Irena Ban

Preparation of Nanosized Copper and Cadmium Chalcogenides by Mechanochemical Synthesis

Nanosized copper and cadmium chalcogenides have been synthesized by mechanochemical route from elementary precursors, using a SPEX 8000M ball mill. Most reactions were carried out in air, while some of the reactions had to be performed under nitrogen to avoid oxidation. The obtained nanoparticles were characterized by X-ray powder diffraction (powder XRD) and transmission electron microscopy (TEM). Following products were obtained and characterized: CuS, CuSe2, Cu7Te5, CdS, CdSe, and CdTe, with particle sizes within 8 and 19 nm.

Kristallstruktur und thermische Analyse von Hydroxylammonium-hexafluorotitanat(IV)-dihydrat und Hydroxylammonium-hexafluoroindat(III)

Summary. Crystals of (NH3OH)2TiF6ċ2H2O have been isolated. The compound crystallizes in the monoclinic system (P21/c, No. 15) with cell parameters of a=6.203(1) Å, b=10.057(1) Å, c=7.464(1) Å, and β=110.653(6)°. Reactions in the system In (OH)3– NH3OHF – HF have been investigated. Crystals of (NH3OH)3InF6 were isolated from aqueous solution. The compound crystallizes in the trigonal system (R3c) with a=b=c=7.764(2) Å, α=β=γ=97.21(4)°. The thermal decomposition of both compounds was studied by TG and DSC analysis; the decomposition products were characterized by X-ray powder diffraction.

Synthese und Untersuchung von Hydroxylammonium‐fluorohafnaten(IV)

Zwei neue Hydroxylammonium-Verbindungen mit Hafnium(IV)-fluorid, (NH3OH)2HfF6 und (NH3OH)3HfF7, wurden aus dem System NH2OH/HF/HfF4/H2O isoliert. Dafur wurde Hafniumfolie in Flussaure (40 % bzw. 20 %) gelost und mit alkoholischer Hydroxylaminlosung umgesetzt. Die Verbindungen wurden analytisch sowie durch thermische- und Rontgenstrukturanalyse charakterisiert. Die Hydroxylammonium-fluorohafnate sind isomorph mit den entsprechenden Fluorozirconaten. Die thermische Zersetzung verlauft in drei bzw. zwei Stufen zum Endprodukt HfF4. Synthesis and Characterization of Hydroxylammonium Fluorohafnates(IV) Two new hydroxylammonium compounds, (NH3OH)2HfF6 and (NH3OH)3HfF7 were isolated from the system NH2OH/HF/HfF4/H2O. The compounds were prepared by dissolving Hf-foil in aqueous hydrofluoric acid (40 % or 20 %) followed by adding of NH2OH in ethanolic solution. The characterization was carried out by chemical, thermal, and structural analyses. The compounds are isomorphic with the hydroxylammonium fluorozirconates. Thermal analysis of (NH3OH)2HfF6 and (NH3OH)3HfF7 showed that they decompose in three or two steps with HfF4 as final product.

Novel drug delivery system based on NiCu nanoparticles for targeting various cells

In the past two decades, several novel nanoparticles (NPs) were shown to have great potential to be used as drug delivering systems. This is especially true for superparamagnetic nanoparticles (MNPs), which exhibit their magnetic properties only when there is an influence of external magnetic fields. These have received much attention in the last couple of years due to a relatively simple chemical structure, ease of preparation, possible preparation in various shapes and very small sizes, as well due to their favorable properties in biomedical applications (e.g., biocompatibility). Controlled drug delivery systems have several advantages compared to traditional pharmaceutical formulations. For example, these can enable drug transportation to the desired site of action in the body, through which, its influence on healthy tissues, as well as unwanted effects, can be minimized. Such form of delivery is most important in case of drugs with a very narrow therapeutic index or if the drug itself is a toxic compound as is the case in many antitumor drugs. In this study, we prepared a novel controlled drug delivery formulation using the sol–gel procedure, composed of Ni67.5Cu32.5 MNPs in a silica matrix. As the model drug, we used the fluorescent dye rhodamine 6G (RHO6G) to ease the evaluation of the delivery performance to various human cells (human fibroblast cell line, HeLa cells, and Caco-2 cells). The drug release performance was assessed also using in vitro drug release studies. The combination of different physico-chemical and morphological methods with biocompatibility studies served as a general evaluation of the novel formulations safety and efficiency. Graphical abstractGraphical abstract

Mechanochemical Route for the Preparation of Nanosized Aluminum and Gallium Sulfide and Selenide

Aluminum and gallium chalcogenides are promising, yet relatively underexplored photoelectric and semiconducting materials. Many studies confirmed the applicability of gallium sulfides and selenides in photovoltaics and as electrode materials. In present work, a simple and convenient mechanochemical method has been developed for preparation of aluminum and gallium sulfide and selenide from elemental powders. The products have been characterized by X-ray powder diffraction (XRPD) and transmission electron microscopy (TEM), including energy-dispersive X-ray spectroscopy (EDX). The following products have been obtained: Al2S3, Al2Se3, Ga2S3, and Ga2Se3, with crystallite sizes in the range 8–12 nm.

NiCu magnetic nanoparticles: review of synthesis methods, surface functionalization approaches, and biomedical applications

Abstract Magnetic nanoparticles (MNPs) have attracted extensive interest in recent years because of their unique magnetic, electronic, catalytical, optical, and chemical properties. Lately, research on bimetallic MNPs based on nickel and copper (NiCu MNPs) gained momentum owing to their desired properties for use in biomedicine, such as their chemical stability, biocompatibility, and highly tunable magnetic properties by means of synthesis parameter tuning. The general interest of using NiCu MNPs in biomedical applications is still low, although it is steadily increasing as can be deduced from the number of related publications in the last years. When exposed to an alternating magnetic field (AMF), superparamagnetic particles (such as NiCu MNPs) generate heat by relaxation losses. Consequently, magnetic hyperthermia in cancer treatment seems to be their most promising application in medicine, although others are emerging as well, such as their use to guide potent drugs to the targeted site or to prolong their localization at a desired site in the body. This review is the first, to the best of our knowledge, that covers the available knowledge related to the preparation of NiCu MNPs using different methods, their resulting properties, and the already developed functionalization methods and that discusses everything mentioned in relation to their possible applicability in biomedicine.

Surface engineering of TiO 2 -MWCNT nanocomposites towards tuning of functionalities and minimizing toxicity

Multiwall carbon nanotubes were coupled with titanium dioxide (in different mole ratios of titanium and carbon) at the nano-scale, using a simple sonochemical and calcination process. The titanium dioxide-multiwall carbon nanotubes nanocomposites were for the first time surface modified with an innovative biotechnology-based reaction by using laccase to activate and covalently graft gallic acid dimers/oligomers/polymers on the nanocomposite surface in order to impart new functionalities and to minimize the nanocomposites’ toxicity. Structure of the titanium dioxide-multiwall carbon nanotubes, before and after surface modification, was investigated with X-ray powder diffraction, infrared, and UV-visible diffuse reflectance spectroscopy analysis, and scanning electron microscopy. The results indicated preferential formation of anatase titanium dioxide on one hand and covalent grafting of gallic acid dimers/oligomers/polymers functionalities on the nanocomposite surface, on the other. After modification, the antioxidant activity was analyzed using 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and photocatalytic activity toward the liquid-phase degradation of methylene blue in aqueous solution under both UV and visible light irradiation. Up to 98% antioxidant activity of the surface modified nanocomposites was established after 24 h of incubation, whereas non-modified nanocomposite induced the formation of the ABTS•+ radicals. In addition, 1.3-2.8-fold reduction in photocatalytic activity was achieved, depending on the irradiation. Accordingly, the gallic acid dimers/oligomers/polymers modified titanium dioxide-multiwall carbon nanotubes appear to simultaneously exhibit photocatalytic activity with an ability to scavenge free radicals, and can thus be considered as engineered nanoparticles with low toxicity.Graphical Abstract