scholarly journals Synthesis of cobalt doped mesoporous silica by using the rice husks as both silicon source and template with its catalytic oxidation of 2-methyl pyridine

2020 ◽  
Vol 189 ◽  
pp. 02022
Author(s):  
Zhongbiao Zhai ◽  
Yingchun Miao ◽  
Xie Gang ◽  
Shanshan Yang ◽  
Jing Chen

Cobalt doped mesoporous silica (Co-SiO2) was prepared using the rice husks as both silicon source and template. Structural characterization of the catalysts was done by various techniques, such as Xray diffraction, FT-IR, N2 adsorption/desorption, and scanning electron microscopy. Co-SiO2 was used as a catalyst for the oxidation of 2-methyl pyridine and exhibited high substrate conversion (94.6%) and good product (2-pyridinecarboxylic acid) selectivity (92.4%). It even exhibited higher selectivity than Co-MTiO2, Co-MCM-41, Co-SBA-15. Fast hot catalyst filtration experiment proved that the catalyst acted as a heterogeneous one and it can be reused with almost the same activity.


2017 ◽  
Vol 1142 ◽  
pp. 220-224 ◽  
Author(s):  
Wan Xia Wang ◽  
Yu Wang ◽  
Hua Meng Gong ◽  
Hong Hao Sun ◽  
Ming Xing Liu

The purpose of this article is to synthesize the thiol-and carboxyl-bifunctionalized mesoporous silica nanoparticles (CMS-SH-COOH). CMS-SH-COOH was successfully synthesized by co-condensation and post-grafting methods. Moreover, the particle size and structural properties of CMS-SH-COOH were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR). The obtained results indicated that the CMS-SH-COOH presented a uniform spherical shape with a wormhole arrangement of the mesopores and a relatively narrow paticle distribition. Therefore, the CMS-SH-COOH might be a great potential carrier for the drug delivery system in the future.



2013 ◽  
Vol 06 (03) ◽  
pp. 1350031
Author(s):  
HABIBEH HADAD DABAGHI ◽  
MAHMOOD KAZEMZAD ◽  
YADOLAH GANJKHANLOU ◽  
AMIR ALI YUZBASHI

Electrochemistry has been introduced as a powerful tool in order to prepare new organometallic reagents for functionalizing of mesoporous silica. Preparation of the reagents was based on electrochemical oxidation of dihydroxybenzene derivatives in the presence of 3-(trimethoxysilyl)-1-propanethiol as a nucleophile. The mechanisms of electrochemical reactions were studied by voltammetric studies. Mesoporous silica SBA-15 was also synthesized in this work through sol-gel hydrothermal method using Genapol PF-10 as structure directing compound. The prepared mesoporous silica was characterized by FT-IR analysis and Barrett–Joiner–Halenda (BJH) pore size and Brunauer–Emmett–Teller (BET) surface area measurement methods using N2 adsorption–desorption isotherm. Finally, the organometallic reagent was covalently grafted on the surface of mesoporous silica. Functionalizing of this material with the new reagent was confirmed by Fourier transform infrared (FT-IR) spectroscopy. The functionalized mesoporous silica by new reagent can be utilized in biological applications.



Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4722
Author(s):  
Lukáš Žid ◽  
Vladimír Zeleňák ◽  
Miroslav Almáši ◽  
Adriana Zeleňáková ◽  
Jaroslava Szücsová ◽  
...  

In this work we describe the relationship between surface modification of hexagonally ordered mesoporous silica SBA-15 and loading/release characteristics of nonsteroidal anti-inflammatory drug (NSAID) naproxen. Mesoporous silica (MPS) was modified with 3-aminopropyl, phenyl and cyclohexyl groups by grafting method. Naproxen was adsorbed into pores of the prepared MPS from ethanol solution using a solvent evaporation method. The release of the drug was performed in buffer medium at pH 2 and physiological solution at pH 7.4. Parent MPSs as well as naproxen loaded MPSs were characterized using physicochemical techniques such as nitrogen adsorption/desorption, thermogravimetric analysis (TG), Zeta potential analysis, Fourier transform infrared spectroscopy (FT-IR), and elemental analysis. The amount of naproxen released from the MPSs into the medium was determined by high-performance liquid chromatography (HPLC). It was shown that the adsorption and desorption characteristics of naproxen are dependent on the pH of the solution and the surface functionalization of the host.



2012 ◽  
Vol 531 ◽  
pp. 161-164 ◽  
Author(s):  
Zong Hua Wang ◽  
Fu Qiang Zhu ◽  
Jan Fei Xia ◽  
Fei Fei Zhang ◽  
Yan Zhi Xia ◽  
...  

Zirconia/graphene (ZrO2/graphene) nanocomposite has been successfully synthesized by a simple method. The as-prepared nanocomposite was characterized using transmission electron microscopy (TEM), FT-IR spectroscopy, power X-ray diffraction (XRD) and nitrogen adsorption-desorption. It was found that tetragonal ZrO2was uniformly deposited on graphene, which resulted in the formation of two-dimensional nanocomposite, it showed a high surface area of 165 m2/g.



2014 ◽  
Vol 997 ◽  
pp. 146-149
Author(s):  
Xiang Guo Meng ◽  
Wen Lu Guo ◽  
Min Luo ◽  
Ping Sun

Ni(II)-imprinted polymer has been prepared by surface imprinting technique based on support matrix of mesoporous silica SBA-15. The obtained adsorbent was characterized by FT-IR, SEM, and nitrogen adsorption-desorption. The compound retained mesoporous structure and the polymer coated inside channels and outside surface hole wall. The adsorption behavior was carried out with Ni(II)-IIP in batch experiments. The results suggested that Ni(II)-IIP could be used as an excellent adsorbent for efficient removal of Ni(II) from aqueous solution.



2012 ◽  
Vol 602-604 ◽  
pp. 62-65
Author(s):  
Yu Yuan Zhi ◽  
Lei Zu ◽  
Kai Gu ◽  
Hui Qin Lian ◽  
Xiu Guo Cui

In this study, first we prepared SBA-15 and sulfonate bearing SBA-15-SO3H.Then we modified the mesoporous silica with PEG to get SBA-15,SBA-15-SH,SBA-15-SO3H,SBA-15-PEG and SBA-15-SH-PEG.The samples were tested by FT-IR, nitrogen adsorption–desorption and TG. The tests showed that both SBA-15and SBA-15-SO3H we prepared had the typical properties of mesoporous materials. SBA-15-PEG and SBA-15-SH-PEG were successfully prepared.



2013 ◽  
Vol 742 ◽  
pp. 452-455
Author(s):  
Guo Li Zi ◽  
Fei Yu ◽  
Fa Gui Yuan ◽  
Jiao He ◽  
Ming Feng Wang ◽  
...  

Cerium-doped microporous-mesoporous composite material (Ce-M-M) was synthesized by the hydrothermal method. Ce-M-M was characterized by N2adsorption-desorption and FT-IR. The results showed that the Ce-M-M has composite pore structure combining both micropores and mesopores, and the pore sizes are mainly located at 1.7 nm, 2.3nm and 2.7nm. The specific surface area of the Ce-M-M was 1288 m2g-1with a pore volume of 0.66 cc/g. In addition, NH3, a harmful component in cigarette mainstream smoke could be effectively reduced 66.9% by using Ce-M-M as an adsorbent.



2009 ◽  
Vol 131 (3-4) ◽  
pp. 538-544 ◽  
Author(s):  
Zhongbiao Zhai ◽  
Yingchun Miao ◽  
Qiaoli Sun ◽  
Huiwang Tao ◽  
Wei Wang ◽  
...  


1998 ◽  
Vol 16 (3) ◽  
pp. 193-216 ◽  
Author(s):  
E.A. El-Sharkawy

Two series of ternary solid catalysts containing Al, Cr and Zn but with different ZN2+ or Cr3+ ion contents were prepared by impregnation methods. All systems were calcined by heating within the temperature range 773–1073 K. Structural characterization of the systems was effected by X-ray diffraction (XRD) methods and by differential thermal analysis (DTA). The textural properties of the precalcined products were measured from adsorption/desorption studies of nitrogen at 77 K. The surface acidities of the precalcined products were also studied using a poisoning method employing pyridine as the probe base. The adsorption and disproportionation of NO at 298 K was followed via in-situ FT-IR spectroscopic methods, while the catalytic activities of the prepared samples towards the dehydration (DHD)/dehydrogenation (DHG) of propan-2-ol were studied using a pulse microcatalytic technique. XRD and DTA analyses showed the presence of γ-A12O3 and ZnCr2O4 in the prepared samples but did not provide any evidence for other detectable species in the ternary solid materials. The disproportionation of NO, as well as the catalytic conversion of propan-2-ol, was apparently strongly influenced by the structural properties of these materials but to a lesser extent by their textural properties.



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