@misc{WessigGerngrossPapeetal.2014, author = {Wessig, Pablo and Gerngroß, Maik and Pape, Simon and Bruhns, Philipp and Weber, Jens}, title = {Novel porous materials based on oligospiroketals (OSK)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-74466}, pages = {31123 -- 31129}, year = {2014}, abstract = {New porous materials based on covalently connected monomers are presented. The key step of the synthesis is an acetalisation reaction. In previous years we used acetalisation reactions extensively to build up various molecular rods. Based on this approach, investigations towards porous polymeric materials were conducted by us. Here we wish to present the results of these studies in the synthesis of 1D polyacetals and porous 3D polyacetals. By scrambling experiments with 1D acetals we could prove that exchange reactions occur between different building blocks (evidenced by MALDI-TOF mass spectrometry). Based on these results we synthesized porous 3D polyacetals under the same mild conditions.}, language = {en} } @article{WessigGerngrossPapeetal.2014, author = {Wessig, Pablo and Gerngroß, Maik and Pape, Simon and Bruhns, Philipp and Weber, Jens}, title = {Novel porous materials based on oligospiroketals (OSK)}, series = {RSC Advances : an international journal to further the chemical sciences}, volume = {2014}, journal = {RSC Advances : an international journal to further the chemical sciences}, number = {4}, issn = {2046-2069}, doi = {10.1039/c4ra04437a}, pages = {31123 -- 31129}, year = {2014}, abstract = {New porous materials based on covalently connected monomers are presented. The key step of the synthesis is an acetalisation reaction. In previous years we used acetalisation reactions extensively to build up various molecular rods. Based on this approach, investigations towards porous polymeric materials were conducted by us. Here we wish to present the results of these studies in the synthesis of 1D polyacetals and porous 3D polyacetals. By scrambling experiments with 1D acetals we could prove that exchange reactions occur between different building blocks (evidenced by MALDI-TOF mass spectrometry). Based on these results we synthesized porous 3D polyacetals under the same mild conditions.}, language = {en} } @misc{CherstvyChechkinMetzler2014, author = {Cherstvy, Andrey G. and Chechkin, Aleksei V. and Metzler, Ralf}, title = {Particle invasion, survival, and non-ergodicity in 2D diffusion processes with space-dependent diffusivity}, number = {168}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-74021}, pages = {1591 -- 1601}, year = {2014}, abstract = {We study the thermal Markovian diffusion of tracer particles in a 2D medium with spatially varying diffusivity D(r), mimicking recently measured, heterogeneous maps of the apparent diffusion coefficient in biological cells. For this heterogeneous diffusion process (HDP) we analyse the mean squared displacement (MSD) of the tracer particles, the time averaged MSD, the spatial probability density function, and the first passage time dynamics from the cell boundary to the nucleus. Moreover we examine the non-ergodic properties of this process which are important for the correct physical interpretation of time averages of observables obtained from single particle tracking experiments. From extensive computer simulations of the 2D stochastic Langevin equation we present an in-depth study of this HDP. In particular, we find that the MSDs along the radial and azimuthal directions in a circular domain obey anomalous and Brownian scaling, respectively. We demonstrate that the time averaged MSD stays linear as a function of the lag time and the system thus reveals a weak ergodicity breaking. Our results will enable one to rationalise the diffusive motion of larger tracer particles such as viruses or submicron beads in biological cells.}, language = {en} }