scholarly journals Synthesis and mechanism of aluminum silicate mesoporous materials by F108 template

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhijun Ma ◽  
Jing Gao ◽  
Xingyuan Weng ◽  
Shuai Yang ◽  
Kai Peng

Abstract Aluminosilicate mesoporous materials were synthesized using F108 template (polyethylene glycol-polypropylene glycolpolyethylene glycol) at a concentration of 0.034 g/ml and the molar ratio of Al2O3 to SiO2 was 0.09. The products were then characterized using nitrogen adsorption/desorption tests, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The effects of various crystallization temperatures as well as sodium hydroxide concentrations on the average diameter, pore volume, surface area, and morphology of the synthetic material were analyzed. Results showed that a sodium hydroxide concentration of 11 mol/L and a crystallization temperature of 130 °C produced a synthetic material with regular pore size and homogeneous arrangement including a specific surface area of 137.62 m2/g, an average pore volume of 0.27 cm3/g, along with an average pore size of 15.33 nm.

2021 ◽  
Vol 21 (7) ◽  
pp. 3868-3871
Author(s):  
Jihee Kim ◽  
Jung Eun Lee ◽  
Abid Farooq ◽  
Sang Chai Kim ◽  
Sang-Chul Jung ◽  
...  

In this study, the effect of Ru-Mn bimetallic catalysts in combination with a zeolite support on the removal of toluene in the presence of ozone at room temperature was investigated. Desili-cated HZSM-5 (DZSM) was fabricated and applied as a Ru-Mn support for the removal of toluene (100 ppm) in the presence of ozone (1000 ppm) at room temperature. The surface area, pore volume, and average pore size of Ru-Mn with a DZSM support (RuMn/DZSM) were measured and compared with those of Ru-Mn/HZSM-5 (RuMn/HZSM). The pore size of RuMn/DZSM (69 Å) was much larger than that of RuMn/HZSM-5 (5.5 Å). In addition, the pore volumes of RuMn/DZSM and RuMn/HZSM were 0.64 and 0.25 cm3/g, respectively. Furthermore, the ratios of Mn3+/Mn4+ and Ovacancy/Olattice of RuMn/DZSM were larger than those of RuMn/HZSM-5. The removal efficiency of toluene of RuMn/DZSM was higher than that of RuMn/HZSM due to its larger pore volume, pore size, and the increased ratios of Mn3+/Mn4+ and Ovacancy/Olattice.


2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Prima Astuti Handayani ◽  
Eko Nurjanah ◽  
Wara Dyah Pita Rengga

<p>Sekam padi merupakan salah satu sumber penghasil silika terbesar, berpotensi sebagai bahan pembuatan silika gel. Abu sekam padi mengandung silika sebanyak 87%-97% berat kering. Sintesis silika gel dari abu sekam padi dilakukan dengan mereaksikan abu sekam padi menggunakan larutan NaOH 1N pada suhu 800C selama 1 jam dan dilanjutkan dengan penambahan larutan asam hingga pH=7. Gel yang dihasilkan selanjutnya didiamkan selama 18 jam kemudian dikeringkan pada suhu dikeringkan menggunakan oven pada suhu 800C hingga beratnya konstan. Hasil percobaan diperoleh bahwa silika gel dengan penambahan CH3COOH menghasilkan yield yang lebih besar dibandingkan penambahan HCl. Berdasarkan analisis FT-IR silika gel yang diperoleh memiliki gugus Si-O-Si dan gugus Si-OH. Silika gel dengan penambahan HCl memiliki surface area sebesar 65,558 m2/g, total pore volume 0,1935 cc/g, dan average pore size sebesar 59,0196 Å. Sedangkan silika gel dengan penambahan CH3COOH memiliki surface area sebesar 9,685 m2/g, total pore volume 0,02118 cc/g, dan average pore size sebesar 43,7357Å. Silika gel dengan penambahan<br />CH3COOH memiliki kemampuan menyerap kelembaban udara yang lebih baik dibanding silika gel dengan penambahan HCl.</p><p> </p><p>Rice hull ash (RHA) is one of the biggest source of silica, potential for sintesis silica gel. RHA contains silica as many as 87 % -97 %. Synthesis of silica gel from rice hull ash was done by reaction using NaOH solution at temperature 800C for 1 hour and followed by the addition of an acid solution until pH=7. The gel were rested with time aging 18 hour, and then dried using oven at temperature 800C until constant weigh. The results obtained that the silica gel with the addition of CH3COOH produce higher yields than the addition of HCl. Based on FT-IR analysis, silica gel has a group of silanol (Si-`OH) and siloxan (Si-O-Si) group. Silica gel with the addition of HCl has a surface area 65,558 m2/g, a total pore volume 0,1935 cc/g, and average pore size 59,0196 Å. While the silica gel with the addition of CH3COOH has a surface area 9.685 m2/g, a total pore volume 0,02118 cc/g, and average pore size 43,7357 Å. Silica gel with the addition of CH3COOH<br />has the ability to absorb humidity better than silica gel with the addition of HCl.</p>


2012 ◽  
Vol 174-177 ◽  
pp. 1010-1014 ◽  
Author(s):  
Hong Bin Liu ◽  
Yang Ju ◽  
Kai Pei Tian ◽  
Jin Hui Liu ◽  
Li Wang ◽  
...  

The pore structure characteristics of reactive powder concrete (RPC) were investigated by means of the mercury injection method at seven temperature levels, namely, 20°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, respectively. The characteristic parameters such as porosity, pore volume, average pore size and threshold aperture varied with temperatures were analyzed. The results indicate that the porosity, pore volume, threshold aperture and other characteristic parameters of RPC increased with the temperature increasing.


2018 ◽  
Vol 80 (2) ◽  
Author(s):  
Klinsmann Cheong Lee Khang ◽  
Mohd Hayrie Mohd Hatta ◽  
Siew Ling Lee ◽  
Leny Yuliati

A series of mesoporous ZnO/TiO2 composites were successfully synthesized using cetyltrimethylammonium bromide surfactant. The composites of different Zn:Ti molar ratios (0.5:1, 0.75:1, and 1:1) were prepared by impregnating ZnO onto mesoporous TiO2. XRD results verified co-existence of both anatase TiO2 and hexagonal wurtzite ZnO in the ZnO/TiO2 composites. Based on the Tauc plots, all the composites showed almost the same band gap energy of approximately 3.21 eV. The fourier transform infrared spectroscopy results successful covering of ZnO on the surface of the TiO2 as the hydrophilicity property of TiO2 decreased remarkably with the loading of ZnO in the composites. N2 adsorption-desorption isotherms of the samples exhibited type-IV isotherm with a hysteresis loop. The Barrett-Joyner-Halenda pore size distribution revealed that the average pore size of the composites was around 3.6 nm, indicating the formation of mesopores dominantly in the samples. The photocatalytic removal of phenol over the samples under UV light irradiation after 3 h decreased in the order: ZnO/TiO2 composites > anatase TiO2 (with surfactant) > anatase TiO2 (without surfactant) > ZnO. The composite with Zn:Ti molar ratio of 0.75:1 has achieved the highest photocatalytic activity of 36.5% in the removal of phenol under UV light irradiation for 3 h.


2019 ◽  
Vol 19 (6) ◽  
pp. 3205-3209 ◽  
Author(s):  
Shangqing Lu ◽  
Qirui Lin ◽  
Sufang Wu

This study focuses on the synergy effect of pore size and specific surface area (SSA) on the carbon dioxide sorption performance. Nano CaO-based CO2 sorbents with various pore size (15–55 nm) under similar SSA, and different SSA (14.50–48.90 m2/g) under similar pore size are prepared using selected organic templates. Results indicate that increasing the proportion of macropore in 47–96 nm could significantly improve sorbent’s sorption rate and corresponding sorption capacity. Besides, sorption capacity could be also by SSA. Moreover, partial correlation analysis reveals that sorption capacity is slightly more dependent on average pore size than SSA.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jing Wang ◽  
Li Fang ◽  
Fangqin Cheng ◽  
Xiaofang Duan ◽  
Rongming Chen

Well-ordered SBA-15 was prepared with a hydrothermal route by sodium silicate derived from coal gangue. The as-prepared sample was analyzed by SAXRD, BET, TEM, and SEM, respectively. The results indicate that at a low hydrothermal temperature of 100∘C the well-ordered mesoporous SBA-15 could be synthesized. The surface area, pore volume, and pore size of the sample are 552 m2/g, 0.54 cm3/g, and 7.0 nm, respectively. It is suggested that coal gangue could be used in obtaining an Si source to prepare mesoporous materials, such as SBA-15.


2014 ◽  
Vol 602-603 ◽  
pp. 279-284
Author(s):  
Li Qun Duan ◽  
Chen Chen Zhang ◽  
Qing Song Ma ◽  
Zhao Hui Chen

Nanoporous carbonaceous materials derived from polysiloxane were first prepared by pyrolysis at 1300°C followed with hydrofluoric acid (HF) etching treatment. Their thermal stability of pore structure in inert condition was investigated in this paper by nitrogen adsorption technique in detail. The specific surface area (SSA) and pore volume (total pore volume, micropore volume, mesopore volume) decreased continually in the heat-treatment temperature range of 1000~1400°C. The average pore size almost kept the same with the raw sample. However, when the temperature exceeded 1400°C, the micropore interconnection began transforming to mesopore structure, which led to the decline of SSA and the increase of average pore size. Furthermore, the pore size distributions (PSDs) curves showed that heat-treatment had an advantage on the transition process of pore structure from disorder to regularity to some extent when heat-treated in the range 1000~1400°C for the most possible reason of relief of residue strain in the carbonaceous materials.


Author(s):  
M. Troubitsin ◽  
Viet Hung Hoang ◽  
L. Furda

The object of our investigation is a biomimetic calcium-phosphate nanocomposite doped by silicate and carbonate anions (BMHAP) synthesized by chemical deposition from aqueous solutions. The obtained samples are investigated using X-ray phase analysis (XRD), FTIR spectroscopy, and low-temperature nitrogen adsorption (BET method). The influence of the techno chemical synthesis parameters on the products characteristics (including phase composition, crystal lattice parameters, average crystallite size, specific surface area) is evaluated. The study on the effect of the synthesis temperature shows that with increasing in temperature from 22°C to 80°C, reveals a slight increase in the parameters of unit cells a and c, which leads to an increase in its volume. There is also a tendency towards a decrease in the average size of coherent scattering regions of crystallites (from 7,52 to 4,65 nm) and specific surface area (from 192,51 to 74,72 m2/g), but the pore volume and average pore diameter of the synthesized powders increases. The effect of the aging time of the sediment in the mother liquor is studied from 0,5 to 24 hours. It is found that with an increase in the maturation time of the sediment, the percent crystallinity of the powders improves by 1,7 times, an increase in the specific surface area from 163,43 to 192,51 m2/g and a slight decrease in the pore volume and average pore size of the samples are observed. The impact of the stirring rate of the reagents is investigated. An increase in speed from 300 to 1300 rpm has been shown to decrease the average crystallite size from 8,80 to 6,41 nm, and as a result, to increase the specific surface area of the synthesized samples from 178,58 to 192,51 m2/g, respectively.


Author(s):  
Yuvarat Ngernyen ◽  
Werawit Phiewruangnont ◽  
Narathorn Mahantadsanapong ◽  
Chantakorn Patawat ◽  
Ketsara Silakate ◽  
...  

Dipterocarpus alatus tree grows prolifically throughout Thailand and can be tapped to yield significant quantities of oil to be used as natural diesel. However, such practices lead to waste dried fruit dropping from the tree. At present, there is no utilization of this dropped fruit, therefore costeffective processes need to be applied to obtain higher value products from this waste. A possible to utilization is the conversion to activated carbon for adsorption applications including the removal of heavy metals, dyes, and other contaminants in water purification and other decontamination process. A major challenge of current commercial activated carbon is the high production cost and recently it has been shown that chemical activators comprise a significant proportion of these costs. This feasibility study investigates the use of Dipterocarpus alatus fruit as raw material to produce low cost activated carbon adsorbents. Activated carbon was prepared from Dipterocarpus alatus fruit: endocarp, mesocarp, and wing by chemical activation with ZnCl2, FeCl3, and KOH. Each part of the fruit was impregnated with 30 wt% activating agent at a ratio of 1:2 for 1 h and then carbonized at 500 oC for a further 1 h. The surface area, pore volume, and average pore size of the resulting carbons were characterized by nitrogen gas adsorption. Activation of mesocarp with ZnCl2, KOH, and FeCl3 gave activated carbons with the surface area of 447, 256, and 199 m2/g, respectively. In the same way, ZnCl2 activation gave a maximum surface area of 312 and 278 m2/g for wing and endocarp, respectively. All of the aforementioned samples have an average pore size of around 2 nm. In contrast, KOH and FeCl3 activation of wing and endocarp produced activated carbon with very low surface area (below 25 m2/g), but with an average pore size of 5- 14 nm. The maximum surface area of activated carbon prepared from Dipterocarpus alatus fruit was higher than some literature examples for activated carbon from other biomass. Consequently, Dipterocarpus alatus fruit demonstrated significant potential as a feedstock for the preparation of low cost activated carbons.


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