Thermal annealing strongly impacts the nano- and microstructure of conjugated polymers. Despite the fundamental importance for the resulting optoelectronic behavior of this class of materials, the underlying crystallization processes have not received the same attention that is encountered in other disciplines of materials science. The question arises whether classical treatment of nucleation a...

Dielectric constant and morphology of BaTiO3-polymer composite films were studied as a function of the filler concentration. The morphology of the films was examined using laser scanning confocal microscopy, which is capable to measure small particle distributions in more details than conventional microscopy. The thin-slice images allowed us to visualize the micronsize particles and the polymer...

Magnetic resonance imaging is used to study changing microstructure and molecular motion during dissolution of poly(vinyl alcohol) (PVA) in water. One-dimensional water concentration profiles were measured as a function of distance from the polymer-solvent interface. Diffusion-weighted profiles were used to calculate the spatial variation of the self-diffusion coefficient of water. The results ...

Two soft lithography based fabrication techniques were employed for fabricating mechanically independent, freely suspended polymer microstructure from poly(n-propyl methacrylate) (PPMA) and poly(methyl methacrylate) (PMMA). Both methods involve a micromolding process followed by thermal bonding to the substrate. The first method, sacrificial layer micromolding, uses a water-soluble sacrificial ...

Precise control of the energy levels in a conjugated polymer is the key to allowing their exploitation in optoelectronic devices. The introduction of spirocycles into conjugated polymers has traditionally been used to enhance their solid state microstructure. Here we present a highly novel method of energetic tuning through the use of electronically active spirocyclic systems. By modifying the ...

Positron annihilation spectroscopy in lifetime measuring mode exploring conventional fast-fast coincidence ORTEC system is employed to characterize free volume structure of commercially available acrylic-type dental restorative composite Charisma® (Heraeus Kulzer GmbH, Germany). The measured lifetime spectra for uncured and light-cured composites are reconstructed from unconstrained x3-term fit...