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Sustainable packaging materials can play a key role in minimizing the environmental footprint of packaged food by preserving its quality and avoiding environmental persistence of plastic waste. Waste to wealth approach can cope with these major challenges by providing for bioavailable active compounds from waste residues. To this regard, humic substances (HS), derived from biowaste oxidative processes, exhibit intrinsic antioxidant and antimicrobial features, which can be significantly boosted by molecular combination with an inorganic nanostructured phase. Herein, this approach has been integrated with the electrospinning technology to design composite films made of electrospun biodegradable and bioderived polymers filled with nanostructured hybrid HS based materials. Therefore, electrospun composites made by including hybrid TiO2_HS nanostructures into PHBV matrix were first produced and then converted into homogeneous and continuous films to obtain an active layer which will be part of a multilayer food packaging solution. These were characterized in terms of morphology, thermal, crystallinity, optical, mechanical and barrier properties as well as antimicrobial performance against Staphylococcus aureus and Escherichia coli, two main strains of food pathogens. The results suggested that the combination of hybrid nanomaterials with electrospinning methodology is a promising and sustainable approach to convert biowaste into multifunctional materials for active packaging., The authors thank the Verde Vita company (s.r.l.) for providing the compost from which the humic substance HS used in this work was extracted. The authors wish to thank the European Union POC Ricerca e Innovazione 2014–2020, Azione I.1 “Dottorati Innovativi con caratterizzazione Industriale”) for funding a XXXV Cycle Ph.D. grant to Dr. Virginia Venezia. The collaboration with this company is foreseen as part of the activity scheduled in the POC doctoral project. The authors would also like to thank the Spanish Ministry of Science and Innovation, project PID2021-128749OB-C31 for financial support., PID2021-128749OB-C31

The transformation of γ-valerolactone (GVL) into levulinic acid (LA) requires the use of bifunctional catalysts allowing the hydrogenation and lactonization steps to occur. The aim of this study is to clarify the role played by both redox (Ru) and acid (Nb) sites of the ruthenium-niobium-silicon mixed oxides catalysts, synthesized by sol-gel route, when this reaction is performed in mild conditions. The catalytic performances of the materials are related to an in-depth morphologic and structural characterization, demonstrating that the interaction between the two metals and their relative amount and dispersion are crucial in determining their activity. The results confirm the hydrogenation-dehydration consecutive reaction network and evidence the possibility to selectively produce either GVL or the intermediate γ-hydroxypentanoic acid by an accurate choice of the catalyst composition.

In this work, mesoporous silica nanoparticles (MSN) hybridized with an organosilane are grafted with hyper-crosslinked poly(vinylbenzyl chloride) (PVBC), which is anchored into the mesopores and onto the external surface of MSN. The obtained nanoparticles are characterized by a MSN-templated hierarchical porosity composed of micropores, mesopores and macropores originated from the hyper-crosslinking of the PVBC phase, with a microporous fraction reaching up to 28% of the total pore volume. Tested for the adsorption of a model dye (Rhodamine 6G, Rh6G), these nanoparticles result much more efficient in Rh6G adsorption with respect to plain MSN, showing a Rh6G uptake of about 125 mg/g in highly concentrated solutions (1000 mg/L) and quite complete removal (about 98%) of the dye in more diluted conditions (30 mg/L) with comparable efficiency in repeated adsorption cycles. Overall results demonstrate the key role of the hierarchical porosity of the hyper-crosslinked PVBC-grafted MSN to tailor their adsorption properties.

Amino functionalized PEGylated silica nanoparticles were prepared by one pot-procedure, based on ammonia catalysed hydrolysis and polycondensation of Tetraethoxysilane (TEOS) and 3-Aminopropyltriethoxysylane (APTS), in alcohol medium (ethanol) (Sather method), containing PEG 5000 monomethyl ether. Particles size was studied using Transmission Electron Spectroscopy (TEM). PEGylation and amino functionalization was investigated through FT-IR and Thermogravimetric analysis (TG). The structure of nanoparticles consists of nanosilica (a few nanometers in size) dispersed into a PEG matrix, produced by entanglement of PEG chains. The stability of the water colloidal suspension depends on the PEG/silica mass ratio, that changes with PEG concentration in the reaction batch. By properly selecting the PEG concentration, nanoparticles smaller than 150 nm were obtained, stable towards aggregation in water media up to 6 months. The observed need of an optimal PEG/silica mass ratio for long-term stability can be explained on the basis of particles structure and assuming that both steric and electrostatic effect concur to stabilisation. (C) 2010 Elsevier BM. All rights reserved.