THE USE OF VAN DER WAALS ADSORPTION ISOTHERMS IN DETERMINING THE SURFACE AREA OF IRON SYNTHETIC AMMONIA CATALYSTS

1935 ◽  
Vol 57 (9) ◽  
pp. 1754-1755 ◽  
Author(s):  
Stephen Brunauer ◽  
P. H. Emmett
Keyword(s):  
Surface Area ◽  
Adsorption Isotherms ◽  
Van Der Waals

Synthesis of hexagonal boron nitride heterostructures for 2D van der Waals electronics

2018 ◽  
Vol 47 (16) ◽  
pp. 6342-6369 ◽  
Author(s):  
Ki Kang Kim ◽  
Hyun Seok Lee ◽  
Young Hee Lee
Keyword(s):  
Boron Nitride ◽  
Surface Area ◽  
Hexagonal Boron Nitride ◽  
Van Der Waals ◽  
Large Surface Area ◽  
Van Der Waals Heterostructures

The construction of large surface area hexagonal boron nitride for van der Waals heterostructures and 2D-layered electronics is reviewed.

scholarly journals Waste phenolic resin derived activated carbon by microwave-assisted KOH activation and application to dye wastewater treatment

2019 ◽  
Vol 8 (1) ◽  
pp. 408-415 ◽  
Author(s):  
Wenhai Hu ◽  
Song Cheng ◽  
Hongying Xia ◽  
Libo Zhang ◽  
Xin Jiang ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Surface Area ◽  
Adsorption Isotherms ◽  
Phenolic Resin ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Koh Activation ◽  
Activation Process ◽  
Dye Wastewater

Abstract The waste phenolic resin was utilized as the raw material to prepare activated carbon (AC) used KOH as the activating agent via microwave heating. The phenolic resin was carbonized at 500°C and then performed with a KOH/Char ratio of 4 and microwave power of 700 W for a duration of 15 min. The physic-chemical characteristics of the AC were characterized by N2 adsorption instrument, FTIR, SEM and TEM. The BET surface area and pore volume of AC were found to be 4269 m2/g and 2.396 ml/g, respectively. The activation process to generate such a phenomenally high surface area of the AC has little reported in open literatures and could pave way for preparation adsorbents that are far superior to the currently marketed adsorbents. The methylene blue (MB) was used as the model to assess its suitability to dye wastewater treatment. Towards this, the MB adsorption isotherms were conducted at three different temperatures and tested with different adsorption isotherm models. The adsorption isotherms could be modeled using Langmuir isotherm. While the kinetics could be used the pseudo-second order kinetics to describe. Thermodynamic results demonstrated that the adsorption process was a spontaneous, as well as an endothermic.

Textural and morphology changes of mesoporous SBA-15 silica due to introduction of guest phase

2017 ◽  
Vol 89 (4) ◽  
pp. 481-491 ◽  
Author(s):  
Roman Bulánek ◽  
Pavel Čičmanec
Keyword(s):  
Surface Area ◽  
Adsorption Isotherms ◽  
Pore Volume ◽  
Vanadium Content ◽  
Phase Effect ◽  
Tem Analysis ◽  
Vanadyl Complex ◽  
Pore Blocking ◽  
Adsorption Layers ◽  
Morphology Changes

AbstractThe research focuses on study of guest phase effect on the surface area and pore volume of SBA-15 with the emphasis on elucidation of reasons for these changes. The changes of surface area and pore volume are evident from evaluated N2 adsorption isotherms of VOx-SBA-15 even for samples with relative low content of supported guest phase, which is “atomically” spread on the surface in the form of anchored monomeric vanadyl species. These species cannot block the pore with diameter of 10 nm, nevertheless the presence of such phase causes decrease in adsorbed nitrogen during physisorption. Comparison of guest phase amount with differences in adsorbed amount of nitrogen led to conclusion that each vanadyl complex prevents adsorption of about one or two N2 molecules in the layer and influences two adsorption layers. Significant pore blocking occurs in the VOx-SBA-15 materials only in the case of presence bulk oxide-like nanospecies. Re-structuralization of silica mimicking phase separation phenomena relying on spinodal decomposition of a system was observed by SEM/TEM analysis and adsorption isotherms inspection for materials with high vanadium content.

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