Functionalization of polymeric surfaces by simple photoactivation of CH bonds

Abstract

A universal photoassisted pathway to functionalize polymeric surfaces is presented by transferring the inert surface sp3 CH bonds into reactive groups, such as SO3H, NH2, SH, and COOH. The proposed method uses acetone as photoinitiator and different phenols with a para substituent XR as the reactants. Acetone excited by UV irradiation acts as a pair of scissors cutting both the surface CH bonds of the polymer substrate and the OH bonds of phenol, leading to the formation of carbon‐centered surface chain free radicals and oxygen‐centered phenoxy free radicals. By coupling of these two radicals, a variety of functional X groups with an R spacer from XR species of different phenol reactants were readily bonded to the polymeric surfaces, where phenol reactants included 4‐hydroxylbenzene sulfonic acid for SO3H, p‐aminophenol and tyramine for NH2, 4‐hydroxythiophenol for SH, and tyrosine for COOH. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Studies on NO releasing from PCU grafted with endogenous NO donors

“…In this paper, a material as an endogenous NO donor was used, which could continuously release NO. Nitric oxide (NO) is well known as a potent antiplatelet agent, and its continuous release from the surface of ECs effectively prevents the adhesion/activation of platelets on normal blood vessel walls 21–23. Thus, it has excellent bio‐compatibility and can be used in the long‐term in bio‐medical devices.…”

“…Thus, it has excellent bio‐compatibility and can be used in the long‐term in bio‐medical devices. PCU has better blood‐compatibility and anti‐oxidation and non‐hydrolyzable properties than polyether urethane,23 and it is more suitable for long‐term in vivo use; thus, it has the potential to modify the surface of PCU by graft copolymerization.…”

A Facile Visible‐Light‐Induced Route to Functionalize Polymeric Substrates by Combining Controlled Radical Grafting Polymerization and Thiol−Yne Click Chemistry with Photoredox Catalyst Ir(ppy)3

“…The immobilization of initiators on LDPE films was operated (for experimental details, please refer to the Supporting Information) . A “sandwich” structure (please see Scheme S1, Supporting Information) was applied to perform the grafting of PMA monomer on LDPE surface under visible light irradiation.…”

“…There are two remarkable features of polymer substrates prepared by this mean: i) free of the protecting acetenyl unit, the SI‐PRCRP is successfully carried out and almost kept acetenyl integrity, and ii) the high concentration of thiol groups in the periphery of the polymer brush grafted onto the substrate surface, which can act as potential handles for further postpolymerization functionalization . At first, bromo‐4‐hydroxyacetophenone (BHAP) as the precursor of the initiator was directly immobilized on the LDPE film substrate by phenoxy radical coupling reaction under UV irradiation . Once we successfully introduce propargyl group on the substrate surface via SI‐PRCRP of PMA on LDPE film, the multi‐thiol group compound pentaerythritoltetra (3‐mercaptopropionate) (PETMP) will subsequently fulfill their duty of introducing extra thiol groups onto the substrate surface via thiol‐yne click reaction.…”

Characterization and functions of Nano-Wool crystallites

“…However, material properties depend not only on the macromolecule but also on the structurethe way the macromolecule is put together [2][3][4][5][6]. Silk fibroin powder has already found its utility as cosmetic materials and functional foods.…”