Changing the morphology of one-dimensional titanate nanostructures affects its tissue distribution and toxicity

2020 ◽  
Vol 36 (4) ◽  
pp. 272-286
Author(s):  
Nahla Kamal ◽  
AH Zaki ◽  
Ahmed AG El-Shahawy ◽  
Ossama M Sayed ◽  
SI El-Dek

The present research investigated the impact of the morphology change of titanate (TiO2) nanostructures on its tissue distribution and toxicity. The TiO2 nanotubes, rods, and ribbons were synthesized by the hydrothermal technique, and the morphology was adjusted by alteration of the hydrothermal duration time. The characterization techniques were X-ray diffraction, high-resolution transmission electron microscopy, dynamic light scattering, and the Brunauer–Emmett–Teller method for measuring the surface area. The intravenously administrated dose (5 mg/kg) was injected as a single dose for 1 day and consecutively for 42 days. The quantitative analysis of accumulated TiO2 nanostructures in the liver, spleen, and the heart was performed using an inductively coupled plasma emission spectrometer, and the organs’ toxicity was estimated by histopathological analysis. The prepared nanostructures exhibited differences in morphology, crystallinity, size distribution, surface area, zeta potential, and aspect ratio. The results revealed a tissue distribution difference between the liver, spleen, and heart of these nanostructures, the distribution order was the liver, spleen, and the heart for all TiO2 nanostructures. The toxicity was induced with different degrees. The nanotubes were the most harmful among the three formats. In summary, changes in the morphology of the TiO2 nanostructures change its distribution and toxicity.

2006 ◽  
Vol 71 (11) ◽  
pp. 1153-1160 ◽  
Author(s):  
Chang Hu-Yuan ◽  
Feng Li ◽  
Li. Hua ◽  
Bin Zhang

As prepared carbon nanotubes were pretreated with nitric acid (CNTs-HNO3) or ammonia (CNTs-NH3). Fourier transform infrared spectroscopy (FTIR) measurements showed that the surface of the nanotubes was functionalized with carboxylic and hydroxyl functional groups after the acid treatment and that basic groups containing nitrogen, such as N-H and C-N, were introduced to the surface of the nanotubes after the ammonia treatment. X-Ray diffraction analysis implied that the nickel residue in the CNTs was effectively removed by acid treatment. However, the nickel residue was only partially eliminated by ammonia pretreatment. NiB amorphous catalysts supported on CNTs-HNO3 and CNTs-NH3 were prepared by the impregnation-chemical reduction method and characterized by transmission electron microscopy (TEM), as well as inductively coupled plasma (ICP) spectroscopy and studied in the selective hydrogenation of acetylene. TEM measurements showed that a high density NiB particles of about 9 nm were homogeneously dispersed on the CNTs-NH3. However, NiB particles (13-23 nm)with amean size of 16 nm were scattered on the CNTs-HNO3.As a result, the activity and selectivity of NiB/CNTs-NH3 were higher than those of NiB/CNTs-HNO3 in the selective hydrogenation of acetylene.


2008 ◽  
Vol 8 (12) ◽  
pp. 6376-6380 ◽  
Author(s):  
Meng-Yen Tsai ◽  
Chung-Yi Yu ◽  
Tsong-Pyng Perng

A new method to prepare amorphous Ca5Ge2O9 nanowires is demonstrated in the present study. Germanium nanoparticles with the size ranging from 10 to 50 nm were first prepared by a vapor condensation technique. Upon immersing the nanoparticles in Ca(OH)2 aqueous solution, hydrated Ca5Ge2O9 nanowires were formed rapidly. The phase was determined by X-ray diffraction, and the stoichiometry of Ca:Ge was further confirmed by energy-dispersive X-ray spectroscopic and inductively coupled plasma-mass spectrometric analyses. The diameter of nanowires varied from several tens to more than 100 nm, and the length increased with aging time up to the completion of reaction. After dehydrating at 400 °C, the nanowires became amorphous, and the stoichiometry of Ca:Ge remained unchanged. A blue-violet luminescence was detected from these amorphous nanowires. The emission band distributed from 300 to 550 nm, with the main peak locating at 380 nm. Ge-associated luminescence centers are proposed to be responsible for this emission. The formation of amorphous Ca5Ge2O9 nanowires may provide a new thinking to prepare other kinds of amorphous one-dimensional nanomaterials.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Tahani Al-Garni ◽  
Nada Al-Jallal ◽  
Ahmed Aouissi

Carbon nanotubes (CNTs) were functionalized and were then used as supports of Fe1.5PMo12O40 (FePMo) Keggin heteropolyanions catalysts. The characterization of the resulting catalysts was investigated by inductively coupled plasma spectrometry (ICP), Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) light spectroscopy, and transmission electron microscopy (TEM). FTIR and XRD results confirmed that FePMo was bounded on CNTs successfully and the Keggin structure was preserved. Characterization by TEM showed that solids with high FePMo content exhibited aggregation of FePMo in large particles. The as-prepared catalysts were tested in the synthesis of propylene carbonate (PC) from CO2 and propylene oxide (PO) in a solvent-free reaction and under mild conditions. Effects of various parameters, such as reaction temperature, reaction time, FePMo content on the support, and catalyst loading on the reaction, were investigated. It has been found that CNTs supported FePMo achieved 57.7% PO conversion and 99.0% PC selectivity, whereas unsupported FePMo led only to 8.5% conversion and 48.6% selectivity. The remarkable enhancement of the catalytic activity over the supported catalyst can be attributed mainly to the better dispersion and reactivity of the FePMo catalyst in the supported material.


2021 ◽  
Vol 340 ◽  
pp. 01026
Author(s):  
Sapar Konuspayev ◽  
Minavar Shaimardan ◽  
Nurlan Annas ◽  
T.S. Abildin ◽  
Y.Y. Suleimenov

Rhodium and rhodium-gold catalysts supported on amorphous aluminosilicates (ASA), titanium dioxide (rutile, TiO2) was prepared in two different ways: absorption and colloidal method. The catalysts were characterized by an inductively coupled plasma optical emission spectrometer (ICP-OES), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The activity and selectivity of the prepared catalysts were tested by the hydrogenation of benzene and toluene. Hydrogenation was conducted at a pressure of 4 MPa and a temperature 80 °C. The bimetallic Rh-Au/ASA catalyst prepared by the absorption method showed higher activity and selectivity in benzene hydrogenation reaction, the same catalyst prepared by the colloidal method demonstrated lower selectivity.


Author(s):  
Ilhem Rekkab-Hammoumraoui ◽  
Abderrahim Choukchou-Braham

A series of metal-loaded (Ru, Pt, Co) alumina catalysts were evaluated for the catalytic oxidation of cyclohexane using tertbutylhydroperoxide (TBHP) as oxidant and acetonitrile or acetic acid as solvent. These materials were prepared by the impregnation method and then characterized by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), H2 chemisorption, Fourier Transformed Infrared Spectroscopy (FTIR), High-Resolution Transmission Electron Microscopy (HRTEM), and X-ray Diffraction (XRD). All the prepared materials acted as efficient catalysts. Among them, Ru/Al2O3 was found to have the best catalytic activity with enhanced cyclohexane conversion of 36 %, selectivity to cyclohexanol and cyclohexanone of 96 % (57.6 mmol), and cyclohexane turnover frequency (TOF) of 288 h-1. Copyright © 2018 BCREC Group. All rights reservedReceived: 26th May 2017; Revised: 17th July 2017; Accepted: 18th July 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018How to Cite: Rekkab-Hammoumraoui, I., Choukchou-Braham, A. (2018). Catalytic Properties of Alumina-Supported Ruthenium, Platinum, and Cobalt Nanoparticles towards the Oxidation of Cyclohexane to Cyclohexanol and Cyclohexanone. Bulletin of Chemical Reaction Engineering & Catalysis, 13(1): 24-36 (doi:10.9767/bcrec.13.1.1226.24-35) 


2012 ◽  
Vol 557-559 ◽  
pp. 1467-1470
Author(s):  
Sheng Xian Xu ◽  
Feng Yi Li

The nanosized RuB amorphous alloys with three different ruthenium contents supported on Al2O3 were prepared by means of impregnation, following the chemical reduction with KBH4 solution. The gas-phase benzene hydrogenation was used as a probe reaction to evaluate the catalytic activity of the prepared catalysts. The catalysts were characterized by BET, inductively coupled plasma (ICP), X-ray diffraction (XRD), and transmission electron micrograph (TEM). The experiment results show that the catalytic activity of the three amorphous alloy catalysts goes up first with the increasing of temperature and has a maximum at 443K; when the Ru loading amount is 0.24 %(wt.%) of the catalyst, which is very few, the conversion of benzene on RuB/Al2O3 amorphous alloy catalyst can reach to 99.50% at 443K.


2011 ◽  
Vol 287-290 ◽  
pp. 1749-1752 ◽  
Author(s):  
Jian Feng ◽  
Wei Xiong ◽  
Yun Jia ◽  
Jin Bo Wang ◽  
De Rong Liu ◽  
...  

The catalytic transfer hydrogenolysis of 2-phenyl-2-propanol was studied over Pd/C catalyst, using formic acid and formate salts as hydrogen donors. The Pd/C catalyst was characterized by powder X-ray diffraction (XRD), inductively coupled plasma (ICP), N2 adsorption/desorption and transmission electron microscopy (TEM). The effects of hydrogen donor, molar ratio of formic acid to 2-phenyl-2-propanol and water content were evaluated. Under mild reaction conditions (80 °C, 2h), 2-phenyl-2-propanol can be hydrogenolyzed to isopropylbenzene with very high selectivity (96.5%) and high conversion (92.8%) in the presence of Pd/C and formic acid. From the viewpoint of environmental friendly principles, this study may open the way to a new approach for the production of propylene oxide.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
K. Elen ◽  
A. Kelchtermans ◽  
H. Van den Rul ◽  
R. Peeters ◽  
J. Mullens ◽  
...  

Due to a dominant one-dimensional growth rate, nanoparticles of zinc oxide often show a rodlike morphology. As a result, the synthesis of small spherical nanoparticles of undoped ZnO remains challenging. This paper presents two procedures that successfully produce a powder consisting of equiaxed zinc oxide nanoparticles: one using a polyethylene glycol- (PEG-) assisted solvothermal method and the other by calcination of zinc oxalate obtained from a microemulsion-mediated method. In the latter, zinc-substituted aerosol OT (AOT) is used as a surfactant. The samples are characterized by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), photon correlation spectroscopy (PCS), and photoluminescence (PL) spectroscopy. Both synthesis techniques produce nanoparticles with similar sizes in the range of 10 to 20 nm. Dense aggregates observed in the calcined powder are infrequent in the case of the solvothermal method.


2006 ◽  
Vol 05 (02n03) ◽  
pp. 285-290 ◽  
Author(s):  
YONGHUA LENG ◽  
XINGGUO LI ◽  
HUAQUAN YANG ◽  
HENGHUI ZHOU

Submicron Li 0.8 CoO 2 particles were prepared by sol–gel method, and then ball-mill grinding method was adopted to make nanosized Li 0.8 CoO 2 powders. The two kinds of powders were then examined by X-ray diffraction (XRD), ICP (inductively coupled plasma), the multi-point BET (Brunauer, Emmett and Teller) and transmission electron micrographs (TEM). It appeared that the Li 0.8 CoO 2 nanoparticles exhibited quite different electrochemical properties, such as higher open-circuit voltage and lower discharge capacity, compared to submicron Li 0.8 CoO 2 particles.


Clay Minerals ◽  
2001 ◽  
Vol 36 (3) ◽  
pp. 447-464 ◽  
Author(s):  
J. M. Huggett ◽  
A. S. Gale ◽  
N. Clauer

AbstractVariegated palaeosols, which formed from weathering of clays, silts and brackish to freshwater limestones, are present in the Late Eocene–Early Oligocene Solent Group of the Hampshire Basin, southern UK. The composition and origin of the clay in three segments of the lower part of the Solent Group have been investigated by X-ray diffraction, microprobe analysis, inductively coupled plasma-mas spectrometry, K/Ar dating, high resolution scanning electron microscopy, analytical transmission electron microscopy and wet chemistry. The detrital clay mineral suite is dominated by illite and smectite with minor kaolinite and chlorite. Seasonal wetting and drying in gley soils has resulted in replacement of smectite by Fe-rich, or illite-rich illitesmectite. Illite has also formed with gypsum and calcite in ephemeral hypersaline alkaline lakes that periodically dried out. This illite may have precipitated directly from solution. X-ray diffraction data and probe analyses indicate that the neoformed illite is Fe-rich. The K and Fe for the illitization are thought to be derived from weathered glauconite reworked from the underlying Bracklesham Group and Barton Beds.


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