@article{LendleinHeuchel2021, author = {Lendlein, Andreas and Heuchel, Matthias}, title = {Shape-memory polymers designed in view of thermomechanical energy storage and conversion systems}, series = {ACS central science}, volume = {7}, journal = {ACS central science}, number = {10}, publisher = {American Chemical Society}, address = {Washington}, issn = {2374-7951}, doi = {10.1021/acscentsci.1c01032}, pages = {1599 -- 1601}, year = {2021}, language = {en} } @article{RietzeTitovGranuccietal.2020, author = {Rietze, Clemens and Titov, Evgenii and Granucci, Giovanni and Saalfrank, Peter}, title = {Surface hopping dynamics for azobenzene photoisomerization}, series = {The journal of physical chemistry : C, Nanomaterials and interfaces}, volume = {124}, journal = {The journal of physical chemistry : C, Nanomaterials and interfaces}, number = {48}, publisher = {American Chemical Society}, address = {Washington}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.0c08052}, pages = {26287 -- 26295}, year = {2020}, abstract = {Azobenzenes easily photoswitch in solution, while their photoisomerization at surfaces is often hindered. In recent work, it was demonstrated by nonadiabatic molecular dynamics with trajectory surface hopping [Titov et al., J. Phys. Chem. Lett. 2016, 7, 3591-3596] that the experimentally observed suppression of trans -> cis isomerization yields in azobenzenes in a densely packed SAM (self-assembled monolayer) [Gahl et al., J. Am. Chem. Soc. 2010, 132, 1831-1838] is dominated by steric hindrance. In the present work, we systematically study by ground-state Langevin and nonadiabatic surface hopping dynamics, the effects of decreasing packing density on (i) UV/vis absorption spectra, (ii) trans -> cis isomerization yields, and (iii) excited-state lifetimes of photoexcited azobenzene. Within the quantum mechanics/ molecular mechanics models adopted here, we find that above a packing density of similar to 3 molecules/nm(2), switching yields are strongly reduced, while at smaller packing densities, the "monomer limit" is quickly approached. The UV/vis absorption spectra, on the other hand, depend on packing density over a larger range (down to at least similar to 1 molecule/nm(2)). Trends for excited-state lifetimes are less obvious, but it is found that lifetimes of pi pi* excited states decay monotonically with decreasing coverage. Effects of fluorination of the switches are also discussed for single, free molecules. Fluorination leads to comparatively large trans -> cis yields, in combination with long pi pi* lifetimes. Furthermore, for selected systems, also the effects of n pi* excitation at longer excitation wavelengths have been studied, which is found to enhance trans -> cis yields for free molecules but can lead to an opposite behavior in densely packed SAMs.}, language = {en} } @misc{Taubert2015, author = {Taubert, Andreas}, title = {Electrospinning of Ionogels: Current Status and Future Perspectives}, series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, journal = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, number = {7}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-1948}, doi = {10.1002/ejic.201402490}, pages = {1148 -- 1159}, year = {2015}, abstract = {Ionogels (IGs), also termed ion gels, are functional hybrid materials based on an ionic liquid (IL) and a polymeric, hybrid, or inorganic matrix. IGs combine the properties of the matrix such as mechanical strength with IL properties like high ionic conductivity, high thermal stability, or catalytic activity. IGs are thus attractive for many applications, but the vast majority of IGs made and published so far are bulk materials or dense films. Applications like sensing or catalysis, however, would benefit from IGs with high surface areas or defined surface morphologies or architectures. In spite of this, only relatively few examples of high-surface-area IGs have been made so far; this has mostly been achieved by electrospinning, which has proven to be a promising strategy towards advanced IGs. The current review discusses first developments and outlines the future potential of electrospun ionogels, predominantly from a materials and inorganic chemistry perspective.}, language = {en} }