Pyroelectric Polyelectrolyte Brushes.

Piezo- and pyroelectric materials are of interest, for example, for energy harvesting applications, for the development of tactile sensors, as well as neuromorphic computing. This study reports the observation of pyro- and piezoelectricity in thin surface-attached polymer brushes containing zwitterionic and electrolytic side groups that are prepared via surface-initiated polymerization. The pyro- and piezoelectric properties of the surface-grafted polyelectrolyte brushes are found to sensitively depend on and can be tuned by variation of the counterion.

Fouling Resistance of Brush-Modified Elastomers.

The most effective antifouling coatings are designed to slowly release biocides that target a broad spectrum of marine organisms. However, as biocides have a deleterious effect on marine life, there is demand for environmentally friendly coatings that resist fouling through physical interactions. We propose a simple platform for the development of such coatings based on bottlebrush-modified elastomers.

Cinematic reflectometry using QIKR, the quite intense kinetics reflectometer.

The Quite Intense Kinetics Reflectometer (QIKR) will be a general-purpose, horizontal-sample-surface neutron reflectometer. Reflectometers measure the proportion of an incident probe beam reflected from a surface as a function of wavevector (momentum) transfer to infer the distribution and composition of matter near an interface. The unique scattering properties of neutrons make this technique especially useful in the study of soft matter, biomaterials, and materials used in energy storage.

Architecture- and Composition-Controlled Self-Assembly of Block Copolymers and Binary Mixtures With Crosslinkable Components: Chain Exchange Between Block Copolymer Nanoparticles.

Chain exchange behaviors in self-assembled block copolymer (BCP) nanoparticles (NPs) at room temperature are investigated through observations of structural differences between parent and binary systems of BCP NPs with and without crosslinked domains. Pairs of linear diblock or triblock, and branched star-like polystyrene-poly(2-vinylpyridine) (PS-PVP) copolymers that self-assemble in a PVP-selective mixed solvent into BCP NPs with definite differences in size and self-assembled morphology are combined by diverse mixing protocols and at different crosslinking densities to reveal the impact of chain exchange between BCP NPs. Clear structural evolution is observed by dynamic light scattering and AFM and TEM imaging, especially in a blend of triblock + star copolymer BCP NPs.

Tuning fullerene miscibility with porphyrin-terminated P3HTs in bulk heterojunction blends.

Understanding and manipulating the miscibility of donor and acceptor components in the active layer morphology is important to optimize the longevity of organic photovoltaic devices and control power conversion efficiency. In pursuit of this goal, a "porphyrin-capped" poly(3-hexylthiophene) was synthesized to take advantage of strong porphyrin:fullerene intermolecular interactions that modify fullerene miscibility in the active layer. End-functionalized poly(3-hexylthiophene) was synthesized via catalyst transfer polymerization and subsequently functionalized with a porphyrin moiety via post-polymerization modification.