Preparation of oligo‐N‐isopropylacrylamide brushes with OH and COOH end‐groups via surface‐initiated NMP

Abstract

Functional brushes have recently emerged as an extremely versatile way to modify surface properties in a robust and controlled way. In this study, well-defined, high density oligo-N-isopropylacrylamide (oligoNIPAM) brushes with AOH and ACOOH end-groups were fabricated through a reliable strategy by the combination of the self-assembly of bimolecular macroazoinitiator on silicon surface and surface-initiated nitroxide mediated polymerization of N-isopropylacrylamide in the presence of chain transfer agent (i.e., 2-mercaptoethanol or 3-mercaptopropionic acid). The living polymerization produced silicon substrate-coated with functional oligoNIPAM with a target molecular weight and a grafting density as high as 8.14 chains nm À2 . The functional oligoNIPAM brushes can be employed for the adsorption of biomacromolecules such as DNA and proteins.

Synthesis of dual-functional poly(6-azidohexylmethacrylate) brushes by a RAFT agent carrying carboxylic acid end groups

“…Moreover, hybrid systems composed of covalently immobilized organic molecules and polymer brushes on silicon substrate via SiC are desirable, because of the stability of the SiC bonds . High‐density polymer brushes have been attached on silicon surfaces via controlled/living radical polymerizations, including nitroxide‐mediated polymerization (NMP), atom transfer radical polymerization (ATRP), single electron transfer living radical polymerization (SET‐LRP), and reversible addition‐fragmentation chain transfer (RAFT) polymerization . In the RAFT polymerization, the chain transfer agent (CTA) is immobilized via the leaving and reinitiating group (R group), resulting in a “grafting from” procedure.…”

Methods of controlled radical polymerization for the synthesis of polymer brushes

“…Its use in the "grafting from" version is prevented by the presence of radicals in the reaction system that are able to initiate linear poly merization. Thus, there are literature data only for graft polymerizations onto the surfaces of nanoparti cles (e.g., magnetite), layers, (e.g., silicon layers), or polymer microspheres [48][49][50]. For instance, the grafting of polystyrene and poly(2 vinylpyridine) onto the surfaces of 10 nm dia Fe 2 O 3 nanoparticles that were preliminarily functionalized with alkoxyamine groups was described [48].…”

Preparation of poly(methyl methacrylate)‐grafted attapulgite by surface‐Initiated radical polymerization

“…16 Recently, a variety of controlled living radical polymerization techniques have been developed rapidly for modifying the surface of nanoparticles with organic polymers, such as atom transfer radical polymerization, 17 nitroxide-mediated polymerization, 18 and reversible addition-fragmentation chain transfer polymerization. 19 These methods provide some advantages such as grafted polymer with controlled molecular weight and narrow polydispersity. However, the condition of most surface-initiated living polymerization on the surface of nanoparticles is usually stringent, and this application is challenging.…”