New calixarene-based nanosponges (CaNSs), i.e., hyper-reticulated polymers constituted by calixarene monomer units joined by means of bis(1,2,3-trialzolyl)alkyl linkers, were synthesized, characterized and subjected to preliminary tests to assess their supramolecular absorption abilities towards a set of suitable organic guests, selected as pollutant models. The synthesis was accomplished by means of a CuAAC reaction between a tetrakis(propargyloxy)calix[4]arene and an alkyl diazide. The formation of the polymeric network was assessed by means of FTIR and 13C{1H} CP-MAS solid-state NMR techniques, whereas morphological characterization was provided by SEM microghaphy. The materials were proved to possess pH-dependent sequestration abilities, due to the presence of the weakly basic triazole linkers. Sequestration efficiency indeed depends on the effective occurrence of both electrostatic and hydrophobic interactions between the guest and the polymer lattice. Thus, our CaNS nanosponges can be considered as a new class of purely synthetic smart absorbent materials.

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Four mixed cyclodextrin‐calixarene nanosponges were tested as possible Drug Delivery Systems, using Tetracycline antibiotic as a suitable model drug. The selected nanosponges featured a different composition ratio between the two host co‐monomer components, and the possible presence of ionisable amine or carboxyl groups deriving from chemical post‐modification. The pH‐dependent absorption and release abilities of the materials were verified; in particular release kinetics showed the occurrence of a simple first‐order profile. The antibacterial activity of nanosponge‐tetracycline composites suitably prepared under sterile conditions was assayed towards both Gram‐positive and Gram‐negative typical bacterial strains, showing in some cases an interesting improvement of the biocidal activity.

Four new composite materials, formed by silver nanoparticles embedded in polyamino‐cyclodextrin nanosponge architectures, were designed exploiting the affinity of polyamino‐cyclodextrins towards Ag+ ions. These materials were characterized by means of different techniques (thermogravimetry, FT‐IR, solid state NMR, SEM, HR‐TEM), and tested as catalysts for the reduction of nitroarenes and the oxidative coupling of anilines. The results obtained showed synergistic activity between the supramolecular binding abilities of the nanosponge matrix and the catalytic properties of the metal nanoparticle, and open the way towards the design of new composite smart nanomaterials with improved catalytic performances.

An application for visualizing the aggregation of structureless atoms is presented. The application allows us to demonstrate on a qualitative basis, as well as by quantitatively monitoring the aggregate surface/volume ratio, that the enhanced reactivity of nanoparticles can be connected with their large specific surface. It is suggested that, along with the use of geometric analogies, this bottom-up approach can be effective in discussing the enhanced reactivity proprieties of nanoparticles. The application is based on a two-dimensional realistic dynamic model where atoms move because of their thermal and interaction potential energies, and the trajectories are determined by solving numerically Newton’s laws according to a Molecular Dynamics (MD) scheme. For this purpose, a web-based MD engine was adapted as needed. It is suggested that, when possible, using a realistic simulation rather than simple animations offers several advantages in the visualization of processes of interest in chemistry education. First, in a simulation the outcome of the process under study is not set a priori but it is the result of the dynamic evolution of the system; furthermore, specific parameters can be systematically varied, and the effects of these changes can be investigated. The application can be used at different levels of detail and in different instruction levels. Qualitative visual observations of the growing aggregates and of the progressive decrease of the reactive surface are suitable at all levels of instruction. Systematic investigations on the effect of changes of the atomic and aggregate sizes and temperature, suitable for senior high school and college courses, are also reported.

The pH‐responsive properties of cyclodextrin‐calixarene nanosponge co‐polymeric materials have been investigated. In particular, ISE‐H+ potentiometric titrations were carried out in order to evaluate the acid‐base properties and the actual amount of ionizable sites present in the materials. Moreover, the relevant pH‐dependent adsorption abilities were evaluated towards a set of selected model organic pollutant molecules by means of adsorption tests and by studying the corresponding adsorption isotherms. The latter ones could be suitably described by means of the Freundlich model. The whole of the experimental results enabled us to clarify some general aspects of the microscopic behavior of the nanosponges considered.

An application for visualizing the dynamic properties of an equimolar binary mixture of isotropic reactive particles is presented. By introducing a user selectable choice for the activation energy, the application is useful to demonstrate qualitatively that the reaction rate depends on the above choice and on temperature. The application is based on a 2D realistic dynamic model where atoms move because of their thermal energies and the trajectories are determined by solving numerically Newton's laws according to a Molecular Dynamics (MD) scheme. Collisions are monitored as time progresses, and every time the collision energy is larger than the selected activation energy, a reactive event occurs. By examining the time evolution of the configurations, it is possible to observe that the number of reactive collisions is always smaller than the total number of collisions. However, the number of reactive events increases on raising the temperature and/or by decreasing the activation energy. The above observations, as well as more quantitative analyses of the simulation data, are useful in elucidating the connections existing among particle kinetic energy, temperature, and activation energy of the reaction. The application can be used at different levels of detail and in different instruction levels. Qualitative visual observations of the progress of the reaction are suitable at all levels of instruction. Systematic investigations on the effect of changes of temperature and activation energy, suitable for senior high school and college courses and useful to gain insight into kinetic models and Arrhenius' law, are also reported.

Evaluation of nuclear magnetic relaxation dispersion (NMRD) curves obtained by the fast field cycling nuclear magnetic resonance (FFC-NMR) relaxometry technique is a valuable tool for analyzing the microscopic dynamics of condensed matter systems. However, quantitative data analysis involves several conceptual and practical issues. Moving forward from previous literature approaches, we propose a new analysis method, relying on the elaboration of the inverse integral transform of the NMRD curve. Our approach results in a true heuristic method, able to unambiguously individuate the dynamic domains in the system, thereby avoiding the possible introduction of any element of discretion. The analysis of some data sets relevant to real samples suggests the possibility that the results obtained with the heuristic method may be actually led back to some distinct physical/chemical features of the systems.