The Study of Bound Water Status and Pore Size Distribution of Chinese Fir and Poplar Cell Wall by Low-Field NMR

With the increasing shortage of timber resources and the advancement of environmental protection projects, many artificial fast-growing forests are planted and used as raw materials in China. There are significant differences in the properties of natural forest wood and artificial fast-growing forest wood, and the properties of wood mainly depend on the change in the status of bound water in the cell wall. In this study, the fiber saturation point (FSP) and pore size distributions within the cell wall of six species of fast-growing forest wood were studied by low-temperature nuclear magnetic resonance (NMR) technology. The effects of species, growth rings, and extractives on the FSP and pore structure were analyzed. The water vapor sorption experiments were performed, and the adsorption isotherms of the samples were fitted through the Guggenheim-Anderson-de Boer (GAB) equation. According to the least-square regression of the adsorption isotherms and combined with the low-temperature NMR experiments, the content and proportion of the different types of bound water were analyzed. The results showed that the average FSP of each Chinese fir was about 40% and that of each poplar was about 35%. There is about a 10% difference between the FSP measured by NMR technology and the adsorption bound water content obtained by adsorption isothermal. The pore size distribution results show that in all samples, the proportion of pores larger than 10.5 nm is very low, about 10%; the proportion of 1.92-10.5 nm pores is about 30%; and the proportion of pores smaller than 1.92nm is more than 50%. This work will be helpful to the study of the wood moisture status and provide reference data for wood modification.

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Experimental investigation on pore size distribution and drying kinetics during lyophilization of sugar solutions

Proceedings of 21th International Drying Symposium ◽

10.4995/ids2018.2018.7310 ◽

2018 ◽

Cited By ~ 1

Author(s):

Petra Foerst ◽

M. Lechner ◽

N. Vorhauer ◽

H. Schuchmann ◽

E. Tsotsas

Keyword(s):

Pore Structure ◽

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Freeze Drying ◽

Three Dimensional ◽

Drying Kinetics ◽

Process Efficiency ◽

Freeze Dried ◽

Pore Size Distributions

The pore structure is a decisive factor for the process efficiency and product quality of freeze dried products. In this work the two-dimensional ice crystal structure was investigated for maltodextrin solutions with different concentrations by a freeze drying microscope. The resulting drying kinetics was investigated for different pore structures. Additionally the three-dimensional pore structure of the freeze dried samples was measured by µ-computed tomography and the pore size distribution was quantified by image analysis techniques. The two- and three-dimensional pore size distributions were compared and linked to the drying kinetics.Keywords: pore size distribution; freeze drying; maltodextrin solution; freeze drying microscope

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Accurate characterization of full pore size distribution of tight sandstones by low‐temperature nitrogen gas adsorption and high‐pressure mercury intrusion combination method

Energy Science & Engineering ◽

10.1002/ese3.817 ◽

2020 ◽

Author(s):

Shuaishi Fu ◽

Qi Fang ◽

Aifen Li ◽

Zhiping Li ◽

Jinliang Han ◽

...

Keyword(s):

High Pressure ◽

Low Temperature ◽

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Gas Adsorption ◽

Combination Method ◽

Nitrogen Gas ◽

Mercury Intrusion

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Comparison of Nitrogen Adsorption and Mercury Penetration Results: II. Pore size Distributions Calculated from Type IV Isotherm Data

Adsorption Science & Technology ◽

10.1177/026361748800500301 ◽

1988 ◽

Vol 5 (3) ◽

pp. 168-190 ◽

Cited By ~ 6

Author(s):

Bruce D. Adkins ◽

Burtron H. Davis

Keyword(s):

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Nitrogen Adsorption ◽

Type Iv ◽

Pore Size Distributions ◽

Nitrogen Desorption ◽

The Difference ◽

Penetration Data ◽

Packed Sphere

The pore distributions calculated from nitrogen desorption and from mercury penetration data are similar for the four materials utilized in this study. While there are small differences in the distributions calculated using different models (Cohan. Foster or Broekhoff-deBoer) with nitrogen adsorption or desorption isotherm data, all three show reasonable agreement with distributions calculated from mercury penetration data. Frequently practical catalysts have such a broad pore size distribution that neither method alone is adequate to measure the total pore size range. The present results suggest a direct comparison, without recourse to a scaling factor, is appropriate when comparing results from the two methods even though the pore size distribution maximum may vary by at least 50% depending upon the model chosen for the calculation. Better agreement may be obtained between the two experimental techniques by adjusting either the nitrogen adsorption data using a packed sphere model or the mercury penetration data by an earlier reported correction ratio. The difference between the two methods becomes less than 20% when a correction procedure is used; however, further studies are needed to define the range of material shaped that these procedures are applicable to.

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Determination of T2 cut-off for shale reservoirs: a case study from the Carynginia formation, Perth Basin, Western Australia

The APPEA Journal ◽

10.1071/aj16184 ◽

2017 ◽

Vol 57 (2) ◽

pp. 664 ◽

Cited By ~ 1

Author(s):

M. Nadia Testamanti ◽

Reza Rezaee ◽

Yujie Yuan ◽

Dawei Pan

Keyword(s):

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Petroleum Industry ◽

Bound Water ◽

Invasive Technique ◽

Sources Of Information ◽

Vacuum Oven ◽

Low Field ◽

Wide Range

Over recent decades, the low-field Nuclear Magnetic Resonance (NMR) method has been consistently used in the petroleum industry for the petrophysical characterisation of conventional reservoirs. Through this non-invasive technique, the porosity, pore size distribution and fluid properties can be determined from the signal emitted by fluids present in the porous media. Transverse relaxation (T2) data, in particular, are one of the most valuable sources of information in an NMR measurement, as the resulting signal decay can be inverted to obtain the T2 distribution of the rock, which can in turn be correlated with porosity and pore size distribution. The complex pore network of shales, which can have a large portion of pore sizes in the nanopore and mesopore range, restricts the techniques that can be used to investigate their pore structure and porosity. The ability of the NMR technique to detect signals from a wide range of pores has therefore prompted the quest for more standardised interpretation methods suitable for shales. Using low-field NMR, T2 experiments were performed on shale samples from the Carynginia formation, Perth Basin, at different saturation levels. The shale samples were initially saturated with brine and the T2 spectrum for each sample was obtained. Then, they were placed in a vacuum oven and their weight monitored until a constant value was reached. T2 curves were subsequently obtained for each of the oven-dried samples and a cut-off value for clay-bound water was calculated.

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Ink-bottle Effect and Pore Size Distribution of Cementitious Materials Identified by Pressurization–Depressurization Cycling Mercury Intrusion Porosimetry

Materials ◽

10.3390/ma12091454 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1454 ◽

Cited By ~ 5

Author(s):

Yong Zhang ◽

Bin Yang ◽

Zhengxian Yang ◽

Guang Ye

Keyword(s):

Pore Structure ◽

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Mercury Intrusion Porosimetry ◽

Cementitious Materials ◽

Limestone Powder ◽

Accurate Estimation ◽

Mercury Intrusion ◽

Pore Size Distributions

Capturing the long-term performance of concrete must be underpinned by a detailed understanding of the pore structure. Mercury intrusion porosimetry (MIP) is a widely used technique for pore structure characterization. However, it has been proven inappropriate to measure the pore size distribution of cementitious materials due to the ink-bottle effect. MIP with cyclic pressurization–depressurization can overcome the ink-bottle effect and enables a distinction between large (ink-bottle) pores and small (throat) pores. In this paper, pressurization–depressurization cycling mercury intrusion porosimetry (PDC-MIP) is adopted to characterize the pore structure in a range of cementitious pastes cured from 28 to 370 days. The results indicate that PDC-MIP provides a more accurate estimation of the pore size distribution in cementitious pastes than the standard MIP. Bimodal pore size distributions can be obtained by performing PDC-MIP measurements on cementitious pastes, regardless of the age. Water–binder ratio, fly ash and limestone powder have considerable influences on the formation of capillary pores ranging from 0.01 to 0.5 µm.

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Pore-Size Distribution of Silica Colloidal Crystals from Nitrogen Adsorption Isotherms

Langmuir ◽

10.1021/acs.langmuir.9b02252 ◽

2019 ◽

Vol 35 (47) ◽

pp. 14975-14982 ◽

Cited By ~ 4

Author(s):

Max A. Maximov ◽

Andrey V. Galukhin ◽

Gennady Y. Gor

Keyword(s):

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Adsorption Isotherms ◽

Colloidal Crystals ◽

Nitrogen Adsorption ◽

Nitrogen Adsorption Isotherms ◽

Silica Colloidal Crystals

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Uncertainty in pore size distribution derived from adsorption isotherms: I. Classical methods

Microporous and Mesoporous Materials ◽

10.1016/j.micromeso.2015.04.026 ◽

2015 ◽

Vol 214 ◽

pp. 210-216 ◽

Cited By ~ 8

Author(s):

S. Hadi Madani ◽

Alexander Badalyan ◽

Mark J. Biggs ◽

Phillip Pendleton

Keyword(s):

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Adsorption Isotherms

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Prediction of soil water retention properties using pore-size distribution and porosity

Canadian Geotechnical Journal ◽

10.1139/cgj-2012-0320 ◽

2013 ◽

Vol 50 (4) ◽

pp. 435-450 ◽

Cited By ~ 25

Author(s):

Christopher T.S. Beckett ◽

Charles E. Augarde

Keyword(s):

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Soil Water ◽

Water Retention ◽

Adsorbed Water ◽

Retention Data ◽

Soil Water Retention ◽

Pore Size Distributions ◽

Water Retention Properties

Several models have been suggested to link a soil's pore-size distribution to its retention properties. This paper presents a method that builds on previous techniques by incorporating porosity and particles of different sizes, shapes, and separation distances to predict soil water retention properties. Mechanisms are suggested for the determination of both the main drying and wetting paths, which incorporate an adsorbed water phase and retention hysteresis. Predicted results are then compared with measured retention data to validate the model and to provide a foundation for discussing the validity and limitations of using pore-size distributions to predict retention properties.

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