scholarly journals Nanoparticle Beads of Chitosan-Ethylene Glycol Diglycidyl Ether/Fe for the Removal of Aldrin

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
G. García Rosales ◽  
P. Ávila-Pérez ◽  
J.O. Reza-García ◽  
A. Cabral-Prieto ◽  
E.O. Pérez-Gómez

This article reports on the preparation of iron nanoparticles (FeNPs) supported in chitosan beads (Chi-EDGE-Fe) for removing aldrin from aqueous solutions. The FeNPs and Chi-EDGE-Fe beads were characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and the Mössbauer spectroscopy (MS) techniques. TEM, XRD, and MS showed that the FeNPs had core-shell structures consisting of a core of either Fe0 or Fe2B and a shell of magnetite. Furthermore, SEM images showed that Chi-EDGE-Fe beads were spherical with irregular surfaces and certain degrees of roughness and porosity, whilst the sorbent mean pore size was 204 nm, and the occluded iron nanoparticles in the chitosan material had diameters of 70 nm and formed agglomerates. The sorbent beads consisted of carbon, oxygen, chlorine, aluminum, silicon, and iron according to the SEM-EDS analysis. Functional groups such as O-H, C-H, -CH2, N-H, C-O, C-OH, and Fe-OH were detected in the FTIR spectra. In addition, a characteristic band appeared at about 1700 cm−1 after the sorption process involving aldrin. MS also showed that the iron nanoparticles in the beads probably oxidized into NPs of α-Fe2O3 as a result of the supporting process. The isotherm of the aldrin removal followed the Langmuir–Freundlich model and presented a maximum adsorption capacity of 74.84 mg/g, demonstrating that chitosan-Fe beads are promising sorbents for the removal of toxic pollutants in aqueous solutions.

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 132
Author(s):  
Maicon O. Miranda ◽  
Bartolomeu Cruz Viana ◽  
Luzia Maria Honório ◽  
Pollyana Trigueiro ◽  
Maria Gardênnia Fonseca ◽  
...  

Titanium and zirconium oxides (TiO2 and ZrO2, respectively) were obtained from alkoxides hydrolyses, and then deposited into palygorskite clay mineral (Pal) to obtain new materials for photocatalytic applications. The obtained materials were characterized by structural, morphological, and textural techniques. X-ray diffraction (XRD) results confirmed the characteristic peaks of oxides and clay transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of the modified palygorskite with both oxides showed that the clay was successfully modified by the proposed method. The increase in the specific surface area of the clay occurred when TiO2 and ZrO2 were deposited on the surface. The photocatalytic activity of these materials was investigated using the Remazol Blue anion dye under UV light. The evaluated systems presented high photocatalytic activity, reaching approximately 98% of dye discoloration under light. Thus, TiO2–Pal and ZrO2–TiO2–Pal are promising clay mineral-based photocatalysts.


2018 ◽  
Vol 32 (8) ◽  
pp. 1078-1091 ◽  
Author(s):  
Sibel Erol Dağ ◽  
Pınar Acar Bozkurt ◽  
Fatma Eroğlu ◽  
Meltem Çelik

A series of polystyrene (PS)/unmodified Na-montmorillonite (Na-MMT) composites were prepared via in situ radical polymerization. The prepared composites were characterized using various techniques. The presence of various functional groups in the unmodified Na-MMT and PS/unmodified Na-MMT composite was confirmed by Fourier transform infrared spectroscopy. Morphology and particle size of prepared composites was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). According to the XRD and TEM results, the interlayer spacing of MMT layers was expanded. SEM images showed a spongy and porous-shaped morphology of composites. TEM revealed the Na-MMT intercalated in PS matrix. The thermal stability of PS/unmodified Na-MMT composites was significantly improved as compared to PS, which is confirmed using thermogravimetric analysis (TGA). The TGA curves indicated that the decomposition temperature of composites is higher at 24–51°C depending on the composition of the mixture than that of pure PS. The differential scanning calorimetry (DSC) results showed that the glass transition temperature of composites was higher as compared to PS. The moisture retention, water uptake, Brunauer–Emmett–Teller specific surface area, and specific pore volume of composites were also investigated. Water resistance of the composites can be greatly improved.


Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 982 ◽  
Author(s):  
Kollur Shiva Prasad ◽  
Shashanka K. Prasad ◽  
Mohammad Azam Ansari ◽  
Mohammad A. Alzohairy ◽  
Mohammad N. Alomary ◽  
...  

In this work, we aimed to synthesize zinc oxide nanoparticles (ZnONPs) using an aqueous extract of Cassia auriculata leaves (CAE) at room temperature without the provision of additional surfactants or capping agents. The formation of as-obtained ZnONPs was analyzed by UV–visible (ultraviolet) absorption and emission spectroscopy, X-ray photoemission spectroscopy (XPS), X-ray diffraction analysis (XRD), energy dispersive X-ray diffraction (EDX), thermogravimetric analysis/differential thermal analysis (TGA-DTA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). The XRD results reflect the wurtzite structure of as-prepared ZnONPs, which produced diffraction patterns showing hexagonal phases. The SEM images indicate that the morphology of as-prepared ZnONPs is composed of hexagonal nanostructures with an average diameter of 20 nm. The HR-TEM result shows that the inter-planar distance between two lattice fringes is 0.260 nm, which coincides with the distance between the adjacent (d-spacing) of the (002) lattice plane of ZnO. The fluorescence emission spectrum of ZnONPs dispersed in ethanol shows an emission maximum at 569 nm, revealing the semiconductor nature of ZnO. As-obtained ZnONPs enhanced the tumoricidal property of CAE in MCF-7 breast cancer cells without significant inhibition of normal human breast cells, MCF-12A. Furthermore, we have studied the antibacterial effects of ZnONPs, which showed direct cell surface contact, resulting in the disturbance of bacterial cell integrity.


2013 ◽  
Vol 678 ◽  
pp. 248-252
Author(s):  
K. Kavi Rasu ◽  
Dhandapani Vishnushankar ◽  
V. Veeravazhuthi

Bismuth sulfide (Bi2S3) and Polyvinyl pyrrolidone (PVP) encapsulated Bi2S3 Nanoparticles are synthesized from aqueous solutions at room temperature. Synthesized samples are subjected to UV-Visible Spectroscopy, X-Ray Diffraction (XRD), Scanning electron microscopy (SEM), Energy Dispersive Analysis of X-ray (EDAX), Transmission Electron Microscopy (TEM) and FT-IR studies and their results are compared. X-ray diffraction spectrum reveals the crystalline nature of the synthesized samples. Grain size value of PVP/ Bi2S3 nanoparticles show a decrease when compared to Bi2S3 nanoparticles and this ensures the good encapsulant effect of PVP on Bi2S3 nanoparticles. SEM images show that all the particles in the synthesized sample are nearly equal in size. From the TEM image we conclude that the particle size lies between 30nm to 70nm. Finally the samples are subjected to EDAX studies for determining their composition.


2021 ◽  
pp. 75-79
Author(s):  
Asha D. V. Bensy ◽  
G. Johnsi Christobel

Marine macroalgae produce numerous bioactive compounds with potential pharmacological properties. In this study, macroalga was collected from the Gulf of Mannar, India and identified as, Turbinaria conoides (J. Agardh). The aqueous extract of T. conoides was used to synthesize iron nanoparticles (NPs). The synthesized iron NPs were characterized by X –ray diffraction analysis, Scanning Electron Microscopy, and Transmission Electron Microscopy. The synthesized NPs showed potent activity against DLD1 and HeLa cell lines.


2020 ◽  
Vol 69 (7) ◽  
pp. 678-693
Author(s):  
R. Aouay ◽  
S. Jebri ◽  
A. Rebelo ◽  
J. M. F. Ferreira ◽  
I. Khattech

Abstract Hydroxyapatite powders were synthesized according to a wet precipitation route and then subjected to heat treatments within the temperature range of 200–800 °C. The prepared samples were tested as sorbents for cadmium in an aqueous medium. The best performances were obtained with the material treated at 200 °C (HAp200), as the relevant sorbent textural features (SBET – specific surface area and Vp – total volume of pores) were least affected at this low calcination temperature. The maximum adsorption capacity at standard ambient temperature and pressure was 216.6 mg g−1, which increased to 240.7 mg g−1 by increasing the temperature from 25 to 40 °C, suggesting an endothermic nature of the adsorption process. Moreover, these data indicated that a thermal treatment at 200 °C enhanced the ability of the material in Cd2+ uptake by more than 100% compared to other similar studies. The adsorption kinetic process was better described by the pseudo-second-order kinetic model. Langmuir, Freundlich, and Dubinin–Kaganer–Radushkevich isotherms were applied to describe the sorption behaviour of Cd2+ ions onto the best adsorbent. Furthermore, a thermodynamic study was also performed to determine ΔH°, ΔS°, and ΔG° of the sorption process of this adsorbent. The adsorption mechanisms were investigated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy-transmission electron microscopy (SEM-TEM) observations.


2019 ◽  
Vol 19 (11) ◽  
pp. 7026-7034 ◽  
Author(s):  
M. Thiruppathi ◽  
M. Vahini ◽  
P. Devendran ◽  
M. Arunpandian ◽  
K. Selvakumar ◽  
...  

The hydrothermally synthesized CuWO4 nanoparticles (NPs) were characterized with different analysis such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM), Energy Dispersive X-ray Spectroscopy (EDX), Cyclic Voltammetry (CV), UV-Visible and Photoluminescence (PL) analysis. The prepared CuWO4 NPs were examined with Electrochemical Impedance Spectroscopy (EIS). SEM images show that CuWO4 NPs are highly spherical shaped morphology and porous in nature. The optical band gap of prepared CuWO4 NPs is found to be 2.12 eV. Photodegradation of diclofenac sodium (DFS) (medical waste) in the aqueous medium with CuWO4 NPs under visible light irradiation shows 98% degradation. The CuWO4 NPs was stable up to 5th cycle it can be used as a reusable photocatalyst for the DFS degradation. The electrical conductivity and dielectric properties of the CuWO4 NPs at room temperature is analyzed by EIS studies. The bulk conductivity value of the prepared nanoparticles is 1.477×10-5 S/cm at room temperature. The conductivity of CuWO4 NPs is found to be due to electrons movement. The CuWO4 NPs shows higher photocatalytic and electrocatalytic activity for decomposition of DFS and methanol electro-oxidation in alkaline medium respectively.


2020 ◽  
Vol 2 (1) ◽  
pp. 118-124
Author(s):  
Parastoo Khalili ◽  
◽  
Majid Farahmandjou ◽  

In this paper, α-Fe2O4@ZnO nanoparticles (NPs) were synthesized by coprecipitation method in the presence of PVP and EG surfactants. The samples were charactrized by x-ray fluorescence (XRF), x-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and fourier transform infrared spectroscopy (FTIR). The XRD results exhibited rhombohedral α-Fe2O3 and wurtzite structure of ZnO. The SEM images showed that the NPs changed from rod-shape to nanoleaves particles after heat treatment. The TEM studies displayed the formation of Fe2O3@ZnO core-shell of as-synthesized NPs. The stretching vibrations peaks in FTIR in the wavenumber of 532 cm-1 and 473 cm-1 ascribed to the Fe and Zn groups. The XRF data indicated decreasing of the Fe weight percent from 22 %Wt. to 25 %Wt., after heat treatment.


Separations ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 224
Author(s):  
Ismat H. Ali ◽  
Mutasem Z. Bani-Fwaz ◽  
Adel A. El-Zahhar ◽  
Riadh Marzouki ◽  
Mosbah Jemmali ◽  
...  

In this study, a gum Arabic-magnetite nanocomposite (GA/MNPs) was synthesized using the solution method. The prepared nanocomposite was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and thermogravimetric analysis (TGA). The prepared composite was evaluated for the adsorption of lead(II) ions from aqueous solutions. The controlling factors such as pH, contact time, adsorbent dose, initial ion concentration, and temperature were investigated. The optimum adsorption conditions were found to be 0.3 g/50 mL, pH = 6.00, and contact time of 30 min. The experimental data well fitted the pseudo-second-order kinetic model and the Langmuir isotherm model. The maximum adsorption capacity was determined as 50.5 mg/g. Thermodynamic parameters were calculated postulating an endothermic and spontaneous process and a physio-sorption pathway.


2019 ◽  
Vol 70 (11) ◽  
pp. 3931-3934
Author(s):  
Irina Fierascu ◽  
Raluca Somoghi ◽  
Cristian Andi Nicolae ◽  
Nicolae Stanica ◽  
Radu Claudiu Fierascu

An inorganic/organic magnetic nanocomposite was synthesized and analytically characterized using X-ray fluorescence, X-ray diffraction, transmission electron microscopy and thermal analysis. The evaluation of the magnetic properties revealed that both the magnetite and the magnetite/chitosan nanocomposite are superparamagnetic with a paramagnetic component, having the saturation magnetization values of 48.04 emu/g, and 41.3 emu/g, respectively. The synthesized material is indented for the adsorption of two known commercial-available pesticides (active ingredients deltamethrin and thiamethoxam, respectively) from aqueous solutions.


Sign in / Sign up

Export Citation Format

Share Document