scholarly journals Facile Method for Preparation of Silica Coated Monodisperse Superparamagnetic Microspheres

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Xuan-Hung Pham ◽  
San Kyeong ◽  
Jaein Jang ◽  
Hyung-Mo Kim ◽  
Jaehi Kim ◽  
...  

This paper presents a facile method for preparation of silica coated monodisperse superparamagnetic microsphere. Herein, monodisperse porous polystyrene-divinylbenzene microbeads were prepared by seeded emulsion polymerization and subsequently sulfonated with acetic acid/H2SO4. The as-prepared sulfonated macroporous beads were magnetized in presence of Fe2+/Fe3+under alkaline condition and were subjected to silica coating by sol-gel process, providing water compatibility, easily modifiable surface form, and chemical stability. FE-SEM, TEM, FT-IR, and TGA were employed to characterize the silica coated monodisperse magnetic beads (~7.5 μm). The proposed monodisperse magnetic beads can be used as mobile solid phase particles candidate for protein and DNA separation.

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.


2022 ◽  
Author(s):  
Monika Patel ◽  
Sunita Mishra ◽  
Ruchi Verma ◽  
Deep Shikha

Abstract Nanotechnology is a completely unique branch of technology that offers with substances in a very small size between (1-100 nm) with various crystal shapes which include spherical nanoparticles, flower shaped, Nano rods, Nano ribbons, and Nano platelets. Metals have ability to produce large number of oxides. These metal oxides play an major role in many areas of chemistry, physics, material science and food science. In this research, Zinc Oxide (ZnO) and Copper (II) oxide nanoparticles were synthesized via sol-gel process using zinc nitrate and copper (II) nitrate as precursor respectively. The characterization of CuO and ZnO nanoparticles was done by using various techniques. X-ray Diffraction (XRD) indicates the crystallinity and crystal size of CuO and ZnO nanoparticle. Fourier transform infrared spectroscopy (FT-IR) was used to get the infrared spectrum of the sample indicating composition of the sample which contains various functional groups. XRD result shows the particle size of CuO at highest peak 29.40140 was 61.25 nm and the particle size of ZnO at highest peak 36.24760 was 21.82 nm. FT-IR spectra peak at 594.56 cm-1 indicated characteristic absorption bands of ZnO nanoparticles and the broad band peak at 3506.9 cm-1 can be attributed to the characteristic absorption of O-H group. The analysis of FT-IR spectrum of CuO shows peaks at 602.09, 678.39, and 730.19cm−1 which refer to the formation of CuO. A broad absorption peak noticed at 3308.2 cm−1 attributed to O–H stretching of the moisture content.


2007 ◽  
Vol 1007 ◽  
Author(s):  
Sorin Ivanovici ◽  
Christoph Rill ◽  
Claudia Feldgitscher ◽  
Guido Kickelbick

ABSTRACTHybrid materials based on polysiloxanes and metal oxides (SiO2, TiO2, ZrO2) were prepared by hydrosilation of allyl acetoacetate (AAA) modified metal alkoxides (M(OR)4; M = Ti, Zr; R = ethyl, isopropyl) or vinyl triethoxysilane with poly(dimethylsiloxane-co-hydrosiloxane) (PDMS-co-PMHS). The obtained compounds acted as single-source precursors in the sol-gel process. Various spectroscopic methods showed the complete functionalization of the polysiloxane chains with the complexes. When alcohols were used as solvents in the sol-gel process, hybrid nanoparticles were obtained, as observed by dynamic light scattering (DLS) measurements, transmission electron microscopy (TEM), and spectroscopic methods such as NMR and FT-IR.


2013 ◽  
Vol 32 (1) ◽  
pp. 165-172 ◽  
Author(s):  
Christie Ying Kei LUNG ◽  
Edwin KUKK ◽  
Jukka Pekka MATINLINNA

2019 ◽  
Vol 07 (01n02) ◽  
pp. 1950002
Author(s):  
Nadir Lalou ◽  
Ahmed Kadari

This work proposes the synthesis of nanocrystalline calcium oxide (CaO) pure and doped with different concentrations of lithium (Li[Formula: see text]) ions by sol–gel process. Calcium nitrate (Ca(NO[Formula: see text]4H2O; 99.99%) and lithium nitrate (LiNO3; 99.99%) were used as precursors. The synthesized powders were characterized by several techniques such as: UV-Vis transmission spectroscopy, Fourier Transform Infra-red spectroscopy (FT-IR) and X-ray diffraction (XRD). The main objective of this paper is to study the influence of lithium (Li[Formula: see text] ratio) on the structural and optical properties of synthesized powders. The band gap values decreased with the increasing of Li[Formula: see text] ions in CaO lattice; the slight change in the band gap was directly related to the energy transfer between the CaO excited states and the 2s levels of Li[Formula: see text] ions. The influence of Li[Formula: see text] doping on the physical properties of CaO nanocrystalline will be studied for the first time in this work; no literature has previously published this kind of impurities.


2012 ◽  
Vol 512-515 ◽  
pp. 207-210
Author(s):  
Quan Wen ◽  
Jian Feng Huang ◽  
Li Yun Cao ◽  
Jian Peng Wu

V2O5 powders were successfully synthesized by the EDTA assistanced ultrasound sol-gel process using NH4VO3 and EDTA, NH3•H2O as raw materials. The synthesized activation energy and the influence of pH values and the calcination temperatures on the phases and microstructures of powders were particularly investigated. The precursor powders and the V2O5 powders were characterized by X-ray diffraction (XRD), fourier transform inelectron microscopy (FT-IR), scanning electron microscopy (SEM) and differential scanning calorimetry-thermal gravimetric (DSC-TG). Results show that the obtained products exhibit good crystallization under the conditions of pH=4, calcination temperature 400~500 °C and calcination time 0.5 h during the synthesizing process. The as-prepared V2O5 powders show preferred growth orientation along (001) plane at the pH=4. By DSC analysis, the ultrasonic cavitation result in the decrease in synthesized activation energy obviously than that was prepared without ultrasonic irradiation.


2009 ◽  
Vol 79-82 ◽  
pp. 663-666 ◽  
Author(s):  
Ming Liang Luo ◽  
Qing Zhi Wen ◽  
Hong Jian Liu ◽  
Jia Lin Liu

Sulfonated-polyethersulfone/TiO2 (SPES/TiO2) nanoparticle composites with different TiO2 content were prepared by a sol-gel process. These composites have nanosized TiO2 rich domains well dispersed within SPES matrix observed by SEM photograph. The effect of TiO2 nanoparticles on the hydrophilicity of SPES was discussed by contact angle goniometer. The mechanism of the hydrophilicity improvement of these composites was analyzed by the molecular interaction theory and FT-IR. The hydrogen bond and coordination bond between SPES and TiO2 nanoparticle were observed. Comparing with the pure SPES, the SPES/TiO2 composites exhibited an outstanding increase in hydrophilicity.


2016 ◽  
Vol 852 ◽  
pp. 585-590
Author(s):  
Lin Sang ◽  
Ning Pan ◽  
Jing Su ◽  
Xiao Mei Tan ◽  
Hang Li ◽  
...  

3at. % Eu3+ doped (Y, Gd)2O3 precursor powders with various compositions were synthesized via a sol-gel process, and the precursors were sintered at different temperatures. XRD, FT-IR, Raman and photoluminescence spectroscopy were used to study the phase, microstructure and luminescent properties of the precursors and the sintered powders. The results show that pure (Y, Gd)2O3 polycrystalline phase can be obtained from sintering the precursors at 700°C. The influences of the host compositions on the microstructures and fluorescence properties were analyzed, and the optimized composition was obtained for 3at. % Eu3+ doped (Y, Gd)2O3 powders.


2011 ◽  
Vol 233-235 ◽  
pp. 151-154 ◽  
Author(s):  
Yi Hu ◽  
Jin Qiang Liu ◽  
Chun Lei Xu

A sol type anti-felting agent containing PPD-[Si(OH)3]2 synthesized and applied to the wool with pad-dry-cure process. The structure of the prepolymer was characterized by FT-IR spectroscopy and the film transparency and the fiber microstructure were proved though UV-vis analysis and WAXD. The results indicated that the coating could endow a better anti-felting effect with low curing temperature at 120°C and 3 min, the area shrinking rate from13.44% of the original fabric decrease to 2.86% of the treated samples without strength decreased and handle changed stiff seriously, which accord with the IWS Test Method 31 standard.


2013 ◽  
Vol 717 ◽  
pp. 108-112
Author(s):  
Noorzahan Begum ◽  
Md Fazlul Bari ◽  
Salmie Suhana Binti Che Abdullah ◽  
R.A. Khairel ◽  
N. Ahmed

A new solid phase extractant silica aerogel immobilized with Cyanex 301 {bis (2,4,4-trimethylpentyl) dithiophosphinic acid} (SAWC) was prepared via a sol-gel method and investigated for the extraction of Zn (II) from aqueous solution by a batch extraction technique. It is found that SAWC can extract about 100% zinc at equilibrium pH 1.7. Prepared SAWC was characterized by FT-IR, BET, EDX and SEM which proved the presence of Cyanex 301 into silica aerogel. Moreover, the material is also easily regenerated and reused in the subsequent removal of Zn (II) in five cycles. Therefore, it could be concluded that it may perform as a solid phase extractant in the extraction of metal ions from the aqueous solution.


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