scholarly journals Adsorptive Capture of Ionic and Non-Ionic Pollutants Using a Versatile Hybrid Amphiphilic-Nanomica

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3167
Author(s):  
Fernando Aguado ◽  
Rosa Martín-Rodríguez ◽  
Carmen Pesquera ◽  
Rafael Valiente ◽  
Ana C. Perdigón
Keyword(s):  
Local Environment ◽  
Optical Measurements ◽  
X Ray Diffraction ◽  
Hybrid Nanomaterial ◽  
Transmission Electron ◽  
Nano Clay ◽  
Saturated Atmosphere ◽  
Hydrophobic Nature ◽  
The Stability ◽  
Functional Nanomaterial

A versatile, functional nanomaterial for the removal of ionic and non-ionic pollutants is presented in this work. For that purpose, the high charge mica Na-4-Mica was exchanged with the cationic surfactant (C16H33NH(CH3)2)+. The intercalation of the tertiary amine in the swellable nano-clay provides the optimal hydrophilic/hydrophobic nature in the bidimensional galleries of the nanomaterial responsible for the dual functionality. The organo-mica, made by functionalization with C16H33NH3+, was also synthesized for comparison purposes. Both samples were characterized by X-ray diffraction techniques and transmission electron microscopy. Then, the samples were exposed to a saturated atmosphere of cyclohexylamine for two days, and the adsorption capacity was evaluated by thermogravimetric measurements. Eu3+ cations served as a proof of concept for the adsorption of ionic pollutants in an aqueous solution. Optical measurements were used to identify the adsorption mechanism of Eu3+ cations, since Eu3+ emissions, including the relative intensity of different f–f transitions and the luminescence lifetime, can be used as an ideal spectroscopic probe to characterize the local environment. Finally, the stability of the amphiphilic hybrid nanomaterial after the adsorption was also tested.

scholarly journals Facile Organometallic Synthesis of Fe-Based Nanomaterials by Hot Injection Reaction

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1141
Author(s):  
Georgia Basina ◽  
Hafsa Khurshid ◽  
Nikolaos Tzitzios ◽  
George Hadjipanayis ◽  
Vasileios Tzitzios
Keyword(s):  
Room Temperature ◽  
Colloidal Particles ◽  
Iron Pentacarbonyl ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Organometallic Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Hot Injection ◽  
The Stability

Fe-based colloids with a core/shell structure consisting of metallic iron and iron oxide were synthesized by a facile hot injection reaction of iron pentacarbonyl in a multi-surfactant mixture. The size of the colloidal particles was affected by the reaction temperature and the results demonstrated that their stability against complete oxidation related to their size. The crystal structure and the morphology were identified by powder X-ray diffraction and transmission electron microscopy, while the magnetic properties were studied at room temperature with a vibrating sample magnetometer. The injection temperature plays a very crucial role and higher temperatures enhance the stability and the resistance against oxidation. For the case of injection at 315 °C, the nanoparticles had around a 10 nm mean diameter and revealed 132 emu/g. Remarkably, a stable dispersion was created due to the colloids’ surface functionalization in a nonpolar solvent.

scholarly journals Study Structure and Properties of Nanocomposite Material Based on Unsaturated Polyester with Clay Modified by Poly(ethylene oxide)

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Tran Duy Thanh ◽  
Nguyen Dang Mao ◽  
Nguyen Thi Kim Ngan ◽  
Ha Thuc Chi Nhan ◽  
Ha Thuc Huy ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Polymer Matrix ◽  
Unsaturated Polyester ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Poly Ethylene Oxide ◽  
Hydrophobic Nature ◽  
Poly Ethylene ◽  
Alkyl Ammonium

In recent years, polymer clay nanocomposites have been attracting considerable interests in polymers science because of their advantages. There are many scientists who researched about this kind of material and demonstrated that when polymer matrix was added to little weight of clay, properties were enhanced considerably. Because clay is a hydrophilic substance so it is difficult to use as filler in polymer matrix having hydrophobic nature, so clay needs to be modified to become compatible with polymer. In this study, poly(ethylene oxide) was used as a new modifier for clay to replace some traditional ionic surfactants such as primary, secondary, tertiary, and quaternary alkyl ammonium or alkylphosphonium cations having the following disadvantages: disintegrate at high temperature, catalyze polymer degradation, and make nanoproducts colorific, and so forth. In order to evaluate modifying effect of poly(ethylene oxide), modified clay products were characterize d by X-ray spectrum. Then organoclay was used to prepare nanocomposite based on unsaturated polyester. Morphology and properties of nanocomposites were measure d by X-ray diffraction, transmission electron microscopy, tensile strength, and thermal stability. The results showed that clay galleries changed to intercalated state in the nanocomposites. Properties of nanocomposites were improved a lot when the loading of the organoclay was used at 1 phr.

scholarly journals Low-temperature hydrothermal synthesis of hierarchical flower-like CuB2O4 superstructures

2020 ◽  
Vol 14 (2) ◽  
pp. 113-118
Author(s):  
Daniel Ursu ◽  
Anamaria Dabici ◽  
Marinela Miclau ◽  
Nicolae Miclau
Keyword(s):  
Thermal Stability ◽  
Low Temperature ◽  
Self Assembly ◽  
Hydrothermal Solution ◽  
Optical Measurements ◽  
Oriented Attachment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
One Step

We report for the first time the fabrication of hierarchical ordered superstructure CuB2O4 with flower-like morphology via a one-step, low temperature hydrothermal method. The tetragonal structure of CuB2O4 was determined by X-ray diffraction and high-resolution transmission electron microscopy. Optical measurements attested of the quality of the fabricated CuB2O4 and high temperature X-ray diffraction confirmed its thermal stability up to 600 ?C. The oriented attachment growth and the hierarchical self-assembly of micrometer-sized platelets producing hierarchical superstructures with flower-like morphology are designed by pH of the hydrothermal solution. The excellent band gap, high thermal stability and hierarchical structure of the CuB2O4 are promising for the photovoltaic and photocatalytic applications.

scholarly journals Improving stability of cerium oxide nanoparticles by microbial polysaccharides coating

2018 ◽  
Vol 83 (6) ◽  
pp. 745-757 ◽  
Author(s):  
Ivana Milenkovic ◽  
Ksenija Radotic ◽  
Branko Matovic ◽  
Marija Prekajski ◽  
Ljiljana Zivkovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cerium Oxide ◽  
Aqueous Media ◽  
Suspension Stability ◽  
X Ray Diffraction ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Ft Ir ◽  
Microbial Exopolysaccharides ◽  
The Stability

Cerium oxide (CeO2) nanoparticles (CONPs) are interesting biomaterials with various applications in biomedicine, cosmetics and the pharmaceutical industry, but with limited practical application because of their low stability in aqueous media. The aim of this study was to obtain CONPs with increased stability by coating the particles. Microbial exopolysaccharides (levan, pullulan) and glucose were used to prepare CONPs under different synthesis conditions. Coating was attempted by adding the carbohydrates during (direct coating) or after (subsequent coating) the synthesis of CONPs. The obtained nanoparticles were characterized by X-Ray diffraction analysis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The suspension stability of the uncoated and coated CONPs in aqueous media was evaluated by measuring the hydrodynamic size, zeta potential and turbidity. The FT-IR spectra revealed the differences between coated CONPs and showed the success of subsequent coating with carbohydrates. Coating with carbohydrates improved the stability the CONP suspension by decreasing the size of aggregated particles. The suspensions of levan- and glucose-coated CONPs had the best stability. In this study, CONPs were prepared using non-toxic materials, which were completely environmentally friendly. The obtained results open new horizons for CONP synthesis, improving their biological applications.

Thermal Stability and Failure Mechanisms of Au/Tiw(N)/Si and Au/TiW(N)/Si02/Si Systems

1996 ◽  
Vol 427 ◽  
Author(s):  
C. R. Chen ◽  
L. J. Chen
Keyword(s):  
Thermal Stability ◽  
Failure Mechanisms ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Single Face ◽  
Face Centered ◽  
The Stability ◽  
Ar Gas

AbstractThermal stability and failure mechanisms of Au/TiW(N)/Si and Au/TiW(N)/SiO2/Si systems have been studied by both conventional and high-resolution transmission electron microscopy, X- ray diffraction and Auger electron spectroscopy. For films deposited in Ar gas containing 20% N2, a single face-centered-cubic phase was the only crystalline phase detected to form. The samples were found to remain stable after annealing at 700 °C for 30 min. The stability temperature for Au/TiW(N)(Ar:N2=80:20)/SiO2/Si samples was found to be higher than those of Au/TiW(N) (Ar:N2=90:10)/SiO2/Si and Au/TiW/SiO2/Si samples.

Dynamic Rheology and Microstructure of Polypropylene/Clay Nanocomposites Prepared Under Sc-CO2 by Melt Compounding

2007 ◽  
Author(s):  
Yang Zhao ◽  
Han-Xiong Huang
Keyword(s):  
Low Frequency ◽  
Complex Viscosity ◽  
Co2 Concentration ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Melt Compounding ◽  
Transmission Electron ◽  
Nano Clay ◽  
Twin Screw ◽  
Negative Effect

The polypropylene (PP)/clay nanocomposites were prepared using a twin screw extruder with the aid of the supercritical carbon dioxide (Sc-CO2). The dynamic rheological properties were measured using a rheometer in the oscillatory mode. X-ray diffraction and transmission electron microscopy were used to characterize the microstructure of extruded nanocomposites. Results showed that an optimized CO2 concentration existed. When the CO2 concentration increased up to the optimized level, the nanocomposites tended to be more viscous, especially at low frequency. Whereas further increasing the CO2 concentration resulted in the decrease in the complex viscosity and dynamic moduli. The presence of Sc-CO2 with the concentration not higher than the optimized level was helpful to promote the degree of dispersion of the nano-clay in PP matrix, and overloaded CO2 would have negative effect on the clay dispersion.

Gelatin as an ecofriendly natural polymer for preparing colloidal silver@gold nanobranches

2016 ◽  
Vol 5 (5) ◽  
Author(s):  
Phuong Phong Nguyen Thi ◽  
Dai Hai Nguyen
Keyword(s):  
Ph Value ◽  
Component Ratio ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Au Nps ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
The Stability ◽  
Maximum Absorption Wavelength

AbstractWe report star-shaped silver@gold (Ag@Au) nanoparticles (NPs) in gelatin suspensions for the purpose of enhancing the stability of Ag@Au NPs. In this case, Ag NPs were designed as nucleating agents, whereas gelatin was used as a protecting agent for Au development. Especially, variable gelatin concentrations were also prepared to explore its ability to increase the stability of Ag@Au NPs. The obtained samples were then characterized by UV-visible spectroscopy, transmission electron spectroscopy (TEM), X-ray diffraction, and Fourier transform infrared spectroscopy. The maximum absorption wavelength of all samples (566–580 nm) indicated that branched Ag@Au@gelatin NPs were successfully synthesized. In addition, our TEM results revealed that the size of branched Ag@Au@gelatin NPs was found to be between 20 and 45 nm as influenced by the component ratio and the pH value. These results can provide valuable insights into the improvement of Ag@Au NP stability in the presence of gelatin.

Characterization, Optical and Impedance Study of ZnSe Nanostructure

2013 ◽  
Vol 699 ◽  
pp. 490-495
Author(s):  
Ramna Tripathi ◽  
Akhilesh Kumar
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Impedance Spectroscopy ◽  
Zinc Selenide ◽  
Relaxation Times ◽  
Complex Impedance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Stability

Zinc selenide nanoparticle has been synthesized using soft chemical routes. The particles were capped using 2-mercaptoethanol to achieve the stability and avoid the coalescence. The as-obtained particles were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV–VIS absorption and photoluminescence (PL) spectra. The impedance studies were carried out as a function of frequency (100 Hz–1 MHz) and temperature (298–373 K) by impedance spectroscopy. An analysis of the complex impedance (z' and z") with frequency is performed assuming a distribution of relaxation times.

Effect of Ambient Atmosphere on Thin Film Reaction of Si3N4 with Ti

1989 ◽  
Vol 170 ◽  
Author(s):  
Seshu B. Desu ◽  
J. Ashley Taylor
Keyword(s):  
Layer Structure ◽  
Chemical Vapor ◽  
Product Formation ◽  
Ambient Atmosphere ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Rapid Thermal Annealer ◽  
The Stability ◽  
Increasing Temperature

AbstractThe reaction of sputtered deposited Ti films of 100 nm thick with low pressure chemical vapor deposited Si3N4 films (300 nm thick) was studied in N2 or Ar, in a rapid thermal annealer. Reactions are followed using x-ray diffraction, Auger electron spectroscopy, and transmission electron microscopy. In argon, the Si3N4 and Ti reaction at low temperatures led to the product formation of two layer structure (TiN/Ti5Si3), with some contaminant oxygen and nitrogen released from the reaction uniformly dissolved throughout the remaining unreacted Ti. At higher temperatures, a three layer structure, TiN/TixSiy/TiN, on unreacted Si3N4 was developed. With increasing temperature the value of x and y decreased from 5 to 0 and 3 to 1, respectively. Reactions in N2 ambient, irrespective of temperature, always produced the three layer structure, but the thickness of TixSiy layer was much smaller than that produced in argon ambient for the corresponding temperatures. The reaction mechanism can be explained in terms of relative diffusion coefficients and the stability of the interfaces.

Sign in / Sign up

Export Citation Format

Share Document