Polymer brushes substrate surface properties

Synthetic strategies for the preparation of polymer brushes (A) physisorption, (B) grafting-to approach via reaction of appropriately end-functionalized polymers with complementary functional groups on the substrate surface, (C) grafting-from approach via surface-initiated polymerization. (Reprinted with permission from Barbey et al. 2009. Polymer Brushes via Surface-Initiated Controlled Radical Polymerization Synthesis, Characterization, Properties, and Applications. Chemical Reviews 109 (ll) 5437-5527 copyright (2009) American Chemical Society.)... 

Abstract The current chapter gives a general overview on surface-initiated nitroxide-mediated polymerization (SI-NMP). More particularly, the developed strategies to perform an SI-NMP process, the various type of substrates including inorganic and organic supports, and the potential of SI-NMP to prepared advanced materials are discussed. Based on a selected number of literature examples it appears that SI-NMP is a versatile and powerful approach to introduce polymer brushes on surfaces and/or tune polymer surface properties. 

Till now, only three reports on the preparation of polymer brushes by means of surface-initiated anionic polymerization on planar substrates with accounts on the morphology and special properties can be found. 

Surface-initiated ATRP was applied not only on planer substrates but also on various kinds of flne particles. The latter systems will be reviewed separately in Sect. 5.1. Porous materials are also fascinating targets for chromatographic application making use of the unique structure and properties of high-density polymer brushes. Wirth et al. were the first to report the grafting of poly(acrylamide) (PAAm) on a porous silica gel [109,110]. 

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. ... 

Recently, the investigation of polymer brushes has been focused on the synthesis of new tethered polymer systems primarily through surface-initiated polymerization (SIP). Previously, the term polymer brushes has been limited to the investigation of block copolymers (qv) or end-functional linear polymers that have been physically or chemically adsorbed to surfaces, respectively (3,4). Recent synthetic efforts using different polymerization mechanisms have resulted in the discovery of many novel properties of polymer brushes. This has been aided no less than the use of innovative and unique surface-sensitive analysis methods as applied to flat substrates and particles. The study of polymer brushes has benefited from improved dielectric, optical, spectroscopic, and microscopic characterization methods. Understanding the chemistry of these grafting reactions and how... 

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. 

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