@article{TEXTUAL,
      recid = {13335},
      author = {Kim, Hojin and van der Naald, Michael and Braaten, Finn A.  and Witten, Thomas A. and Rowan, Stuart J. and Jaeger,  Heinrich M.},
      title = {Shear thickening in suspensions of particles with dynamic  brush layers},
      journal = {Soft Matter},
      address = {2024-07-25},
      number = {TEXTUAL},
      abstract = {Control of frictional interactions among liquid-suspended  particles has led to tunable, strikingly non-Newtonian  rheology <em>via</em> the formation of strong flow  constraints as particles come into close proximity under  shear. Typically, these frictional interactions have been  in the form of physical contact, controllable <em>via</em>  particle shape and surface roughness. We investigate a  different route, where molecular bridging between nearby  particle surfaces generates a controllable constraint to  relative particle movement. This is achieved with  surface-functionalized colloidal particles capable of  forming dynamic covalent bonds with telechelic polymers  that comprise the suspending fluid. At low shear stress  this results in particles coated with a uniform polymer  brush layer. Beyond an onset stress <em>σ</em>* the  telechelic polymers become capable of bridging and generate  shear thickening. Over the size range investigated, we find  that the dynamic brush layer leads to dependence of  <em>σ</em>* on particle diameter that closely follows a  power law with exponent −1.76. In the shear thickening  regime, we observe an enhanced dilation in measurements of  the first normal stress difference  <em>N</em><small><sub>1</sub></small> and reduction in the  extrapolated volume fraction required for jamming, both  consistent with an effective particle friction that  increases with decreasing particle diameter. These results  are discussed in light of predictions for suspensions of  hard spheres and of polymer-grafted particles.},
      url = {http://knowledge.uchicago.edu/record/13335},
}