Green sol-gel nanotechnology

Green methods for synthesis, engineering and application of ceramic nanophases

Principal investigator: Magda Blosi
Involved personnel: Andrea Brigliadori, Anna Luisa Costa, Antonio Crimaldi, Lara Faccani, Davide Gardini, Simona Ortelli, Marina Serantoni, Ilaria Zanoni

This research area deals with the synthesis of nanophases (oxides or metals) by means of eco-friendly wet chemical methods easily scalable on large scale production. Such methods, starting from the metal salt precursors by means of bottom up approaches, allow the attainment of nanoparticles with controlled size, shape and composition which can be applied for different applications (coatings, catalysts, pigments). Nanoparticles are prepared as:

• stable colloidal suspensions of nanoparticles (sols)
• nanopowders, in the form of soft aggregates
• nanostructured microgranules

Materials

Nano and micrometrics powders

• Nano-Ag: is mainly developed for its antibacterial properties as surface coating or encapsulated inside eco-friendly matrices for a controlled antimicrobial release (Ceramized textiles)
• Nano-TiO2: is a versatile material exploited for different functions, as well as the preparation of photoactive or super-hydrophobic/super-hydrophilic coatings. TiO2NPs can be granulated into nanostructured micro powders suitable for their application within photoreactors for water treatment (slurry configuration, fixed/fluid bed) (Water purification)
• Nano-SiO2: used as coatings with tuneable wettability or as inert matrix for the encapsulation of active nanophases
• Nano-Al2O3: prepared by means of both solvent-based and water-based procedures and used as coatings with tuneable wettability, achieving superhydrophobic and superoleophobic behaviour on metals, glasses, ceramics and paper.

Micro-incapsulate materials

• granules of marker composites based on silica and luminescent complexes of transition metals
• photocatalytic granules based on nanoTiO2 embedded on a silica matrix (Ceramized textiles)
• Pt/graphene catalysts embedded on TiO2/SiO2 matrix for oxidation reactions
• CaO-MgO catalysts embedded on SiO2 matrix and usable in hydrogen transfer reactions
• Ag NPs encapsulated in starch matrix

Processes

Sol-gel synthesis
Nanometal and nanometal-oxide sols are usually prepared by sol gel routes(water-based, organic-based, microwave-assisted, hydrothermal), achieving versatile suspensions able to be applied as catalysts, pigments, thermal nanofluids or for multifunctional coatings (antibacterial, hydro-oloephobic, photocatalytic, photoluminescent) on several surfaces (ceramics, metals, textiles, paper).

Encapsulation technique
A mixed sol of an inert matrix with an active nanophase is instantaneously dried (by spray or freeze-drying) so providing inert nanostructured granules acting as micro-containers of active nano charges points. This method is low cost and versatile, enabling the preparation of granules with a marked homogeneous composition and a high specific surface area. For these reasons, this procedure is particularly suitable for producing multicomponent catalysts.

Principal collaborations
University of Milano Bicocca (Dept. Earth and Environmental Sciences)
University of Bologna (Dept. of Industrial Chemistry)
University of Parma Dept. of Medicine and Surgery
Trinity College Dublin (Dept Clinical Medicine)
Colorobbia Italia SpA

Projects
PROTECT
BIORIMA
ASINA
SABYNA

Pubblications and patents

• A. Lolli, M. Blosi, S. Ortelli, A.L. Costa, I. Zanoni, D. Bonincontro, F. Carella, S. Albonetti, Innovative synthesis of nanostructured composite materials by a spray-freeze drying process: Efficient catalysts and photocatalysts preparation, Catalysis Today 334 (2019) 193-202
• A. Lolli, V. Maslova, D. Bonincontro, F. Basile, S. Ortelli, S. Albonetti, Selective Oxidation of HMF via Catalytic and Photocatalytic Processes Using Metal-Supported Catalysts, Molecules 23 (2018) 2792
• I. Zanoni, V. Fiorini, M. Rosado, B. Ballesteros, M. Androulidaki, M. Blosi, S. Ortelli, S. Stagni, M. Dondi, A.L. Costa, Encapsulation of cationic iridium(III) tetrazole complexes into a silica matrix: synthesis, characterization and optical properties, New J. Chem. 42 (2018) 9635-9644
• S. Ortelli, A.L. Costa, Nanoencapsulation techniques as useful tool towards “safer by molecular design”, Nano-Structures & Nano-Objects 13 (2018) 155–162
• Magda Blosi, Simona Ortelli, Anna Luisa Costa, Michele Dondi, Alice Lolli, Sara Andreoli , Patricia Benito and Stefania Albonetti, Bimetallic Nanoparticles as Efficient Catalysts: Facile and Green Microwave Synthesis, Materials 2016, 9(7), 550
• A. Costa, M. Blosi “Process for the preparation of nanoparticles of noble metals in hydrogel and nanoparticles thus obtained” (PCT/IB2016/050501)