Plasma-Driven Tuning of Dielectric Permittivity in Graphene.

Materials with tunable negative electromagnetic performance, i.e., where dielectric permittivity becomes negative, have long been pursued in materials research due to their peculiar electromagnetic (EM) characteristics.

Heterogenization of Heteropolyacid with Metal-Based Alumina Supports for the Guaiacol Gas-Phase Hydrodeoxygenation.

Because of the global necessity to decrease CO emissions, biomass-based fuels have become an interesting option to explore; although, bio-oils need to be upgraded, for example, by catalytic hydrodeoxygenation (HDO), to reduce oxygen content. This reaction generally requires bifunctional catalysts with both metal and acid sites. For that purpose, Pt-AlO and Ni-AlO catalysts containing heteropolyacids (HPA) were prepared.

Bactericide Activity of Cellulose Acetate/Silver Nanoparticles Asymmetric Membranes: Surfaces and Porous Structures Role.

The antibacterial properties of cellulose acetate/silver nanoparticles (AgNP) ultrafiltration membranes were correlated with their integral asymmetric porous structures, emphasizing the distinct features of each side of the membranes, that is, the active and porous layers surfaces. Composite membranes were prepared from casting solutions incorporating polyvinylpyrrolidone-covered AgNP using the phase inversion technique. The variation of the ratio acetone/formamide and the AgNP content resulted in a wide range of asymmetric porous structures with different hydraulic permeabilities.

Effect of Graphene vs. Reduced Graphene Oxide in Gold Nanoparticles for Optical Biosensors-A Comparative Study.

Aiming to develop a nanoparticle-based optical biosensor using gold nanoparticles (AuNPs) synthesized using green methods and supported by carbon-based nanomaterials, we studied the role of carbon derivatives in promoting AuNPs localized surface plasmon resonance (LSPR), as well as their morphology, dispersion, and stability. Carbon derivatives are expected to work as immobilization platforms for AuNPs, improving their analytical performance. Gold nanoparticles (AuNPs) were prepared using an eco-friendly approach in a single step by reduction of HAuCl·3HO using phytochemicals (from tea) which act as both reducing and capping agents.

Unprecedented Mechanochemical Synthesis and Heterogenization of a C-Scorpionate Au(III) Catalyst for Microwave-Assisted Biomass Valorization.

The transformation of biomass, a carbon resource presenting a huge potential to produce valuable chemicals, requires the search for sustainable catalytic routes. This work proposes the microwave-assisted oxidation of biomass -derived substrates, such as glycerol and the furfural derivatives 5-(hydroxymethyl)furfural (HMF) and 5-hydroxymethyl-2-furancarboxylic acid (HFCA), using the C-scorpionate dichloro-gold(III) complex [AuCl(κ-Tpm)]Cl (Tpm = HCpz; pz = pyrazol-1-yl) as a catalyst, as prepared and supported on graphene, in solvent-free conditions. The unprecedented application of a mechanochemical procedure (in a planetary ball mill, in solid state) to synthesize a C-scorpionate complex, the [AuCl(κ-Tpm)]Cl, is disclosed.

Dataset for the synthesis, characterisation and application of cobalt and nitrogen co-doped TiO nanoparticles on triclosan photodegradation using visible LED light.

The growing threat of emerging waterborne contaminants is a global concern, fuelled in part by the ineffectiveness of current remediation strategies. One of the most prominent remediation strategies is catalytic photodegradation, particularly with TiO nanoparticles (NPs), but its full utilization is hampered by using only UV radiation, which is scarce in sunlight. To fully benefit from the sunlight abundance, several efforts are focused on the tailoring of TiO to make it more active in visible (Vis) light.

Cotton decorated with CuO-Ag and CuO-Ag-AgBr NPs via an in-situ sacrificial template approach and their antibacterial efficiency.

Cotton fabrics decorated with CuO-Ag and CuO-Ag-AgBr NPs have been prepared using chemically immobilized CuO NPs as sacrificial templates. The objective is to prepare CuO-Ag heterostructures with Ag being intimately in contact with CuO NPs by galvanic replacement reactions without addition of any external reducing agent. Field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis were used to study the morphology and the chemical composition of the nanocomposites formed on the fabrics.

Preclinical In Vitro Assessment of Submicron-Scale Laser Surface Texturing on Ti6Al4V.

Loosening of orthodontic and orthopedic implants is a critical and common clinical problem. To minimize the numbers of revision surgeries due to peri-implant inflammation or insufficient osseointegration, developments of new implant manufacturing strategies are indicated. Ultrafast laser surface texturing is a promising contact-free technology to modify the physicochemical properties of surfaces toward an anti-infectious functionalization.

Catalytic Performance of a Magnetic Core-Shell Iron(II) C-Scorpionate under Unconventional Oxidation Conditions.

For the first time, herein is reported the use of a magnetic core-shell support for a C-scorpionate metallic complex. The prepared hybrid material, that consists on the C-scorpionate iron(II) complex [FeCl{κ-HC(pz)}] (pz, pyrazolyl) immobilized at magnetic core-shell particles (FeO/TiO), was tested as catalyst for the oxidation of secondary alcohols using the model substrate 1-phenylethanol. Moreover, the application of alternative energy sources (e.

Cotton fabrics decorated with nanostructured Ag/AgX (X:Cl,Br) as reusable solar light-mediated bactericides: A comparative study.

In this study, cotton fabrics decorated with Ag/AgCl and Ag/AgBr NPs were produced by a simple hydrothermal treatment using AgCl and AgBr as precursors. Their morphological features as well as, chemical composition and structural and luminescence properties were compared. Their water disinfection aptitude against E.

Surface and mechanical properties of a nanostructured citrate hydroxyapatite coating on pure titanium.

The presence of a biomimetic HAP coating on titanium surface, which reduces the structural stiffness, is essential to improve implants biocompatibility and osteointegration. In this study, new citrate-HAP (cHAP) coatings were produced by a simple hydrothermal method on pure titanium (Ti) surface, without requiring any additional pretreatment on this metal surface. The formed cHAP coatings consisting of nanorod-like hydroxyapatite particles, conferred nanoroughness and wettability able to endow improved biological responses.

Ultrasound and Radiation-Induced Catalytic Oxidation of 1-Phenylethanol to Acetophenone with Iron-Containing Particulate Catalysts.

Iron-containing particulate catalysts of 0.1-1 µm size were prepared by wet and ball-milling procedures from common salts and characterized by FTIR, TGA, UV-Vis, PXRD, FEG-SEM, and XPS analyses. It was found that when the wet method was used, semi-spherical magnetic nanoparticles were formed, whereas the mechanochemical method resulted in the formation of nonmagnetic microscale needles and rectangles.

Antimicrobial Activity of Silver Camphorimine Complexes against Strains.

Hydroxide [Ag(OH)L] (L = L, L, L, L), oxide [{AgL}}(μ-O)] (L = L, L, L, L, L) or chloride [AgL]Cl, [Ag(L)]Cl complexes were obtained from reactions of mono- or bicamphorimine derivatives with Ag(OAc) or AgCl. The new complexes were characterized by spectroscopic (NMR, FTIR) and elemental analysis. X-ray photoelectron spectroscopy (XPS), ESI mass spectra and conductivity measurements were undertaken to corroborate formulations.

Silver Nanoparticles on Cellulose Surfaces: Quantitative Measurements.

In this work, cellulose films pre-activated with carbonyldiimidazole (CDI) and grafted with 1,6-hexanediamine, were decorated with silver nanoparticles (AgNPs). The generation of AgNPs was followed by quartz crystal microbalance (QCM). The obtained films were characterized by X-Ray Photoelectron Spectroscopy (XPS) and imaged by atomic force microscopy (AFM).

Hydrophilic Carbon Nanomaterials: Characterisation by Physical, Chemical, and Biological Assays.

A highly hydrophilic carbon nanomaterial was generated by using an electrochemical approach, and its structure, chemical composition, redox properties, antioxidant activity and effects on cells were characterised. It was found that the nanomaterial possesses a structure dominated by sp carbon atoms in a non-ordered carbon network formed by small clusters (<2 nm) of a carbonaceous material. This material has an outstanding capability for donating electrons and an unusual ability to bind metal cations.

Search for cytotoxic compounds against ovarian cancer cells: Synthesis, characterization and assessment of the activity of new camphor carboxylate and camphor carboxamide silver complexes.

Five silver camphor complexes of formulae [Ag(L)(L')] (1,3,5) or [Ag(L)(L')] (2,4) were synthesized from silver nitrate and the suitable camphor carboxylate (L) or camphor carboxamides (L, L). The complexes were characterized by elemental analysis and spectroscopic techniques (NMR, FTIR, XPS). Computational calculations support coordination of the carboxylate group to silver, in the case of complex 2 and combined mixed keto/carboxylate in the case of complex 1.

Comparison of microwave and mechanochemical energy inputs in the catalytic oxidation of cyclohexane.

The effect of microwave and mechanochemical ball milling energy inputs was studied for the peroxidative oxidation (with aqueous H2O2) of cyclohexane to cyclohexanol and cyclohexanone, over CoCl2 and/or V2O5 dispersed (μm scale) catalysts. A maximum total yield of cyclohexanol and cyclohexanone of 43% after 1 h of reaction at 30 °C, in acetonitrile and under microwave irradiation (5 W), was achieved over the CoCl2-V2O5 (3 : 1) catalyst prepared by ball milling. Cyclohexanol is the main final product with a selectivity of up to 93% over cyclohexanone.

Hybrid chitosan-TiO/ZnS prepared under mild conditions with visible-light driven photocatalytic activity.

Thin films of chitosan (CS) coated on glass substrates were used as support for the immobilization of nanostructures TiO/ZnS via a mild chemical process followed by a hydrothermal treatment at 90 °C. The preparation route involved the coating of the CS film on the glass substrate followed by the deposition of a thin layer of Ti(OBu) precursor and immersion in a solution of Zn(OCCH) and NaS. After a hydrothermal treatment at 90 °C, an even layer of TiO anatase decorated by ZnS nanorods was generated.

Effect of Phenolic Compounds on the Synthesis of Gold Nanoparticles and its Catalytic Activity in the Reduction of Nitro Compounds.

Gold nanoparticles (AuNPs) were prepared using an eco-friendly approach in a single step by reduction of HAuCl₄ with polyphenols from tea extracts, which act as both reducing and capping agents. The obtained AuNPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet⁻visible spectroscopy (UV⁻vis), and X-ray photoelectron spectroscopy (XPS). They act as highly efficient catalysts in the reduction of various aromatic nitro compounds in aqueous solution.

Facile functionalization of cotton with nanostructured silver/titania for visible-light plasmonic photocatalysis.

In the present work, a simple, reliable and cost-effective approach to functionalize cotton fabrics with Ag-TiO nanoparticles strongly bound to the fibres and with visible-light-responsive photo-activity is presented. The hybrid cotton-Ag-TiO fabrics were characterized by Raman, AFM, FE-SEM, TGA, XPS GSDR, and LIL to confirm the generation of metallic Ag nanoparticles and crystalline TiO and investigate how the concentration of Ag and TiO precursors affected the morphology and the luminescence properties of the nanostructured layer grafted on the cotton fibres. The photocatalytic activity of the cotton-Ag-TiO hybrid systems was evaluated by the discoloration of Remazol Brilliant Blue R in water under a xenon lamp irradiation (sunlight simulator) equipped with selective filters.

Voltage-polarity dependent multi-mode resistive switching on sputtered MgO nanostructures.

Resistive switching in metal-insulator-metal nanosctructures is being intensively studied for nonvolatile memory applications. Here, we report unipolar resistive switching in Pt/MgO/Ta/Ru structures, with a 30 nm oxide barrier. A forming process was needed to initiate the resistive switching, which was then observed for all Set and Reset voltage polarity combinations.

DPPG Liposomes Adsorbed on Polymer Cushions: Effect of Roughness on Amount, Surface Composition and Topography.

The adsorption of intact liposomes onto solid supports is a fundamental issue when preparing systems with encapsulated biological molecules. In this work, the adsorption kinetic of 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (sodium salt) liposomes onto cushions prepared from commom polyelectrolytes by the layer-by-layer technique was investigated with the main objective of finding the surface conditions leading to the adsorption of intact liposomes. For this purpose, different cushion surface roughnesses were obtained by changing the number of cushion bilayers.

Human mesenchymal stem cell behavior on femtosecond laser-textured Ti-6Al-4V surfaces.

Aim: The aim of the present work was to investigate ultrafast laser surface texturing as a surface treatment of Ti-6Al-4V alloy dental and orthopedic implants to improve osteoblastic commitment of human mesenchymal stem cells (hMSCs).

Materials & Methods: Surface texturing was carried out by direct writing with an Yb:KYW chirped-pulse regenerative amplification laser system with a central wavelength of 1030 nm and a pulse duration of 500 fs. The surface topography and chemical composition were investigated by scanning electron microscopy and x-ray photoelectron spectroscopy, respectively.

Synthesis, characterization and heterogeneous catalytic application of copper integrated mesoporous matrices.

Ordered copper integrated mesoporous silicate catalysts (CuMSC) have been synthesized by the utilization of the amphiphilic tri-block copolymer pluronic F127 as a structure directing agent (SDA) under acidic aqueous conditions. The mesophase of the materials was investigated using small-angle powder X-ray diffraction and transmission electron microscopic (TEM) image analysis. N2 adsorption-desorption studies show that the BET surface area of CuMSC (214-407 m(2) g(-1)) is lower than that of pure silica (611 m(2) g(-1)) and has smaller average pore dimensions (4.