Polymer strategies in perovskite solar cells
Anna Isakova and Paul D. Topham
Since their emergence in 2013, perovskite solar cells have reached
remarkable efficiencies exceeding 22%. Such rapid development of this
technology has been possible, in part, due to the feed of ideas from previous
research in organic photovoltaics (OPVs) and light emitting diodes (OLEDs).
This comprehensive review discusses the various polymer strategies that have
led to the success of perovskite devices: from hole and electron transporting
materials to polymer templating agents.
Liquid crystal elastomer actuators: Synthesis, alignment,
Ruvini S. Kularatne, Hyun Kim, Jennifer M. Boothby and Taylor H. Ware
This work explores coatings with thermally switchable wetting behavior, based
on block copolymers that possess both hydrophilic and hydrophobic segments.
The amphiphilic block copolymers were synthesized by coupling allyl-ended
poly(ethylene oxide) (PEO) and hydride-ended poly(dimethylsiloxane) (PDMS)
oligomers via a Pt catalyst. One near-symmetric diblock possessed an orderdisorder
transition temperature (TODT) of 64 °C. When cooled through TODT in
ambient air, the PDMS domains wet the film’s surface, producing a hydrophobic
coating with a water contact angle (CA) = 90°.
Controlling domain orientation of liquid crystalline block
copolymer in thin films through tuning mesogenic
He-Lou Xie, Xiao Li, Jiaxing Ren, Camille Bishop, Christopher G. Arges
and Paul F. Nealey
Controlling the macroscopic orientation of nanoscale periodic structures of
amphiphilic liquid crystalline block copolymers (LC BCPs) is important to a variety
of technical applications (e.g., lithium conducting polymer electrolytes). To study
LC BCP domain orientation, a series of LC BCPs containing a poly(ethylene
oxide) (PEO) block as a conventional hydrophilic coil block and LC blocks
containing azobenzene mesogens is designed and synthesized.
Ion condensation onto self-assembled nanofibers
Elad Deiss-Yehiely, Julia H. Ortony, Baofu Qiao, Samuel I. Stupp and
Monica Olvera de la Cruz
Self-assembled peptide amphiphile (PA) nanofibers are a class of
supramolecular materials with promising applications in nanotechnology.
Alignment of nanofibers, which is essential for biomaterials applications,
is achieved at low salt concentrations in the PA nanofiber suspensions.
Regardless of its importance, the effect of ion concentration on the properties
of these nanostructures remains unexplored. Using atomistic molecular
dynamics simulations, canonical PA nanostructures are investigated to elucidate
the relationship between counterion condensation and morphological changes.