APS March Meeting 2016
Volume 61, Number 2
Monday–Friday, March 14–18, 2016;
Baltimore, Maryland
Session A4: Polymer Dynamics: An Honor Session for Sir Sam Edwards
8:00 AM–11:00 AM,
Monday, March 14, 2016
Room: Ballroom IV
Sponsoring
Units:
DPOLY GSOFT GSNP
Chair: Gary Grest, Sandia National Laboratories
Abstract ID: BAPS.2016.MAR.A4.5
Abstract: A4.00005 : Nanotribology of charged polymer brushes*
10:24 AM–11:00 AM
Preview Abstract
Abstract
Author:
Jacob Klein
(Weizmann Institute of Science)
Polymers at surfaces, whose modern understanding may be traced back to early
work by Sam Edwards$^{\mathrm{1}}$, have become a paradigm for modification
of surface properties, both as steric stabilizers and as remarkable boundary
lubricants$^{\mathrm{2}}$.
Charged polymer brushes are of particular interest, with both technological
implications and especially biological relevance where most macromolecules
are charged. In the context of biolubrication, relevant in areas from dry
eye syndrome to osteoarthritis, charged polymer surface phases and their
complexes with other macromolecules may play a central role. The hydration
lubrication paradigm, where tenaciously-held yet fluid hydration shells
surrounding ions or zwitterions serve as highly-efficient friction-reducing
elements, has been invoked to understand the excellent lubrication provided
both by ionized$^{\mathrm{3}}$ and by zwitterionic$^{\mathrm{4}}$ brushes.
In this talk we describe recent advances in our understanding of the
nanotribology of such charged brush systems. We consider interactions
between charged end-grafted polymers, and how one may disentangle the steric
from the electrostatic surface forces$^{\mathrm{5}}$. We examine the limits
of lubrication by ionized brushes, both synthetic and of biological origins,
and how highly-hydrated zwitterionic chains may provide extremely effective
boundary lubrication$^{\mathrm{6}}$. Finally we describe how the lubrication
of articular cartilage in the major joints, a tribosystem presenting some of
the greatest challenges and opportunities, may be understood in terms of a
supramolecular synergy between charged surface-attached polymers and
zwitterionic groups$^{\mathrm{7}}$.
1. Dolan {\&} Edwards, \textbf{Proc. Roy. Soc. A}, \textbf{337}, 509 (1974).
2. Klein et al. \textbf{Nature, 370}, 634 (1994).
3. Raviv et al., \textbf{Nature}, \textbf{425}, 163 (2003).
4. Chen et al., \textbf{Science}, \textbf{323} 1698 (2009).
5. Peretz et al., to be published.
6. Tairy et al., \textbf{Macromolecules}, \textbf{48}, 140 (2015).
7. Seror et al., \textbf{Nature Communications}, \textbar 6:6497 \textbar
(2015); Jahn et al., \textbf{Annual Reviews of Biomedical Engineering}
(2016)
*Work supported by European Research Council (HydrationLube), Israel Science Foundation (ISF), Petroleum Research Fund of the American Chemical Society, ISF-NSF China Joint Program
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2016.MAR.A4.5