increased (e.g., Đ from 1.32 to 2.39 for σ from 0.21 to 0.61 chains/nm2). All grafting densities showed extended chains in the concentrated polymer brush regime, with brush length, lb, scaling with degree of polymerization, lb ∼ Na, where a = 1.39, 1.47, and 1.84 for the high, mid, and low grafting density sets. This study provides the first experimental insight into the effects of increasing chain dispersity on brush properties of nanoparticle systems. Furthermore, this system offers a facile method to tune dispersity of grafted brushes concurrent with the grafting polymerization. We expect this work to be of significant interest to the ongoing study of fundamental properties of polymer brushes as well as these materials finding use in polymer composite applications and provide enhanced mechanical properties compared to their monodisperse analogues.

Publisher URL: http://dx.doi.org/10.1021/acs.macromol.7b00608

DOI: 10.1021/acs.macromol.7b00608

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.