Biphasic calcium phosphate scaffolds with controlled pore size distribution prepared by in-situ foaming

2019 ◽  
Vol 95 ◽  
pp. 363-370 ◽  
Author(s):  
Lenka Novotna ◽  
Lukas Kucera ◽  
Ales Hampl ◽  
Daniel Drdlik ◽  
Jaroslav Cihlar ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Biphasic Calcium Phosphate

Carbon-Doped Hollow Titania with Tuneable Shell Architecture for Supercapacitors

2016 ◽  
Vol 69 (2) ◽  
pp. 183 ◽  
Author(s):  
Juanrong Chen ◽  
Fengxian Qiu ◽  
Ying Zhang ◽  
Shunsheng Cao
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
High Performance ◽  
Electrode Materials ◽  
Carbon Doping ◽  
Narrow Pore Size Distribution ◽  
Carbon Doped

A new trend in supercapacitor research has focussed on the construction of inexpensive electrode materials with high capacitor performances. In this study, we demonstrate the successful preparation of carbon-doped hollow titania spheres. The as-prepared titania spheres not only exhibit an advantage over existing methods because they are created in situ by directly carbonizing cationic polystyrene templates without the addition of carbon precursors, but also feature a narrow pore size distribution and a tuneable shell architecture. When the materials were applied as supercapacitor anodes, the electrochemical results reveal the superior performances of the supercapacitors over that of commercial P25. The higher performances were attributed to carbon doping. Thus, the reported C-doped hollow titania shows more potential as electrode materials for high-performance supercapacitors.

Water Adsorption in Nanoporous Carbon Characterized by in Situ NMR: Measurements of Pore Size and Pore Size Distribution

2014 ◽  
Vol 118 (16) ◽  
pp. 8474-8480 ◽  
Author(s):  
Hai-Jing Wang ◽  
Alfred Kleinhammes ◽  
Thomas P. McNicholas ◽  
Jie Liu ◽  
Yue Wu
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Water Adsorption ◽  
Nanoporous Carbon ◽  
In Situ Nmr

scholarly journals In-Situ Pore Structure Analysis During Aging and Drying of Gels

1990 ◽  
Vol 180 ◽  
Author(s):  
Douglas M. Smith ◽  
Pamela J. Davis ◽  
C. Jeffrey Brinker
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Pore Fluid ◽  
Structure Evolution ◽  
High Ph ◽  
Drying Rates

ABSTRACTThe use of NMR relaxation measurements for the in-situ study of pore structure evolution during gel aging and drying is illustrated. The change in the pore size distribution and surface area of both wet and dried gels is examined as a function of aging conditions including temporal aging, thermal aging, changing pH, and changing pore fluid. The effect of pore fluid pH on dissolution/reprecipitation in ordered packings of monodisperse silica spheres is also examined as a model system for particulate gels. As expected, the pore size distribution narrows with increasing time of treatment in high pH pore fluids. Interpretation of high pH results for the wet state is complicated by a microporous layer which forms on colloidal silica resulting in significantly larger wet surface area as compared to the final dried material. Narrowing of the pore size distribution, which is of interest for maximizing drying rates, is maximized in the least time by using either high pH or repeated ethanol washes for the base-catalyzed gel (B2) used.

scholarly journals Full-scale pore size distribution features of uranium-bearing sandstone in the northwest of Xinjiang, China

2021 ◽  
Vol 8 (5) ◽  
pp. 202036
Author(s):  
Sheng Zeng ◽  
Hao Li ◽  
Ni Zhang ◽  
Bing Sun ◽  
Jinzhu Li ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Pore Volume ◽  
Gas Adsorption ◽  
Full Scale ◽  
Uranium Recovery ◽  
Distribution Features ◽  
Pore Types

As an important nuclear fuel, uranium in sandstone uranium deposits is mainly extracted by in situ leaching. The porosity of sandstone is one of the important indexes determining in situ leaching efficiency. Moreover, the microscopic pore size distribution (PSD) of the uranium-bearing layer has an important effect on porosity. It is necessary to feature the pore structure by various techniques because of the different pore types and sizes in the uranium layer. In this paper, combined with nitrogen gas adsorption, nuclear magnetic resonance techniques and scanning electron microscopy, the full-scale PSD features of uranium-bearing sandstone in the northwest of Xinjiang are effectively characterized. The results show that pores structure of uranium-bearing sandstone include dissolution pores ( d ≤ 50 nm), intergranular pores (50 nm < d ≤ 200 µm) and microfractures. Intergranular pores of 60 nm and 1 µm are the significant contributors to pore volume. The effects of the pore volume of two pore types (dissolution pores and intergranular pores) on the porosity of uranium-bearing sandstone are analysed. The results show that intergranular pores have the greater influence on the porosity and are positively correlated to the porosity. Dissolution pores have little effect on the porosity, but it is one of the key factors for improving uranium recovery. Moreover, the greater the difference of PSD between sandstones, the stronger the interlayer heterogeneity of uranium-bearing sandstone. This kind of interlayer heterogeneity leads to the change of permeability in the horizontal direction of strata. It provides a basis for a reasonable setting of well type and well spacing parameters.

Calculation of Pore Size Distribution in the Ellipsometric Porosimetry: Method and Reliability

1999 ◽  
Vol 565 ◽  
Author(s):  
K. P Mogilnikov ◽  
V. G Polovinkin ◽  
F. N Dultsev ◽  
M. R Baklanov
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Porous Silica ◽  
Solid Substrate ◽  
Silica Films ◽  
Ellipsometric Porosimetry ◽  
Method Of Calculation ◽  
Organic Adsorbates

AbstractEllipsometric porosimetry allows measurement of the pore size distribution in a thin porous film deposited on top of any solid substrate. The most important concept of this technique is the use of in-situ ellipsometry to determine the amount of adsorbate adsorbed/condensed in the film. Changes in refractive index and film thickness are used for calculation of the amount of adsorbate. A room temperature porosimetry based on adsorption of vapours of some organic solvents has been developed. In this paper, a method of calculation of the pore size distribution and reliability of the ELP results is discussed and the validity of the Gurvitsch rule for organic adsorbates (toluene, heptane, CCl4) is examined. Porous silica films on top of Si wafers were used for this analysis.

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