Poly(glycerol-co-glyceric acid) Functionalized Nanodiamonds by Nitroxyl Radical-Catalyzed Oxidation of Primary Alcohols in Poly(glycerol) as Scaffolds for Further Conjugation

Abstract

Poly(glycerol) (PG) functionalization is versatile to make various nanoparticles dispersible in aqueous media. In addition, the abundant hydroxy groups in PG give scaffolds for further modification to introduce suitable functional groups. For example, carboxylic group (−COOH) has been introduced through the reaction of hydroxy (−OH) group in PG with succinic anhydride. However, ester linkage in the succinate moiety in the PG layer is subjected to hydrolysis. In this work, we develop an alternative way for a novel −COOH containing PG functionalized detonation nanodiamonds (DND-PG-COOH) via oxidation of primary −OH group of PG chain by nitroxyl radical catalysts well-known as TEMPO or its analogues. The content of −COOH is found to be precisely controlled by the amount of oxidant.