Effects of trace metals and organic additives on porosity and dielectric constant of high purity mesoporous silica filmsElectronic supplementary information (ESI) available: nitrogen adsorption/desorption isotherm and pore distribution chart. See http://www.rsc.org/suppdata/cc/b3/b304903e/

2003 ◽  
pp. 1830
Author(s):  
Jerome C. Birnbaum ◽  
Glen E. Fryxell ◽  
Xiaohong Li ◽  
Chris A. Coyle ◽  
Glen C. Dunham ◽  
...  
2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Junhyun Choi ◽  
Yosep Han ◽  
Soyeon Park ◽  
Jayhyun Park ◽  
Hyunjung Kim

Silicate mesoporous materials were synthesized with nonionic surfactant and their surfaces were modified by oleic acid adsorption. Infrared spectrometer, nitrogen adsorption-desorption isotherm, scanning electron microscopy, and thermogravimetric analyses were used to investigate the structure of oleic acid modified mesoporous material. The effects of heat treatment at various temperatures on oleic acid modified materials were also studied. Oleic acids on silica surfaces were found to be bonded chemically and/or physically and be capable of enduring up to180°C. The adsorbed oleic acid improved the hydrothermal stability of mesoporous silica and assisted mesopore structure to grow more in hydrothermal treatment process by preventing the approach of water.


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.


2011 ◽  
Vol 204-210 ◽  
pp. 1245-1249 ◽  
Author(s):  
Quan Min Xue ◽  
Ying Shu Liu ◽  
Peng Huo

A promising adsorbent for CO2removal was prepared by introducing methyl-diethyl-amine (MDEA) into mesoporous silica SBA-15 using impregnation method. The MDEA modified adsorbents were characterized by X-ray powder diffraction (XRD) and nitrogen adsorption/desorption. Surface area, pore size and pore volume of MDEA-modified SBA-15 adsorbent decreased with the increasing of MDEA loading, while the loaded MDEA could not change the structure of the adsorbents. The adsorption performance of CO2on the adsorbents was conducted in a dynamic setup. Dynamic adsorption performance changed with change of the amount of loaded MDEA. In addition, not only the adsorbent was regenerable by purging with the purified gas, but also the adsorption performance is stable in adsorption cycles. The results indicated that the MDEA modified adsorbents were novel for removing CO2for biogas upgrading.


2019 ◽  
Vol 37 (3-4) ◽  
pp. 333-348 ◽  
Author(s):  
Ning Yuan ◽  
Hui Cai ◽  
Tian Liu ◽  
Qi Huang ◽  
Xinling Zhang

In the present work, coal fly ash-derived mesoporous silica material (CFA-MS) has been successfully fabricated without employing any extra silica source. The obtained CFA-MS was characterized by Fourier transform infrared spectroscopy, nitrogen adsorption–desorption measurement, powder X-ray diffraction and transmission electron microscopy. Nitrogen adsorption–desorption measurement disclosed that CFA-MS possesses Brunauer–Emmett–Teller-specific surface area of 497 m2·g−1 and pore volume of 0.49 cm3·g−1, respectively. Furthermore, CFA-MS was evaluated for the adsorptive removal of methylene blue from aqueous solution. Several influence parameters on the removal of methylene blue including contact time, pH, initial concentration and temperature were studied in detail. Moreover, Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models were employed for interpretation of the adsorption process, while the pseudo-first-order and pseudo-second-order kinetics equations were applied to investigate the adsorption kinetics. Results in the current work demonstrate that CFA-MS can be used as an efficient adsorbent for methylene blue removal.


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 512-515 ◽  
pp. 2412-2418
Author(s):  
Xiao Dan Zhang ◽  
Zhui Hui Hu ◽  
Dong Hui Zhang

Silver ion modified mesoporous silica (Ag-AMS-2) was prepared by using N-lauroyl-L-glutamic acid as structure directing agents and applied to dimethly sulfide (DMS) removal at ambient temperatures. The silver ion interacted with the amino group through coordination bonds and then the silver ion were as the adsorptive sites of the DMS. These Ag-AMS-2 materials were characterized by X-ray diffraction (XRD), nitrogen adsorption desorption, high-resolution transmission electron microscopy (HRTEM), thermal analysis and inductively coupled plasma optical emission spectrometry (ICP-OES). The performance of these Ag-AMS-2 materials as DMS adsorbents was tested using a dynamic breakthrough test. And these samples showed high removal efficiency and high saturation adsorption capacity of DMS.


2007 ◽  
Vol 121-123 ◽  
pp. 1313-1316
Author(s):  
H.D. Liu ◽  
Yun Fa Chen

Mesoporous silica particles doped with iron was prepared with a novel method. Nitrogen adsorption-desorption test indicated that the BET surface area decreased with the increasing of iron doping amount. Small-angle X-ray diffractometry (SAXD) analysis showed that more iron dopant gave rise to less orderly structured product. FITRanalysis were all carried out to study the iron valent and distribution state in the as-made mesoporous silica particles.


2014 ◽  
Vol 11 (2) ◽  
pp. 419-428
Author(s):  
Baghdad Science Journal

Three mesoporous silica with different functional group were prepared by one-step synthesis based on the simultaneous hydrolysis and condensation of sodium silicate with organo - silane in the presence of template surfactant polydimethylsiloxane - polyethyleneoxide (PDMS - PEO). The prepared materials were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), atomic force microscopy (AFM) and nitrogen adsorption/desorption experiments. The results indicate that the preparation of methyl and phenyl functionalized silica were successful and the mass of methyl and phenyl groups bonded to the silica structure are 15, 38 mmol per gram silica. The average diameter of the silica particles are 103.51, 167.25 , and 86.41 nm while the average pore diameter are 6.7, 16.4, and 2.7 nm for unfunctionalized, methyl, and phenyl functionalized silica respectively.


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.


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