A MULTI-SAMPLE HOLDER ASSEMBLY FOR THE QUANTASORB® SURFACE AREA ANALYZER

1987 ◽  
Vol 67 (3) ◽  
pp. 709-713
Author(s):  
H. KODAMA ◽  
M. JAAKKIMAINEN ◽  
R. DUCOURNEAU
Keyword(s):  
Surface Area ◽  
Gas Flow ◽  
Gas Adsorption ◽  
Detection Sensitivity ◽  
Gas Flows ◽  
Sample Holder ◽  
Standard Samples ◽  
Surface Areas ◽  
Measuring Surface ◽  
Bet Method

An inexpensive and simple multi-sample holder assembly was designed and constructed for the Quantasorb® surface area analyzer which is based on the BET gas adsorption isotherm principle. Four sample holder U-tubes were connected in parallel in order to maintain all samples equidistant from the detector. This arrangement keeps high gas detection sensitivity and minimizes the occurrence of unwanted turbulent gas flows in the system. The system was tested by measuring surface areas of reference standard samples. Excellent agreement was obtained. Key words: BET method, gas adsorption, gas flow sytem, parallel connection

TEM measurement of surface area of automotive catalysts

1994 ◽  
Vol 52 ◽  
pp. 776-777
Author(s):  
M. H. Yao ◽  
D. R. Liu ◽  
R. J. Baird ◽  
R. K. Usmen ◽  
R. W. McCabe
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Average Particle Size ◽  
Weighted Average ◽  
Average Particle ◽  
Automotive Catalysts ◽  
Surface Areas ◽  
Measuring Surface ◽  
Major Factors ◽  
Average Size

The specific surface area of supported noble metal particles in an automotive catalyst is defined as the exposed surface area per unit mass of these particles. It is of great importance to know this parameter, since this is one of the major factors that determine the effectiveness of the catalyst. Commonly used methods for characterizing catalysts, such as X-ray diffraction and TEM, do not directly provide a measure of surface area, but, instead, provide a measure of the “average size” of supported particles. Moreover, the “average sizes” obtained from different experimental techniques are often not comparable. Furthermore, many previous electron microscopy catalyst studies measured only simple average particle size, and no detailed procedure for measuring area-weighted average size or surface area appear to have been reported.In the current study, a procedure for measuring surface area of supported particles by transmission electron microscopy(TEM) was developed, and applied to measure surface areas of various production three-way automotive catalysts.

A Low-Cost, Rapid Method for Determining Carbon Black Surface Area

1983 ◽  
Vol 56 (2) ◽  
pp. 440-449 ◽  
Author(s):  
Jerry B. Pausch ◽  
Caroline A. McKalen
Keyword(s):  
Carbon Black ◽  
Surface Area ◽  
Low Cost ◽  
Control Procedure ◽  
Simple Method ◽  
Surface Areas ◽  
Measuring Surface ◽  
Headspace Gas ◽  
Black Surface ◽  
Area Data

Abstract For practical use of this method as a quality control procedure for carbon black, a combination of 4 mm3 and 6 mm octane doses appears to be the best compromise for a sample size of 0.1 g. These conditions cover well, a surface area range of 10–140 m2/g and surface areas up to 180 m2/g can be estimated. Larger doses of octane will extend the linear range on the high side, but the slope of the calibration curve is reduced significantly. A smaller slope yields lower precision. The regular testing of standards appears necessary to achieve optimum accuracy of surface area. At the present time, the method is calibrated against nitrogen surface area data, so the advantage of octane more closely simulating the rubber molecule is lost. We need to obtain adsorption isotherms that are better defined throughout the linear adsorption coefficient range for a number of carbon blacks, and thus become self-calibrated against octane. A more versatile dosing technique is preferred to enable these experiments to be run. An alternate approach is to correlate the headspace results with data obtained by other techniques such as CTAB. The advantages of automated headspace gas chromatography for measuring surface area have been outlined before . It is a rapid and simple method, which also exhibits relatively low labor involvement. The number of samples capable of being analyzed per day is significantly higher than by any other technique.

scholarly journals Sorption of Methylene Blue for Studying the Specific Surface Properties of Biomass Carbohydrates

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1115
Author(s):  
Tatiana Skripkina ◽  
Ekaterina Podgorbunskikh ◽  
Aleksey Bychkov ◽  
Oleg Lomovsky
Keyword(s):  
Methylene Blue ◽  
Specific Surface ◽  
Surface Area ◽  
Surface Characterization ◽  
Gas Adsorption ◽  
Comparative Method ◽  
Nitrogen Adsorption ◽  
Surface Areas ◽  
Nitrogen Adsorption Isotherms ◽  
Adsorption Desorption

The surface area is an important parameter in setting any biorefining technology. The aim of this study was to investigate the applicability of sorption of methylene blue to characterize the surface of the main biomass carbohydrates: α-cellulose, sigmacell cellulose, natural gum, β-glucan, and starch. The morphology of particles of the model objects was studied by scanning electron microscopy. Nitrogen adsorption isotherms demonstrate that the selected carbohydrates are macroporous adsorbents. The monolayer capacities, the energy constants of the Brunauer–Emmett–Teller (BET) equation, and specific surface areas were calculated using the BET theory, the comparative method proposed by Gregg and Sing, and the Harkins–Jura method. The method of methylene blue sorption onto biomass carbohydrates was adapted and mastered. It was demonstrated that sorption of methylene blue proceeds successfully in ethanol, thus facilitating surface characterization for carbohydrates that are either soluble in water or regain water. It was found that the methylene blue sorption values correlate with specific surface area determined by nitrogen adsorption/desorption and calculated from the granulometric data. As a result of electrostatic attraction, the presence of ion-exchanged groups on the analyte surface has a stronger effect on binding of methylene blue than the surface area does. Sorption of methylene blue can be used in addition to gas adsorption/desorption to assess the accessibility of carbohydrate surface for binding large molecules.

The in vitro Uptake of Fluoride by Secretory and Maturation Stage Bovine Enamel

1988 ◽  
Vol 67 (2) ◽  
pp. 487-490 ◽  
Author(s):  
R.A. Fridell ◽  
A. Lussi ◽  
M.A. Crenshaw ◽  
J.W. Bawden
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Organic Matrix ◽  
Maturation Stage ◽  
Fluoride Uptake ◽  
Surface Areas ◽  
Bet Method ◽  
Two Stages ◽  
Bovine Enamel

The objectives of this study were to determine the specific surface area of secretory-stage and of maturation-stage enamel, to compare the fluoride uptake by isolated enamel at these two stages on a surface-area basis, and to examine the effect of the organic matrix on the fluoride uptake by whole enamel. Fetal bovine secretory and maturation stage enamel samples were collected, and a portion of the enamel at each developmental stage was treated with hydrazine for removal of the organic matrix. The specific surface areas of the enamel mineral, as determined by the multi-point BET method, were 59.3 m2/ g in the secretory stage and 37.9 m2/g in the maturation stage. Whole and deproteinated enamel samples were equilibrated in buffered solutions containing 10 -5 to 10-3 mol/L fluoride, and the uptake was measured with a fluoride specific electrode. The results indicate that the in vitro fluoride uptake was controlled solely by the surface area of the apatitic mineral and that the organic matrix did not contribute to the fluoride uptake.

Measuring surface area of airborne titanium dioxide powder agglomerates: relationships between gas adsorption, diffusion and mobility-based methods

2011 ◽  
Vol 13 (12) ◽  
pp. 7029-7039 ◽  
Author(s):  
Ryan F. LeBouf ◽  
Bon Ki Ku ◽  
Bean T. Chen ◽  
David G. Frazer ◽  
Jared L. Cumpston ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Surface Area ◽  
Gas Adsorption ◽  
Titanium Dioxide Powder ◽  
Measuring Surface ◽  
Dioxide Powder

Pore size distribution and adsorption selectivity of sepiolite

Clay Minerals ◽  
1990 ◽  
Vol 25 (1) ◽  
pp. 99-105 ◽  
Author(s):  
S. Inagaki ◽  
Y. Fukushima ◽  
H. Doi ◽  
O. Kamigaito
Keyword(s):  
Surface Area ◽  
Outer Surface ◽  
Adsorbed Water ◽  
Total Surface Area ◽  
Effective Size ◽  
Adsorption Selectivity ◽  
Surface Areas ◽  
Bet Method ◽  
The Mean ◽  
The Difference

AbstractMicropore distribution and effective size of the channels of natural sepiolite from Turkey were measured by the BET method. Before the BET measurement, the samples were treated under a water vapour atmosphere at various pressures to fill progressively the sepiolite micropores with water. The surface areas measured by means of N2 adsorption decreased with increased vapour pressures of water. The outer surface area was estimated by comparison of the surface area of the vacuum-dried sepiolite with that filled with adsorbed water. The total surface area was ∼290 m2/g, and the outer surface area was 170 m2/g, the difference being attributed to the structural micropores of the sepiolite. The ratio of the surface areas possessed by the channels and that of the outer surface suggest that the mean thickness of the sepiolite fibre was ∼12 nm. The effective size of the channels was estimated from the number of various-sized molecules sorbed by the sepiolite, the results showing that molecules larger than benzene could not migrate into the channels.

Volume-specific surface area by gas adsorption analysis with the BET method

2020 ◽  
pp. 265-294 ◽  
Author(s):  
Neil Gibson ◽  
Petra Kuchenbecker ◽  
Kirsten Rasmussen ◽  
Vasile-Dan Hodoroaba ◽  
Hubert Rauscher
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Gas Adsorption ◽  
Adsorption Analysis ◽  
Bet Method
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