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Gold nanoparticles (AuNPs) are among the most intensely studied nanoscale materials, finding numerous applications in several fields such as catalysis, biomedicine and microelectronics. [1] AuNPs can be synthesized by several chemical procedures reported in literature, where in general the Au(III) precursor is reduced by a reducing agent and the AuNPs formed stabilized by the use of a stabilizing agent. [2] Recently, we presented stable silica-supported gold nanoparticles 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. [3] In this work we describe another convenient method to prepare functionalized-silica nanoparticles able to reduce in situ HAuCl4 precursor. The silica nanoparticles were synthetized, first, by co-condensation of tetraethoxysilane and an organo-silane alkyne-terminated (PPTEOS) (SiO2-Yne) [4] and then post-functionalized by thiol/yne coupling with cysteamine, silica nanoparticles SiO2-Thio-Yne are obtained with sulphide and primary amine, known for their capability to stabilize gold nanoparticles. [5] . Scheme 1. Synthesis of alkyne-modified silica nanoparticles and subsequent thiol/yne coupling. By simply adding an aqueous solution of HAuCl4 to SiO2-Yne (d 77 ± 10 nm) or to SiO2-Thio-Yne we achieved in both case AuNPs anchored on the silica surface. These systems were fully-characterized by FT-IR, XPS spectroscopy, DLS ,UV-Vis, TOF-SIMS and TEM microscopy.

Imidazolium salts incorporating functional groups on the cation and/or anion, represent a class of compounds having great versatility due to their applications as ionic liquids (ILs) or N-heterocyclic carbene precursors (NHCs). Our research in this field has been dealing with the synthesis of (Boc)-protected and deprotected amino-functionalized imidazolium cations [NHR1CH2CH2imR2]+ ([1]+, R1 = Boc, H; R2 = Me, Bz, Trit) and related NHC-Ag(I) and Rh(I) complexes.1 We have also demonstrated that [NH2CH2CH2imMe]+ plays a dual role in gold chemistry: i) can give the gold(III)-aminoethyl imidazolium aurate salt [Cl3AuNH2(CH2)2ImMe)][AuCl4] (2) used in the preparation of catalytically active gold nanoparticle-containing polycarbonate membranes or ITO glasses;2 ii) can act as a primary amino-functionalized NHC precursor to give the dimeric, photoluminescent complex [Au2(NH2(CH2)2imMe)2][NO3]2 (3).3 We now present some very recent results of a research focused on the preparation of detonation nanodiamond(ND)/AuNPs hybrid materials. Two different experimental routes are followed for the decoration of ND by AuNPs, that are in turn prepared by an innovative electroless approach using the gold complex 2. Structure and morphology at the nanoscale level of the AuNPs-on-ND deposits have been deeply investigated by electron microscopy (FE-SEM, HR-TEM) and diffraction (XRD) techniques. The optical properties of these systems have been determined by performing scattering and UV-Vis absorption measurements and by comparing the experimental data with simulated extinction spectra. The preliminary results of the present research establish the first rules for future designs of more complex AuNPs/ND systems.

The production of yttria ceramics by green-gelcasting technique was developed through: (1) optimization of aqueous yttria slurries; (2) optimization of the gelcasting process; (3) thermal treatments and characterization of the final microstructures. Different dispersants were tested. Zeta potential characterization of the dispersed state was performed. Dynamic light scattering (DLS) measurements on the suspensions showed a strong aging effect of polyacrylate dispersants. Rheological measurements identified the exact Tg temperatures of the gelling agent. The yttria suspensions were ball milled with the dispersant for 24 h and heated at 65 °C, while the gelling agent as added to the ceramic suspension after solubilization in a separate solvent at 90 °C. The resulting mixture was de-aired under vacuum and casted into PE or silicon moulds. The casted bodies were dewatered, debonded at 500 °C and sintered in air or under vacuum at 1,660-1,700 °C. The microstructure of the sintered bodies with final relative density between 90%-95% was analyzed by scanning electron microscope (SEM).

In recent years considerable attention has been drawn to the deposition of metal nanoparticles onto conducting substrates due to its great importance in the fabrication of practical devices such as heterogeneous catalytic systems (i.e. application in fuel cell), electronic sensors, and biosensors [1-3]. Several methods have been reported to accomplish this purpose [4-6] among these electrosynthesis has been proved to be very striking because of the simple instrumentation and the capability to readily control the size and morphology of the as-deposited nanostructures through adjusting the electrochemical parameters [7-9]. In this report we present the electrodeposition studies of Au, Pt and bimetallic Au-Pt nanoparticles (AuNPs, PtNPs and Au-PtNPs) on Indium Tin Oxide (ITO) or and Pure Graphite Sheet (PGS) surfaces. The effect of some variables as the presence of additives (i.e. KI or surfactants), the electrodeposition time, the kind of precursor (i.e. Gold(III)-Aminoethyl Imidazolium Aurate Salt) or the precursors molar ratio (i.e. Au and Pt) employed, on the nanoparticles size and distribution, have been also investigated. Morphological observations have been carried out using CVs, SEM, UV-Vis spectroscopy and XRD patterns. Finally, the electrocatalytic activity towards Methanol (MeOH) oxidation in alkaline or acid medium has been studied as dependence of the different morphology. This study could offer a new approach to cost-effective electrodeposition of metal nanoparticles with excellent electrochemical properties.

In the past decade the study of superparamagnetic nanoparticles has been intensively developed also for technological application: among others biomedical application as magnetically assisted drug delivery, contrast agents in MRI, cell separation, hyperthermia therapy. All of these applications require that the nanoparticles have high magnetization, and abovefuthermore all these applications also need a peculiar surface coating which has to be nontoxic and biocompatible. Among various magnetic nanoparticles, magnetite has attracted growing interest in design magnetic nanostructure materials due to its existing properties such as supeparamagnetism, high field irreversibility and high saturation field. Silica is a versatile platform with many intrinsic features, such as low toxicity, proper design and derivatization yields particularly stable colloids even in physiological conditions. In this work, core-shell magnetite/silica (Fe3O4@SiO2) nano structures were designed, synthesized and functionalized with fluorescent dyes. The coating process was applied to magnetite nanoparticles dispersed in an aqueous solution.

preparazioni miscele deodoranti a base di idrotalcite e argento nanostrutturato

Imidazolium salts incorporating functional groups on the cation and/or anion, represent a class of compounds having great versatility due to their wide range of applications as task specific ionic liquids (ILs)1 or N-heterocyclic carbene precursors (NHCs)2. Recently our research in this field has been dealing with the high-purity synthesis of (Boc)-protected and deprotected amino-functionalized imidazolium cation [NHR1CH2CH2ImR2]+ ([1]+, R1 = Boc, H; R2 = Me, Bz, Allyl) and related NHC-Ag(I) silver complexes3. In this contribution we show that [NH2CH2CH2ImMe]+ can play a dual role in gold chemistry. It has been employed to give the novel gold(III)-aminoethyl imidazolium aurate salt [Cl3AuNH2(CH2)2ImMe)][AuCl4] (2) used in the preparation of catalytically active gold nanoparticle-containing polycarbonate membranes or ITO glasses4. In addition [NH2CH2CH2ImMe]+ acts as a NHC precursor and by reacting the corresponding NHC-Ag(I) carbene with ClAu(tht) the dimeric, photoluminescent complex 3 shown in Figure is obtained.

In recent years considerable attention has been drawn to the deposition of metal nanoparticles onto conducting substrates due to its great importance in the fabrication of practical devices such as heterogeneous catalytic systems, electronic sensors and biosensors [1,2]. Several methods have been reported to accomplish this purpose [3-4] among these electrosynthesis has been proved to be very striking because of the simple instrumentation and the capability to readily control the size and morphology of the as-deposited nanostructures through adjusting the electrochemical parameters [5-7]. In this report we present the electrodeposition studies of Au, Pt and bimetallic Au-Pt nanoparticles (AuNPs, PtNPs and Au-PtNPs) on ITO surfaces. The effect of some variables as the presence of additives (i.e. KI or surfactants), the electrodeposition time, the kind of precursor (i.e. Gold(III)-Aminoethyl Imidazolium Aurate Salt, see Scheme I) or the precursors molar ratio (i.e. Au and Pt) employed, on the nanoparticles size and distribution, have been also investigated. Morphological observations have been carried out using CVs (see Fig.1), SEM (see Fig.2), UV-Vis spectroscopy and XRD patterns. Finally, the electrocatalytic activity towards Methanol (MeOH) oxidation in alkaline medium has been studied as dependence of the different morphology. This study could offer a new approach to cost-effective electrodeposition of metal nanoparticles with excellent electrochemical properties.

In the past few years, nanoparticle production by a size-controlled or shaped-controlled procedure has become a new and interesting research focus. Silver nanoparticle, (AgNPs) materials have a wide range of applications: can be used as antistatic materials, cryogenic superconducting materials [1], biosensor materials [2], catalysis [3], antibacterial materials [4], etc. With regard to the latter application, because of their effective antimicrobial properties and low toxicity toward mammalian cells, AgNPs have become one of the most commonly used nanomaterials in consumer products and in membrane-based water filtration systems [5]. The toxicity of AgNPs to bacteria is greatly influenced by AgNPs particle size and shape [6]. Generally, the shape, size and size distribution of silver particles can be controlled by adjusting the reaction conditions such as reducing agent, stabilizer and so on [7] or employing different synthetic methods. During the last few years, many methods have been employed to prepare silver nanoparticles [8]. Room-temperature ionic liquids (RTILs) seem well positioned to address the challenge of preparing stable, active silver nanoparticles, due to their high chemical and thermal stability, negligible vapor pressure, recyclability, high conductivity and wide electrochemical window [9]. Moreover, low interfacial tensions result in high nucleation rates, allowing formation of very small particles because Ostwald ripening occurs only weakly. Further, the chemical and physical interaction between the ionic liquid and the metal plays a decisive role in controlling the size and structure of the nanoparticles [10]. In this work, the functionalized RTIL, 1-(2-aminoethyl)-3-methylimidazolium salts [IL-NH2]X (X = BF4, NO3) [11], were employed in the reduction of aqueous AgNO3 with NaBH4 in different IL:Ag molar ratio. The resulting, stabilized silver nanoparticles retained long-term stability without special protection and were characterized by Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), UV-vis spectroscopy and Thermal Gravimetric Analysis (TGA). The role played by the IL’s counter ion as well as the IL:Ag molar ratio, in the AgNPs morphology, size and size distribution is presented and discussed. References [1] S. Hirano, Y. Wakasa, A. Saka, S. Yoshizawa, Y. Oya-Seimiya, Y. Hishinuma, A. Nishimura, A. Matsumoto, H. Kumakura, Physica C 392 458 (2003). [2] X.L. Ren, F.Q. Tang, Acta Chim. Sinica 60 393 (2002). [3] H.J. Zhai, D.W. Sun, H.S. Wang, J. Nanosci. Nanotechnol. 6 1968 (2006). [4] H.Q. Jiang, S. Manolache, A.C.L. Wong, F.S. Denes, J. Appl. Polym. Sci. 93 1411 (2004). [5] J.R. Morones, J.L. Elechiguerra, A. Camacho, K. Holt, J.B., Kouri, J.T. Ramirez, M.J. Yacaman, Nanotechnology 16 2346 (2005). [6] S. Pal, Y.K., Tak, J.M., Song, Appl. Environ. Microbiol. 73, 1712. (2007). [7] B.L. He, J.J. Tan, Y.L. Kong, H.F. Liu, J. Mol. Catal. A: Chem. 221 121 (2004). [8] H.S. Wang, X.L. Qiao, J.G. Chen, S.Y. Ding, Colloids Surf. A: Physicochem. Eng. Aspects 256 111 (2005). [9] H. Li, R. Liu, R. X. Zhao, Y. F. Zheng, W. X. Chen and Z. D. Xu, Cryst. Growth Des. 6 2795 (2006). [10] M. Antonietti, D.B. Kuang, B. Smarsly and Y. Zhou, Angew. Chem., Int. Ed. 43 4988 (2004). [11] L. Busetto, M.C. Cassani, C. Femoni, A. Macchioni, R. Mazzoni, D. Zuccaccia, J. Organomet. Chem. 693, 2579 (2008).

We have recently described the synthesis and characterization of amino-functionalized N-heterocyclic carbene complexes of silver(I), Ag(I)-NHCs, using the Boc-protected and deprotected 1-(2-aminoethyl)-3-methyl imidazolium salts [NH2(CH2)2ImMe]X, [1]X (X = I, PF6) as carbene precursors [1]. We are now presenting the preparation of a new gold(III)-alkylamino imidazolium aurate salt [Cl3AuNH2(CH2)2ImMe)][AuCl4] (2). Demonstrating the great versatility of the amino-functionalized imidazolium salts, such compound is an useful precursor for the preparation of gold nanoparticle (AuNPs) films via the layer-by-layer (LBL) assembly method [2]. Assembling appropriate polyelectrolytes such as poly(ethyleneimine) (PEI) on Indium Tin Oxide Glasses (ITO) a monolayer film of 2 can be easily grafted on the surface and after subsequent reduction, well controlled, in size and distribution, immobilized AuNPs can be generated. The morphology of the AuNPs layers was investigated by using AFM and SEM microscopy and X-ray diffraction (XRD). References [1] L. Busetto, M.C. Cassani, C. Femoni, A. Macchioni, R. Mazzoni, D. Zuccaccia, J. Organomet. Chem. 693, 2579 (2008). [2] J.F. Quinn, A.P.R. Johnston, G.K. Such, A.N. Zelikin, F. Caruso, Chem. Soc. Rev. 36, 707 (2007).

We have recently described the synthesis and characterization of amino-functionalized N-heterocyclic carbene complexes of silver(I), Ag(I)-NHCs, using the Boc-protected and deprotected 1-(2-aminoethyl)-3-methyl imidazolium salts [NH2(CH2)2ImMe]X, [1]X (X = I, PF6) as carbene precursors [1]. We are now presenting the preparation of a new gold(III)-alkylamino imidazolium aurate salt [Cl3AuNH2(CH2)2ImMe)][AuCl4] (2) (Figure 1). Demonstrating the great versatility of the amino-functionalized imidazolium salts, such compound is an useful precursor for the preparation of gold nanoparticle (AuNPs) films via the layer-by-layer (LBL) assembly method [2]. Assembling appropriate polyelectrolytes such as poly(ethyleneimine) (PEI) on Indium Tin Oxide Glasses (ITO) a monolayer film of 2 can be easily grafted on the surface and after subsequent reduction, well controlled, in size and distribution, immobilized AuNPs can be generated. The morphology of the AuNPs layers was investigated by using AFM and SEM microscopy and X-ray diffraction (XRD). References [1] L. Busetto, M.C. Cassani, C. Femoni, A. Macchioni, R. Mazzoni, D. Zuccaccia, J. Organomet. Chem. 693, 2579 (2008). [2] J.F. Quinn, A.P.R. Johnston, G.K. Such, A.N. Zelikin, F. Caruso, Chem. Soc. Rev. 36, 707 (2007).

The synthesis of the Boc-protected 1-(2-NHBoc-ethyl)-3-R-imidazolin-2-ylidene, NHBociy, (R = Me, (1a), allyl (1b), benzyl, (1c)) and their straightforward transformation into the deprotected NH2iy (2a-c) is reported. The salts [1]X and [2]X (X = I, Br, PF6, BF4, NO3) are all viscous liquids at room temperature and can be considered as ionic liquids (ILs)1 whereas the tetrachloroaurate salts are yellow solids. Imidazolium salts are typical N-Heterocyclic carbene (NHCs) precursor2 and the reaction with Ag2O leads to the formation of silver carbenes Ag(I)-NHCs presenting in the solid state different bonding motifs determined by X-ray diffraction analysis, whereas PGSE NMR experiments were employed to investigate the hydrodynamic dimension of the imidazolium salts and silver complexes and, consequently, to gain information on the level of aggregation in solution. PGSE NMR studies were complemented by NOE NMR investigations in order to obtain information on anion-cation relative orientation within aggregates.3 Rh(I)- and Pd(II)-NHC complexes were obtained either by i) direct deprotonation of the imidazolium salts with suitable metal precursors or ii) by using the silver complexes as transmetallating agents; properties of the resulting complexes were studied with NMR spectroscopy and X-ray crystallography. Alongside with the NHC research line described above we have started to investigate the role of 2 as stabilizers for the synthesis of gold and silver nanoparticles and in the second part of this contribution preliminary results concerning this topic will be presented.4,5 [1] Wasserscheid, P.; Welton, T. (Ed.), Ionic Liquids in Synthesis, Wiley-VCH, Weinheim, Germany, 2002, p. 1. [2] Crabtree, R.H. Coord. Chem. Rev. 2007, 251, 595 ff.: a volume completely dedicated to recent developments in the organometallic chemistry of N-heterocyclic carbenes. [3] Busetto, L.; Cassani, M.C.; Femoni, C.; Macchioni, A.; Mazzoni, R.; Zuccaccia, D. J.Organomet.Chem. 2008 in press. [4] Dahl, J.A.; Maddux, B.L.S.; Hutchinson, J.E. Chem. Rev. 2007, 107, 2228. [5] Ballarin, B.; Cassani, M.C.; Scavetta, E.; Tonelli, D. Electroch. Acta 2008 in press.

In this article we have evaluated some of the factors (pH, solvent composition and dye structure) that influence the dyeing of hair with dyes from direct semipermanent categories. These dyes, in fact, have been used more and more in cosmetic industry over the last years, due to their lesser aggressiveness vs. hair fibres. Two different dye classes are investigated: phenylene diamine (HC), well known for their low molecular weight and their small size, and a series of Basic dyes, characterized by the same ionic charge (positive) but with different sizes and different polar groups in the molecule. pH and dyebath composition result critical factors controlling the diffusion and adsorption process

For many years, the electronic transducers have been dominated by inorganic materials. However, mechanical flexibility is often necessary as this would allow the integrated circuits to be twisted, bent and rolled without any effect on the electrical characteristics of the device. On the basis conducting polymers have attracted much interest for the development of biosensors due to their propertiesto be excellent materials for immobilization of biomolecules, favouring the rapid transfer of the charges produced by the biochemical reactions to the electronic circuitry used for the signal elaboration. In 2000 Sirringhaus et al. (Science 290, 2123) have demonstrated a direct inkjet printing of complete transistor circuits, based on solution-processed polymer conductors, insulators and self-organizing semiconductors and recently we have developed a set of techniques for the realization of computer-assisted design and fabrication of third generation biosensors based on synthetic macromolecules, as charge-transfer mediators and protective layers, and biological molecules, as sensing elements (Setti et al., 2005), which was named biopolytronics. With ink jet technology, virtually any complex bioelectronic pattern can be directly printed to a flexible or rigid surface in the size of a pixel using electronic and biological inks, giving very high-resolution patterns. Here we present an overview on biopolytronics reporting possible approaches for formulating biologically and electronically active water-based inks for thermal inkjet technology, containing respectively different enzymatic activities (redox enzymes such as glucose oxidase and peroxidase) and conjugated polymers (conducting polymers such as PEDOT/PSS and regioregular poly(3-hexylthiophene), r-P3HT), opening the way for a wide range of possibilities in the realization of bioelectronic devices using inkjet technology.

Over the past two decades, polypyridyl complexes of d6 metal ions, owing to their peculiar electrochemical and photophysical properties, have received great attention. In particular, even though a wide range of nitrogen rich aromatic ligands have been employed in the design of mono and dinuclear ruthenium complexes, tetrazole compounds have been only rarely considered in such kind of chemistry. Thus, as the extension of some previous studies,[1] we now report our results about the synthesis and the characterization of new mono and dinuclear Ru(II) polypyridyl complexes containing various 5-substituted tetrazolate ligands. A complete survey of the main coordinative, electrochemical and structural features of these complexes will be discussed as well as some interesting results about their light emitting properties.[2] References [1] Palazzi, A.; Stagni, S.; Bordoni, S.; Monari, M.; Selva, S. Organometallics 2002, 21, 3774;. Palazzi, A.; Stagni, S.; Monari, M.; Selva, S. J. Organomet. Chem. 2003, 669, 135. [2] Vos, J.G.; Ward, M.D.; Duati, M.; Stagni, S. Tasca, S.; Lynch, F.C., Bohlen, H. Inorg. Chem. 2003, 42, 8377.