IMpose Pressure And Change Technology - Sistemi nanostrutturati confinati in matrici zeolitiche

How do supramolecular nanoaggregates form and behave under high pressure conditions? And what can occur when they are confined in nanocavities? The investigation and understanding of the behavior of molecules and porous materials under the combined effects of applied pressure, spatial confinement and constraints in morphology at the nanoscale - a challenge which has never been endeavored so far - would mean advance for fundamental sciences and significant impact on technology. ImPACT will exploit such a “hyperconfinement” regime to create supramolecular organization, new nanosystems of controlled morphology and, at the same time, to extend the application range of a class of materials of outstanding relevance for innovative technologies by improving their functional properties.

The hyperconfined systems will be synthesized in the form of ordered arrays of nanosized supramolecular aggregates, by adopting a simple bottom-up approach: molecular building blocks, dissolved in a liquid medium, will be “injected” in zeolite cavities by applied pressures up to 10 GPa. The peculiarity of zeolites of being crystalline pressure-resistant nanostructured moulds will be exploited to achieve pressure-induced segregation and organization of the molecular building blocks in

shape-controlling arrays of nanosized cavities. The choice of different zeolite topologies characterized by different channel apertures and cage dimensions (CHA, MFI, FAU and LTL) would allow us to tailor hyperconfined systems of chosen size, morphology and dimensionality. Achievement of these goals would lead to a set of practical strategies to produce template- and pressure-driven synthesis of ordered architectures of nanosized supersystems, where hyperconfinement effects might

be thoroughly tested and investigated. The physico-chemical characterization of these materials will be performed by adopting a multi-technique approach based on the integration of experimental and theoretical methodologies.

ImPACT will also study the pressure-induced effects on organic-inorganic hybrid microporous materials currently applied in strategic areas, from sustainable energy technologies to biomedical sciences. Specifically, ImPACT will focus on host-guest dye-zeolite L hybrids, where the photoactive molecules are organized in one-dimensional nanostructures inside the zeolite channels. The excellent optical properties, chemical stability and biocompatibility of these composites make them

key components of artificial antenna systems, sensors, light emitting and bionano devices, such as in-vivo markers of tumor cells. Owing to the relevance of dye-zeolite L hybrids for “environmental sustainability” and “human health” (two among the key-themes of the EU programme “Horizon 2020”), we will study their response to high pressure conditions. We plan to exploit irreversible changes of the optical properties, which could improve their functionality, in order to expand the

applications of this technologically strategic class of materials.

To unravel and understand at molecular level size/shape/compression dependent phenomena, we will adopt a systematic integrated experimental-theoretical characterization strategy, based on the use of in-situ and ex-situ diffraction, with both conventional and non conventional sources (i.e. synchrotron and neutron), vibrational spectroscopies (IR, Raman), UV-Vis and luminescence experiments, spectroscopic properties simulations, along with molecular dynamics simulations. The studies will be performed under increasing pressure to analyze the effects of the different space confinement and/or loading on the properties of the material. In addition, decompression experiments will be performed in order to investigate the reversibility/irreversibility of the process. Our goals are to: i) determine, at high pressure conditions, the structure of the microporous materials containing the hyperconfined molecules; ii) provide a thorough atomistic level picture of the structure

and morphology of the hyperconfined species, of their interactions with the zeolite cavities and of the effects of the zeolitic cages shape; iii) explore the effects of different types of space constraints imposed to the species encapsulated in different channels systems or framework cages, and analyze the combined effects of pressure and low-dimensionality on the spectroscopic properties of the supramolecular aggregates (vibrational frequencies, UV-vis and luminescence bands); iv)

evidence hyperconfinement-induced chemical reactions, and try to control them by a careful choice of applied pressure and cavity shape; v) study pressure-driven effects on dye-zeolite L composites of relevant technological interest with the aim to a) establish a pressure range within which the functionalities of these materials are maintained; b) evaluate whether the improvements of the optical properties of the composite induced by the applied pressure could be maintained at the operative

conditions of the dye-zeolite L- based devices; vi) create novel classes of hybrid functional materials by hyperconfinement of photoactive molecules L-zeolites and investigate their properties.

Since the results of this project will impact not only on the scientific community but also on advanced technology and sustainable development, they will be spread among the largest possible audience using both the usual tools of scientific communication and social networks.