We study the friction between a flat solid surface where polymer chains have been end-grafted and a cross-linked elastomer at low sliding velocity. The contribution of isolated grafted chains’ penetration in the sliding elastomer has been early identified as a weakly velocity dependent pull-out force. Recent experiments have shown that the interactions between the grafted chains at high graftin...

Dispersing nanoparticles in a polymer matrix is intrinsically challenging because of unfavorable entropic interactions between the matrix and the nanoparticle. Similar to suspensions of larger colloidal particles, it has been found that thermodynamically stable dispersions of nanoparticles can be achieved in polymer matrices when the nanoparticles are decorated with dense layers of polymer teth...

We report on the fabrication of micropatterned polymer surfaces that allow the reversible inversion of surface topography, charge, and wettability. Micropatterned surfaces were prepared by grafting two oppositely charged polyelectrolytes (poly(acrylic acid) and poly(2-vinylpyridine)) using a combination of photolithography, "lift off", and "grafting to" techniques. The switchable surfaces are o...

We report a facile and versatile scanning probe based approach-dip-pen nanodisplacement lithography (DNL)--for manipulating nanostructures of polymer brushes. Nanostructured polymer brushes with sizes as small as 25 nm are made by DNL patterning of the initiator molecules and subsequent surface-initiated polymerization. Nanoconfinement effects including chain collapsing and spreading are observ...

We investigate the structure of end-tethered polyelectrolytes using Monte Carlo simulations and molecular theory. In the Monte Carlo calculations we explicitly take into account counterions and polymer configurations and calculate electrostatic interaction using Ewald summation. Rosenbluth biasing, distance biasing, and the use of a lattice are all used to speed up Monte Carlo calculation, enab...

Hydrophobic and oleophobic resistant coatings are realized on nylon cotton textiles by plasma induced polymerization of modified pyrrole monomers. This process creates a chemical bond between the polymer textile fibers for an improved mechanical adherence. A post-grafting with short fluorinated chains gives non-wetting properties. Two other improvements tested compared in terms adherence wettin...

The aim of the research work was to chemically modify guar gum(GG) as a pH sensitive co-polymer and formulating intestinal targeting ESO nanoparticles (NPs) using the synthesized co-polymer. Poly acrylamide-grafted-guar gum (PAAm-g-GG) co-polymer was synthesized by free radical polymerization. Chemical modification of PAAm-g-GG by alkaline hydrolysis results in formation of a pH-sensitive co-po...

Grafting polymerization was a valuable method for the modification of the chemical and physical properties of polymer surfaces. In this paper, the grafting of cationic vinyl monomer with quaternary ammonium groups, methacryloxyethyltrimethyl ammonium chloride (DMC), onto the isotactic polypropylene (iPP) granule was performed by suspension solid-state grafting process. The techniqu...

OBJECTIVE Aseptic loosening of artificial knee joints induced by wear particles from a tibial polyethylene (PE) insert is a serious problem limiting their longevity. This study investigated the effects of grafting with our original biocompatible phospholipid polymer 2-methacryloyloxyethyl phosphorylcholine (MPC) on the insert surface. METHODS The hydrophilicity of the PE surface was determine...