The adsorption of copper ions and Reactive Red 120 azo dye (RR-120) as models of water pollutants on unmodified halloysite (H-NM), as well as halloysites modified with sulfuric acid (H-SA) and (3-aminopropyl)triethoxysilane (H-APTES), was investigated. The results showed that adsorption of both the adsorbates was pH-dependent and increased with the increase in halloysite dosage. The adsorption kinetics were evaluated and the results demonstrated that the adsorption followed the pseudo-second-order model.
View Article and Find Full Text PDFThis study shows that the simple approach of keeping anodic TiO nanotubes at 70 °C in ethanol for 1 h results in improved photoelectrochemical water splitting activity due to initiation of crystallization in the material amplified by the light-induced formation of a Ti -V states under UV 365 nm illumination. For the first time, the light-induced Ti -V states are generated when oxygen is present in the reaction solution and are stable when in contact with air (oxygen) for a long time (two months). We confirmed here that the amorphous or nearly amorphous structure of titania supports the survival of Ti species in contact with oxygen.
View Article and Find Full Text PDFCorrosion protection systems based on hexavalent chromium are traditionally perceived to be a panacea for many engineering metals including magnesium alloys. However, bans and strict application regulations attributed to environmental concerns and the carcinogenic nature of hexavalent chromium have driven a considerable amount of effort into developing safer and more environmentally friendly alternative techniques that provide the desired corrosion protection performance for magnesium and its alloys. Part I of this review series considers the various pre-treatment methods as the earliest step involved in the preparation of Mg surfaces for the purpose of further anti-corrosion treatments.
View Article and Find Full Text PDFAlthough hexavalent chromium-based protection systems are effective and their long-term performance is well understood, they can no longer be used due to their proven Cr(VI) toxicity and carcinogenic effect. The search for alternative protection technologies for Mg alloys has been going on for at least a couple of decades. However, surface treatment systems with equivalent efficacies to that of Cr(VI)-based ones have only begun to emerge much more recently.
View Article and Find Full Text PDFOwing to the unique active corrosion protection characteristic of hexavalent chromium-based systems, they have been projected to be highly effective solutions against the corrosion of many engineering metals. However, hexavalent chromium, rendered a highly toxic and carcinogenic substance, is being phased out of industrial applications. Thus, over the past few years, extensive and concerted efforts have been made to develop environmentally friendly alternative technologies with comparable or better corrosion protection performance to that of hexavalent chromium-based technologies.
View Article and Find Full Text PDFThe carbon black N-220 surface was subjected to modification through H2O2 oxidation and deposition of aminopropyltriethoxysilane. The pristine (CB-NM) and modified materials (CB-Ox and CB-APTES) were characterized by N2 adsorption−desorption isotherms, scanning electron microscopy, energy-dispersive X-ray spectroscopy (SEM-EDS), thermogravimetry, and FTIR spectroscopy. Carbon black samples were applied as adsorbents for the removal of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chlorophenoxyacetic acid (MCPA) herbicides from aqueous solutions.
View Article and Find Full Text PDFWe introduce for the first time a core-shell structure composed of nanostructured self-standing titania nanotubes (TNT, light absorber) filled with Au nanowire (AuNW) array (electrons collector) applied to the photoelectrocatalytic water splitting. Its activity is four times higher than that of reference TNT-Ti obtained with the same anodizing conditions. The composite photoanode brings a distinct photocurrent generation (8 mA cm at 1.
View Article and Find Full Text PDFIn this paper, a stainless steel fiber coated electropolymerized aniline, without and with carbon nanotubes (SS/PANI and SS/PANI/CNT), along with CNTs modified carbon paste electrodes (CPEs), were prepared. The electrodes were characterized by differential pulse voltammetry (DPV) and applied for the detection of 4-chlorophenol (4-CP). For all the electrodes, the oxidative peak current showed a linear dependence on the 4-CP concentration in the range of 0.
View Article and Find Full Text PDFBiologically derived polymers are a very attractive subject for investigation, due to the strict pro-ecological requirements imposed by developed countries, including zero-waste and zero-carbon policies as well as volatile organic compound (VOC) limits. Synthesis of biologically-derived polyesters from natural rosin and bio-diols, showing softening temperatures suitable for application in VOC-free paints and varnishes, was performed to create a desired, future commercial product, that meet the aforementioned requirements regarding VOC and elimination of petroleum-based raw materials. Prepared polymers were used in the formulation of coating materials whose properties: cross-linking behavior, glass transition temperature, thermal stability, storage modulus, hardness, cupping resistance, adhesion, chemical resistance, gloss, haze, color, and anti-corrosive behavior in the salt chamber were investigated and discussed.
View Article and Find Full Text PDFWe investigate the co-catalytic activity of PtCu alloy nanoparticles for photocatalytic H evolution from methanol-water solutions. To produce the photocatalysts, a few-nanometer-thick Pt-Cu bilayers are deposited on anodic TiO nanocavity arrays and converted by solid-state dewetting via a suitable thermal treatment into bimetallic PtCu nanoparticles. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results prove the formation of PtCu nanoalloys that carry a shell of surface oxides.
View Article and Find Full Text PDFA comprehensive review of the publications about rosin-based chemicals has been compiled. Rosin, or colophony, is a natural, abundant, cheap and non-toxic raw material which can be easily modified to obtain numerous useful products, which makes it an excellent subject of innovative research, attracting growing interest in recent years. The last extensive review in this research area was published in 2008, so the current article contains the most promising, repeatable achievements in synthesis of rosin-derived chemicals, published in scientific literature from 2008 to 2018.
View Article and Find Full Text PDFIllumination of anatase in an aqueous methanolic solution leads to the formation of Ti sites that are catalytically active for the generation of dihydrogen (H ). With increasing illumination time, a light-induced self-amplification of the photocatalytic H production rate can be observed. The effect is characterized by electron paramagnetic resonance (EPR) spectroscopy, reflectivity, and photoelectrochemical techniques.
View Article and Find Full Text PDFChem Commun (Camb)
January 2019
Here we investigate the band-level energetics of "black" hydrogenated titania in different polymorphs using in situ photoelectrochemical measurements and XPS valence band measurements. We find that the conduction band of black rutile is higher in energy than in black anatase by 0.4 eV.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
July 2017
Deposition of plazmonic metal nanoparticles on nanostructured oxide templates is an important part in preparation and design of suitable substrates for surface-enhanced Raman scattering (SERS) measurements. In this contribution we analyze the influence of the Ag deposition methods (magnetron sputtering and evaporation in vacuum, which are often used interchangeably) on SERS activity of the resultant Ag-n/ZrO/Zr composite samples fabricated. We found that deposition of the same amount of Ag (0.
View Article and Find Full Text PDFBackground/aims: Merkel cell carcinoma (MCC) is a rare high-grade neuroendocrine tumour of the skin. It has been speculated that MCCs express somatostatin receptors (SSTRs), but this has never been assessed in a large series of MCCs. The main aim of this study was to assess the expression of SSTR2A and SSTR5 in MCC tumours.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
September 2014
The aim of this study was to perform calculations using the method of Car-Parrinello molecular dynamics, leading to the optimized geometry of the molecules of 1,4-benzenedicarboxylic acid (terephthalic acid) in crystals, for the hydrogen form and three variants of substitution of deuterium atoms inside a carboxyl group. Based on the results, trajectories and dipole moments were calculated, what makes possible to simulate vibrations in different systems, and to make calculation of theoretical infrared spectra and atomic power spectra. Theoretical results were compared with the experimental spectra, which verifies the correctness of the method and also was compared with the results obtained by quantum-mechanical calculations using DFT for the isolated dimer.
View Article and Find Full Text PDFMutations in two genes encoding cell cycle regulatory proteins have been shown to cause familial cutaneous malignant melanoma (CMM). About 20% of melanoma-prone families bear a point mutation in the CDKN2A locus at 9p21, which encodes two unrelated proteins, p16(INK4a) and p14(ARF). Rare mutations in CDK4 have also been linked to the disease.
View Article and Find Full Text PDFObjective: To assess the relative frequency of the different causes of pompholyx evoked in the literature.
Design: Prospective survey.
Setting: Clinical outpatient setting.
Patients treated with immunosuppressive agents are prone to developing lymphoproliferative disorders, in particular Epstein-Barr virus-associated lymphoproliferative disease. This complication was reported first in post-transplanted patients treated with cyclosporine, and, more recently, in patients receiving long-term methotrexate therapy for inflammatory disease. We describe the case of a 70-year-old female patient with multifocal cutaneous lymphoproliferative disease occurring in the course of long-term, weekly methotrexate therapy for rheumatoid arthritis.
View Article and Find Full Text PDFIntroduction: The Meige's syndrom is characterized by the presence of bilateral, symmetrical, dystonic cramp of face muscles or muscles of middle line of body, the respiratory muscles and muscles of throat. The etiology of Meige's syndrome is uncertain. The disorders of basal ganglia function and neurotransmitters' imbalance (dopamine and acetylocholine) can be with reason of pronouncement of symptoms presumably.
View Article and Find Full Text PDFThe aim of this paper was analysis of vocal fold paresis in the patients referred to ENT Department in Wrocław in the years 1993-2002. The study was performed on the base of 304 patients--209 women and 131 men. The average patient's age was 56 years.
View Article and Find Full Text PDFWe have described two cases of oedema and hypertrophic changes of the larynx which cause remains unknown. We have shown in our paper diagnostic difficulties connected with these cases. A brief review of the literature is presented.
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