scholarly journals High-quality mesoporous SiO2 nanospheres via a confined jet impingement continuous microchannel reactor

2021 ◽  
Author(s):  
Qiang Chen ◽  
Kai Chen ◽  
Feng Yu ◽  
Aixia Guo ◽  
Siqing Zou ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Particle Diameter ◽  
Jet Impingement ◽  
High Specific Surface Area ◽  
Lithium Silicate ◽  
Average Particle ◽  
Microchannel Reactor

Abstract High surface area mesoporous silica (SiO2) nanospheres has been considered an ideal material for the catalytic, adsorption and drug delivery. However, synthesis of ultra-high specific surface area mesoporous silica nanoparticles with well-defined sphere structure and small particle size (< 200 nm) is still challenging. Here, a two-stream confined jet impingement continuous microchannel reactor is proposed to produce novel mesoporous silica nanospheres (MSNs) with ultra-high specific surface area (SSA) and abundant worm-like meso-porosity. The as-obtained MSNs with worm-like mesoporous structure were produced with average particle diameter of 142 ~ 207 nm, high SSA of 1347 ~ 1854 m2/g, total pore volume of 0.86 ~ 1.23 cm3/g and pore diameter of 2.6 ~ 3.3nm. Moreover, the shear force field in the microchannel reactor on the mesoscopic structure of MSNs was simulated by mesoscopic kinetics. Additionally, MSNs was used as the silicon source to synthesize lithium silicate (Li4SiO4), which enhanced carbon dioxide (CO2) adsorption of 27.18 wt% at 650 ℃.

High specific surface area ordered mesoporous silica COK-12 with tailored pore size

2019 ◽  
Vol 280 ◽  
pp. 133-143 ◽  
Author(s):  
Laura M. Henning ◽  
Diego Díaz Cubas ◽  
Maria G. Colmenares ◽  
Johannes Schmidt ◽  
Maged F. Bekheet ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Ordered Mesoporous Silica ◽  
Ordered Mesoporous

Study on the Preparing of Nanowhite Carbon Black by Silica Fume

2013 ◽  
Vol 423-426 ◽  
pp. 554-559 ◽  
Author(s):  
Xin Zhi ◽  
Zhan Cheng Guo
Keyword(s):  
Carbon Dioxide ◽  
Carbon Black ◽  
Specific Surface ◽  
Surface Area ◽  
Silica Fume ◽  
Specific Surface Area ◽  
Particle Diameter ◽  
Complete Response ◽  
High Specific Surface Area ◽  
Precipitated Silica

This research through the study on the properties of silicon dust, put forward in combination with lime kiln tail gas recycling carbon dioxide, preparation of precipitated silica (nanoWhite Carbon Black) of high value utilization technology, and studied and summarized process of the dissolution and precipitation by carbon dioxide. The silica fume is in amorphous form, and it has some special powder properties such as ultra fine grain size and high specific surface area and high chemical activity, these provide favorable foundation for low energy consumption process of recycling the powder. In the dissolution stage, the optimization reaction time is about 40 minutes, this time to complete the process of the reaction more than 90%. And the reaction is the fastest in the first 20 minutes, complete response 75% of the reaction. In the stage of carbonization, with increase of the concentration of the precursor, the particle diameter becomes larger, but the specific surface area of the powder will reduce, the porosity and the surface activity of it will reduce corresponding.

scholarly journals USE OF OPAL-CRYSTOBALITE-TRIDIMITE MICRO-FILLER IN DENSE AGGREGATE CONCRETE

2020 ◽  
pp. 8-17
Author(s):  
N. Lukutcova ◽  
A. Pykin ◽  
E. Chivikova
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Particle Diameter ◽  
Component Composition ◽  
Average Particle ◽  
Maximal Effect ◽  
Aggregate Concrete ◽  
Optimal Value ◽  
Cement System

Opal-cristobalite-tridimite micro-filler (OCTMF) as a component of dense aggregate concrete (DAC), obtained by grinding of sedimentary siliceous rock – abiomorphic silicite fractions of 0.315-0.63 mm was studied considered. The chemical-mineral composition and microstructure of the of OCTMF particles were determined. Comparative analysis of the relationship between particle size distribution, average particle diameter, specific surface area of OCTMF particle and grinding period in shock-abrasive and cavitation mills was carried out. The conductometric express method was applied to study the effect of the OCTMF specific surface area on hydration activity of cement system. The optimal value of OCTMF specific surface area was (880–900 m2/kg), achieved as a result of cavitation dispersion for 5–10 minutes, that provides increasing in t hydration activity of cement system by 52–54 %. The effect of the consumption of components on strength of the DAC after 28 days of hardening was determined using mathematical statistics method. That allows predicting this parameter by varying the component composition of the concrete mix. An assessment of the OCTMF efficiency was made. It was established, the maximal effect of the OCTMF is at concentration up to 5 % (by wt. of cement), that provides an increasing the design compressive strength of DAC up to 126 %.

scholarly journals Preparation of spherical aminopropyl-functionalized MCM-41 and its application in removal of Pb(II) ion from aqueous solution

2019 ◽  
Vol 8 (1) ◽  
pp. 275-284 ◽  
Author(s):  
Yi Lin ◽  
Jinjia Xu ◽  
Bhosale Sanjana Sudhakar ◽  
Junjie Gu ◽  
Ruoyu Hong
Keyword(s):  
Aqueous Solution ◽  
Mesoporous Silica ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Synthesis Methods ◽  
Silica Microspheres ◽  
Mesoporous Silica Microspheres ◽  
Mcm 41

Abstract Mesoporous silica microspheres were prepared by the polymerization-induced colloid aggregation (PICA) and pseudomorphic synthesis methods. The prepared microspheres have high specific surface area and MCM-41 type structure. In the PICA process, acidic silica sol was utilized as silica source and the effect of molar ration (formaldehyde/urea) was investigated. Moreover, the influences of reaction time and temperature were also studied. The specific surface area of porous and mesoporous silica microspheres were 186.4 m2/g and 900.4 m2/g, respectively. The materials were characterized by SAXS, FTIR, SEM, TEM and nitrogen sorption measurements. The prepared silica microspheres were functionalized by (3-Aminopropyl)triethoxysilane and then used to remove the lead from aqueous solution. The result indicates that the grafted silica microspheres have rapid adsorption capacity and good reproducibility. The adsorption data was fitted well with the Langmuir isotherm model, and the maximum adsorption capacities for MCM-41 silica microspheres were 102.7 mg/g.

Facile Synthesis of CeO2/SnO2 N-N Heterostructure

2019 ◽  
Vol 891 ◽  
pp. 200-205 ◽  
Author(s):  
Pimpan Leangtanom ◽  
Nattharinee Charoenrat ◽  
Sukon Phanichphant ◽  
Viruntachar Kruefu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Particle Size ◽  
High Specific Surface Area ◽  
Element Composition ◽  
Precipitation Method ◽  
Average Particle ◽  
Tem Analysis ◽  
Co Precipitation

Cerium oxide and tin oxide nanocomposites (CeO2-SnO2 NCs) were successfully synthesized via a simple co-precipitation method. The structure and properties of the synthesized materials were characterized using several X-ray and electron-based techniques including XRD, FE-SEM, TEM, EDS and BET to unravel the structure, morphology, element composition and specific surface area. The XRD and BET results showed that the NCs have the characteristic crystalline structures of SnO2 and CeO2-SnO2 NCs, and high specific surface area (66.45 and 86.29 m2/g), respectively. Amorphous phase of CeO2 and SnO2 were not found in XRD patterns. EDS analysis confirms the absence of all element composition and the FE-SEM and TEM analysis observed as particles having the clear spherical morphologies with the average particle size of of SnO2 and CeO2-SnO2 NCs was about 13 and 10 nm, respectively.

The Physical and Chemical Properties of Fly Ash fom Municipal Solid Wastes Incineration

2011 ◽  
Vol 194-196 ◽  
pp. 2065-2071
Author(s):  
Man Tong Jin ◽  
Cai Ju Huang ◽  
Zan Fang Jin
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Particle Diameter ◽  
Average Particle ◽  
Municipal Solid Wastes ◽  
Mswi Fly Ash ◽  
Treatment Technology

Fly ash from the municipal solid waste incineration (MSWI) which contains a small amount of heavy metals becomes a threat to human health and other living organisms once emitted into the environment, and has to be treated before disposal. This study focuses on the characteristics of the MSWI fly ash, which involve mineral composing, granularity distributing, specific surface area, pore diameter and pore volume of fly ash, leaching toxicity and chemical species of heavy metals. The experiment results confirm that the fly ashes are mainly composed of sylvite, halite, portlandite and calcium sulfate hydrate, with the the average particle diameter of 15.082 μm and the specific surface area of 4.290 m2/g, and the heavy metals such as Pb, Cu, Cr in the MSWI fly ash are mobile except Hg. This research provides critical information for appropriate MSWI fly ash treatment technology.

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