Multifunctional leather finishing vs. applications, through the addition of well-dispersed flower-like nanoparticles

In the present paper, multifunctional flower-like nanoparticles were synthesized to be used in the leather finishing. They are capable of conferring simultaneously and synergistic antimicrobial, self-cleaning, light resistance, hydrophobic, mechanical, thermal, and fluorescent properties due to the presence of Ag, TiO2, and SiO2 NPs. These nanoparticles form a "flower-like" structure in which the "pistil" is made up of TiO2 and the "petals" that surround it of silver nanoparticles and silica nanoparticles, whose dimensions are of the order of ten nanometers. Their surfaces enjoy abundant hydrophilic functionalities to be dispersed within inks commonly used during the leather finishing process. Leathers functionalized with these nanomaterials showed significantly improved self-cleaning properties after 15 h of exposure to UV light, and antibacterial properties 10 times higher than that shown by the untreated samples. Aging tests were performed (ISO 105-B02, ISO 17228, SAEJ 2412). ΔE, color variation decreased by approximately 30%, if compared with samples not refined with flower-like NPs. Furthermore, the results of the mechanical tests (ISO 17076, FCA 50444) evidence amazing properties, e.g. abrasion resistance more than significantly improved, increase in resistance from 1500 cycles for the untreated samples to 3000 cycles for the leathers finished with flower-like NPs. The contact angle analysis, capturing the angle that traces the air-water to water-substrate interface from the origin of the air-water-substrate contact point at the edge, is practically unchanged after 10 s in the case of nanoparticles containing finishing.

Rough and Porous Micropebbles of CeCu2Si2 for Energy Storage Applications

Supercapacitors have attracted considerable attention due to their advantages, including being lightweight and having rapid charge-discharge, a good rate capability, and high cyclic stability. Electrodes are one of the most important factors influencing the performance of supercapacitors. Herein, a three-dimensional network of rough and porous micropebbles of CeCu2Si2 has been prepared using a one-step procedure and tested for the first time as a supercapacitor electrode. The synthesized material was extensively characterized in a three-electrode configuration using different electrochemical techniques, such as cyclic voltammetry (CV), galvanostatic charge and discharge (GCD) tests, and electrochemical impedance spectroscopy (EIS). CeCu2Si2 shows rather high mass-capacitance values: 278 F/g at 1 A/g and 295 F/g at 10 mV/s. Moreover, the material exhibits remarkable long-term stability: 98% of the initial capacitance was retained after 20,000 cycles at 10 A/g and the Coulombic efficiency remains equal to 100% at the end of the cycles.

Iron Selenide Particles for High-Performance Supercapacitors

Nowadays, iron (II) selenide (FeSe), which has been widely studied for years to unveil the high-temperature superconductivity in iron-based superconductors, is drawing increasing attention in the electrical energy storage (EES) field as a supercapacitor electrode because of its many advantages. In this study, very small FeSe particles were synthesized via a simple, low-cost, easily scalable, and reproducible solvothermal method. The FeSe particles were characterized using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) measurements, and electrochemical impedance spectroscopy (EIS), revealing enhanced electrochemical properties: a high capacitance of 280 F/g at 0.5 A/g, a rather high energy density of 39 Wh/kg and a corresponding power density of 306 W/kg at 0.5 A/g, an extremely high cycling stability (capacitance retention of 92% after 30,000 cycles at 1 A/g), and a rather low equivalent series resistance (RESR) of ~2 Ω.

Improving electrical conductivity of leather surface: a new technology versus industrial applications

The present study takes into account the consumer requirement of an even more massive use of touch screen devices, where the leather has to compete with the modern textile fibers in terms of technological performances, with particular reference to the newest technologies for the production of conductive gloves and other kinds of conductive goods, like shoes, garments, and others. Most of the known technologies able to provide materials with a unique ability to discharge static electricity and conductivity comparable with the human body concern the use of textile fibers. On the other hand, the goal of the present work is to delve into the application of technologies for leather matrix, with particular reference to the use of carbon-based nanomaterials, and attention to economical and/or practical aspects.

Self-Suspended Nanoparticles for N-Alkylation Reactions: A New Concept for Catalysis

The catalytic activity of snowman-like and core-shell Fe3O4/Au nanoparticles (NPs), obtained through a "wet chemistry" approach which directly restitutes nanocatalysts stable and highly active in the reaction medium, was tested towards N-alkylation reactions. The nanocatalysts were tested for the synthesis of secondary amines. The core-shell NPs, thanks to the surface properties, homogeneous dispersion and intimate connection with reagents in the catalyst medium, exhibited an excellent catalytic activity (e. g. >99 % yield and conversion of aniline in very short time and mild conditions). Owing to the magnetic part, the nanoparticles can be easily separated and reused, showing an almost stable activity after 10 cycles.

Active biocatalyst for biodiesel production from spent coffee ground

Physical adsorption preserving activity and support reusability was used to directly bond lipase from Thermomyces lanuginosus on citric acid (CA) modified Fe₃O₄/Au magnetic nanoparticles. A new faster approach has been used for CA ligand exchange, which ensures an high payload of stable enzyme. The immobilized lipase was tested for the biodiesel production from spent coffee ground in a solvent free system. It retains, after 60 days, more than 90% of its initial activity. Biodiesel yield of 51.7%, after 3 h of synthesis, which increases up to ∼100% after 24 h indicating an enzymatic fast kinetic, was measured. No significant decrease, during the first three cycles of use, of the lipase activity occurs. The biodiesel presents an ester content of 98.4 ± 0.23 in agreement with the EN14214. The iodine value of 76.67 (g iodine/100 g) is in agreement with the European standard.

On the formation of iron(III) hydroxo acetate complexes

The formation of hydroxo acetate complexes of iron (III) ion has been studied at 25 degrees C in 3 M (Na)ClO4 ionic medium by measuring with a glass electrode the hydrogen ion concentration in Fe(ClO4)3-HClO4-NaAc mixtures (Ac = acetate ion). The acetate/metal ratio ranged from 0 to 6, the metal concentration varied from 0.005 to 0.06 M, whereas [H+] was stepwise decreased from 0.1 M to initial precipitation of hydroxo-acetates. This occurred, depending on the acetate/metal ratio, in the -log[H+] range 1.85-2.7. The potentiometric data are consistent with the presence of Fe3(OH)3Ac3(3+), Fe2(OH)2(4+), Fe3(OH)4(5+), Fe3(OH)5(4+) and, as minor species, of Fe3(OH)2Ac6+, FeAc2+, FeAc2+, FeOH2+ and Fe(OH)2+. Previously published EMF measurements with redox and glass half-cells were recalculated to refine the stability constants of FeAc2+, FeAc2+ and Fe3(OH)2Ac6+. Formation constants *beta pqr for pFe(3+)+(q-r)H2O + rHAc reversible Fep(OH)(q-r)(Ac)r3p-q + qH+ (in parenthesis the infinite dilution value): log*beta 111 = -1.85 +/- 0.02 (-0.67 +/- 0.15), log*beta 122 = -3.43 +/- 0.02 (-1.45 +/- 0.15); log*beta 363 = -5.66 +/- 0.03 (-2.85 +/- 0.40), log*beta 386 = -8.016 +/- 0.006 (-4.06 +/- 0.15), log*beta 220 = -2.88 +/- 0.02 (-2.84 +/- 0.05), log*beta 340 = -6.14 +/- 0.18 (-6.9 +/- 0.4), log*beta 350 = -8.44 +/- 0.09 (-7.65 +/- 0.15).

A potentiometric study on oxalate and citrate complexes of tin(II)

The formation of oxalate and citrate complexes of the Sn2+ ion in 1 M Na(ClO4) at 25 degrees C was investigated in the -log[H+] range 2 to 5 by potentiometric titrations using glass and tin amalgam electrodes. The tin concentration was varied from 0.5 to 5 mM and the concentration of the ligands from 1 to 40 mM. The experimental data have been explained by the formation of the oxalato complexes SnC2O4(aq) and Sn(C2O4)2(2-) and of the citrate complexes (C3H5O7(3-) = citrate ion) SnC3H5O7-, SnHC3H5O7(aq), SnH2C3H5O7+ and Sn(OH)C3H5O7(2-). The equilibrium constants were refined by the computer program SUPERQUAD. The final values of the constants on the medium scale and in the infinite dilution reference state are given in Table 2.

Wheat transformation with glutenin gene

The rheological properties of wheat grains are associated with the composition of the starchy endosperm in high molecular weight (HMW) glutenin proteins. The HMW glutenin 1xDy12 subunit gene was co introduced with the screenable bar and the reporter gus marker genes in the commercial spring wheat Minaret cultivar (cv). The gene of interest and the marker genes were carried by two separated plasmids, the pBS10BH1 and the pAhC25 respectively. Seven days old calli initiated from immature embryos were bombarded by use of the PDS-1000/He device. A number of different bombardment and culture conditions were tested. These parameters were evaluated on the basis of GUS transient expression. Among those a 4 degrees C cold pre-treatment of the spikes before immature embryos were excised, the culture medium incorporating activated charcoal, silver nitrate and glucose yielded higher GUS transient expression rate. The selective agent bialaphos was maintained at various stages during culture from induction of somatic embryogenesis to rooting of regenerated plantlets. 137 bialaphos resistant plants were obtained among which 109 were carried to maturity. Transgenic plants were characterized by PCR, Southern and SDS-PAGE analysis of the glutenin content.