Hydrates are ice-like crystalline structures of hydrogen-bonded water molecules that trap a guest molecule. Hydrates have several applications, including carbon sequestration, gas separation, desalination, etc. A classical major challenge associated with artificial hydrate formation is the very long induction time to nucleate hydrates.
View Article and Find Full Text PDFDental and orthopedic implants have become routine medical technologies for tooth replacement and bone fixation. Despite significant progress in implantology, achieving sufficient osseointegration remains a challenge, often leading to implant failure over the long term. Nanotechnology offers the potential to mimic the natural patterns of living tissues, providing a promising platform for tissue engineering and implant surface design.
View Article and Find Full Text PDFMaterials 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.
View Article and Find Full Text PDFTwo samples of spent tire rubber (rubber A and rubber B) were submitted to thermochemical conversion by pyrolysis process. A450, B450 and A900, B900 chars were obtained from rubber A and rubber B at 450 °C and 900 °C, respectively. The chars were then applied as recovery agents of Nd and Dy from aqueous solutions in mono and bicomponent solutions, and their performance was benchmarked with a commercial activated carbon.
View Article and Find Full Text PDFOver the last few years, there has been increasing interest in the use of amorphous carbon thin films with low secondary electron yield (SEY) to mitigate electron multipacting in particle accelerators and RF devices. Previous works found that the SEY increases with the amount of incorporated hydrogen and correlates with the Tauc gap. In this work, we analyse films produced by magnetron sputtering with different contents of hydrogen and deuterium incorporated via the target poisoning and sputtering of CD molecules.
View Article and Find Full Text PDFSpent tire rubber-derived chars and their corresponding HPO and CO-activated chars were used as adsorbents in the recovery of Pb(II) ion and (W(VI)) oxyanion from synthetic solutions. The developed chars (both raw and activated) were thoroughly characterized to have insight about their textural and surface chemistry properties. HPO-activated chars presented lower surface areas than the raw chars and an acidic surface chemistry which affected the performance of these samples as they showed the lowest removals of the metallic ions.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFCarbon nanomaterials endowed with significant luminescence have been synthesized for the first time from an abundant, highly localized waste, the wet pomace (WP), a semi-solid by-product of industrial olive oil production. Synthetic efforts were undertaken to outshine the photoluminescence (PL) of carbon nanoparticles through a systematic search of the best reaction conditions to convert the waste biomass, mainly consisting in holocellulose, lignin and proteins, into carbon dots (CDs) by hydrothermal carbonization processes. Blue-emitting CDs with high fluorescence quantum yields were obtained.
View Article and Find Full Text PDFMolybdenum disulphide (MoS) is a layered material with interesting photocatalytic properties. In this study, a layered MoS was produced using a hydrothermal method. The obtained material was characterised by XRD (X-ray diffraction), XPS (X-ray photoelectron spectroscopy), SEM (scanning electron microscopy), UV-Vis spectroscopy, DLS (dynamic light scattering), and zeta potential analysis.
View Article and Find Full Text PDFAiming 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.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFCotton 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.
View Article and Find Full Text PDFLoosening 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.
View Article and Find Full Text PDFMaterials (Basel)
September 2020
An experimental and theoretical investigation on microwave plasma-based synthesis of free-standing N-graphene, i.e., nitrogen-doped graphene, was further extended using ethanol and nitrogen gas as precursors.
View Article and Find Full Text PDFIn 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.
View Article and Find Full Text PDFThe ability to change the secondary electron emission properties of nitrogen-doped graphene (N-graphene) has been demonstrated. To this end, a novel microwave plasma-enabled scalable route for continuous and controllable fabrication of free-standing N-graphene sheets was developed. High-quality N-graphene with prescribed structural qualities was produced at a rate of 0.
View Article and Find Full Text PDFPhys Chem Chem Phys
February 2020
Free-standing N-graphene was synthesized using a microwave plasma-based method at atmospheric pressure conditions through a single step and in a controllable manner. Using ethanol and ammonia as precursors, N-graphene with low relative amount of bonded oxygen and low level of saturated sp carbon bonds was produced. Adjusting the injection position of the nitrogen precursor in the plasma medium leads to selectivity in terms of doping level, nitrogen configuration and production yield.
View Article and Find Full Text PDFIn this paper, the effect of femtosecond laser nanotexturing of surfaces of Ti6Al4V and Zr implants on their biological compatibility is presented and discussed. Highly regular and homogeneous nanostructures with sub-micrometer period were imprinted on implant surfaces. Surfaces were morphologically and chemically investigated by SEM and XPS.
View Article and Find Full Text PDFIn 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).
View Article and Find Full Text PDFIntensification of chemical processes according to the motto "faster, simpler, greener" is among the main concerns nowadays. One of the ways of intensification is the application of synergistic catalytic effects when the overall efficiency of a composite catalyst is much higher than the sum of the component activities. Here, we report on the preparation of synergistic catalytic materials by a simple and straightforward ball milling procedure.
View Article and Find Full Text PDFThe functionalization of cotton fabric with photoactive TiO-Ag-AgBr nanostructured layer has been successfully developed using a low temperature non-aqueous sol-gel route and aqueous suspension of AgBr. Evidence for the growth of TiO layer and the immobilization of AgBr nanoparticles have been confirmed by Raman, XRD and XPS. GSDR analysis revealed a strong absorption in the visible region brought by surface Plasmon resonance (SPR) of Ag nanocrystals generated at the surface of AgBr.
View Article and Find Full Text PDFA 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.
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