Effects of Surface Properties and Solvent PH Values on the Adsorption/Desorption Abilities of Mesoporous SBA-15 to Methylene Blue Molecules

2012 ◽  
Vol 518-523 ◽  
pp. 352-355
Author(s):  
Hui Liu ◽  
Hong Liang Li ◽  
Meng Xue Wang ◽  
Jing Jing Sang ◽  
Xiu Song Zhao

Methylene blue (MB) was used as model molecule to investigate the effects of surface properties and solvent pH values on the adsorption and desorption (or release) behaviors of mesoporous SBA-15 materials. It was found that the treatment of SBA-15 with a pH 7.8 aqueous solution can enhance the adsorption rate and capacity in comparison with the pristine SBA-15. The effect of pH values on MB releasing from the weak base treated SBA-15 and the pristine one have been studied and been compared in pH values range from 0.5 to 7.0. Both of them showed a maximum releasing rate at about pH 2 and all of the treated SBA-15 samples showed a higher releasing quantity than the pristine ones. The influence mechanisms of base treatment on the adsorption ability and that of pH values on the releasing properties of SBA-15 samples have been analyzed and been discussed based on the composition, the morphology, the surface area and pore size distribution and adsorption/desorption measurements.

Author(s):  
Eduardo A. Kamenetzky ◽  
David A. Ley

The microstructure of polyacrylonitrile (PAN) beads for affinity chromatography bioseparations was studied by TEM of stained ultramicrotomed thin-sections. Microstructural aspects such as overall pore size distribution, the distribution of pores within the beads, and surface coverage of functionalized beads affect performance properties. Stereological methods are used to quantify the internal structure of these chromatographic supports. Details of the process for making the PAN beads are given elsewhere. TEM specimens were obtained by vacuum impregnation with a low-viscosity epoxy and sectioning with a diamond knife. The beads can be observed unstained. However, different surface functionalities can be made evident by selective staining. Amide surface coverage was studied by staining in vapor of a 0.5.% RuO4 aqueous solution for 1 h. RuO4 does not stain PAN but stains, amongst many others, polymers containing an amide moiety.


2011 ◽  
Vol 194-196 ◽  
pp. 385-388
Author(s):  
Hong Juan Wang ◽  
Feng Qiang Sun ◽  
Ming Zhong Ren ◽  
Qing Wei Guo

Nanoporous SnO2with high photocatalytic activity has been successfully prepared by a photochemical method, using SnCl2aqueous solution as a precursor. The as-synthesized sample was characterized by XRD, N2 adsorption-desorption and UV-vis. The photocatalytic activity of the sample was evaluated by degrading methylene blue (MB) aqueous solution under the UV light source and was compared with that of the commercial titania (Degussa P25). The results showed that the produced SnO2can degrade MB solution quickly and has comparative photocatalytic performance with P25 for degrading MB. This facile method supplies an effective way to prepare SnO2photocatalyst.


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.


2016 ◽  
Vol 315 ◽  
pp. 42-51 ◽  
Author(s):  
Masoud Jahandar Lashaki ◽  
John D. Atkinson ◽  
Zaher Hashisho ◽  
John H. Phillips ◽  
James E. Anderson ◽  
...  

2015 ◽  
Vol 814 ◽  
pp. 286-291
Author(s):  
Bo Tao Wang

Adopting the chemical activation method, the high specific surface area activated carbon (AC) was prepared by the solid mixing method using Daqing petroleum cokes as raw materials and KOH as activator. The influence of the ratio of KOH to carbon, activation temperature and activation time on the iodine and methylene blue adsorption properties of the AC were studied. The micro-graphitic structure of the AC was studied by X-ray diffraction (XRD). The BET specific surface area, BJH pore size distribution and pore volume of the AC were determined by N2 adsorption (at 77K). The experimental results show that the high specific surface area AC can be prepared with the ratio of KOH to carbon of 4, activation temperature of 800°C and activation time of 1h. The specific surface area was as high as 2142 m2/g with the iodine adsorption value of 288mg/g and methylene blue adsorption value of 1266mg/g. The XRD and BJH results also show that amorphous carbon was the dominating form, and the pore size distribution represents micropore structure.


2007 ◽  
Vol 544-545 ◽  
pp. 227-230
Author(s):  
Z. X. Yang ◽  
Jeong Bae Yoon ◽  
J.O. Kim ◽  
Kyu Hong Hwang ◽  
B.S. Jun ◽  
...  

Porous concretes with continuous voids have been gaining more interest as an ecological material because of their useful functions such as water permeability and adsorption ability. So pore size distribution and the shape of especially open pores are the key point to permeability. In this study, the size and shape of pores of water permeable concrete were primary controlled by the size and shape of aggregates and secondly by the expanding agents to the cement pastes. 2 types of raw coase aggregate, type I and type C which mean fabricated by impact crusher and concrusher, were taken into uses and 3 sizes of aggregate were used, namely 3 to 5mm, 5 to 13 mm, and 13 to 20 mm. The compressive strength was found to be higher when using impact crushed aggregate. And the smaller size of aggregate was used, the higher compressive strength was achieved.


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