Grafted polymers grafting from” approach

The preparation of polymer brushes by controlled radical polymerization from appropriately functionalized polymer chains, surfaces or particles by a grafting from approach has recently attracted a lot of attention.742 743 The advantages of growing a polymer brush directly on a surface include well-defined grafts, when the polymerization kinetics exhibit living character, and stability due to covalent attachment of the polymer chains to the surface. Most work has used ATRP or NMP, though papers on the use of RAFT polymerization in this context also have begun to appear. 

Hijazi, I., et al., Formation of Linear and Hyperbranched Porphyrin Polymers onto Carbon Nanotubes via CuAAC Grafting from" Approach. Journal of Materials Chemistry, 2012. 22(39) p. 20936. 

Many applications of surface modified maferials (such as in molecular electronics, separation science or continuous flow catalysis) require the use of mechanically and pressure-stable carriers. Grubbs et al. and later Nuzzo et al. reported on the surface modification of Si(lll). Conversion of surface Si - H into Si-allyl groups allowed them to pursue the grafting-from approach shown in Schemes [36,37]. The thickness of the polymer layer could be... 

The grafting from approach (polymers are grown from initiators bound to surfaces) is a superior alternative because the functionality, density, and thickness of the polymer brushes can be controlled with almost molecular precision. 

So far, there have been only few reports about the synthesis of amphipolar polymer brushes, i.e. with amphiphilic block copolymer side chains. Gna-nou et al. [115] first reported the ROMP of norbornenoyl-endfunctionalized polystyrene-f -poly(ethylene oxide) macromonomers. Due to the low degree of polymerization, the polymacromonomer adopted a star-like rather than a cylindrical shape. Schmidt et al. [123] synthesized amphipolar cylindrical brushes with poly(2-vinylpyridine)-block-polystyrene side chains via radical polymerization of the corresponding block macromonomer. A similar polymer brush with poly(a-methylstyrene)-Wocfc-poly(2-vinylpyridine) side chains was also synthesized by Ishizu et al. via radical polymerization [124]. Using the grafting from approach, Muller et al. [121, 125] synthesized... 

Fig. 32 Schematic presentation of grafting to and grafting from approaches for synthesis of binary polymer brushes...

The grafting from approach is based on the initial immobilization of initiators on to the nanotube surface followed by in situ polymerisation with the formation of the polymer molecules bound to the nanotube. The benefit of this technique is that polymer-functionalised nanotubes with high grafting density can be produced. However, this method requires a strict control of the amounts of initiator and substrate. 

Polymer-grafted Carbon Nanotubes via Grafting From Approach... 

Scheme 5.2 A cartoon for polymer brushes grown from the CNT surface (a), and the monomers used in the functionalization of CNTs via the ATRP grafting from approach (b). ...

Polymer-grafted Carbon Nanotuhes via Grafting From Approach 143... 

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