1. Characterization of Single-Chain Nanoparticles and Star Polymers using Gel Permeation Chromatography combined with Viscometric Studies Ashley Hanlon, and Erik Berda*. Department of Chemistry, University of New Hampshire. Star Polymer Design Star Polymer Synthesis MHS and Conformation Plots Summary and Conclusions Acknowledgements Introduction Single-Chain Nanoparticles References (1) Frank, P. G.; Tuten, B. T.; Prasher, A.; Chao, D.; Berda, E. B. Macromolecular rapid communications 2014, 35, 249-253. (2) Gao, Haifeng, Macromol. Rapid Commun. 2012, 33, 722-734. (3) Gao H.; Matyjaszewski, K..J. Am. Chem. Soc., 2007, 129, 11828-11834. (4) Schneider, Y.; McVerry, B.; Bazan, G. Macromol. Chem. Phys. 2011, 212, 507-514. (5) Lyon, C. K.; Prasher, A.; Hanlon, A. M.; Tuten, B. T.; Tooley, C. A.; Frank, P. G.; Berda, E. B. Polym. Chem. 2015, 6, 181-197. Scheme 1: Schematic representation of star polymer design This research serves to explore the underutilized abilities of a GPC combined with multiple in-line detectors. Much information can be gained by exploiting the viscometric and multi-angle light scattering data to distinguish between different polymer architectures. Exploiting the abilities of GPC characterization of star polymers and SCNPs will help to identify their unique properties and potentially aid to expand the value of utilizing GPC for other types of macromolecular architectures. The exploration of different polymer architectures, such as star polymers or single-chain nanoparticles, is rapidly increasing due to the ability to synthetically tailor specific properties and the potential to utilize these types of polymers in many areas including catalysis, imaging, nanoreactors, and nanomedicine. While both of these polymer systems show promising properties and applications their characterization can be a challenge. Gel permeation chromatography (GPC) is a vital tool in polymer characterization and when using multiple in-line detectors such as multi-angle light scattering (MALS) and viscometry much qualitative and quantitative data can be gained. We have been able to demonstrate the successful synthesis, and isolation of multiple arm star polymers and single-chain nanoparticles. A detailed characterization was achieved through the use of GPC to aid in the analysis of unique macromolecular architectures. A contrast of viscometric data of unique polymer architectures and linear polymer analogs supported the transformation from rod like arms or linear polymer chains to a sphere like highly branched stars or nanoparticles. A contrast of viscometric data of star polymers to linear polymer analogs through the use of molecular conformation plots indicate the star polymers are highly branched species. The viscosity properties of the star polymers differ significantly from linear polymers. Comparisons of the slopes from Mark-Houwink plots of log intrinsic viscosity as a function of log molecular weight supported the transformation from rod like arms to a sphere like star. The Army Research Office for support through award W911NF-14-1-0177, and NIST for support through award 70NANB15H060 Polymer SCNP Peak Mn (kg/mol) Mw (kg/mol) PDIR  (nm) Intrinsic viscosity (mL/g) Arm26.535.41.233.71.3 Purified Star 74710161.3611.012.2 Peak Mn (kg/mol) Mw (kg/mol) PDIR  (nm) Intrinsic viscosity (mL/g) Arm15.317.81.173.111.8 Purified Star 3403801.1211.112.6 Mn (kg/mol)Mw (kg/mol)PDIR  (nm) Intrinsic viscosity (mL/g) MI 5.085.551.092.414.8 Copolymer 81.0104 1.286.421.5 PeakMn (kg/mol)Mw (kg/mol)PDIR  (nm) Intrinsic viscosity (mL/g) PMMA Arm11.511.81.032.35.8 PS Arm2.562.701.051.34.6 Star2482831.147.210.0 PeakMn (kg/mol)Mw (kg/mol)PDIR  (nm) Intrinsic viscosity (mL/g) Star102013301.339.98.6 Polystyrene standard 9259501.0327.1152.8 Mn (kg/mol)Mw (kg/mol)PDIR  (nm) Intrinsic viscosity (mL/g) Polymer26.330.7 1.172.85.0 Nanoparticle50.362.3 1.242.40.5 Star Polymer VS. Linear Polymer Arm Star Peak Mn (kg/mol) Mw (kg/mol) PDIR  (nm) Intrinsic viscosity (mL/g) Arm 2.562.70 1.05 1.3 4.6 Star 102013301.339.98.6 Purification of Star Polymers