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Our research group has previously reported the preparation of gold nanoparticles (AuNPs) supported on different functionalized silica supports. We started using commercial polyethyleneimine-functionalized silica bead [1] and we continued preparing silica nanoparticles functionalized with alkynyl carbamate moieties. [2] Recently, we have focused on the straightforward synthesis of AuNPs anchored on commercial, micrometric oxide supports (i.e. SiO2, Al2O3, TiO2) previously modified with the di-functional organosilane [3-(2-propynylcarbamate)propyl]triethoxysilane (PPTEOS) by a grafting procedure. After being thoroughly characterized by several complementary techniques (XPS, TEM, SSNMR, AAS etc.), the catalytic activity of these systems (Au/OS@Yne) has been evaluated in the oxidation of alcohols both in batch and continuous-flow systems. [3] Furthermore, we have extended the same synthetic procedure to the preparation of a novel and magnetically recoverable catalyst, consisting of AuNPs supported on functionalized nano-magnetite (Au/Fe3O4@Yne). We now present the latest results obtained in the study of the catalytic application of Au/SiO2@Yne and Au/Fe3O4@Yne in the alkynes hydroamination reaction, which is considered the most atom efficient process for the formation of a series of nitrogen-containing compounds. Indeed, this transformation takes place without the formation of any side product and leads to the production of enamine, imine or substituted amines, which have a significant importance as bulk and fine chemicals or building blocks in organic synthesis. [1] S. Fazzini , D. Nanni , B. Ballarin , M. C. Cassani , M. Giorgetti , C. Maccato, A. Trapananti, G. Aquilanti and S. I. Ahmed, J. Phys. Chem. C. 2012, 116, 25434−25443; M. Giorgetti, G. Aquilanti, B. Ballarin, M. Berrettoni, M. C. Cassani, S. Fazzini, D. Nanni and D. Tonelli, Anal. Chem. 2016, 88, 6873-6880; [2] S. Fazzini, M. C. Cassani, B. Ballarin, E. Boanini, J. S. Girardon, A.S. Mamede, A. Mignani and D. Nanni, J. Phys. Chem. C. 2014, 118, 24538-24547; M. C. Cassani, B. Ballarin, D. Barreca, E. Boanini, E. Bonansegna, G. Carraro, S. Fazzini, A. Mignani, D. Nanni, D. Pinelli, RSC Adv. 2016, 6, 25780-25788. [3] B. Ballarin, D. Barreca, E. Boanini, M. C. Cassani, P. Dambruoso, A. Massi, A. Mignani, D. Nanni, C. Parise, A. Zaghi, ACS Sus. Chem. Eng. 2017, 5, 4746-4756.

THE FABRICATION OF STABLE SUPPORTED METAL NANOPARTICLES SUITABLE FOR HETEROGENEOUS CATALYSIS OR ENVIRONMENTAL APPLICATIONS, TO PREVENT NANOPARTICLES AGGREGATION AND TO FACILITATE CATALYST RECYCLING, IS THE GOAL OF OUR RESEARCH GROUP OF THIS LAST DECADE. THIS PAPER PRESENT CONVENIENT, STRAIGHTFORWARD, EASY METHODS TO OBTAIN POLYETHYLENEIMINE FUNCTIONALIZED SILICA BEADS, ORGANOSILANE-COATED INDIUM TIN OXIDES OR HYDROPHILIC NUCLEPORE TRACK-ETCHED POLYCARBONATE MEMBRANES (PC) FUNCTIONALIZED WITH GOLD OR SILVER NANOPARTICLES

Indium Tin Oxide (ITO) substrates were functionalized with the following FAS: 2,2,3,3,4,4,5,5,6,6,6-undecafluoro-N-[3-(trimethoxysilyl)propyl]hexanamide (RF = C5F11), containing an embedded amide between the perfluoroalkyl chain and the syloxanic moiety, and the 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyltriethoxysilane (RF = C6F13), with the perfluoroalkyl group linked to the syloxanic moiety through a simple hydrocarbon chain. Subsequently, the obtained systems were functionalized with Au nanoparticles (AuNPs) by immersion into a solution of citrate-stabilized AuNPs. All the samples have been characterized by FE-SEM and XPS. Moreover, the wetting behaviour, as well as the resistivity to a charge transfer of the different surfaces before and after AuNPs depositions, have been investigated. Finally, the application of such systems as catalysts for methanol electro-oxidation under alkaline conditions has been investigated, revealing the synergic role played by FAS and AuNPs in promoting a remarkable electrocatalytic activity

Recently, we presented the preparation, without any need of additional reducing and/or stabilizing agents, of a variety of stable silica-supported gold nanoparticles (AuNPs) by using as the only reactants an aqueous solution of chloroauric acid (HAuCl4) and different functionalized-silica supports. We started using commercial polyethyleneimine-functionalized silica bead [1] and we went on preparing silica nanoparticles with alkynyl carbamate moieties [2]. We now present the results of our recent work with supported AuNPs, which has been focused on the synthesis of a material with the right features for the application as catalyst in a continuous flow system. Indeed, flow chemistry is recognized by the Green Chemistry Institute (GCI) as a key area for research activities in the aim of developing sustainable manufacturing [3]. [1] S. Fazzini , D. Nanni , B. Ballarin , M. C. Cassani , M. Giorgetti , C. Maccato, A. Trapananti, G. Aquilanti and S. I. Ahmed, J. Phys. Chem. C. 116 (2012) 25434−25443. M. Giorgetti, G. Aquilanti, B. Ballarin, M. Berrettoni, M. C. Cassani, S. Fazzini, D. Nanni and D. Tonelli, Anal. Chem. 88 (2016) 6873-6880. [2] S. Fazzini, M. C. Cassani, B. Ballarin, E. Boanini, J. S. Girardon, A.S. Mamede, A. Mignani and D. Nanni, J. Phys. Chem. C. 118 (2014) 24538-24547. [3] C. Wiles and P. Watts, Green Chem. 16 (2014), 55-62.

Recently, we presented the preparation, without any need of additional reducing and/or stabilizing agents, of a variety of stable silica-supported gold nanoparticles (AuNPs) by using as the only reactants an aqueous solution of chloroauric acid (HAuCl4) and different functionalized-silica supports. We started using commercial polyethyleneimine-functionalized silica bead and we went on preparing silica nanoparticles with alkynyl carbamate moieties. We now present the results of our recent work with supported AuNPs, which has been focused on the synthesis of a material with the right features for the application as catalyst in a continuous flow system. Indeed, flow chemistry is recognized by the Green Chemistry Institute (GCI) as a key area for research activities in the aim of developing sustainable manufacturing. The silica-supported AuNPs have been prepared by the simple grafting of commercial available silica with the alkyne terminated organosilane [3-(2-propynylcarbamate)propyl]triethoxysilane (PPTEOS), followed by the addition of HAuCl4 to obtain the in situ formation of the target AuNPsanchored systems. The resulting material (Au/SiO2@Yne) has been characterized with various techniques, such as atomic absorption spectroscopy (AAS), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). Afterwards, Au/SiO2@Yne has been employed as heterogeneous catalyst in the oxidation of alcohols to their corresponding carbonyl compounds. The reaction conditions have been chosen with particular attention to the green aspect, therefore the oxidation have been carried out using a mixture of tert-butanol and water as solvent and hydrogen peroxide as the oxidant agent.

An overview discussing the main methods to obtain hair shape modification is presented, beginning from historically well known and traditional procedures to obtain waving to newest systems for hair straightening.

Raman and IR spectroscopy were used to investigate the changes induced in yak hair keratin by the straightening treatment based on glyoxylic acid. The amino acidic residues that appeared involved in the reaction with glyoxylic acid were serine and lysine; the involvement of the latter was deduced by the spectroscopic detection of iminic species, resulting from the reaction between the aminic group of lysine and the carbonyl group of glyoxylic acid. The reaction with glyoxylic acid induced conformational rearrangements that mainly involved the fibre bulk rather than the cuticle. Changes in the average tyrosine environment and its hydrogen-bonding state were detected: at increasing glyoxylic acid incorporation, the tyrosine residues appeared more exposed, probably because of H-bond interactions with the COOH group. The distribution of the disulfide bridge conformation was also affected, although no cleavage of the S-S bond was detected, in agreement with the shiny and healthy appearance of the fibres.

Recently, we presented stable silica-supported gold nanoparticles (AuNPs) suitable for catalysis, obtained by using as the only reactants a gold precursor, chloroauric acid (HAuCl4), and commercial polyethyleneimine-functionalized silica beads (SiO2-PEI), with the need for neither external reducing agents nor conventional stabilizing moieties. In this work we describe another convenient method to prepare silica-supported gold nanoparticles. The silica nanoparticles were synthetized, first, by co-condensation of tetraethoxysilane and an organo-silane alkyne-terminated (SiO2-Yne), and then post-functionalized by thiol/yne coupling with cysteamine (SiO2@Thio-Yne). By simply adding the obtained systems to an aqueous solution of HAuCl4 the spontaneous formation of AuNPs was observed in both cases and in very short times with diameters in the range of 10 to 20 nm. These new systems were fully-characterized by FT-IR, XPS spectroscopy, DLS , UV-Vis and TEM microscopy.