72 research outputs found
Radiometric Analysis of Silver Iodide Sols
With the ultimate goal to investigate (a) the formation of the
solid phase by precipitation from electrolytic solutions, and (b)
processes characteristic of the interaction between the solid phase
and the electrolytic solution, the well-known radiometric methods
of analyses have been applied, as well as new radiometric methods
for the analysis of colloidal system developed. The methods applied
are extremely sensitive, selective, and accurate. The new methods
have been checked up by comparison of the obtained results with
the standard classical methods, such as X-ray diffraction, turbidimetry,
conductometry, differential thermic analysis, and also by
published data
Photocatalytic fabrics based on reduced graphene oxide and TiO2 coatings
Supplementary data associated with this article can be found, in the online version, at: http://dx.doi.org/10.1016/j.mseb.2015.04.013The purpose of this work is to obtain photocatalytic fabrics based on reduced graphene oxide (RGO) and TiO2 coatings on polyester fabrics. The influence of the applied number of RGO coatings on properties such as light absorption, conductivity, electroactivity and photocatalytic properties of the fabrics was established. An improvement of these properties with the number of RGO coatings applied was obtained. FESEM, EDX, XPS and FTIR-ATR showed the incorporation of the TiO2 nanoparticles on the fabrics. FTIR-ATR showed the formation of a bidentate carboxylic ligand with titanium atoms. The photocatalytic properties of the fabrics were tested with Rhodamine B dye solutions. Photocatalytic efficiency increased with the number of RGO coatings, due to the increased light absorption, and better electrical properties. The charge transfer resistance (Rct) and its time constant (τ) decreased, indicating a better electron transfer which helps to increase the lifetime of the pair electron/hole.Authors
wish
to
thank
to
the
Spanish
Ministerio
de
Ciencia
e
Innovación
(contract
CTM2011-23583)
for
the
financial
sup
port.
J.
Molina
is
grateful
to
the
Conselleria
d’Educació,
Formació
i
Ocupació
(Generalitat
Valenciana)
for
the
Programa
VALi+D
Postdoctoral
Fellowship.
Electron
Microscopy
Service
of
the
UPV
(Universitat
Politècnica
de
València)
is
gratefully
acknowledged
for
help
with
FESEM
and
EDX
characterization.
Timothy
Vickers
is
gratefully
acknowledged
for
help
with
English
revision.info:eu-repo/semantics/publishedVersio
Synthesis and physicochemical characterization of titanium oxide and sulfated titanium oxide obtained by thermal hydrolysis of titanium tetrachloride
Stimulus responsive graphene scaffolds for tissue engineering
Tissue engineering (TE) is an emerging area that aims to repair damaged tissues and organs by combining different scaffold materials with living cells. Recently, scientists started to engineer a new generation of nanocomposite scaffolds able to mimic biochemical and biophysical mechanisms to modulate the cellular responses promoting the restoration of tissue structure or function. Due to its unique electrical, topographical and chemical properties, graphene is a material that holds a great potential for TE, being already considered as one of the best candidates for accelerating and guiding stem cell differentiations. Although this is a promising field there are still some challenges to overcome, such as the efficient control of the differentiation of the stem cells, especially in graphene-based microenvironments. Hence, this chapter will review the existing research related to the ability of graphene and its derivatives (graphene oxide and reduced graphene oxide) to induce stem cell differentiation into diverse lineages when under the influence of electrical, mechanical, optical and topographic stimulations
Hydrogen Peroxide Production on a Carbon Nitride–Boron Nitride‐Reduced Graphene Oxide Hybrid Photocatalyst under Visible Light
Safe decontamination of cytostatics from the nitrogen mustards family. Part one: cyclophosphamide and ifosfamide
Irena R Štenglová Netíková,1 Luboš Petruželka,2,3 Martin Štastný,1,2 Václav Štengl1 1Department of Oncology, 1st Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic; 2Department of Material Chemistry, Institute of Inorganic Chemistry ASCR v.v.i., Rež, Czech Republic; 3Faculty of Environment, J.E. Purkyne University in Ústí nad Labem, Ústí nad labem, Czech Republic Introduction: Macrocrystalline oxides of alkaline earth metals (Mg and Ca) or light metals (Al and Ti) can respond to standard warfare agents such as sulfur mustard, soman, or agent VX. In this paper, we compared the decontamination ability of sodium hydroxide (NaOH) and sodium hypochlorite (NaClO) for nitrogen mustards (cyclophosphamide [CP] and ifosfamide [IFOS]) with a new procedure using a destructive sorbent based on nanocrystalline and nanodispersive titanium dioxide (TiO2) as a new efficient and cheap material for complete decontamination of surfaces.Methods: Titanium (IV) dioxide nanoparticles were prepared by the homogeneous hydrolysis of titanium(IV) oxysulfate (TiOSO4) with urea. The as-prepared TiO2 nanoparticles were used for the fast and safe decontamination of cytostatics from the nitrogen mustard family (CP and IFOS) in water. The adsorption–degradation process of cytostatics in the presence of TiO2 was compared with decontamination agents (0.01 M solution of sodium hydroxide and 5% solution of sodium hypochlorite). The mechanism of the decontamination process and the degradation efficiency were determined by high-performance liquid chromatography with mass spectrometry.Results: It was demonstrated that a 0.01 M solution of sodium hydroxide (NaOH) decomposes CP to 3-((amino(bis(2-chloroethyl)amino)phosphoryl)oxy)propanoic acid and sodium hypochlorite formed two reaction products, namely, IFOS and 4-hydroxy-cyclophosphamide. IFOS is cytotoxic, and 4-hydroxy-cyclophosphamide is a known metabolite of CP after its partial metabolism by CYP/CYP450. IFOS degrades in the pres¬ence of NaOH to toxic IFOS mustard. Titanium(IV) dioxide nanoparticles adsorbed on its surface CP after 5 minutes and on IFOS after 10 minutes. The adsorption–degradation process of CP in water and in the presence of TiO2 led to 4-hydroxy-cyclophosphamide and IFOS, respectively, which decayed to oxidation product 4-hydroxy-ifosfamide.Conclusion: Nanodispersive TiO2 is an effective degradation agent for decontamination of surfaces from cytostatics in medical facilities. Keywords: cyclophosphamide, ifosfamide, ifosfamide mustard, titanium(IV) dioxide, degradation, decontamination agent
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