Microporous carbide-derived carbons are an important structural class for various technological applications. We present two possible strategies based on molecular dynamics simulations for modeling microporous amorphous carbon. In addition, we have investigated the influence of the precursor structure and simulation parameters on the porosity of the final model structure. We observed a minor influence of the precursor structure on the porosity and found that the structural properties such as pore size and hybridization in the modeled carbon structures agree well with experimental findings. Moreover, CO 2 adsorption isotherms have been simulated using Monte Carlo simulations for comparsion with experimental data. In this context, we have also considered partially oxidized carbon structures for which an increased uptake of CO 2 was observed.

Supercapacitors are regarded as a promising technology for novel, powerful energy-storage systems. The mechanism of energy storage in these capacitors is not fully understood yet because of the complex molecular mechanisms at the atomistic scale. Exploring the processes at the nanoscale provides necessary fundamental and thorough insights for improving the performance of such devices. In this work, we present a combined computational and experimental study on electrode–electrolyte interactions in electric double-layer capacitors. The influence of pore size and surface chemistry of carbon-based electrode material on interactions with the electrolyte has been investigated for an organic and inorganic electrolyte using density functional theory calculations. In addition, solvent effects on the interaction strength have been systematically explored. We found that experimentally determined effects of pore confinement can be linked with calculated interaction energies, providing a suitable descriptor for virtual prescreening approaches. Our results show that the pore size significantly affects the interaction quality with the electrolyte. This effect and the influence of chemical functionalization have a stronger impact on the interaction with anions than with cations. Moreover, our studies indicate that solvent effects are especially important for surface functional groups that allow for hydrogen bonding. Overall, our results provide relevant information on how structural and electronic effects affect confinement, wettability, and mobility of electrolyte molecules, which is important for boosting and tuning the performance of supercapacitors.

In order to realize a versatile high throughput production of micro-optical elements, UV-curable polymer composites containing titanium dioxide nanoparticles were prepared and characterized. The composites are based on an industrial prototype epoxy polymer. Titanium dioxide nanoparticles smaller than 10 nm were synthesized by the nonaqueous sol method and in situ sterically stabilized by three different organic surfactants. The composites exhibit high transparency. Distinct alteration of optical transmission properties for visible light and near IR wavelength range could be avoided by adaption of the stabilizing organic surfactant. Most importantly, the refractive index (RI) of the composites that depends on the fraction of incorporated inorganic nanoparticles could be directly tuned. E.g. the RI at a wavelength of 635 nm of a composite containing 23 wt% titanium dioxide nanoparticles is increased to 1.626, with respect to a value of 1.542 for the pure polymer. Furthermore, it could be demonstrated that the prepared inorganic-organic nanocomposites are well suited for the direct fabrication of low-cost micro-optical elements by nanoimprint lithography. A low response of the optical composite properties to temperature treatment up to 220 °C with a shrinkage of only about 4% ensures its application for integrated micro-optical elements in industrial production.

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