Rigid stars: properties and functions

Abstract

The properties of star-shaped adamantane multipodes with different types of rigid branches with various lengths are discussed. The expectation based on theoretical considerations was that such multipodes would display an enhanced solubility both in low molar mass solvents and in polymer matrices. These multipodes have a three-dimensional star-like shape, are able to crystallize but can also be obtained in the glassy state, and they show a relaxational behavior typical for polyarylates. They are soluble in various low molar mass organic solvents much better than linear rigid molecules of the same chemical constitution and of similar length and they are miscible in polymer matrices up to concentrations of 30 wt%. The multipodes were found to influence the dielectric and mechanical properties of the matrix polymers significantly.

Morphology Control in Biphasic Hybrid Systems of Semiconducting Materials

“…Summing up, experiments by us and other groups as well as simulations show that, contrary to expectations raised by the pioneering papers in this field, uncoated TP structures are not compatible with melts of flexible polymers. However, they can be made compatible by grafting suitable polymers onto them.…”

“…In this paper, we will focus on the simplest space‐filling geometry, branched tetrapods (TPs). These nanoparticles have originally been suggested for use as filler particles for mechanical reinforcement of flexible polymers, and they have also been applied in solar cells . In the context of semiconducting materials, TPs are interesting because they can promote charge transport in all three spatial directions, regardless of the orientation of the TPs .…”

“…Nanocomposites have been investigated in detail concerning e.g. “molecular reinforcement” (the distribution of fibers in flexible polymers) or the placement of inorganic nanoparticles in block copolymer structures . Numerous investigations in the field of nanocomposites have been carried out motivated by promising observations such as significant property changes at very low volume fractions of the added nanoparticles and the possibility to incorporate new functions through the integration of nanoparticles providing specific properties .…”