Surface Area and Pore Structure of Low-Porosity Cement Pastes

AbstractThe pore structure of low porosity cement pastes containing varying quantities of silica fume has been examined using mercury intrusion porosimetry (MIP) and nitrogen adsorption (NA) measurements. The water:solid ratio for all DSP pastes studied was 0.18. It was observed that, as for conventional pastes, removal of water by solvent replacement with methanol minimizes changes to the pore structure. Vacuum or oven drying severely reduces specific surface area and obscures important trends.It was found that capillary porosity in excess of 10 nm (100 Å) is essentially absent and that the pore volume measured can be considered an intrinsic part of the binding phase. The influence of silica fume and curing times on pore structure has been measured and the implications of the data will be discussed. Comparisons will be made with conventional cement pastes.

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Studies on fibre reinforced portland cement pastes I. Surface area and pore structure

Cement and Concrete Research ◽

10.1016/0008-8846(74)90022-2 ◽

1974 ◽

Vol 4 (6) ◽

pp. 869-880 ◽

Cited By ~ 2

Author(s):

R.Sh. Mikhail ◽

A.M. Yossef

Keyword(s):

Portland Cement ◽

Pore Structure ◽

Surface Area ◽

Cement Pastes

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Hardened portland blast-furnace slag cement pastes: I. Effects of additives on surface area and on pore structure

Cement and Concrete Research ◽

10.1016/0008-8846(74)90052-0 ◽

1974 ◽

Vol 4 (5) ◽

pp. 807-820 ◽

Cited By ~ 4

Author(s):

R.Sh. Mikhail ◽

W.E. Mourad ◽

V.K. Gouda

Keyword(s):

Blast Furnace ◽

Pore Structure ◽

Surface Area ◽

Blast Furnace Slag ◽

Slag Cement ◽

Cement Pastes ◽

Furnace Slag

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Tuning the hierarchical pore structure of graphene oxide through dual thermal activation for high-performance supercapacitor

Scientific Reports ◽

10.1038/s41598-021-81759-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jeongpil Kim ◽

Jeong-Hyun Eum ◽

Junhyeok Kang ◽

Ohchan Kwon ◽

Hansung Kim ◽

...

Keyword(s):

Graphene Oxide ◽

Pore Structure ◽

Specific Capacitance ◽

Surface Area ◽

Thermal Annealing ◽

High Performance ◽

Annealing Process ◽

Supercapacitor Electrode ◽

Simple Method ◽

Surface Areas

AbstractHerein, we introduce a simple method to prepare hierarchical graphene with a tunable pore structure by activating graphene oxide (GO) with a two-step thermal annealing process. First, GO was treated at 600 °C by rapid thermal annealing in air, followed by subsequent thermal annealing in N2. The prepared graphene powder comprised abundant slit nanopores and micropores, showing a large specific surface area of 653.2 m2/g with a microporous surface area of 367.2 m2/g under optimized conditions. The pore structure was easily tunable by controlling the oxidation degree of GO and by the second annealing process. When the graphene powder was used as the supercapacitor electrode, a specific capacitance of 372.1 F/g was achieved at 0.5 A/g in 1 M H2SO4 electrolyte, which is a significantly enhanced value compared to that obtained using activated carbon and commercial reduced GO. The performance of the supercapacitor was highly stable, showing 103.8% retention of specific capacitance after 10,000 cycles at 10 A/g. The influence of pore structure on the supercapacitor performance was systematically investigated by varying the ratio of micro- and external surface areas of graphene.

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Nanometer Pore Structure Characterization of Taiyuan Formation Shale in the Lin-Xing Area Based on Nitrogen Adsorption Experiments

Minerals ◽

10.3390/min11030298 ◽

2021 ◽

Vol 11 (3) ◽

pp. 298

Author(s):

Chenlong Ding ◽

Jinxian He ◽

Hongchen Wu ◽

Xiaoli Zhang

Keyword(s):

Specific Surface ◽

Pore Structure ◽

Surface Area ◽

Specific Surface Area ◽

Shale Gas ◽

Pore Volume ◽

Ordos Basin ◽

Total Pore Volume ◽

Nitrogen Adsorption ◽

Taiyuan Formation

Ordos Basin is an important continental shale gas exploration site in China. The micropore structure of the shale reservoir is of great importance for shale gas evaluation. The Taiyuan Formation of the lower Permian is the main exploration interval for this area. To examine the nanometer pore structures in the Taiyuan Formation shale reservoirs in the Lin-Xing area, Northern Shaanxi, the microscopic pore structure characteristics were analyzed via nitrogen adsorption experiments. The pore structure parameters, such as specific surface area, pore volume, and aperture distribution, of shale were calculated; the significance of the pore structure for shale gas storage was analyzed; and the main controlling factors of pore development were assessed. The results indicated the surface area and hole volume of the shale sample to be 0.141–2.188 m2/g and 0.001398–0.008718 cm3/g, respectively. According to the IUPAC (International Union of Pure and Applied Chemistry) classification, mesopores and macropores were dominant in the pore structure, with the presence of a certain number of micropores. The adsorption curves were similar to the standard IV (a)-type isotherm line, and the hysteresis loop type was mainly similar to H3 and H4 types, indicating that most pores are dominated by open type pores, such as parallel plate-shaped pores and wedge-shaped slit pores. The micropores and mesopores provide the vast majority of the specific surface area, functioning as the main area for the adsorption of gas in the shale. The mesopores and macropores provide the vast majority of the pore volume, functioning as the main storage areas for the gas in the shale. Total organic carbon had no notable linear correlation with the total pore volume and the specific surface area. Vitrinite reflectance (Ro) had no notable correlation with the specific surface area, but did have a low “U” curve correlation with the total pore volume. There was no relationship between the quartz content and specific surface area and total pore volume. In addition, there was no notable correlation between the clay mineral content and total specific surface area and total pore volume.

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