Scaling Laws for the Swelling of Neutral and Charged Polymer Brushes in Good Solvents

2002 ◽  
Vol 35 (2) ◽  
pp. 499-507 ◽  
Author(s):  
M. Biesalski ◽  
J. Rühe
Keyword(s):  
Polymer Brushes ◽  
Scaling Laws ◽  
Charged Polymer

Binding of ionic surfactants to charged polymer brushes grafted onto porous substrates

2002 ◽  
Vol 954 (1-2) ◽  
pp. 89-97 ◽  
Author(s):  
Haruhiko Ogawa ◽  
Kazuyuki Sugita ◽  
Kyoichi Saito ◽  
Min Kim ◽  
Masao Tamada ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Ionic Surfactants ◽  
Charged Polymer ◽  
Porous Substrates

Dynamics of water, hydrated-ions and charged polymers in highly-confined films, and their role in friction modification

2003 ◽  
Vol 790 ◽  
Author(s):  
Jacob Klein ◽  
Uri Raviv ◽  
Susan Perkin ◽  
Nir Kampf ◽  
Suzanne Giasson
Keyword(s):  
Polymer Brushes ◽  
Aqueous Media ◽  
Free Water ◽  
Aqueous Salt Solution ◽  
Ball Bearings ◽  
High Concentration ◽  
Charged Surfaces ◽  
Hydrated Ions ◽  
Charged Polymer ◽  
The One

ABSTRACTRecent studies have revealed that, in contrast to non-associating liquids such as oils or organic solvents, salt-free water retains a viscosity close to its bulk value even when confined to films thinner than some 3 nm, indeed down to only one or two monolayers thick [1,2]. For the case of high concentration aqueous salt solution compressed down to subnanometer films between charged surfaces, the trapped hydrated ions serve to act as molecular ball-bearings, sustaining a large load while remaining very fluid under shear [3]. This behaviour is attributed to the tenacity of the hydration sheaths together with their rapid relaxation time. Finally, a very recent study [4] has shown that when charged polymer brushes in aqueous media are compressed and slid past each other, they provide a lubrication that is considerably superior to that afforded by neutral brushes: This is attributed on the one hand to the resistance to mutual interpenetration of the chains due to entropic barriers in the good-solvent conditions, and, on the other hand, to the hydration-sheaths on the charged polymer segments which can act – as noted above – as molecular ball-bearings.

scholarly journals Scaling and Interactions of Linear and Ring Polymer Brushes via DPD Simulations

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 541 ◽  
Author(s):  
Martin Jehser ◽  
Gerhard Zifferer ◽  
Christos Likos
Keyword(s):  
Polymer Brushes ◽  
Scaling Laws ◽  
Dissipative Particle Dynamics ◽  
Surface Concentration ◽  
Double Layers ◽  
Radius Of Gyration ◽  
Repulsion Potential ◽  
The Difference ◽  
Coated Surfaces ◽  
Perpendicular Component

Single and double layers of polymer coated surfaces are investigated by means of Dissipative Particle Dynamics (DPD), focusing on the difference between grafted ring and linear chains. Several different surface coverages σ , as well as chain lengths N and brush separations D, are analyzed for athermal, i.e., good solvent, conditions. The size in the form of the radius of gyration R g , the shape as asphericity δ ∗ , and orientation β ∗ , as well as density profiles as functions of distance from grafting plane ρ ( z ) , are studied. The effect of an added bond repulsion potential to suppress bond crossing in DPD is analyzed. Scaling laws of R g and its components R g ⊥ and R g ∥ are investigated. We find R g ∝ N ν , ν = 0.588 for surface coverages below the overlap surface concentration σ ∗ . For σ > σ ∗ we find R g ⊥ ∝ N ν ⊥ , ν ⊥ ≅ 1 and R g ∥ ∝ N ν ∥ , ν ∥ = 1 / 2 of ring brushes with the standard DPD model and ν ∥ ≅ 2 / 5 with added bond repulsion. The σ dependence of the radius of gyration was found to be R g ∝ σ μ with μ = 1 / 3 for surface coverages grater than σ ∗ . The perpendicular component R g ⊥ scales independent of the bond repulsion potential as R g ⊥ ∝ σ μ ⊥ , μ ⊥ = 1 / 3 , whereas the scaling of the parallel component exhibits a topological repulsion dependence R g ∥ ∝ σ μ ∥ , μ ∥ = − 1 / 12 for standard DPD and μ ∥ = − 1 / 6 for bond repulsion.

Approaching charged polymer brushes

2011 ◽  
Author(s):  
Long Chen ◽  
Holger Merlitz ◽  
Su-zhen He ◽  
Chen-xu Wu ◽  
Jens-Uwe Sommer
Keyword(s):  
Polymer Brushes ◽  
Charged Polymer

Charged Polymer Brushes: Counterion Incorporation and Scaling Relations

1998 ◽  
Vol 81 (19) ◽  
pp. 4172-4175 ◽  
Author(s):  
Heiko Ahrens ◽  
Stephan Förster ◽  
Christiane A. Helm
Keyword(s):  
Polymer Brushes ◽  
Scaling Relations ◽  
Charged Polymer

The kinetic friction coefficient of neutral and charged polymer brushes

Soft Matter ◽  
2013 ◽  
Vol 9 (10) ◽  
pp. 2966 ◽  
Author(s):  
Florent Goujon ◽  
Aziz Ghoufi ◽  
Patrice Malfreyt ◽  
Dominic J. Tildesley
Keyword(s):  
Friction Coefficient ◽  
Polymer Brushes ◽  
Kinetic Friction ◽  
Charged Polymer
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