scholarly journals Synthesis and Characterization of Hydrophilic gama-Fe2O3 Nanoparticles for Biomedical Applications

2019 ◽  
Vol 70 (6) ◽  
pp. 2026-2031
Author(s):  
Teodora Malaeru ◽  
Elena Enescu ◽  
Gabriela Georgescu ◽  
Delia Patroi ◽  
Eugen Manta ◽  
...  

The hydrophilic g-Fe2O3 nanoparticles coated with polyvinylpyrrolidone (PVP) were prepared in one step of the modified polyol method combined with an additional heat treating. The presence of maghemite (g-Fe2O3) phase was confirmed by using X-ray diffraction (XRD) and Raman Spectrometry on powder. FT-IR spectroscopy confirmed the presence of PVP on the nanoparticles surface and the Zeta potential also supported the coating of nanoparticles with a layer of PVP and a good stability in aqueous medium. SEM analysis showed that the prepared g-Fe2O3 nanoparticles have a spherical structural morphology with the tendency of agglomeration. Hysteresis loop shows a ferromagnetic behaviour at room temperature with a saturation magnetization up to 57 emu/g.

2020 ◽  
Vol 71 (10) ◽  
pp. 89-99
Author(s):  
Teodora Malaeru ◽  
Delia Patroi ◽  
Elena Enescu ◽  
Gabriela Georgescu ◽  
Eugen Manta ◽  
...  

In this study, L-lysine coated �a-Fe2O3 nanoparticles were synthesized by a chemical approach in two steps. In the first step �a-Fe2O3 nanoparticles were synthesized by a polyol-reduction method. XRD analysis confirmed the presence of cubic maghemite phase with an average crystallite size of 9.2 nm. SEM analysis showed that the prepared �a-Fe2O3 nanoparticles have a spherical structural morphology with the tendency of agglomeration and with size in the range 8.36- 10.69 nm. The �a-Fe2O3 nanoparticles were coated with L-lysine in the second stage in an aqueous dispersion with ultrasonication followed by a gentle heating at 40��C. FT-IR spectroscopy confirmed the presence of L-lysine on the nanoparticles surface and the Zeta potential also supported the coating of nanoparticles with a hydrophilic layer of amino acid (L-lysine) and a good stability in aqueous medium. Hysteresis loop shows a ferromagnetic behavior at room temperature for both samples.


2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.


1996 ◽  
Vol 433 ◽  
Author(s):  
W Pérez ◽  
Sampriti Sen ◽  
J. Cordero ◽  
E. Ching-Prado ◽  
R.S. Katiyar ◽  
...  

AbstractThin films of SrTiO3 (STO) and SrxBa1−xTiO3 (SBT) with x = 0.35, 0.5, 0.9, and prepared by excimer laser deposition on LaAlO3 and MgO were studied. SEM analysis indicates that the surfaces of these films are smooth with isolated pores, except the SBT(x=0.5)/LaAlO3 sample, where a high concentration of large pores was found. X-ray diffraction (XRD) results show well oriented films. External FT-IR reflection studies reveals a band around 500 cm−x, which shows a significant frequency shift with increasing component concentration. Also, this IR-reflectivity band presents no changes between the SBT(x=0.9)/LaALO3 sample annealed at 750°C and the same film annealed at 850°C. On other hand, the STO/LaAlO3 and STO/MgO films show differences in frequency position of this reflectivity band. Raman spectra of the SBT sample with x ≥ 0.35 show broad bands associated with the BaTiO3 (BTO) material. However, all the phonons bands are broader than those in BTO, in particular the band around 309 cm−. Raman results suggest that the spectrum is a consequence of a breakdown in the translational symmetry due to defects. Raman scattering also indicates a similarity between SBT(x=0.9) at 750°C and that at 850°C. Micro-Raman and EDX analysis show that STO/MgO and SBT(x=0.35)/LaAlO3 films are close to the expected stoichiometry, while STO/LaAlO3 and SBT(x=0.9) films present deficiencies of titanium and oxygen.


Author(s):  
Neelam Verma ◽  
Nitu Trehan

Quercetin is a flavonoid present in herbs, fruits and vegetables. It acts as an antioxidant, anticancer and anti-inflammatory agent. Molecularly Imprinted Polymers (MIPs) were prepared for quercetin by non-covalent approach in the presence of monomer acrylamide, EGDMA as the crosslinker, AIBN as the initiator and methanol and ethyl acetate as porogenic solvents. Most stable MIPs were synthesized using methanol as the solvent. Step wise removal of the template with methanol and acetic acid (9:1) left binding sites that retain complementary specificity and affinity. These stable MIPs were analysed by FT-IR technique. It was observed that there was hydrogen bonding between the template and the functional monomer. This study was further supported by NMR analysis for MIPs and NMIPs (control polymer) that cavity for quercetin has been created in MIPs and absent in the case of NMIPs. MIPs were characterized by SEM analysis that showed more clusters in case of MIPs than NMIPs as an effect of imprinting. These MIPs can be used for extraction of quercetin from herbs in a one step process.


2018 ◽  
Vol 28 (2) ◽  
pp. 100 ◽  
Author(s):  
Rashed Taleb Rasheed

Titanium dioxide (TiO2) nanostructures were synthesized via the hydrolysis of TiCl4 in alcohol / water solution/with sodium hydroxide solution in the ice-bath (0-5 ◦C). The particles were char-acterized by using X-ray diffraction technique (XRD), spectroscopy of Ultra Violet-Visible (UV / Visible) and infrared (FT-IR), atomic force microscope (AFM) and scanning electron micro-scope (SEM) analysis were used in order to gain information about the material, morphology, size and the shape of the particles


2021 ◽  
Vol 2129 (1) ◽  
pp. 012009
Author(s):  
R Nedjai ◽  
N A Kabbashi ◽  
M Z Alam ◽  
M F R Al-Khatib

Abstract Chemical agents have a good influence on the formation of activated carbons, surface characteristic, and its adsorption properties. In this study, the effect of activating agents (ZnCl2, KOH, and H3PO4) on baobab fruit shell (BFS) were evaluated. The characteristics of the baobab fruit shell based activated carbon (BF-ACs) were evaluated through the yield and iodine number. BF-ACs were also characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), and nitrogen (N2) adsorption. SEM analysis illustrates those porous structures formed on the surface of BF-ACs were with different sizes. The XRD analysis show that the main structures of BF-ACs are amorphous. FT-IR data demonstrates the presence of different surface groups on the produced BF-ACs. Among activating agent, the KOH was observed to the most appropriate for the production of activated carbon with a large surface area (1029.44 m2/g) from baobab fruit shell.


2011 ◽  
Vol 412 ◽  
pp. 82-85
Author(s):  
Hui Zhang ◽  
Xiao Hui Wang ◽  
Zhi Bin Tian ◽  
Cai Fu Zhong ◽  
Yi Chi Zhang ◽  
...  

A convenient one-step solvothermal method has been developed to synthesize monodispersed barium titanate nanocrystals with an average size of 5 nm. The key point of this method is the controlling of hydrolysis of Ti (OC4H9)4with Diethylene glycol (DEG). The as-prepared BaTiO3nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), FT-IR and TG/DTA analysis. The monodispersed BaTiO3nanoparticles obtained by this method have an average size of 5 nm with a narrow size distribution and a lattice tetragonality of 1.0069, which is promising for the ferroelectric science and its industry application.


Molbank ◽  
10.3390/m1179 ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. M1179
Author(s):  
Eleftherios Halevas ◽  
Antonios Hatzidimitriou ◽  
Barbara Mavroidi ◽  
Marina Sagnou ◽  
Maria Pelecanou ◽  
...  

A novel Cu(II) complex based on the Schiff base obtained by the condensation of ortho-vanillin with gamma-aminobutyric acid was synthesized. The compounds are physico-chemically characterized by elemental analysis, HR-ESI-MS, FT-IR, and UV-Vis. The complex and the Schiff base ligand are further structurally identified by single crystal X-ray diffraction and 1H and 13C-NMR, respectively. The results suggest that the Schiff base are synthesized in excellent yield under mild reaction conditions in the presence of glacial acetic acid and the crystal structure of its Cu(II) complex reflects an one-dimensional polymeric compound. The molecular structure of the complex consists of a Cu(II) ion bound to two singly deprotonated Schiff base bridging ligands that form a CuN2O4 chelation environment, and a coordination sphere with a disordered octahedral geometry.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 593
Author(s):  
Juan Miranda-Pizarro ◽  
Macarena G. Alférez ◽  
M. Dolores Fernández-Martínez ◽  
Eleuterio Álvarez ◽  
Celia Maya ◽  
...  

A straightforward method for the preparation of trisphosphinite ligands in one step, using only commercially available reagents (1,1,1-tris(4-hydroxyphenyl)ethane and chlorophosphines) is described. We have made use of this approach to prepare a small family of four trisphosphinite ligands of formula [CH3C{(C6H4OR2)3], where R stands for Ph (1a), Xyl (1b, Xyl = 2,6-Me2-C6H3), iPr (1c), and Cy (1d). These polyfunctional phosphinites allowed us to investigate their coordination chemistry towards a range of late transition metal precursors. As such, we report here the isolation and full characterization of a number of Au(I), Ag(I), Cu(I), Ir(III), Rh(III) and Ru(II) homotrimetallic complexes, including the structural characterization by X-ray diffraction studies of six of these compounds. We have observed that the flexibility of these trisphosphinites enables a variety of conformations for the different trimetallic species.


1996 ◽  
Vol 459 ◽  
Author(s):  
E. Ching-Prado ◽  
W. Pérez ◽  
A. Reynés-Figueroa ◽  
R. S. Katiyar ◽  
D. Ravichandran ◽  
...  

ABSTRACTThin films of SrBi2Nb2O9 (SBN) with thicknesses of 0.1, 0.2, and 0.4 μ were grown by Sol-gel technique on silicon, and annealed at 650°C. The SBN films were investigated by Raman scatering for the first time. Raman spectra in some of the samples present bands around 60, 167, 196, 222, 302, 451, 560, 771, 837, and 863 cm−1, which correspond to the SBN formation. The study indicates that the films are inhomogeneous, and only in samples with thicknesses 0.4 μ the SBN material was found in some places. The prominent Raman band around 870 cm−1, which is the A1g mode of the orthorhombic symmetry, is assigned to the symmetric stretching of the NbO6 octahedrals. The frequency of this band is found to shift in different places in the same sample, as well as from sample to sample. The frequency shifts and the width of the Raman bands are discussed in term of ions in non-equilibrium positions. FT-IR spectra reveal a sharp peak at 1260 cm−1, and two broad bands around 995 and 772 cm−1. The bandwidths of the latter two bands are believed to be associated with the presence of a high degree of defects in the films. The experimental results of the SBN films are compared with those obtained in SBT (T=Ta) films. X-ray diffraction and SEM techniques are also used for the structural characterization.


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