Aerogels have recently started to be considered as "advanced materials"; therefore, as a general consideration, aerogels' toxicity testing should focus on their functionality which resides in their nanoscale open internal porosity. To assess the hazards of organic aerogels, testing at three levels may characterize their biophysical, in vitro and in vivo toxicity, defining distinct categories of aerogels. At the first level of testing, their abiotic characteristics are investigated, and the best aerogel(s) is forwarded to be tested at level 2, wherein in vitro methodologies may mainly evaluate the aerogels' cellular behavior. Within level 2 of testing, the main characteristics of toxicity are investigated and the selected aerogels are introduced to in vivo animal models at level 3. In the animal model testing, target organs are investigated along with systemic parameters of toxicity. Some study cases are presented for organic or anorganic aerogels. Within this tiered workflow, aerogels-based materials can be tested in terms of human health hazard.

Two series of random copolymers containing at the same time two fluorescent groups, carbazole and coumarin, linked to a poly(norbornene dicarboximide) backbone have been prepared by controlled ring-opening metathesis polymerization (ROMP), promoted by Grubbs' third generation catalyst (G3). The relative amount of the two functionalities was systematically varied along the copolymer chain, and the high degree of structural control observed allowed also for the preparation of a block copolymer with an equimolar content of fluorophore groups. In comparison to the related homopolymers, all the random copolymers exhibited in solution typical photoluminescence due to the carbazole or coumarin moiety, together with fluorescence arising from the energy transfer from the donor carbazole groups to the acceptor coumarin groups. This energy transfer seems to occur through intramolecular interactions, as it is not observed in the block copolymer and in the 50/50 homopolymer blend. On the other hand, in the solid state also the energy transfer from carbazole to coumarin through interchain interactions can take place. Of note, moving from solution to solid state fluorescence analysis, a blue shift of the band related to the energy transfer phenomenon is observed. This finding could be related to a combined effect of energy and electron transfer from donor to acceptor.

An increasing number of aerogels as nanostructured highly porous materials are entering the market in every day products, with an attractive portfolio of properties for emerging applications ranging from health care and leisure to electronics, cosmetics, energy, agriculture, food and environmental. However, the novelty in properties and forms of aerogels makes the development of a legislative framework particularly challenging for ensuring the safe development and use of nano-enabled products. The presented safety regulatory Compendium intends to share knowledge with the international aerogels community, as well as end-users and stakeholders, on the regulatory and safe handling procedures, as best safety practices, to be followed during the production process, handling, transport and end-use of aerogel-based formulations to mitigate human and environmental risks considering lack of data availability for this purpose in general.

A new Morita-Baylis-Hillman Adduct (MBHA) derivative 7 was designed and synthesized to obtain a reactive molecule potentially capable of labelling basic amino acid residues. Compound 7 was easily prepared and characterized from the point of view of its photophysical and photochemical features before then to be used in labelling experiments with amino acid.

The polymerization of some 1,3-dienes (i.e., butadiene, isoprene and myrcene) with the catalyst system obtained by combining the imino-pyridine iron complex shown in Figure 1 with methylaluminoxane was examined.1 The polymers were characterized by FT-IR and NMR (1H, 13C and 2D), and were found to exhibit different structure depending on the monomer structure: an essentially syndiotactic 1,2 polymer from butadiene, a predominantly alternating cis-1,4-alt-3,4 polymer containing short cis-1,4 sequences (three units) along the polymer chain from isoprene, and finally an alternating cis-1,4-alt-3,4 polymer containing longer cis-1,4 sequences (five units) along the polymer chain from myrcene, were obtained.

In recent years, the research activity in the field of stereospecific polymerization of conjugated dienes1 has particularly focused on the study of new catalytic systems based on organometallic complexes of transition metals and lanthanides with various types of organic ligands (e.g., phosphines, pyridyl-imines, bis-imines) and with a well-defined structure.2 The results obtained have clearly shown that, at least in principle, each transition metal or lanthanide could be able to provide active and selective catalytic systems for the polymerization of 1,3-dienes once the right combination of metal, ligand and diene monomer was chosen. Following this idea, in the framework of our research work dealing with the synthesis and the characterization of transition metal compounds and the study of their behavior in the polymerization of 1,3-dienes, we have taken into consideration copper. We have in particular examined the polymerization of butadiene, isoprene and myrcene with catalysts obtained by combining bipyridyl and imino-pyridyl copper complexes (see figure alongside) with methylaluminoxane (MAO), exhibiting a quite good activity.3,4 The system (I)/MAO gave a predominantly 1,2 polybutadiene, a crystalline syndiotactic 3,4-polyisoprene (Tm 114°C) and a highly crystalline cis-1,4 poly(2,3-dimethyl-1,3-butadiene) (Tm 198°C); the system (II)/MAO gave from butadiene a slightly crystalline syndiotactic 1,2 polymer; from isoprene a predominantly alternating cis-1,4/3,4 polymer in which however short cis-1,4 sequences (three units) can be detected along the polymer chain, with a Tg value of about -30°C; from myrcene a predominantly alternating cis-1,4/3,4 polymer in which however longer cis-1,4 sequences (five units) are present along the polymer chain, with a Tg value of about -60°C. The results obtained highlight once more the fundamental role played by the ligand structure and the monomer structure on the selectivity in the polymerization of 1,3-dienes. The above complexes, together with the bis-iminopyridyl ones, were also tested for the polymerization of ethylene, obtaining however not very active catalysts.

The role of packaging is crucial in the modern food industry, since it contributes to contain, transport, and preserve the food quality and safety [1]. Recently, polysaccharides-based hydrogels have caught the attention of food packaging producers, as they are natural biodegradable and biocompatible polymers, usable as delivery systems of health-beneficial antioxidant and antimicrobial substances, able to extend the shelf-life of fresh products [2, 3]. The expectations of this work are focused on the synthesis and an in-depth characterization of hydrogels from modified starch, for intelligent food packaging applications. Agrifood wastes were used as feedstock of starch thus reducing the impact of wastes on the environment and meeting the increasing demand for ecofriendly products [4]. After chemical modification of starch, by oxidation reaction with sodium periodate (NaIO4) in water, aldehyde derivatives of great interest were produced that can be further modified into carboxylic acid, primary alcohol, or imines (Schiff-bases). Simultaneously, they open the scenario on the creation of physical and chemical crosslinking, without using crosslinking agents, by applying a more sustainable approach for the low toxicity of reagents and byproducts [5, 6]. After modification, starch-based hydrogels showed enhanced resistance to dissolution degradation rate, high swellability, and improved mechanical strength. Successively, the synthesized hydrogels were "loaded" with selected molecules, and the antibacterial activity was measured against Escherichia coli ATCC 8739. Two approaches were followed for testing the capability of these materials to act as drug carriers: i) by adsorption of peppermint essential oil; ii) by crosslinking the Asparagine to the starchy aldehyde derivatives (via Schiff-base). A drug release profile was proven by means of qNMR spectroscopy [7]. Based on these results, the produced starch-based hydrogels are potentially suitable materials for producing bio-sustainable adsorbent pads with a high capacity for holding liquids from fresh foods, able to preserve and extend the shelf-life of packaged foods, by inhibiting bacterial growth.

Polysaccharides-based hydrogels have caught the attention of the biomedical industry, as they are natural biodegradable and biocompatible polymers, usable as delivery systems of health-beneficial antioxidant and antimicrobial substances. The expectations of this work are focused on the synthesis and an in-depth characterization of hydrogels from modified starch, usable as drug delivery systems for biomedical applications. Agri-food wastes were used as feedstock of starch thus reducing the environmental impact of wastes and meeting the increasing demand for eco-friendly products. After chemical modification of starch by oxidation reaction with sodium periodate (NaIO4) in water, aldehyde derivatives were produced. The oxidized products were frozen, thus obtaining hydrogels with enhanced resistance to dissolution degradation rate, and high swellability, and which were characterized bydifferent techniques such as NMR, FTIR and TEM. Subsequently, the synthesized hydrogels were "loaded" by the adsorption of peppermint essential oil, known from the literature to possess beneficial biological functions including antiviral, antimicrobial, anti-inflammatory, and antioxidant effects. The ability of hydrogels to act as delivery systems was proven by means of qNMR spectroscopy, determining a drug release profile. Furthermore, the antibacterial activity showed interesting results. The synthesized hydrogels are suitable materials for producing dressings able to promote the wound healing process.

Polysaccharides-based hydrogels have caught the attention of the biomedical industry, as they are natural biodegradable and biocompatible polymers, usable as delivery systems of health-beneficial antioxidant and antimicrobial substances. The expectations of this work are focused on the synthesis and an in-depth characterization of hydrogels from modified starch, usable as drug delivery systems for biomedical applications. Agri-food wastes were used as feedstock of starch thus reducing the environmental impact of wastes and meeting the increasing demand for eco-friendly products. After chemical modification of starch by oxidation reaction with sodium periodate (NaIO4) in water, aldehyde derivatives were produced. The oxidized products were frozen, thus obtaining hydrogels with enhanced resistance to dissolution degradation rate, and high swellability, and which were characterized by different techniques such as NMR, FTIR and TEM. Subsequently, the synthesized hydrogels were "loaded" by the adsorption of peppermint essential oil, known from the literature to possess beneficial biological functions including antiviral, antimicrobial, anti-inflammatory, and antioxidant effects. The ability of hydrogels to act as delivery systems was proven by means of qNMR spectroscopy, determining a drug release profile. Furthermore, the antibacterial activity showed interesting results. The synthesized hydrogels are suitable materials for producing dressings able to promote the wound healing process.

Polybutylene succinate (PBS) is one of the most important and commercially available biodegradable polyesters obtained by polycondensation between succinic acid and butanediol [1]. It is endowed with high mechanical properties, comparable to polyethylene (PE) and polypropylene (PP); high thermal, chemical resistance and high heat deflection temperature. However, its applications suffer of some limitations due to softness, gas barrier properties and melt viscosity, limiting its practical use. To overcome these problems, the introduction of inorganic materials into biopolymers has been envisioned as a viable option to improve the structural properties of PBS and promote the exploitation in different application fields. The sequential infiltration synthesis (SIS), based on atomic deposition of Al2O3 on PBS, via trimethylaluminum (TMA) and H2O precursors, provides an attractive option for the production of a polymer-inorganic hybrid material. After the growth of Al2O3 in freestanding ~30 ?m thick PBS films by SIS process at 70°C, changes on PBS microstructure and mass uptake in the films were evaluated as a function of the number of SIS cycles [2]. Results evidenced that mass uptake in the PBS films was much higher than in standard polymethylmethacrylate (PMMA) films, at the same process conditions. This study evaluates changes on PBS microstructure vs mass uptake and explores the reactivity of the PBS functional groups, (ester and ether) after TMA treatment, through solution Nuclear Magnetic Resonance spectroscopy (NMR) thus suggesting a plausible reaction mechanism able to justify structural changes in PBS [3].

The shelf life of a food products is the time during which food remains safe under defined storage conditions, maintaining the desired sensory, chemical, physical and biological characteristics in compliance with the label declaration [1]. Many physical factors could influence the shelf life like temperature changes, light exposure, gases transmission, humidity changes as well as contamination with microorganism and spores. Packaging plays a critical role in extending the shelf life of food products, preventing or reducing the environmental interactions. Recent EU regulations promoted a growing interest in bio-based materials production for replacement of the traditional petro-plastics, limiting the accumulation problem and reducing the environmental pollution. NMR spectroscopy represents a valid approach to evaluate the effects of packaging on the shelf life of foods and possible chemical contamination. [2]. Moreover, NMR spectroscopy has already demonstrated its pivotal role in metabolomics [3,4] allowing to monitor in a single experiment different classes of chemical compounds, and its capabilities in microstructural characterization of packaging materials. In this study the analyses of polar and organic extracts of seasoned zucchini stored at 4°C for 35 days, in plastic and compostable trays, performed by NMR in combination with chemometrics, are reported.

A series of new (oxa)norbornene dicarboximide monomers, decorated with carbazole and coumarin as pendant fluorophore groups, were synthesized and characterized. Their behaviour in ring-opening metathesis polymerization (ROMP) was explored in the presence of commercial Grubbs' third generation catalyst G3 and cis -selective catalyst GZ. Norbornene dicarboximide (NDI) monomers were successfully polymerized by both the catalysts, while oxanorbornene dicarboximide (ONDI) analogues showed scarce reactivity toward polymerization promoted by GZ. The nature of the spacer (ethylene orp-xylene) between the NDI unit and the chromophore seems to not affect the outcome of the polymerization. Moving from G3 to GZ, it was possible to synthetize NDI- based polymers with cis-olefin content increasing from 47 to 89%, depending on the nature of the pendant fluorophore group. The obtained polymers showed photoluminescence in solution and solid state owing to the carbazole or coumarin fragment, regardless of the nature of the spacer and cis-olefin amount. Interestingly, a significant excimer emission due to the overlap of carbazole groups was observed for a carbazole-functionalized polymer film, as a result of the combined effect of two factors, the stiffness of the spacer (p-xylene) linking the NDI moiety to the fluorophore and the high stereoregularity degree (83% cis) of the main chain.

This article describes data related to the research paper entitled "ROMP of norbornene and oxanorbornene derivatives with pendant fluorophore carbazole and coumarin groups" [1]. Six novel norbornene and oxanorbornene dicarboximides derivatives functionalized with carbazole or coumarin moieties, are synthesized and investigated in the preparation of fluorescent polymers by Ring-Opening Metathesis Polymerization (ROMP). Herein, we report on the characterization of all these compounds by 1D and 2D Nuclear Magnetic Resonance (NMR), UV-Visible and fluorescence spectroscopy. The characterization data include information obtained from H-1, C-13, Homonuclear Correlation Spectroscopy (H-1-H-1 COSY) and Heteronuclear Single Quantum Coherence (H-1-C-13 HSQC). The absorbence and fluorescence spectra for all these compounds are given. This work provides useful characterization data for the design of new norbornene and oxanorbornene-based monomers with fluorescent carbazole and coumarin groups, which can be employed for the synthesis of functional materials via ROMP. (C) 2022 The Authors. Published by Elsevier Inc.

The introduction of inorganic materials into biopolymers has been envisioned as a viable option to modify the optical and structural properties of these polymers and promote their exploitation in different application fields. In this work, the growth of Al2O3 in freestanding ~30-?m-thick poly(butylene succinate) (PBS) films by sequential infiltration (SIS) at 70 °C via trimethylaluminum (TMA) and H2O precursors was investigated for the first time. The incorporation of Al2O3 into the PBS matrix was clearly demonstrated by XPS analysis and SEM-EDX cross-sectional images showing a homogeneous Al2O3 distribution inside the PBS films. Raman measurements on infiltrated freestanding PBS show a reduction of the signal related to the ester carbonyl group as compared to pristine freestanding PBS films. Accordingly, FTIR and NMR characterization highlighted that the ester group is involved in polymer-precursor interaction, leading to the formation of an aliphatic group and the concomitant rupture of the main polymeric chain. Al2O3 mass uptake as a function of the number of SIS cycles was studied by infiltration in thin PBS films spin-coated on Si substrates ranging from 30 to 70 nm. Mass uptake in the PBS films was found to be much higher than in standard poly(methyl methacrylate) (PMMA) films, under the same process conditions. Considering that the density of reactive sites in the two polymers is roughly the same, the observed difference in Al2O3 mass uptake is explained based on the different free volume of these polymers and the specific reaction mechanism proposed for PBS. These results assessed the possibility to use SIS as a tool for the growth of metal oxides into biopolymers, paving the way to the synthesis of organic-inorganic hybrid materials with tailored characteristics.

The selective detection of metal ions in water, using sustainable detection systems, is of crescent importance for monitoring water environments and drinking water safety. One of the key elements of future chemical sciences is the use of sustainable approaches in the design of new materials. In this study, we design and synthesize a low-cost, water-soluble potassium salt of 3,4,9,10-perylene tetracarboxylic acid (PTAS), which shows a selective optical response on the addition of Cu2+ and Pb2+ ions in aqueous solutions. By using a water-soluble chromophore, the interactions with the metal ions are definitely more intimate and efficient, with respect to standard methods employing cosolvents. The detection limits of PTAS for both Cu2+ and Pb2+ are found to be 2 mu M by using a simple absorbance mode, and even lower (1 mu M) with NMR experiments, indicating that this analyte-probe system is sensitive enough for the detection of copper ions in drinking water and lead ions in waste water. The complexation of PTAS with both ions is supported with NMR studies, which reveal the formation of new species between PTAS and analytes. By combining a low-cost water-soluble chromophore with efficient analyte-probe interactions due to the use of aqueous solutions, the results here obtained provide a basis for designing sustainable sensing systems.

We synthetized a new rod-coil block copolymer (BCP) based on the semicondu-cting polymerpoly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b ]dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl}) (PTB7) and poly-4-vinylpyridine (P4VP), tailored to produce water-processable nanoparticles (WPNPs) in blend with phenyl-C71-butyric acid methyl ester (PC BM). The copolymer PTB7-b-P4VP was completely characterized by means of two-dimensional nuclear magnetic resonance (2D-NMR), matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS), size-exclusion chromatography (SEC), and differ-ential scanning calorimetry (DSC) to confirm the molecular structure. The WPNPs were prepared through an adapted miniemulsion approach without any surfactants. Transmission electron microscopy (TEM) images reveal the nano-segregation of two active materials inside the WPNPs. The nanostructures appear spherical with a Janus-like inner morphology. PTB7 segregated to one side of the nanoparticle, while PC BM segregated to the other side. This morphology was consistent with the value of the surface energy obtained for the two active materials PTB7-b-P4VP and PC BM. The WPNPs obtained were deposited as an active layer of organic solar cells (OSCs). The films obtained were characterized by UV-Visible Spectroscopy (UV-vis), atomic force microscopy (AFM), and grazing incidence X-ray diffraction (GIXRD). J-V characteristics of the WPNP-based devices were measured by obtaining a power conversion efficiency of 0.85%. Noticeably, the efficiency of the WPNP-based devices was higher than that achieved for the devices fabricated with the PTB7-based BCP dissolved in chlorinated organic solvent.

Caratterizzazione microstrutturale di polimeri, derivati da acido adipico, mediante spettroscopia di Risonanza Magnetica Nucleare (NMR) in soluzione allo scopo di determinare la purezza, la microstruttura e l'eventuale presenza di inquinanti presenti nel materiale, e/o l'occorrenza di reazioni secondarie.

Some novel monoalkyl-N-aryl-substituted iminopyridine iron chloride complexes, differing in the nature of the substituent at the iminic carbon and at the ortho position of the aryl ring, were synthesized and characterized. For one of them, single crystals were obtained, which allowed for the determination of its crystalline structure, in which the iron center is coordinated to the chlorides and to the two nitrogen atoms of the ligand. The coordination around iron is distorted tetrahedral, a coordination mode rarely identified for FeCl2 adducts with bidentate nitrogen ligands. All the complexes were used, in combination with methylaluminoxane, for the polymerization of 1,3-butadiene and isoprene, providing syndiotactic 1,2 poly(1,3-butadiene)s and poly(isoprene)s with a predominantly cis-1,4/3,4 alternating structure, in which short cis-1,4 sequences of three or five units, whose length depends on the nature of the ligand on the iron atom, are present. A detailed NMR characterization (1H-, 13C-, and 2D experiments) of the resultant poly(isoprene)s is reported, and a tentative scheme for the formation of the novel isoprene polymers is proposed.

Caratterizzazione microstrutturale di polimeri di sintesi realizzati da "Pirelli"