Rough surfaces possess complex topographies, which cannot be characterized by a single parameter. The selection of appropriate roughness parameters depends on a particular application. Large datasets representing surface topography possess orderliness, which can be expressed in terms of topological features in high-dimensional dataspaces reflecting properties such as anisotropy and the number of lay directions. The features are scale-dependent because both sampling length and resolution affect them. We study nanoscale surface roughness using 3 × 3, 4 × 4, and 5 × 5 pixel patches obtained from atomic force microscopy (AFM) images of brass (Cu Zn alloy) samples roughened by a sonochemical treatment. We calculate roughness parameters, correlation length, extremum point distribution, persistence diagrams, and barcodes. These parameters of interest are discussed and compared.

A model nanocomposite releases drug within 40 minutes under UV irradiation.

In the last two decades, a large number of self‐assembled materials were synthesized and they have already found their way into large‐scale industry and science. Hydrogen‐bond‐based supramolecular adducts are found to have unique properties and to be perfect host structures for trapping target molecules or ions. Such chemical systems are believed to resemble living matter and can substitute a living cell in a number of cases. Herein, a report on an organic material based on supramolecular assembly of barbituric acid and melamine is presented. Surprisingly, the structure is found to host and stabilize radicals under mild conditions allowing its use for biological applications. The number of free radicals is found to be easily tuned by changing the pH of the environment and it increases when exposed to light up to a saturation level. We describe a preparation method as well as stability properties of melamine–barbiturate self‐assembly, potentiometric titration, and hydrogen ions adsorption data and EPR spectra concerning the composite.

Supramolecular organic systems can be used as a host for the encapsulation of small organic molecules. Here, we chose melamine barbiturate as a robust system capable of supramolecular assembly and the Rhodamine 6G dye entrapment as a guest molecule. The encapsulation of the dye was investigated by UV-visible spectroscopy, SEM and optical fluorescent microscopy while the insight into the crystal structure of the system was obtained by single crystal and powder XRD. For investigation of the system’s properties on a molecular level, the DFT and Classical Molecular Dynamics methods were utilized. Surprisingly, both theoretical and experimental data show not only the successful encapsulation of Rhodamine 6G molecules inside the supramolecular assembly, but also that inclusion of such molecules leads to the drastic improvement in the organic crystal shape. The melamine barbiturate in presence of the Rhodamine 6G molecules tend to form crystals with lesser degree of twinning and higher symmetry in shape than the ones without dye molecules.

Adjustment of the environmental acidity is a powerful method for fine-tuning the outcome of many chemical processes. Numerous strategies have been developed for the modification of pH in bulk as well as locally. Electrochemical and photochemical processes provide a powerful approach for on-demand generation of ion concentration gradients locally at solid-liquid interfaces. Spatially organized in individual way electrodes provide a particular pattern of proton distribution in solution. It opens perspectives to iontronics which is a bioinspired approach to signaling, information processing, and storing by spatial and temporal distribution of ions. We prove here that soft layers allow to control of ion mobility over the surface as well as processes of self-organization are closely related to change in entropy. In this work, we summarize the achievements and discuss perspectives of ion gradients in solution for information processing.