Determining Pore Structure and Growth Mechanisms in Templated Nanoporous Low-k Films

2005 ◽  
Vol 863 ◽  
Author(s):  
Hua-Gen Peng ◽  
Richard S. Vallery ◽  
Ming Liu ◽  
William E. Frieze ◽  
David W. Gidley ◽  
...  
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Host Matrix ◽  
3 Dimensional ◽  
Nanoporous Films ◽  
Size Growth ◽  
Positronium Annihilation Lifetime Spectroscopy ◽  
The Relationship ◽  
Low K

AbstractTemplating is one of the most popular methods for generating nanocomposite and nanoporous films and the resultant pore size and pore interconnection length depend strongly on porogen concentration/porosity among other factors. Positronium Annihilation Lifetime Spectroscopy (PALS) analysis has been performed on a series of films produced using increasing concentrations of a type of cyclodextrin (CD) porogen in a modified silsesquioxane host matrix. PALS reveals the relationship between the resulting pore structure (both size and interconnection length) and porosity, which can be used to deduce pore shape. At low porogen concentration, isolated pores are resolved, but the pore size is consistent with a cluster of two or three CD molecules, rather than an individual one. As the porosity increases, the aggregation of the porogen domains appears to be more 3-dimensional (pseudo-random) with gradual increase in pore size. Computer simulations using a random pore growth model show consistent trends for pore size growth, but the agreement is poor for interconnection length. It is a key demonstration of the usefulness of PALS in untangling the fundamental pore structure and its evolution in porosity. PALS characterization of porosity provides novel feedback in the understanding and design of nanoporous materials.

Electrical, Mechanical, and Structural Properties of Fluoro-Containing Poly(silsesquioxanes) Based Porous Low k Thin Films

2003 ◽  
Vol 766 ◽  
Author(s):  
Jingyu Hyeon-Lee ◽  
Jihoon Rhee ◽  
Jungbae Kim ◽  
Jin-Heong Yim ◽  
Seok Chang
Keyword(s):  
Thin Films ◽  
Pore Size ◽  
Dielectric Constants ◽  
Commercial Application ◽  
Porous Films ◽  
Low Dielectric ◽  
Nanoporous Films ◽  
Positronium Annihilation ◽  
Positronium Annihilation Lifetime Spectroscopy ◽  
Low K

AbstractLow dielectric fluoro-containing poly(silsesquioxanes) (PSSQs) have been synthesized using trifluoropropyl trimethoxysilane (TFPTMS), methyl trimethoxysilane (MTMS), and 2, 4, 6, 8-tetramethyl-2, 4, 6, 8-tetra(trimethoxysilylethyl) cyclotetrasiloxane. The properties of fluorocontaining PSSQs based thin films were studied by electrical, mechanical, and structural characterization. Film was spun on a silicon substrate, baked at 150°C and 250°C for 1 minute, respectively, and cured in the furnace at 420°C for 1 hour under vacuum condition. Thermally decomposable trifluoropropyl groups of the fluoro-containing PSSQ were served as a pore generator and partially contributed to lower a dielectric constant. â-cyclodextrin (CD) was also employed as a pore generator. The concentration of the pore generator in the film was varied from 0 to 30 %. The dielectric constants of the porous PSSQ films were found to be in the range of 2.7 – 1.9 (at 100 kHz). Hardness and Young's modulus of the films were measured by nano-indentation. The elastic modulus and hardness of the porous films were well correlated with the concentration of the pore generators. Positronium Annihilation Lifetime Spectroscopy (PALS) was employed to characterize a pore size of the porous fluoro-containing PSSQ film. The pore size of the film was less than 2.2 nm. The nanoporous films showed quite promising properties for commercial application.

Characterization of Nanoporous Low-k Thin Films by Contrast Match SANS

2003 ◽  
Vol 766 ◽  
Author(s):  
Ronald C. Hedden ◽  
Barry J. Bauer ◽  
Hae-Jeong Lee
Keyword(s):  
Thin Films ◽  
Pore Size ◽  
Mass Density ◽  
Solvent Mixture ◽  
Wall Material ◽  
Ion Scattering ◽  
Low Dielectric ◽  
The Matrix ◽  
Low K

AbstractSmall-angle neutron scattering (SANS) contrast variation is used to characterize matrix properties and pore size in nanoporous low-dielectric constant (low-k) thin films. Using a vapor adsorption technique, SANS measurements are used to identify a “contrast match” solvent mixture containing the hydrogen– and deuterium-containing versions of a probe solvent. The contrast match solvent is subsequently used to conduct SANS porosimetry experiments. With information from specular X-ray reflectivity and ion scattering, the technique is useful for estimating the mass density of the matrix (wall) material and the pore size distribution. To illustrate the technique, a porous methylsilsesquioxane (MSQ) spin-on dielectric is characterized.

Sorption Hysteresis Characterization of CH4 and CO2 on Anthracite, Bituminous Coal, and Lignite at Low Pressure

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Zhenjian Liu ◽  
Zhenyu Zhang ◽  
Yiyu Lu ◽  
Sing Ki Choi ◽  
Xiaoqian Liu
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Bituminous Coal ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Low Pressure ◽  
Wide Distribution ◽  
Co2 Sorption ◽  
Sorption Hysteresis

Sorption hysteresis characterization of CH4 and CO2 on lignite, bituminous coal, and anthracite were studied to improve the understanding of the interaction between gas molecules and different ranks of coal and further improve the precision of the adsorption methods in characterizing pore structure at low pressure. Pore structure of three ranks of coal was investigated with scanning electron microscopy (SEM) and nitrogen (N2) adsorption. Then, CH4 and CO2 sorption isotherms were measured using the gravimetric method under 288, 308, and 328 K. The N2 sorption isotherms show that a wide distribution of pore size existed in three coal samples, and with the process of coalification, the specific surface area (SSA) decreased and then increased, while the pore size of coal monotonically decreased. This is confirmed by SEM observation. The measured sorption isotherms were then decomposed into simultaneously running adsorption and absorption branches based on the assumption that the former is totally reversible and the latter completely irreversible. The reconstructed adsorption branches can be well described by both Langmuir model and Dubinin–Radushkevich (D–R) equation. The absorption, which represents the sorption hysteresis portion, increased with pressure, but decreased with temperature. The absorbed amount of gas increased with pressure, but the absorption of CO2 increased concavely with gas pressure while CH4 followed an upward exponential function. Also, the absorption varied with coal rank, following a U-shaped function. This study can provide new insights to CH4 and CO2 sorption hysteresis on coal and other organic geomaterials.

Numerical Algorithm for Pore Size Distribution Characterization of Materials from 3D Images

2013 ◽  
Vol 699 ◽  
pp. 584-589 ◽  
Author(s):  
Neven Ukrainczyk ◽  
Eduard Koenders ◽  
Klaas van Breugel
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Numerical Algorithm ◽  
Digital Image ◽  
Medial Axis ◽  
Characterization Of Materials ◽  
2D And 3D

This paper presents an image based numerical method proposed to obtain information regarding pore structure and organization of pores within materials based on 3D digital image input. The output of the numerical algorithm is a pore size distribution of materials. The algorithm is based on the combination of the two digital image processing algorithms: 1) a medial axis thinning algorithm to obtain 3D skeleton of the pore structure, and 2) the distance transform of an image. The method is tested on simple 2D and 3D microstructures of packed spheres, demonstrating the performance of the proposed method.

Fractal Characteristics of the Middle-Upper Ordovician Marine Shale Nano-Scale Porous Structure from the Ordos Basin, Northeast China

2021 ◽  
Vol 21 (1) ◽  
pp. 274-283
Author(s):  
Liang Liu ◽  
Wuling Mo ◽  
Min Wang ◽  
Nengwu Zhou ◽  
Yu Yan ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Pore Structure ◽  
Pore Size ◽  
Ordos Basin ◽  
Fractal Dimensions ◽  
Upper Ordovician ◽  
Average Pore ◽  
Marine Shale ◽  
Fractal Characteristics ◽  
The Relationship

The fractal characteristics of marine shale from the Middle-Upper Ordovician Wulalike Formation (O2w) in the southwest margin of the Ordos Basin are studied. Based on low-temperature nitrogen adsorption experiments, the FHH (Frenkel-Halsey-Hill) model was employed to investigate the relationship between the marine shale composition, such as TOC, mineral content and shale gas content, and pore structure parameters, such as BET specific surface area, average pore diameter, porosity and fractal dimension. The results show that the pore size distribution curve of shale slowly decreased after the pore size was greater than 50 nm, the pore size distribution showed multiple peaks, and the peak value was mainly in the range of 2–10 nm. Most pores are nanopores, although the pore type and shape are different. Two different fractal dimensions D1 and D2 are obtained from the two segments with relative pressures of 0–0.5 and 0.5–1.0, respectively: the D1 range is 2.77–2.82, and the D2 range is 2.63–2.66. As D1 is larger than D2, the pore structure of small pores is more uniform than that of large pores in the shale samples. The relationship between the fractal dimensions D1 and D2 and the total organic carbon (TOC) content is a convex curve. Fractal dimension D reaches its maximum when TOC is 0.53 wt.%. Fractal dimension D decreases with increasing specific surface area, porosity and average pore size. The fractal dimension has a different influence on the gas storage and migration in shale; the larger the fractal dimension is, the stronger the heterogeneity and the more complex the pore structure, and this outcome is conducive to the storage of gas in shale but not beneficial to the permeability and production of gas.

scholarly journals Production and Characterization of Scaffold Made of Hydroxyapatite and Pectin From Green Cincau Leaf (Premna Oblongifolia Merr)

INSIST ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 119
Author(s):  
Sudirman Habibie ◽  
Yesi Tristiyanti ◽  
Dwi Gustiono ◽  
Dachyar Effendi ◽  
Sri Yadial Chalid ◽  
...  
Keyword(s):  
Citric Acid ◽  
Cell Growth ◽  
Pore Size ◽  
Growth Medium ◽  
Bone Cell ◽  
Natural Polymers ◽  
3 Dimensional ◽  
Dimensional Matrix ◽  
Freeze Dryer

Scaffold is a 3-dimensional matrix created as a new bone cell growth medium made from natural polymers and bioceramics. The extracted pectin from green Cincau leaves (Premna oblongifolia Merr) and hydroxyapatite (HA) are used in the manufacture of scaffolds. Pectin was extracted using citric acid with variation concentration of 0, 0.1, 0.2 and 0.3% (w / v). The 3% (w / w) HA-pectin mixture, dried freeze using a freeze dryer. The characterization of extracted pectin and HA-pectin scaffold was then performed. The results showed that pectin of green Cincau leaves had low methoxyl content, which was 1.364 to 5.022%. The resulting scaffold has a pore size ranging from 8.25 to 115 µm while the scaffold resistance to the load, ie 0.03 to 0.15 MPa. The scaffold porosity that has been made is 15.33 to 40.97% while the density is 0.69 to 1.02 g/cm3.

scholarly journals Multiscale Research on Pore Structure Characteristics and Permeability Prediction of Sandstone

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
M. A. Shi-Jia ◽  
L. I. N. Yuan-Jian ◽  
L. I. U. Jiang-Feng ◽  
Kundwa Marie Judith ◽  
Ishimwe Hubert ◽  
...  
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Target Material ◽  
Future Research ◽  
Distribution Method ◽  
Binary Images ◽  
Permeability Prediction

The random existence of many irregular pore structures in geotechnical materials has a decisive influence on its permeability and other macroscopic properties. The analysis and characterization of the micropore structure of the material and its permeability are of great significance for geotechnical engineering. In this study, digital images with different magnifications were used to examine the pore structure and permeability of sandstone samples. The image processing method is used to obtain binary images, and then, the pore size distribution method is used to calculate the pore size distribution. Therefore, based on the Hagen-Poiseuille formula, we get the prediction value of material’s permeability and compare it with the value obtained from mercury intrusion porosimetry (MIP). It is found that different microscopic images with different magnification and various statistical methods of pore size have a specific influence on the characterization of pore structure and permeability prediction. The porosity of different magnifications is not the same, and the results obtained at higher magnifications are more consistent with the results obtained with MIP. With the increase of magnification, we can observe more pores in large sizes. The effect of CPSD (continuous pore size distribution) in pore size statistics is better than that of DPSD (discrete pore size distribution). In permeability prediction, the prediction result of higher magnification images are closer to the instrument test value, and the value of DPSD is more significant than that of CPSD. In future research, an appropriate method should be selected to obtain a reasonable prediction of the permeability of the target material.

Characterization of dual-structure pore-size distribution of soil

2009 ◽  
Vol 46 (2) ◽  
pp. 129-141 ◽  
Author(s):  
X. Li ◽  
L. M. Zhang
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Void Ratio ◽  
Experimental Results ◽  
Dual Porosity ◽  
Porosity Structure ◽  
The Relationship ◽  
Comprehensive Study

The microporosity structure of soil provides important information in understanding the shear strength, compressibility, water-retention ability, and hydraulic conductivity of soils. It is a soil characteristic that depends on sample preparation method and wetting–drying history. A comprehensive study of the microporosity structure of a lean clay with sand was conducted in this research to investigate variations of the microporosity structure during compaction, saturation, and drying processes. Scanning electron microscopy was used to observe the microporosity structure of soil sample surfaces. Mercury intrusion porosimetry was used to measure the microporosity structure quantitatively by showing the relationship between cumulative pore volumes and pore radius. The experimental results show that a dual-porosity structure (i.e., interaggregate pores and intra-aggregate pores) forms during the compaction process. The interaggregate pores are compressible and the associated volume is closely related to the final void ratio of the compacted sample. Changes to interaggregate pores is dominant during compaction, but changes to intra-aggregate pores is dominant during saturation and drying. Based on the experimental results, a dual-porosity structure model was developed by relating the pore-size distribution to the void ratio. Consequently, the pore-size distribution at any void ratio can be predicted.

Characterization of Pore Structure of Hardened Cement-Asphalt Paste by Mercury Intrusion Porosimetry

2014 ◽  
Vol 1004-1005 ◽  
pp. 1589-1593 ◽  
Author(s):  
Sheng Zhang ◽  
Xi Ling Zhou ◽  
Ke Ren Zheng ◽  
You Jun Xie ◽  
Qiang Fu
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Mercury Intrusion Porosimetry ◽  
Total Porosity ◽  
Pore Distribution ◽  
Hardened Cement ◽  
Volume Distribution ◽  
Mercury Intrusion ◽  
Two Peaks

To know the pore structure of cement-asphalt pastes, mercury intrusion porosimetry was applied to measure the total porosity, pore distribution and accumulative volume distribution of pore size and the pore structures were analyzed. The results show that the total porosities decline with increase in ages and reduction in A/C ratio. The total porosities declines from 28% at 1d, to 15.8%~17.2% at 28d; the most probable pore size declines from 20nm at 1d to 5nm at 28d.At 28d, there is an increase in the magnitude of pore size between100nm and 5μm; the volume faction of smaller than 5μm is 40~50%; and the amount of pore size smaller than 5nm account for 6%.There are two peaks (5μm & 50μm) in the curves of pore distribution.

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