Differential pore size distribution

Fig. 3. Effect of dodecanol in the porogenic solvent on the differential pore size distribution of molded poly(glycidyl methacrylate-co-ethylene dimethacrylate) monoliths (Reprinted with permission from [62]. Copyright 1996 American Chemical Society). Conditions polymerization time 24 h, temperature 70 °C, polymerization mixture glycidyl methacrylate 24%, ethylene dimethacrylate 16%, cyclohexanol and dodecanol contents in mixtures 60/0 (curve 1), 57/3 (curve 2), 54/6 (curve 3), and 45/15 vol.% (4)...

The parameters D and Dk > whether for macro (denoted by subscript m) or for micro (denoted by subscript ju) regions, are normal bulk and Knudsen diffusion coefficients, respectively, and can be estimated from kinetic theory, provided the mean radii of the diffusion channels are known. Mean radii, of course, are obtainable from pore volume and surface area measurements, as pointed out in Sect. 3.1. For a bidisperse system, two peaks (corresponding to macro and micro) would be expected in a differential pore size distribution curve and this therefore provides the necessary information. Macro and micro voidages can also be determined experimentally. 

FIGURE 1.6 Influence of the polymerization temperature on the porosity of polyfglycidyl methacrylate-co-ethylene dimethacrylate) monoliths determined by MIP. (a) Differential pore size distribution curves of the polyfglycidyl methacrylate-co-ethylene dimethacrylate) rods, prepared by 22 h polymerization at a temperature of 55°C ( ), 12 h at 70°C ( ), and a temperature increased during the polymerization from 50°C to 70°C in steps by 5°C lasting 1 h each and kept at 70°C for another 4h ( ). (Reprinted with permission from Svec, F. and Frechet, Chem. Mater., 1, 707, 1995. Copyright 1995, American Chemical Society.) (b)... 

Fig. 6.26. Differential pore size distribution profiles of porous polymeric monolithic capillary columns with mode pore diameters of 255 (curve 1), 465 (2), 690 (3), and 1000 nm (4) (Reprinted with permission from [64]. Copyright 1997 American Chemical Society).

Figure 2. Differential pore size distributions of Goynuk limestone at different conversions at 860°C.

These results were also confirmed by the investigation of the porous structure of the diamond powders by the adsorption-structural method. It was established that the differential pore-size distribution of the initial and treated powder practically coincide, i.e., the hydrogen treatment mainly influences the state of the surface, whereas its influence on the porous structure is insignificant. 

Figure 2. Nitrogen adsorption isotherms at 77K for the OMM samples with multifunctional mercury-specific ligands 1-benzoyl-3-propylthiourea (OMM-1 and OMM-2), 2,5-dimercapto-1,3,4-thiadiazole (OMM-3) and the corresponding differential pore size distributions. OMM-a, OMM-b and OMM-c refer to the calcined MCM-41, MCM-48 and SBA-15 samples, respectively. For clarity the isotherms are offset vertically by 1000 ccSTP/g for OMM-a and OMM-1 samples and by 500 ccSTP/g for OMM-b and OMM-2 samples. The PSD plots are offset vertically by 2 ccg 1nm 1 for OMM-a and OMM-1 and by lccg-1 nm"1 for OMM-b and OMM-2 samples.

Figure 4.11 Differential pore size distribution of a Y-AI2O3 membrane by the nitrogen adsorption/desorption method [Anderson etal., 1988]...

Figure 15. Adsorption and desorption isotherm of nitrogen on the following adsorbents (1) Xh r, (2) Xh-a, (3) Xb-a- Inserted diagram differential pore size distribution as a function of pore radius (R) for the same adsorbents.

FIGURE 14.5 Differential pore size distribution for common adsorbents. 

The parameter <5 in the above equation can be determined from the differential pore size distribution,... 

Figure 4.6 Differential pore size distribution curves for the sheets prepared by polymerization of 24% glycidyl methacrylate and 16% ethylene dimethacrylate in 54% cyclohexanol and 6% dodecanol at temperatures of (1) 55, (2) 60, (3) 65, (4) 70, (5) 80, and (6) 90°C. (Reprinted from [383] with permission of the American Chemical...

Figure 4.7 Differential pore size distribution curves of the polyfglycidyl methacrylate-co-diethylene glycol dimethacrylate) prepared by suspension polymerization at the temperatures (1) 90 and (2) 70 C initiated by (a) benzoyl peroxide and (b) 2,2-azo(bis-isobutyronitrile). (Reprinted from [383] with permission of the American Chemical Society).

Figure 4.8 Differential pore size distribution curves of porous polymer of monolithic capillary columns obtained by in situ polymerization of 40% ethylene dimethacrylate with 60% mixture of butyl methacrylate and 2-acrylamido-2-methyl-1-propanesulfonic acid in 10% water and 90% mixture of 1-propanol and 1,4-butanediol taken in various ratios mode pore diameter (1) 255, (2) 465, (3) 690, and (4) 1000 nm. Reprinted from [385] with permission of the American Chemical Society).

Figure 27.7 showed the differential pore size distribution curve for the Norit AC. This carbon has the whole pore set micro-, meso-, and macropores. The overall specific surface area of this carbon is 1700m /g. 

The differential pore size distributions obtained by Sanjeevi et al. [3] are shown in Figs, 10 and 11. The raw collagen fibers prepared from a portion of bovine belly hide have mesopores with radii of 3.9-7.7nm and micropores with radii of 0.35-0.55nm (mean, 0.45 nm). They suggested that a micropore diameter of 0.9nm is... 

Plotting Avi/Ar, vs. r, yields the so-called differential pore size distribution, probably the most widely used characteristic of a porous solid. 

By measuring the volume, of mercury intruded into pores under pressure P(, the differential pore size distribution, Au,/Ar, vs. Yi, can be arrived at by noting that... 

In gas adsorption measurements, there is a critical lower value of relative pressure, e.g., / // o 0.4 for nitrogen, below which capillary condensate cannot exist as a separate phase, no matter whether the pore system extends to finer pores or not this is a consequence of the existence of so-called tensile strength limit [6]. As a result of this, a very narrow false maximum may appear on the differential pore size distribution at its fine-pore end, typically between 17 and 20 A in the case of nitrogen. 

Fig. 4-8. Differential pore size distribution of a Linde molecular sieve and molecular sieve carbon [4.27].

Figure 1. Differential pore size distributions derived from the desorption branch of nitrogen physisorption at 77 K (STP 273.15 K, 1 atm), (a) Pt5PC, (b) Pt2NP both calcined in air at 573 K.

Figure 11 Differential pore size distribution curves of the poly(glycidyl methacrylate-co-ethylene dimethacrylate) beads (1) and monolith (2) prepared at a temperature of 70 C.

The total volume of mercury VHg(p) penetrating the pores of the material at pressure p leads via equation (1.2) to the integral volume Vp(r) of all pores with radii (p) larger than r < p < oo, i. e. Vp(r) = VHg(p). By differentiation to the pore radius r this yields the differential pore size distribution of the material. This method is valuable to investigate macro- and mesopores (lUPAC, cp. Sect. 3), but not for micropores, i. e. it is limited to pore radii r > 1 nm. 

Differential pore size distribution curve created by KOH activation of MEGO and determined from BET surface area analyzer. Source Zhu, Y. et al. 2011. Science, 1537. With permission.)... 

Plots of A V/ Vb are shown in Figure 2.25 using a log-normal distribution of n (op) as input. The n (ao) distribution is cutoff at a = 0.52 C m and normalized according to the finite width of the integration region. Corresponding differential pore size distributions are obtained from the relation... 

Figure 23-10 shows the differential pore size distribution curves of heat-treated gels after aging in the wet state under various ammona concentration and/or temperature conditions. Since the equilibrium solubility of amorphous sihca increases at higher temperature and under pH conditions higher than typically 10, the median size of resultant... 

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