Reversible adhesion between a hydrogel and a polymer brush

Sudre, Guillaume; Olanier, Ludovic; Tran, Yvette; Hourdet, Dominique; Creton, Costantino

doi:10.1039/c2sm25868d

Cited by 89 publications

(106 citation statements)

References 45 publications

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“…In recent years, polymer brushes have been shown to be a useful class of materials for many medical and biological applications [13,14]. For example, custom synthetic polymers have great potential in drug delivery and molecular recognition [15], and tethering polymer chains onto surfaces can effectively reduce friction [16,17], and control adhesion [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Determination of the molar mass of surface-grafted weak polyelectrolyte brushes using force spectroscopy

Al-Baradi

Tomlinson

Zhang³

et al. 2015

Polymer

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The molar mass and dispersity of a polycation, poly[2-(dimethyl amino)ethyl methacrylate)] (PDMAEMA) grafted from a poly(methyl methacrylate) (PMMA) backbone, was measured by single-molecule force spectroscopy (SMFS) and shown to be consistent with results from gel permeation chromatography for the same comb polymer in aqueous solution. Comparison was then made between the comb polymer and PDMAEMA brushes that were grown from the substrate, as a function of the pH and ionic strength of the surrounding medium, and the limits of reliable characterization of the polymers are determined. A large discrepancy was observed between the responses of the comb and brush layer at low pH when the PDMAEMA molecules are extended from the supporting substrate. Here it is believed that the atomic force microscope (AFM) tip can penetrate the comb layer and selectively desorb side-chains of the comb. In the case of the well solvated PDMAEMA brushes at high pH, the tip preferentially selects larger chains, resulting in an over-estimate of the brush molar mass. The addition of salt also influenced the molar mass obtained by this technique. It is believed that salted brushes did not adhere well to the AFM tip, with subsequent desorption resulting in an underestimate of the molar mass. However, SMFS was shown to be capable of demonstrating the effect of salt on brush conformation, with greater swelling after the addition of a small amount of NaCl, but a significant decrease when 100 mM is added.

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Section: Introductionmentioning

confidence: 99%

Determination of the molar mass of surface-grafted weak polyelectrolyte brushes using force spectroscopy

Al-Baradi

Tomlinson

Zhang³

et al. 2015

Polymer

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“…This makes them particularly interesting for controlled release, 7 tunable assembly of coated nanoparticles, 8 responsive nanoactuators 9,10 or for antifouling surfaces. 11,12 More recently, complex systems produced by embedding surfactants, 13,14 gels 15,16 or nanoparticles [17][18][19][20] into polymer brushes have been studied, from which multiresponsive coatings with enlarged applicability as stimuli-responsive systems can be designed. Among them, there are some examples of polyelectrolyte (PE) chains adsorbed onto charged polymer brushes.…”

Section: Introductionmentioning

confidence: 99%

Temperature responsive behavior of polymer brush/polyelectrolyte multilayer composites

et al. 2016

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aThe complex interaction of polyelectrolyte multilayers (PEMs) physisorbed onto end-grafted polymer brushes with focus on the temperature-responsive behavior of the system is addressed in this work. The investigated brush/multilayer composite consists of a poly(styrene sulfonate)/poly(diallyldimethylammonium chloride) (PSS/PDADMAC) multilayer deposited onto the poly(N-isopropylacrylamide-bdimethylaminoethyl methacrylate) P(NIPAM-b-DMAEMA) brush. Ellipsometry and neutron reflectometry were used to monitor the brush collapse with the thickness decrease as a function of temperature and the change in the monomer distribution perpendicular to the substrate at temperatures below, across and above the phase transition, respectively. It was found that the adsorption of PEMs onto polymer brushes had a hydrophobization effect on PDMAEMA, inducing the shift of its phase transition to lower temperatures, but without suppressing its temperature-responsiveness. Moreover, the diffusion of the free polyelectrolyte chains inside the charged brush was proved by comparing the neutron scattering length density profile of pure and the corresponding PEM-capped brushes, eased by the enhanced contrast between hydrogenated brushes and deuterated PSS chains. The results presented herein demonstrate the possibility of combining a temperature-responsive brush with polyelectrolyte multilayers without quenching the responsive behavior, even though significant interpolyelectrolyte interactions are present. This is of importance for the design of multicompartment coatings, where the brush can be used as a reservoir for the controlled release of substances and the multilayer on the top as a membrane to control the diffusion in/out by applying different stimuli.

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“…There is a tension between the pH and salt dependence of polyelectrolytes, since pH is often considered to convey "smart" properties to the material, with an aim of triggering an environmental stimulus, e.g. for adhesion [17][18][19][20] and drug delivery [21,22]. The addition of salt screens ions and consequently reduces the effect of pH, which is particularly important in physiological environments.…”

Section: Introductionmentioning

confidence: 99%

Salt Dependence of the Tribological Properties of a Surface-Grafted Weak Polycation in Aqueous Solution

et al. 2017

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The nanoscopic adhesive and frictional behaviour of end-grafted poly[2-(dimethyl amino)ethyl methacrylate] (PDMAEMA) films (brushes) in contact with gold-or PDMAEMA-coated atomic force microscope tips in potassium halide solutions with different concentrations up to 300 mM is a strong function of salt concentration. The conformation of the polymers in the brush layer is sensitive to salt concentration, which leads to large changes in adhesive forces and the contact mechanics at the tip-sample contact, with swollen brushes (which occur at low salt concentrations) yielding large areas of contact and friction-load plots that fit JKR behaviour, while collapsed brushes (which occur at high salt concentrations) yield sliding dominated by ploughing, with conformations in between fitting DMT mechanics. The relative effect of the different anions follows the Hofmeister series, with I − collapsing the brushes more than Br − and Cl − for the same salt concentration.

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Reversible adhesion between a hydrogel and a polymer brush

Cited by 89 publications

References 45 publications

Determination of the molar mass of surface-grafted weak polyelectrolyte brushes using force spectroscopy

Determination of the molar mass of surface-grafted weak polyelectrolyte brushes using force spectroscopy

Temperature responsive behavior of polymer brush/polyelectrolyte multilayer composites

Salt Dependence of the Tribological Properties of a Surface-Grafted Weak Polycation in Aqueous Solution

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