The nitroxide-mediated copolymerization of 2-hydroxypropyl acrylate (HPA) with N-acryloylmorpholine (Amor) or N,N-dimethylacrylamide (DMA) was investigated using N-tert-butyl-N-(1′-diethylphosphono-2,2′-dimethylpropyl)-O-(2-carboxyl-prop-2-yl) (BlocBuilder) alkoxyamine initiator and additional free nitroxide (SG-1). Different reaction conditions, such as the concentration of additional SG-1, were tested to optimize the homopolymerizations using a Chemspeed ASW2000 automated parallel synthesizer. Best control for the homopolymerizations (polydispersity indices of 1.2−1.3) of all three monomers was achieved using 20% additional SG-1 (relative to the initiator) at a reaction temperature of 110 °C for 2 M solutions in N,N -dimethylformamide and a monomer/initiator ratio of 100/1. Libraries of P(Amor-stat-HPA) and P(DMA-stat-HPA) were synthesized with 0−100 mol % HPA with 10 mol % increments using the optimized conditions obtained for the homopolymerizations. The resulting polymers had narrow molecular weight distributions, and their compositions, determined using 1H NMR spectroscopy and elemental analysis, were close to the theoretical compositions. In addition, all copolymers of both libraries had single glass transition temperatures (T g), and the transition temperatures decreased from the T g of P(Amor) (147 °C) and P(DMA) (111 °C) to the T g of P(HPA) (22 °C) with increasing HPA content. The cloud point of P(HPA) showed concentration dependence as well as a concentration dependent hysteresis. The cloud points of aqueous solutions of the copolymer libraries could be tuned from 21.4 to 88.0 °C and to 82.9 °C for P(Amor-stat-HPA) and P(DMA-stat-HPA), respectively, at a concentration of 1 wt %. LCST behavior was observed for copolymers with >40 wt % HPA in P(Amor-stat-HPA) and >55 wt % HPA in the P(DMA-stat-HPA) library.

Synthesis of supported nanoparticles with controlled size and uniform distribution is a major challenge in nanoscience, in particular for applications in catalysis. Cryo-electron tomography revealed with nanometer resolution the 3D distribution of phases present during nanoparticle synthesis via impregnation, drying, and thermal treatment with transition metal salt precursors. By conventional methods a nonuniform salt distribution led to clustered metal oxide nanoparticles (NiO, Co 3 O 4 ). In contrast, freezedrying restricted solution mobility during drying and a more uniform nanoparticle distribution was obtained. By this fundamental insight into catalyst preparation, controlled synthesis of supported catalysts was achieved in a way that is also applicable for other nanostructured materials.

In this paper we discuss a problem-solving methodology and present guidance for troubleshooting defects in ITO-free all-solution processed organic solar cells with an inverted cell architecture.