Hydrophilic polymers, polymer brushes effect

We have previously demonstrated that hydrophilic polymer brushes can effectively reduce the interfacial friction in an aqueous environment under low-sliding-speed conditions.In those studies, we employed grafting to approaches to generate polymer brushes on a variety of substrates. By applying the grafting from method described in this work, the formation of high-surface-density polyelectrolyte brushes became feasible. To date, only little experimental work has been dedicated to the macroscopic lubrication properties of polymer brushes prepared with a grafting from method. ... 

In this work, we wiU discuss the characteristic size-exclusion effect and excellent protein repeUency of concentrated brushes on the basis of our experimental data previously reported with poly(2-hydroxyethyl methacrylate) (PHEMA) brushes. PHEMA is a hydrophilic, biocompatible polymer, but the biocompatibility of PHEMA cast film is reported to be not as good as e.g., poly(2-methacryloxyethyl-phosphorylcholine) and poly(2-metho-xyethylacrylate) cast films. Hence any favorable results on the PHEMA brushes could be ascribed more to the structural,... 

We have stndied the macroscopic frictional properties of high-density polymer brushes prepared by surface-initialed ATRP of methyl methacrylate (MM A) [31] and hydrophilic methacrylates [32, 33] from silicon substrates. Friction tests were carried out using a stainless steel or glass ball as the sliding probe under a normal load of 100 MPa from the viewpoint of practical engineering applications. This chapter reviews the macroscopic frictional properties of polymer brushes under a high normal load, the dependence of solvent qnaUty, the effect of humidity on hydrophilic brnsh, and wear resistance, and we compare these with alkylsilane monolayers. 

Hydrophilic modification of the PTFE membranes is performed for treatment of potable water and waste water. Xu et al. reported the graft copolymerization of AAc and NaSS binary monomers from the high energy EB pre-irradiated PTFE microporous membrane [137]. The AAc/NaSS binary monomers exhibited synergistic effect and improved the graft polymerization reaction with the pre-irradiated PTFE membrane. The water flux decreased with the increase in NaSS concentration. The grafted polymer brushes on the PTFE membrane decreased the water contact angle and produced a stable hydrophilic surface. 

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