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Sorption nitrogen

The uptake values obtained for MEC adsorption are in good agreement with the results obtained for nitrogen sorption. As expected, the lower adsorption capacity belongs to SBA-15. After Al incorporation by direct-synthesis, the surface areas and pore volumes... [Pg.203]

Figure 3. Nitrogen sorption isotherms, DFT pore size distributions (inset) and XRD patterns (inset) of MCM-41-IBU obtained after different immersion times... Figure 3. Nitrogen sorption isotherms, DFT pore size distributions (inset) and XRD patterns (inset) of MCM-41-IBU obtained after different immersion times...
As discussed above, hysteresis loops can appear in sorption isotherms as result of different adsorption and desorption mechanisms arising in single pores. A porous material is usually built up of interconnected pores of irregular size and geometry. Even if the adsorption mechanism is reversible, hysteresis can still occur because of network effects which are now widely accepted as being a percolation problem [21, 81] associated with specific pore connectivities. Percolation theory for the description of connectivity-related phenomena was first introduced by Broad-bent et al. [88]. Following this approach, Seaton [89] has proposed a method for the determination of connectivity parameters from nitrogen sorption measurements. [Pg.23]

Comparison between Nitrogen Sorption and Mercury Intrusion... [Pg.27]

Fig. 1.18A shows the pore size distribution for nonporous methacrylate based polymer beads with a mean particle size of about 250 pm [100]. The black hne indicates the vast range of mercury intrusion, starting at 40 pm because interparticle spaces are filled, and down to 0.003 pm at highest pressure. Apparent porosity is revealed below a pore size of 0.1 pm, although the dashed hne derived from nitrogen adsorption shows no porosity at aU. The presence or absence of meso- and micropores is definitely being indicated in the nitrogen sorption experiment. [Pg.27]

Another example of a macroporous methacrylate-based polymer support is shown in Fig. 1.19 [101]. Again, only the relevant pore range is displayed. The pores around 1 pm are fully revealed by mercury intrusion, whereas with nitrogen sorption, above 0.1 pm, essentially no pores can be detected. [Pg.28]

Surface area measurements reported for sorbitol powders have been obtained using the BET method of nitrogen sorption [7,26,28]. Values ranged from 0.4 to 1.5 m" /g can be obtained depending on the vendor and grade of material. [Pg.483]

Table 2.1.6.4 Nitrogen sorption data of the Co(ll)-Jacobsen complex immobilized on AI-MCM-41 by ion exchange or impregnation. Table 2.1.6.4 Nitrogen sorption data of the Co(ll)-Jacobsen complex immobilized on AI-MCM-41 by ion exchange or impregnation.
Figure I. Nitrogen sorption on Pittsburgh coal desorption points are solids solid curves indicate isotherms of ascending temperature sequence and broken curves, descending temperature sequence... Figure I. Nitrogen sorption on Pittsburgh coal desorption points are solids solid curves indicate isotherms of ascending temperature sequence and broken curves, descending temperature sequence...
Nitrogen sorption measurements were performed on a Quantachrome Autosorb 6B (Quantachrome Corporation, Boynton Beach, FL, USA). All samples were degassed at 423 K before measurement for at least 12 hours at 1 O 5 Pa. Mercury-porosimetrie has been measured on a Porosimeter 2000 (Carlo Erba Instruments) Scanning electron micrographs were recorded using a Zeiss DSM 962 (Zeiss, Oberkochen, Germany). The samples were deposited on a sample holder with an adhesive carbon foil and sputtered with gold. [Pg.2]

Additionally, the microwave treatment during the crystallization process at high temperature may cause the metastable mesophase to collapse into the denser or amorphous phase in synthetic mixture as well as provide the favorable condition for the formation of silicalite-1. A summary of parameters obtained by nitrogen sorption is shown in Table 2. In Table 2, pore diameters of major peaks ( ) for sample II-IV are increased from 2.5 to 2.87 nm as extending the microwave irradiation. It implied that the additional space created in the mesoporous channels, as a consequence of the pore size enlargement, that is filled by extra water [16]. [Pg.112]

A low temperature nitrogen sorption was carried out on an automated physisorption instrument (ASAP 2000, Micromeritics Instrument Corporation). Before the measurement, the sample was degassed at 350 C for 4-5 h until the vacuum of system was better than 0.67 Pa. The data for micropore were obtained from t-plot, and those for mesopore and distribution of mesopore were calculated by BJH method (using desorption curve). The single point total pore volume at high relative pressure was taken as the total volume. [Pg.392]

Summary of butanol, water, benzene and nitrogen sorption data... [Pg.621]

The LPS silica is prepared by extracting the water from a low solids hydrogel with an organic solvent to avoid the compression of aqueous surface tension. This leaves a fragile catalyst of very high pore volume. Such preparations often provide dramatic examples of the effect of pore volume because the same gel dried directly in an oven will frequently be less active or even completely dead. Invariably, nitrogen sorption shows the inactive silica to contain a low pore volume mainly inside small pores, e.g., less than 60 A diameter. In contrast, the active sample dried by extraction usually has equal or greater volume inside small pores, and, in addition, considerable volume... [Pg.70]

Fio. II. Nitrogen sorption isotherm of two catalysts made from the same hydrogel, i.e., one very active, the other completely dead. The active sample was specially dried by extraction with an organic solvent of low surface tension to protect the larger pores. [Pg.71]

This is also true of nitrogen sorption in hydrated zeolites. [Pg.113]

The observed variation of nitrogen sorption capacity at atmospheric pressure with content of presorbed water is shown in Figure 2. In all cases, the nitrogen capacity is seen to fall off regularly with increasing amounts of presorbed water, the rate of fall being highest in zeolite NaA and lowest in zeolite NaY. [Pg.113]


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See also in sourсe #XX -- [ Pg.91 ]

See also in sourсe #XX -- [ Pg.71 , Pg.88 , Pg.99 , Pg.103 ]




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Comparison between Nitrogen Sorption and Mercury Intrusion

Mercury intrusion and nitrogen sorption

Nitrogen Sorption Measurements

Nitrogen sorption isotherms

Nitrogen sorption isotherms, porosity

Nitrogen sorption porosimetry

Sorption capacity, nitrogen

Zeolite nitrogen sorption

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