1 H DOSY NMR provides a simple and convenient method to determine both the molecular weight and the solution properties of poly(N-acryloylmorpholine) (PNAM) in various organic and aqueous solvents. This technique is used to measure the average diffusion coefficient D PNAM of a library of PNAM samples of increasing molecular weights synthesized by reversible addition fragmentation chain transfer controlled radical polymerization. In all solvents, the highly linear relationship between Log D PNAM and Log M w yields calibration curves that can be used for the reliable determination of the molecular weight of various types of PNAM samples. In addition, the slope of the calibration curves can be considered as the Flory exponent δ characterizing the solvent-polymer interaction. The measurements show that CDCl 3 and D 2 O are theta solvents for PNAM and that δ slightly decreases in phosphate buffer solution (PBS), pH 7.4, and upon addition of MeOD in D 2 O. highly biocompatible [6] and show similar properties. [7] In addition, PNAM is synthesized by radical polymerization (unlike PEG). Therefore, NAM can be advantageously copolymerized with a large choice of co-monomers such as functional monomers that can be used to bind biomolecules or other entities of interest in lateral position of the polymer chains.For many years now, PNAM and related copolymers have been considered for various bio-related applications. Cross-linked networks were used for gel-phase synthesis of peptides, [8][9][10] semi-permeable membranes for plasma separation, [11] polymeric supports for gel chromatography [12,13] and capillary electrophoresis. [14] Linear PNAM was also used for drug delivery applications, protecting liposomes from blood clearance, [15] or increasing the lifetime of enzymes both in vitro and in vivo. [16] More recently, we and others conducted in-depth studies about the homo- [17][18][19][20] and co-polymerization [21,22] of NAM by the reversible addition fragmentation chain transfer (RAFT) controlled radical polymerization

Fluorescent RAFT polymer probes with an activated ester reactive end-group can be advantageously used to label native proteins.