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Women have an intense pain in the labor. Amount of pain varies greatly and it depends on the emotional, mental, physical status of women and environmental factors. The pain is caused by various physiological factors and triggers a cascade of biochemical reactions in the woman’s body. Intense pain brings suffering to women and can do damage to the fetus. Effective and safe anesthesia delivery is extremely important task for modern medicine. The article describes the essence of the most popular methods of pain relief during labor, discussed their positive and negative properties. Search literature for the review of various special medical and general Internet search engines. There are medication and non-medication methods of pain relief in labor. Non-medication method is non-invasive and healthier for a maternity patient and a child but their effectiveness is disputable. Medication methods of pain relief are presented injection of opioid analgesics and non-opioid analgesics, inhalation and neuroaxial anesthesia methods. Every method has advantages and disadvantages. Opioid analgesics reduce the pain for a few hours however cause a large number of undesirable effects such as nauseaand sleepiness of maternity patient, respiratory distress and depression of consciousness of newborn. Study of non-opioid analgesics showed a high analgesic activity but it was not study enough to use for pain relief in labor. Today the most common method is neuroaxial analgesia. It relieves the pain effectively and has no effect on the fetus but it has some disadvantages.The question of the influence of the neuroaxial methods of anesthesia on the duration of the labor is controversial. Promising is the use of inhaled anesthetics in particular xenon. But these methods are not study enough. All currently used labor pain relief methods are not ideal as far as each method has its own characteristics and bad effects. In each particular case the method of labor pain relief must be selected individually, it’s necessary to take into consideration the psychological and physical condition of the woman and obstetric situation.

It has been shown for the first time that the use of hydrogen peroxide allows precipitation of rare earth orthophosphates (La–Tb) from phosphoric acid solutions at temperatures below 100°C. Either anhydrous or hydrated orthophosphates with monazite or rhabdophane structure, respectively, can be obtained depending on rare earth element position in lanthanide series and precipitation conditions (orthophosphoric acid and hydrogen peroxide concentration). Hydrated orthophosphates with rhabdophane structure can be prepared by precipitation with hydrogen peroxide for all studied rare earth elements.

Titanium dioxide nanoparticles, obtained using the sol–gel method and modified with organic solvents, such as acetone, acetonitrile, benzene, diethyl ether, dimethyl sulfoxide, toluene, and chloroform, were used as the filler of polydimethylsiloxane-based electrorheological fluids. The effect of electric field strength on the shear stress and yield stress of electrorheological fluids was investigated, as well as the spectra of their dielectric relaxation in the frequency range from 25 to 106 Hz. Modification of titanium dioxide by polar molecules was found to enhance the electrorheological effect, as compared with unmodified TiO2, in accordance with the widely accepted concept of polar molecule dominated electrorheological effect (PM-ER). The most unexpected result of this study was an increase in the electrorheological effect during the application of nonpolar solvents with zero or near-zero dipole moments as the modifiers. It is suggested that nonpolar solvents, besides providing additional polarization...

Effect of conditions of nanocrystalline cerium dioxide preparation from aqueous solutions on its composition and physicochemical properties and on dielectric characteristics of CeO2 suspensions in polydimethylsiloxane PMS-20 and the magnitude of electrorheological effect for these suspensions has been analyzed. Relationship between physicochemical properties of CeO2 nanopowders and polarization and functional characteristics of electrorheological fluids derived therefrom has been established.

The development of advanced composite biomaterials combining the versatility and biodegradability of polymers and the unique characteristics of metal oxide nanoparticles unveils new horizons in emerging biomedical applications, including tissue regeneration, drug delivery and gene therapy, theranostics and medical imaging. Nanocrystalline cerium(IV) oxide, or nanoceria, stands out from a crowd of other metal oxides as being a truly unique material, showing great potential in biomedicine due to its low systemic toxicity and numerous beneficial effects on living systems. The combination of nanoceria with new generations of biomedical polymers, such as PolyHEMA (poly(2-hydroxyethyl methacrylate)-based hydrogels, electrospun nanofibrous polycaprolactone or natural-based chitosan or cellulose, helps to expand the prospective area of applications by facilitating their bioavailability and averting potential negative effects. This review describes recent advances in biomedical polymeric material practices, highlights up-to-the-minute cerium oxide nanoparticle applications, as well as polymer-nanoceria composites, and aims to address the question: how can nanoceria enhance the biomedical potential of modern polymeric materials?

A new selective method for the synthesis of nanocrystalline manganese dioxide (α-, β-, and γ-MnO2) based on the reaction of potassium permanganate with 2,4,6-triamino-1,3,5-triazine (melamine) under hydrothermal conditions has been proposed. Effect of synthesis conditions on the phase composition of the products has been revealed. A new manganese-containing phase with layered structure has been prepared.

Cerium oxide (CeO2) nanoparticles are regarded as one of the most promising materials for biomedical applications. Due to their antioxidant activity CeO2 nanoparticles are capable of protecting cells from oxidative stress induced by various physical or chemical factors. In this paper we have investigated the protective effect of CeO2 nanoparticles in the model of oxidative stress induced by low-temperature argon plasma, which is characterized by multiply damaging factors, including different types of radiation (ultraviolet and infrared), free radicals and reactive oxygen species. It was shown that citrate-stabilized cerium oxide nanoparticles protect primary embryonic mouse fibroblasts from the action of plasma, maintaining a high level of cell viability.

We studied the effects of nanodispersed ceria on wound healing in vitro and in vivo. It was found that cerium dioxide stimulated wound healing, which manifested in shrinkage of burn wound area (by 1.5 times) and intensification (by 2.4 times) marginal epithelialization.

Fabrication of metal–organic frameworks (MOFs) as films on surfaces is a challenging and actively developed field in the context of potential applications of surface-integrated MOFs (SURMOFs) in sensing, catalysis and molecular electronics. Herein, we report a method for the preparation of composites of graphene oxide (GO) and zinc tetracarboxyphenyl porphyrin SURMOFs, which are potentially useful as synergetic catalysts on planar solid supports. The SURMOF films were assembled via layer-by-layer coordination of zinc porphyrins with ZnAc2 clusters on the ultrathin surface coatings of GO. We found that non-covalent adsorption of zinc acetate on the GO films is essential for anchoring porphyrin molecules in the growth-initiating template layer. UV-vis spectroscopy provided evidence for a stepwise assembly of the deposited SURMOF films. By using a combination of X-ray diffraction, scanning electron microscopy and atomic force microscopy methods, we show that the resulting GO-associated SURMOFs exhibit a leaflet-like planar morphology with out-of-plane periodicity. Because of the influence of the well-defined surface geometry, the molecular organization in thin SURMOFs is different from that of synthetic bulk materials with a similar composition. The results of BET method measurements suggest that the fabricated SURMOF films have exceptionally large surface areas and adsorption capacities. Our results provide a basis for new types of composite SURMOF structures using GO surface coatings as growth-guiding scaffolds for metal–organic coordination networks integrated with various solid supports.

One of the main reasons for limiting the widespread clinical use of mesenchymal stem cells (MSCs) is a low speed of their proliferation in vitro. In this regard, the search for new safe and effective growth stimulants is an urgent task. In this study, we investigated the effect of nanocrystalline cerium oxide doped with gadolinium (Ce1-х Gdх Oy), on the morphofunctional characteristics and proliferative activity of MSCs derived from dental pulp. It was shown that the introduction of Ce1-х Gdх Oy nanoparticles into the culture of dental MSCs provides the activation of proliferation of the cells in a dose-dependent manner. High concentrations of Ce1-х Gdх Oy nanoparticles inhibit the proliferation of the cells; however, this does not lead to further development of apoptosis and cell death. The obtained results indicate that the nanocrystalline cerium oxide can be considered as a basis for the development of highly efficient and low-cost supplements for culturing MSCs.

Since their discovery in the late 19th century, cerium (IV) phosphates have been a very poorly studied class of rare earth compounds. In this paper, a facile method of amorphous cerous phosphate gels preparation is proposed, starting from nanocrystalline ceria and allowing for large-scale synthesis of these compounds. The use of this method provides deeper insight into the chemical composition and structure of cerous phosphate gels, and enables the peculiarities of their crystallization under hydrothermal conditions in H 2 O and H 3 PO 4 aqueous solutions to be traced. Only Ce + 3 compounds crystallize in a neutral medium if they are present in the composition of the cerous phosphate gels. For Ce + 4 compounds to crystallize, a significant amount of orthophosphoric acid should exist in a reaction mixture. These features are likely to be related to the fact that crystalline Ce + 4 orthophosphates can only exist in the form of acid salts.

The processes of structural rearrangement in a model membrane, i.e., an arachic acid monolayer formed on a colloidal solution of cerium dioxide or magnetite, are studied in situ in real time by the methods of X-ray standing waves and 2D diffraction. It is shown that the character of the interaction of nanoparticles with the monolayer is determined by their nature and sizes and depends on the conditions of nanoparticle synthesis. In particular, the structure formation in the monolayer–particle system is greatly affected by the stabilizer (citric acid), which is introduced into the colloidal solution during synthesis.

We have demonstrated the influence of cerium dioxide nanoparticles on the immunogenicity of the influenza vaccine on an example of liquid split inactivated Vaxigrip vaccine. Antibody titers were analyzed using the hemagglutination inhibition (HI) assay. Seroprotection, seroconversion, the geometric mean titers (GMTs) and the factor increase (FI) in the GMTs were calculated. The effect of nano-ceria surface stabilizer on the enhancement of immunogenicity was shown. The vaccine modified by citrate-stabilized nano-ceria, in contrast to a non-modified Vaxigrip vaccine, did not provide an adequate level of seroprotection, and seroconversion after vaccination was 66.7% on days 49–63 for virus strain А(H1N1) and 100% on day 49 for virus strain B/Yamagata. For the low immunogenic influenza B virus, the rise in antibody titers (GMT/IF) was 24.38/3.28 after the first injection and 50.40/6.79 on day 49. For the vaccine modified by non-stabilized nano-ceria, for all virus strains under study, on day 63, upon immunization notable levels of seroprotection, seroconversion and GMT/IF were registered (higher than for the non-modified Vaxigrip vaccine). The successful attempt to modify the influenza vaccine demonstrates the possible ways of increasing the specific activity of vaccines using nano-ceria.

A water- and alcohol-soluble cerium oxide-curcumin conjugate was obtained by co-evaporation with poly(N-vinylpyrrolidone) (PVP). A nanocomposite consisting of hybrid organic-inorganic particles was stable in a wide range of pH values. Its properties were evaluated using nine cell lines: normal (MDBK, ST, Vero) and malignant (L929, T98G, HEp-2, A549, RIN-m5F, Hep G2). PVP-stabilised nanoceria was shown to inhibit autoxidation of curcumin, to enhance curcumin photostability, to promote bioaccumulation and to affect curcumin cytotoxicity and photocytotoxicity, depending on cell type, being more toxic to cancer cells in a selective manner. Under the conditions of UVA/UVC or H2O2-induced oxidative stress, the nanoceria-PVP-curcumin (NPC) conjugate was found to possess a selective cytotoxicity: it caused drastic inhibition of metabolic activity or a decrease in the total number of tumour cells, while in non-transformed cultures under the same conditions, the nanoceria-PVP-curcumin conjugate protected cells from these damaging factors. The NPC-conjugate, unlike curcumin itself, demonstrated a photosensitising effect in tumour cell cultures, while protecting non-transformed cultures from the damaging effects of UV radiation or oxidative stress. Based on the results obtained, we strongly believe that this novel hybrid material has enhanced characteristics compared to other curcumin formulations, and can be considered as a potent drug for biomedical applications, including cancer therapy.

Tungsten oxide sol, containing highly crystalline nanoparticles of orthorhombic WO3 and having good sedimentation stability, was synthesized using a facile, ultrasonic-assisted technique. An additional steric stabilizer, dextran, was proposed to enhance the stability of WO3 nanoparticles in biological media and to reduce their in vivo toxicity. The cytotoxicity of dextran-stabilized and nonstabilized WO3 sols was studied in vitro using dental pulp stem (DPS) cell lines and breast cancer (MCF-7) cell lines. Both tungsten oxide sols demonstrated low cytotoxicity and low genotoxicity for both stem cells and malignant cells and only slightly reduced their metabolic activity in the concentration range studied (from 0.2 to 200 μg/ml). The data obtained support possible theranostic applications of tungsten oxide colloidal solutions.

A series of polyimide/CeO2 nanocomposite films were fabricated based on three polymer matrices. The prepared films were characterized by scanning electron microscopy (SEM), thermomechanical analysis (TMA), and also simultaneous thermogravimetric (TGA) and differential thermal analysis (DTA), the latter two having been performed both in air and in inert (argon) atmosphere. Ceria nanoparticles were shown to be well dispersed in the PI matrix. TGA analysis revealed that the effect of ceria nanoparticles on thermal and thermo-oxidative stability of the nanocomposites depends strongly on the chemical nature of the polyimide. Thus, thermal properties of a nanocomposite based on the polyimide containing SO2-groups in the elementary unit of the polymer chain were found to be substantially enhanced upon incorporation of the nanoparticles in the matrix. In contrast, the polyimide with no sulfonic groups had a decreased thermo-oxidative stability being doped with CeO2 nanoparticles. The possible mechanism of polymer matrix – ceria nanoparticles interactions determining the nanocomposite thermal stability change is discussed.

Photochromic tungsten oxide (WO3) nanoparticles stabilized by polyvinylpyrrolidone (PVP) were synthesized to evaluate their potential for biomedical applications. PVP-stabilized tungsten oxide nanoparticles demonstrated a highly selective cytotoxic effect on normal and cancer cells in vitro. WO3 nanoparticles were found to induce substantial cell death in osteosarcoma cells (MNNG/HOS cell line) with a half-maximal inhibitory concentration (IC50) of 5 mg/mL, while producing no, or only minor, toxicity in healthy human mesenchymal stem cells (hMSc). WO3 nanoparticles induced intracellular oxidative stress, which led to apoptosis type cell death. The selective anti-cancer effects of WO3 nanoparticles are due to the pH sensitivity of tungsten oxide and its capability of reactive oxygen species (ROS) generation, which is expressed in the modulation of genes involved in reactive oxygen species metabolism, mitochondrial dysfunction, and apoptosis.

A comprehensive study of the radioprotective action mechanisms of ultra-small, citrate-stabilized, nanocrystalline cerium oxide (CeO2 nanoparticles, nanoceria) in vitro and in vivo was carried out. CeO2 nanoparticles were shown to significantly reduce the levels of hydrogen peroxide and hydroxyl radicals in aqueous solutions under X-ray irradiation. Pretreatment of primary mouse fibroblasts by CeO2 nanoparticles in a wide range of concentrations (10−5 to 10−9 M) protects cells from radiation-induced oxidative stress, maintaining a high level of dehydrogenase activity. A protective effect of CeO2 nanoparticles is also manifested in a decrease in the number of apoptotic cells and the level of reactive oxygen species (ROS) in a culture of primary mouse fibroblasts in vitro, as well as in a significant reduction (up to 50% of the control) of cytogenetic damage of mouse bone marrow in vivo. The intraperitoneal administration of CeO2 nanoparticles (200 nM) increased the rate of survival of mice exposed to X-ray radiation at a lethal dose, both in the prophylactic and the therapeutic schemes of administration, testifying the protection at the molecular, cellular and organism levels. The physical, chemical and biological origins of the protective action of CeO2 nanoparticles upon exposure of living systems to ionizing radiation in vitro and in vivo are discussed.

We report on the preparation of novel electrorheological (ER) fluids based on a nanocrystalline ceria suspension in polydimethylsiloxane (PMS-20 silicone oil). Dielectric relaxation spectra of ER fluids were analyzed in the frequency range from 25 Hz to 106 Hz; the values of dielectric permittivity, dielectric loss tangents and tensile strengths of the prepared ER fluids in applied external electric fields up to 5 kV mm−1 were measured. Relaxation characteristics of the dielectric spectra were interpreted in terms of the Cole–Davidson model. The results obtained indicate that the ceria-based materials exhibit excellent ER performance, which depends strongly on the CeO2 concentration in the fluids. High tensile stress values (more than 20 kPa) were registered for ceria-based ER fluids in 5 kV mm−1 static electric fields.

A novel, facile, and versatile microwave-assisted method of high-yield synthesis of layered rare earth hydroxo compounds (LRHs) is proposed. Layered yttrium hydroxonitrates synthesized by the microwave-assisted technique crystallize in the form of thin hexagonal plates aggregated into spheroidal particles. Depending on the conditions of microwave-assisted hydrothermal synthesis, the formation of several phases differing in interplanar spacing along the [00l] direction is possible. The materials obtained are shown to possess good anion-exchange properties. This work provides a route to large-scale synthesis of LRH-based advanced materials.

We synthesised a new type of photochromic tungsten oxide nanoparticles, analysed their photocatalytic activity and carried out a thorough analysis of their effect on prokaryotic and eukaryotic organisms. Ultrasmall hydrated tungsten oxide nanoparticles were prepared by means of hydrothermal treatment of tungstic acid in the presence of polyvinylpyrrolidone as a template, stabiliser and growth regulator. Tungstic acid was synthesised through an ion-exchange method using sodium tungstate solution and a strongly acidic cation exchange resin. Upon illumination, photochromic nanoparticles of WO 3 were shown to increase greatly their toxicity against both bacterial (both gram-positive and gram-negative – P . aeruginosa , E . coli and S . aureus ) and mammalian cells (primary mouse embryonic fibroblasts); under the same conditions, fungi ( C . albicans ) were less sensitive to the action of tungsten oxide nanoparticles. UV irradiation of primary mouse fibroblasts in the presence of WO 3 nanoparticles demonstrated a time- and dose-dependent toxic effect, the latter leading to a significant decrease in dehydrogenase activity and an increase in the number of dead cells. WO 3 nanoparticles were photocatalytically active under both UV light and even diffused daylight filtered through a window glass, leading to indigo carmine organic dye discolouration. The obtained experimental data not only show good prospects for biomedical applications of tungsten trioxide, but also demonstrate the need for clear control of biosafety when it is used in various household materials and appliances.

Leveraging the technology's unique ability to selectively place multiple materials throughout a part volume, the authors demonstrate a new approach for the fabrication of a new physical security feature for additively manufactured parts. Specifically, the authors create photopolymer suspensions featuring quantum dots – a nanoparticle that absorbs ultraviolet light and emits light in the visible spectrum – that are then embedded into objects created by PolyJet material jetting. While the quantum dots appear ordered at the macroscale, their stochastic arrangement at the microscale (via the inkjetted droplet) provide the randomness necessary to serve as the key element of a Physical Unclonable Function, essentially transforming the 3D printed object itself as an anti-counterfeiting system. In this work the authors explore the effects of quantum dot loading on optical signatures of the nanoparticles in the photopolymer matrix. Quantum dot loadings as low as 5 × 10 −3 wt.% can be detected inside the object with a fluorescent microscope, while this same concentration is invisible to the naked eye. By adjusting the magnification of the fluorescent microscope, we demonstrate the feasibility of a new paradigm for three-dimensional security patterns.

We present experimental evidence of complete fractal properties inheritance in the course of first-order phase transition from amorphous to monoclinic or tetragonal zirconia under hydrothermal conditions. This phenomenon takes place either under rapid microwave heating or conventional heating regardless of starting fractal dimension value. Exactly the same effect is observed for hafnia. The similarity of the local structures of amorphous and crystalline zirconia as well as relatively soft crystallization conditions could be the definite reasons for the conservation of the mesostructure in the course of phase transition.

A method for the synthesis of stable aqueous sols of nanocrystalline solid solutions Ce1−xGdxO2-δ (x = 0.10, 0.15, 0.20) and Y0.9Eu0.1VO4 and nanocomposites Ce1 − xGdxO2-δ/Y0.9Eu0.1VO4 stabilized by biocompatible low-molecular-weight polyacrylic acid was proposed. Polyacrylic acid was shown to be a promising matrix for the preparation of polyfunctional composite materials.

Purpose – This paper aims to provide a review of available published literature in which nanostructures are incorporated into AM printing media as an attempt to improve the properties of the final printed part. The purpose of this article is to summarize the research done to date, to highlight successes in the field, and to identify opportunities that the union of AM and nanotechnology could bring to science and technology.Design/methodology/approach – Research in which metal, ceramic, and carbon nanomaterials have been incorporated into AM technologies such as stereolithography, laser sintering, fused filament fabrication, and three‐dimensional printing is presented. The results of the addition of nanomaterials into these AM processes are reviewed.Findings – The addition of nanostructured materials into the printing media for additive manufacturing affects significantly the properties of the final parts. Challenges in the application of nanomaterials to additive manufacturing are nevertheless numerous.Re...

We have developed a process for the synthesis of nanostructured sodium calcium tripolyphosphate with the use of organic templates, including amino acids (glycine and L-aspartic, L-glutamic, and ɛ-aminocaproic acids), polysaccharides (sodium and calcium alginates and maltodextrin), and Trilon B. The synthesized sodium calcium tripolyphosphate nanopowders have been characterized by scanning electron microscopy, X-ray diffraction, and IR spectroscopy. The particle size of the nanopowders is shown to be determined by the properties of the template and ranges from ∼20 nm to ∼20 μm. We have studied the biological activity of peroxo derivatives of sodium calcium tripolyphosphate for Escherichia coli.

We report a detailed study of structural and chemical transformations of amorphous hydrous zirconia into sulfated zirconia-based superacid catalysts. Precipitation pH is shown to be the key factor governing structure, composition and properties of amorphous sulfated zirconia gels and nanocrystalline sulfated zirconia. Increase in precipitation pH leads to substantial increase of surface fractal dimension (up to � 2.7) of amorphous sulfated zirconia gels, and consequently to increase in specific surface area (up to � 80 m 2 /g) and simultaneously to decrease in sulfate content and total acidity of

67 Accepted November 20, 2012. Address correspondence to Thomas A. Campbell, Research Associate Professor, Associate Director for Outreach, Institute for Critical Technology and Applied Science (ICTAS), Virginia Tech, 325 Stanger Street, MC 0193, Blacksburg, VA 24061, USA. Tel: (540) 231-8359; Fax: (540) 231-0970; E-mail: tomca@vt.edu Additive MAnufActuring As A disruptive technology: iMplicAtions of three-diMensionAl printing

A novel method is proposed for preparing biocompatible aqueous CeO2 sols, which allows purposefully adjusting particle sizes and biochemical properties of nanocrystalline ceria (NC). The usefulness of this method for preparing aqueous sols of Ce1 − x Gd x O2 − x/2 solid solutions is demonstrated. Nanocrystalline ceria has been demonstrated to have a size-dependent activity in hydroxyl radical inactivation and in protecting mouse fibroblast cells (L929) from oxidative stress induced by hydrogen peroxide administration.

Nanocrystalline ceria possesses a unique complex of physical and chemical properties making it highly bioactive material. In this review, modern data on the action of nanocrystalline ceria on cells, micro- and macroorganisms are analyzed. Special attention is paid to the analysis of the factors affecting protective properties of CeO2 with respect to the living systems.

Nanocrystalline (

Here we describe the electrochemical oxidation of an assembly of gold nanoparticles (Au NPs) attached to glass/indium-tin-oxide (ITO) electrodes as a function of particle size. We synthesized Au NP arrays with NP diameters ranging from 8 to 250 nm by electrodeposition of Au from HAuCl(4) in H(2)SO(4) at potentials of -0.2 to 0.8 V versus Ag/AgCl using chronocoulometry to keep the amount of Au deposited constant. The average Au NP size increased with increasing deposition potential. The chemical reduction of HAuCl(4) by NaBH(4) in trisodium citrate solution led to 4 nm average diameter Au NPs, which we chemisorbed to the glass/ITO electrode. Linear sweep voltammograms (LSVs) obtained on the glass/ITO/Au NP (4 to 250 nm) electrodes (with a constant coverage of Au in terms of Au atoms per cm(2)) from 0.5 to 1.1 V in 0.01 M potassium bromide plus 0.1 M HClO(4) showed a positive shift in oxidation potential from 734 +/- 1 mV to 913 +/- 19 mV with increasing Au NP diameter. The shift agrees qualitatively with that predicted by a shift in the redox potential based on a difference in free energy associated with a change in surface energy as a function of particle size. On the basis of the charge during Au deposition versus the charge during oxidation, the oxidation process produces a mixture of Au(III)Br(4)(-) (25%) and Au(I)Br(2)(-) (75%). A glass/ITO electrode coated with a mixture of 4 and 250 nm Au NPs revealed 2 oxidation peaks, consistent with the two Au NP size populations present on the surface.

Anodic dissolution of nickel and nickel silicide in a 0.5 M H2SO4 solution in the presence of halide and thiocyanate ions is studied with the use of cyclic voltammetry. Main regularities of the effect of anions on the mechanism and kinetics of the anodic dissolution of the metal and its silicide are found. The results obtained reveal different nature of the passivation processes and different compositions of the oxide films formed on Ni and NiSi.

Nanocrystalline fluorinated titania has been prepared using microwave-assisted hydrothermal crystallization of hydrous titania in a NH 4 F aqueous solution. Thus, obtained TiO 2 has exhibited excellent photocatalytic activity in the reaction of crystal violet dye photodegradation – up to twofold higher than the photocatalytic activity of the commercial Evonik Aeroxide ® TiO 2 P25 photocatalyst. Hydrothermal treatment temperature and the concentration of ammonium fluoride in the reaction mixture have been shown to be key parameters, providing the most significant effect on the microstructure and photocatalytic activity of titania.

We report a facile method for fabrication of highly concentrated electrostatically stabilized colloidal solutions containing ultra-small cerium (IV) oxide crystallites having a narrow size distribution (3–5 nm according to x-ray diffraction, and 10–30 nm according to dynamic light scattering). The proposed method comprises hydrothermal treatment of ceric ammonium nitrate aqueous solutions having concentrations over 0.2 M, in the temperature range of 80–100 °C, and the formation of nanoceria sediments, which can be easily peptized in both protic (water, isopropanol) and aprotic (DMF) media, forming stable and transparent CeO2 sols.

A method of panthenol-stabilized cerium dioxide nanoparticles synthesis was developed and their effect on the survival rate of human epidermoid cancer cells HEp-2 and diploid epithelial swine testicular cell line (ST-cells) under oxidative stress conditions induced by hydrogen peroxide introduction and UV irradiation was studied. The results obtained indicate that the use of panthenol as a stabilizer supposedly provides a substantial increase in the efficiency of protection. The degree of protection is determined by panthenol-to-ceria molar ratio. The combination of panthenol and nano-ceria protects biological objects under study from reactive oxygen species (ROS) and UV-irradiation more effectively than individual panthenol or ceria. The protective action of panthenol-stabilized cerium dioxide nanoparticles depends strongly on their composition and the means of their application.

Non-spherical CdSe quantum dots were synthesized through high temperature reduction of cadmium and selenium in the presence of TOP (tri-n-octylphosphine) and TOPO (tri-n-octylphosphine oxide). The high affinity of phosphine oxide to the surface of CdSe nanocrystals typically leads to the formation of spherical particles with diameters between 1.5 and 10 nm. However, with lower temperatures and longer reaction times relative to conventional synthesis techniques, the formation of non-spherical nanocrystals dominated. The three reaction temperatures that were studied were 230, 250, and 270 °C. Results verify the need to quench CdSe nanocrystals immediately following the injection of selenium dissolved in TOP (TOPSe) if spherical particles are the desired shape. Nanocrystal shape evolves from sphere to rectangle to hexagon or triangle as the reaction time is extended regardless of temperature. The highest yield of rectangular particles (~89 %) was achieved while maintaining a temperature of 250 °C for 20 min.

Here we describe the galvanic exchange of surface-grown Ag nanorods (NRs) and nanowires (NWs) with PdCl(4)(2-) as a function of the PdCl(4)(2-) concentration. The morphology of the resulting AgPd alloy nanostructures depends on the galvanic exchange rate, which increases with increasing PdCl(4)(2-) concentration over a specific concentration range. When the concentration of PdCl(4)(2-) exceeds 7.5 × 10(-5) M (or ratio of moles of PdCl(4)(2-) in solution to moles of Ag on the surface542), rapid galvanic exchange results in Pd deposition over the entire Ag nanostructure in the early stages of exchange. When the concentration of PdCl(4)(2-) is in the range of 1.0 × 10(-5) to 5.0 × 10(-5) M (moles of PdCl(4)(2-) in solution to moles of Ag on the surface = 13-54), Pd deposition occurs preferentially at high energy twin plane defects in the form of well-spaced nanoparticles during the early stages of exchange. In later stages, the Pd deposits grow and coalescence into a rough shell, and etching of the Ag leads to a presumably hollow nanostructure. Composition analysis by linear sweep voltammetry as a function of time shows that the galvanic exchange rate is much slower than the diffusion-limited rate and, when correlated with UV-vis spectroscopy, shows that less than 10% Pd in the nanostructure completely dampens the Ag-localized surface plasmon band.

Summary Additive manufacturing ( aka , 3D printing) holds strong potential for the formation of a new class of multifunctional nanocomposites. With the ability to print complex 3D objects layer by layer, additive manufacturing with nanomaterials could be leveraged in new ways toward greater control over material properties across part dimensions. Multifunctionality through embedding of nanomaterials can further extend capabilities of nanocomposites to properties such as gradients in thermal and electrical conductivity, photonic emissions tunable for wavelength, and increased strength and reduced weight. Here we discuss the promises offered by nanomaterials-based additive manufacturing as a new paradigm for nanocomposite functionality.

We report structural changes in amorphous hydrated zirconia caused by high intensity ultrasonic treatment studied by means of small-angle neutron scattering (SANS) and X-ray diffraction (XRD). It was established that sonication affects the mesostructure of ZrO2×xH2O gels (i.e. decreases their homogeneity, increases surface fractal dimension and the size of monomer particles). Ultrasound induced structural changes in hydrated zirconia governs its thermal behaviour, namely decreases the rate of tetragonal to monoclinic zirconia phase transition.