Two-step synthesis of polymer fibre material comprising indium-, bismuth-, or antimony-doped nanosized tin oxides

In this paper, we present a method of formation of polymer fibre materials comprising dispersed oxides of rare and trace elements. The results of X-ray diffraction and spectral analyses show that the optimum synthesis conditions of the antimony-doped tin oxide, indium-doped tin oxide, and bismuth-doped tin oxide particles are provided using the "reverse" hydrolytic co-precipitation of hydroxides from chloride solutions combined with the subsequent thermal treatment at 1000°C. Durable fixation of nanoparticles on the fibre surface is confirmed by the atomic emission spectrometry with inductively coupled plasma and transmission electron microscopy. The results show that spraying of a free stream of the thermoplastic polymer melt with a gas stream containing nanoparticles allows obtaining fibre materials, which possess catalytic, photosensitive, as well as heat and sound insulating properties

Hydrophobic sorbents based on ultrathin polymer fibers for trapping oil products

Relevance. Increasing negative effects of hydrocarbon production on aquatic ecosystems and tightening of legislative norms on discharge of oil and oil product contaminated water into marine waters. Among various methods used to remove oil from aqueous solutions the most appropriate one is adsorption method. It is explained by its high degree of purification, safety, availability, manufacturability, universality of application. Synthetic materials based on ultrafine fibers have optimal characteristics for manufacturing sorbents for oil removal on their basis. However, the large-scale application of these materials is limited by their high cost, complexity of manufacturing, which excludes the secondary use of polymers as feedstock. In this regard, there is a growing need for economically and environmentally effective hydrophobic materials for sorptive treatment of aqueous media from oil and petroleum products. Aim. To determine sorption properties of hydrophobic fibrous materials produced via pneumatic formation for use as effective hydrocarbon sorbents for liquidation of oil spills in sea and water treatment on oil production platforms. Objects. Sorbents based on polypropylene and polyethylene terephthalate ultrafine fibers. Methods. Gravimetric, spectral analysis, transmission electron microscopy, gas chromatography. Results. The paper introduces the results of investigation of sorption properties of untreated ultrafine fibers obtained by pneumatic atomization and modified by microwave radiation. The authors have carried out the comparative analysis of water absorption and the influence of contact time and acidity of the medium on the degree of sorption of samples obtained from hydrophobic polymers. Promising application of sorbents based on polypropylene ultrathin fibers for oil products extraction from aqueous media was revealed. It is established that modification reduces water absorption of polypropylene sorbents and leads to an insignificant decrease in sorption properties due to changes in the supramolecular structure of polypropylene fiber samples

Investigation of supramolecular structure of the rare and rare-earth elements nanoparticles carrier when modified using microwave irradiation

In this paper, we present an IR and XRD study of the polypropylene fibrous nanoparticles carrier when its surface modified with rare and rare-earth elements nanoparticles using microwave irradiation, by the example of SnO2/TiO2 hetero-nanoparticles. The paper shows that the smectic mesomorph structure of the non-modified polypropylene fibrous carrier transforms into the monoclinic α-crystalline due to microwave irradiation. At the same time, the carrier material remains stereoregular and keeps its helical structure

Superficial acid-base properties of polymer fibres

Protolytic properties of fine fibre plastics based on polypropylene, polyethyleneterephthalate and polycarbonate were investigated. Acidic (carboxylic, hydroxyl) and basic Lewis sites (esters, carbonates, epoxies) were discovered on fibres surface using IR spectroscopy. The number of active groups of various nature and their pKa values were evaluated by potentiometric titration in aqueous and non-aqueous media. The tested fibres possess a low capacity for both acidic and basic sites on it. The results indicate that all the polymer fibre materials (PFM) due to the presence of carboxyl groups on the surfaces, enable modification of their surfaces with metal nanoparticles, thereby giving them unique properties, e.g., photocatalytic and bactericidal

Properties of polydisperse tin-doped dysprosium and indium oxides

The results of investigations of the complex permittivity, diffuse-reflectance, and characteristics of crystal lattices of tin-doped indium and dysprosium oxides are presented. Using the methods of spectroscopy and X-ray diffraction analysis, it is shown that doping of indium oxide with tin results in a significant increase of the components of the indium oxide complex permittivity and an appearance of the plasma resonance in its diffuse-reflectance spectra. This indicates the appearance of charge carriers with the concentration of more than 1021 cm−3 in the materials. On the other hand, doping of the dysprosium oxide with the same amount of tin has no effect on its optical and electromagnetic properties