Pore Size Distribution Measurements Research Articles

A simple approach for predicting soil water characteristic curve of clayey soils using pore size distribution data

The soil water characteristic curve (SWCC) of soils can be derived from the measured pore size distribution (PSD) data by applying capillary models. This method is limited for clayey soils due to the PSD changes during SWCC testing. In this study, a suction-dependent multimodal PSD model based on probability theory is developed and used to derive SWCC. The model is validated by simulating the drying branches of SWCCs of four compacted Lias Clay samples with different initial states. A good consistency between the measured and predicted SWCC is shown.

Novel membrane bioreactor system using combination of an intermittent electric field and moving biomedia for treatment of genuine wastewater

ABSTRACT This work presented an endeavour to evolve a novel membrane bioreactor that merges an electro bioreactor (EMBR) and moving biomedia (moving bed) aiming for enhancing the biological treatment and alleviating membrane fouling. Nanocomposite membranes comprise disparate contents of ZnONPs were prepared and the one with optimum performance was harnessed for the prolonged operations. Results revealed that the mean pore size, pore size distribution, roughness parameters and contact angle measurements were declined upon the addition of ZnO-NPs. In the meantime, the permeate flux was improved by 357% at 1.5 g ZnO-NPs loading weight. Combining the biological, membrane and electrochemical processes into one EMBR system has mitigated the inherent membrane fouling by 90%, whereas this percent went further and reached more than 94% with the presence of the electric field and moving bed. The EMBBR systems have showcased a worthy enhancement in their retention capacity, and were capable to achieve 88%, 90% and 95% retention against NO3, PO4-P and COD, respectively. Likewise, during the membrane long-term operation, a sustained stable permeate flux up to 51 days was witnesses while the membrane has operated for continuous 113 days prior to cleaning.

Characterization of porous polyacrylonitrile membranes by liquid-liquid displacement technique

In this work, series of PAN membranes were prepared by the combined VIPS/NIPS method using different solvents. These membranes were investigated by using liquid-liquid displacement method for membrane pore size distribution and membrane permeance measurements. Wide range of pores size (30-60 nm) and membrane permeance up to 400 L/m2·h·bar were achieved depending on the casting conditions. It was shown that longer exposure in water vapor leads to higher pore size and at the same time makes membrane less permeable due to low asymmetry of porous structure..

Biological and Mechanical Properties of Denture Base Material as a Vehicle for Novel Hydroxyapatite Nanoparticles Loaded with Drug.

Purpose: This study aimed to evaluate the biological and mechanical properties of the poly(methyl methacrylate) (PMMA) denture base material as a vehicle incorporating novel hydroxyapatite nanoparticles (HA-NP) loaded with metronidazole (MZ) drug. Methods: HA-NP was prepared via wet-chemical-method, characterized by XRD, SEM/EDX, TEM, Fourier-transform infrared spectroscopy (FTIR), as well as the measurement of surface area and pore-size distribution. Four drug delivery formulas were prepared in the form of discs (10 x 2 mm) as follows: F1 (MZ/ HA-NP/PMMA), F2 (HA-NP/ PMMA), F3 (control-PMMA) and F4 (MZ/PMMA). Characterization of all formulas was performed using differential scanning calorimetry (DSC) and FTIR. MZ release rate, antimicrobial properties against three oral pathogens, cytotoxicity (MTT assay) and surface micro-hardness were also assessed. Statistical analysis of data was performed using one-way ANOVA test (P < 0.05). Results: DSC thermograms showed compatibility among MZ, HA-NP and PMMA along with physical stability over 6 months storage period at room temperature. FTIR spectroscopy proved the absence of any possible chemical interaction with MZ. MZ-HA-NP/PMMA formula showed relatively better drug release compared to MZ-PMMA. Both formulas showed statistically significant antimicrobial potentials against two microbial strains. MTT demonstrated reduction in cell cytotoxicity after 96 hours with the least value for HA-NP. Surface micro-hardness revealed non-significant reduction compared with the control PMMA. Conclusion: A novel biocompatible drug nanocarrier (HA-NP) was developed and incorporated in PMMA denture base material as a vehicle to allow prolonged sustained drug release to manage oral infections.

Oil-water pore occupancy in the Vaca Muerta source-rocks by NMR cryoporometry

Abstract The main motivation of this work is to determine quantitatively the pore occupancy of water and oil in some source rocks. The pore occupancy might be imposed by differences in chemical composition, wettability behavior and sorption of fluids in organic and inorganic porosities and will dramatically affect the hydrocarbons flow through the porous medium. We address this issue using NMR cryoporometry in two phase situations complemented by other NMR measurements. Using oil-wet samples originating from the Vaca Muerta formation, oil saturation as large as 70% were obtained by simply immersing fully water saturated samples into decane. At 100% water saturation, the measured pore size distributions indicate two main peaks around 2 and 80 nm. After immersion into oil, the pores occupied by water in the presence of decane are mostly around 2 nm and less. The pore sizes occupied by decane in the presence of water can then be deduced by subtracting the distributions obtained at 100% water saturation and after spontaneous drainage. Oil is mainly located in pores around 80 nm. These measurements are confirmed by high resolution SEM images showing the presence of porosity in the organic matter (sponge-like structure). Most of the oil can be associated with the porous organic matter network. These observations are complemented by the determination of the porosity below 2 nm and the water connectivity. From D2O diffusion experiments at 100% water saturation, we observed that about 19% of the total porosity is non-exchangeable with D2O. From the measurements of the liquid signal at −29 °C, we observed that on average 58% of the total porosity is located in pores smaller than 2 nm.

Low-Pressure Membrane for Water Treatment Applications

Three ultrafiltration membranes were prepared using phase separation techniques. The membranes were characterized by scan electron microscope, porosity, pore size distribution measurement, and mechanical properties. The membrane performance was carried out using synthetic solutions from humic acid and tap water to express the contaminated drinking water. The polyvinylidene difluoride (M2) has the highest tensile strength 33.2 MPa with elongation of 52.3%, while polyacrylonitrile (M3) has the lowest mechanical properties, tensile strength 16.4 MPa with elongation of 42.7%. Polyethersulfone membrane (M1) provides the highest removal of humic acid, which was 99.5, 98.8, and 98.2% using feed concentrations 0.1, 0.3, and 0.5 g/l, respectively, while M3 provides the highest permeate flux which was 250, 234.4, and 201.4 l/m2 h using feed concentrations 0.1, 0.3, and 0.5 g/l, respectively. Analysis of water samples indicates that the prepared membranes can be used to treat the contaminated drinking water which produced the high quality of drinking water after treatment.

Multiple Approaches to Quantifying the Effective Porosity of Lacustrine Shale Oil Reservoirs in Bohai Bay Basin, East China

An effective porosity is defined as the ratio of volume of interconnected pore space to total volume of a porous sample. It controls the magnitude of fluid flow and is a key parameter in the assessment of recoverable resources. However, its accurate measurement in tight formations is challenging, due to their complex pore structure and lithofacies heterogeneity. In this study, porosities of sixteen lacustrine shale samples from the second Member of the Kongdian Formation (Ek2) in the Cangdong Sag, Bohai Bay Basin were measured and compared using multiple methods and sample sizes to compare and contrast the effective porosity results. The methods included helium pycnometry (HP; cubes of 1 cm3 and grains at 500-841 μm), water immersion porosimetry (WIP; cubes), mercury intrusion porosimetry (MIP; cubes), and nuclear magnetic resonance (NMR; cubes). Finally, samples were completely sealed using paraffin for bulk density measurements to evaluate the extent of potential clay swelling in shale samples involving probing fluids. Results from the HP, WIP, and MIP methods for skeletal density, bulk density, and effective porosity with cubic samples were compared. While very similar skeletal densities were found for all three methods, a lower bulk density, and therefore lower porosity, from the MIP approach can be attributed to the experimental conditions (e.g., vacuum efficiency, applied pressure, wettability of water/helium vs. mercury) and the probable presence of pores with diameters larger than 50 μm not measurable by MIP. Furthermore, the HP porosity of granular samples with 500-841 μm grain sizes can be regarded as approaching the total porosity. The complicated relationship between WIP and NMR porosities may result from the heat-induced volatilization of moisture in pores during NMR tests, and countercurrent imbibition of water replacing the residual hydrocarbons during the saturation process for sample preparation in both tests. The swelling behavior of the lacustrine Ek2 shale with water is not significant because of the low content of expansive clay minerals. In summary, the WIP and HP methods are recommended for effective porosity measurement, whereas the NMR and MIP methods are invaluable for the measurement of pore-size distribution, with additional information on the effective porosity.

Transport characteristics of liquid-gas interface in a capillary membrane pore

Interface displacement of two phases mainly caused by replacement of one fluid with another one can occur inside the membrane pore during membrane preparation and characterization. This phenomenon is exemplified by measurement of liquid entry pressure (LEP) in membrane distillation, measurement of pore size and pore size distribution by the bubble point method, measurement of pore size and pore size distribution by porometry, wetting of dry membrane and also drying of wet membrane. In most of the theoretical studies, focus was on the transmembrane pressure required for one phase to enter into the membrane pores filled with another phase and little attention was paid to the movement of interface in the capillary. This paper attempts to discuss quantitatively the movement of interface, water/air interface in particular. Therefore, movement of interface was tracked using a well-founded model and consequently the pressure and velocity at the interface and the required time for replacement were studied. In addition, the influence of different parameters including pore radius, contact angle, and membrane thickness was assessed. It was found that the low resistance for the air flow, assumed in Washburn's equation, can be justified as an approximation. Moreover, the model proposed in this work can predict that the pressure at the water/air interface (when air replaces liquid water) may become significantly lower than the atmospheric pressure at the pore exit, causing pore shrinkage. As well, the pressure at the air/water interface (when liquid water replaces air) may become significantly higher than the feed pressure applied at the pore entrance, causing pore expansion.

Vehicular traffic effects on hydraulic properties of a Crosby silt loam under a long-term no-till farming in Central Ohio, USA

Changes in soil properties have been reported under several long-term no-till (NT) studies, however, the magnitude of changes in soil hydraulic properties with the use of new generation heavy machinery under NT farming is not widely documented on a long term basis. Therefore, a site under long-term NT production system was selected, where a known compaction force of 0 Mg axle load (control, C-0), two (C-2) and four (C-4) passages of 2.5 Mg water wagon axle load was applied to cover the entire plot for 20 consecutive years to assess changes in soil hydraulic properties at a site in the Central Ohio, USA. The field was under NT-based corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation since 1997. An additional three plots were established in a natural woodlot (30 m adjacent from the compaction field plots) as the baseline to compare the impact of compaction under a NT managed agricultural soil. Total of 24 (three per treatment for each depth) undisturbed soil cores was collected in November 2016 from 0 to 10 cm and 10 to 20 cm depths by using a hammer based manual core sampler for determination of soil hydraulic properties (soil water retention-SWR, plant available water), and to measure pore size distribution and air porosity. Results revealed that vehicular traffic induced significant changes in SWR at 0 and -6 kPa soil water potential (ψ). A reduction of SWR by 7.9 to 3.2% under C-2, by 6.6 to 0% under C-4 and by 2.4 to 0.8% under C-0 was observed at -6 to -300 kPa compared to that for the wooded soil. The soil under C-4 treatment had the lowest air porosity. Furthermore, the volume of pores with diameter >10 μm under C-4 was reduced by 8.3% compared to C-0 and by 7.6% compared to the wooded soil. Soil water content (transmission, plant available and residual water) followed a trend similar to that of the pore volume distribution for soil subjected to vehicular traffic-induced compaction. The data supports the conclusion that two or four passages of 2.5 Mg axle load of vehicular traffic under NT farming moderately changed SWR, plant available water, pores size distribution and air porosity compared to that of the wooded soil. However, the magnitudes of changes in soil hydraulic properties due to vehicular passages of 2.5 Mg axle load were not consistent under the NT production system. Thus, further monitoring of the impacts of compaction on soil hydraulic properties particularly on some other properties (e.g., water infiltration and air permeability) across the years is needed for better assessment of the relationships between crop production and soil hydraulic properties as well as soil resilience.

Physico-chemical and biological properties of electrospun poly-L-lactic acid/hydroxyapatite nano-composite scaffold for bone regeneration

The main goal of tissue engineering is to design scaffolds with the suitable microenvironment, prominent mechanical properties, adequate biocompatibility, and biodegradability. In the present study, Poly-L-lactic acid (PLLA)/10% hydroxyapatite (HA) nano-composite (PLLA/HA) scaffold and pure PLLA scaffold were fabricated via electrospinning technique. They were then assessed for their potential as substrates for the cell culture. The scaffolds were characterized by scanning electron microscope, thermogravimetric analysis, differential thermal analysis, and fourier transform infrared spectroscopy. The results showed the dispersion and integration of HA nanoparticles in the composite scaffold. Pore size distribution measurements indicated that the scaffold pore size in terms of Ferret diameter varies between 0.1 and 22.0 µm. In vitro degradation behavior of the scaffold in phosphate buffered saline (PBS) was obtained by measuring water uptake, weight loss, and pH change of the PBS during the degradation period. We observed that the degradation of the scaffold could be markedly accelerated by HA nanoparticle (10%). It was also shown that acidification of the PBS due to the PLLA degradation is suppressed by the HA nanoparticles. Finally, human umbilical-cord-derived mesenchymal stem cells (hUC-MSCs) were used to evaluate the cellular support of the composite scaffolds. The presence of HA nanoparticles in the PLLA fibrous scaffolds resulted in promoting the attachment and the proliferation of the hUC-MSCs. This study suggests that the PLLA/HA scaffold could be the material of choice for functional bone tissue engineering.

Preparation of a biomimetic ionic liquids hybrid polyphosphorylcholine monolithic column for the high efficient capillary microextraction of glycopeptide antibiotics

An ionic liquid hybrid zwitterionic polymer capillary microextraction (CME) column was prepared for the biomimetic enrichment of glycopeptides by one-step copolymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 1-butyl-3-vinylimidazolium bromide, in the presence of crosslinker trimethylolpropane trimethacrylate (TMA). The resultant monolith was characterized by scanning electron microscopy (SEM), fourier transform infrared (FT-IR) spectroscopy and pore size distribution measurement. Due to the incorporation of zwitterionic MPC owning a unique biomimic structure (i.e. hydrophilic cation/anion and hydrophobic long-alkyl chain), the monolithic column has large pore size and good biocompatibility, exhibiting high extraction efficiency, permeability and fast mass transfer to targets. Besides, the use of ionic liquids (ILs) as co-monomer in the polymerization endows the monolith with enhanced mechanical stability, uniformity and multiple interactions. The prepared column was successfully applied in CME coupled to capillary electrochromatography (CEC) for the efficient enrichment and separation of glycopeptide antibiotics in foodstuff. The method demonstrated a wide linear range (50.0–18000.0 µg L-1), low detection limits (5.0–10.0 µg L-1, S/N = 3) and satisfied recoveries (76.0–109.7%). This work shows the advantage of fine-tuning biomimetic monoliths in application-specific CME–CEC.

Pt/Fe/N/C Catalyst with Improved Activity and Stability Toward Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cell

Proton exchange membrane fuel cell (PEMFC) is promising in transportation applications due to its advantages such as cleanliness, high efficiency, easy operation, low working temperature and fast start-up[1]. Pt-based catalysts have been accepted as oxygen reduction reaction (ORR) catalyst in PEMFC since their high activity and stability. In last decade, FeN/C catalysts have received much attention since their excellent activity toward ORR. However, the high price and rare reserves of platinum, as well as the poor stability of FeN/C restrict the large-scale application of Pt-based and FeN/C catalysts[2-3]. In this work, platinum-based catalysts with FeN co-doped carbon support were prepared by ethylene glycol reduction method. Their activity and stability toward ORR were investigated by electrochemical techniques. The structure and physical characteristics of catalysts and their supports were studied by an array of techniques such as Brunauer-Emmet-Teller (BET)surface area and pore size distribution measurements, transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and etc.The electrochemical results showed that Pt/FeNGR using Fe, N co-doped graphene as carbon support had best initial ORR activity but poor stability. While Pt/FeNBP, using FeNBP which obtained by pyrolyzed the mixture of Black Pearl 2000 (BP), iron acetate and 1,10-phenanthroline at 900°C in amonia for 10 minutes, had much better stability than commercial Pt/C catalyst.Combined the results obtained from electrochemical techniques, BET, TEM, XPS, etc, the doping of Fe and N on carbon materials modified their physical characteristics such as surface area, defects, types of elements and functional group on surface, etc. The dispersion and size of platinum particles, the interaction between platinum particles and carbon support were improved due to the modification of carbon supports. Most of surface nitrogen in Pt/Fe(N)GR existed as pyridine N and N-Fe may be the key factor for its better initial ORR activity. The large surface area of BP, and the most of surface nitrogen existed in Pt/Fe(N)BP as graphite-N may be crucial to its best stability.

Some Applications of a Field Programmable Gate Array Based Time-Domain Spectrometer for NMR Relaxation and NMR Cryoporometry

NMR Relaxation (NMRR) is an extremely useful quantitative technique for material science, particularly for studying polymers and porous materials. NMR Cryoporometry (NMRC) is a powerful technique for the measurement of pore-size distributions and total porosities. This paper discusses the use, capabilities and application of a newly available compact NMR time-domain relaxation spectrometer, the Lab-Tools Mk3 NMR Relaxometer &amp; Cryoporometer [Lab-Tools (nano-science), Ramsgate, Kent, UK (2019)]. Being Field Programmable Gate Array based means that it is unusually compact, which makes it particularly suitable for the lab bench-top, in the field and also mobile use. Its use with a variable-temperature NMR probe such as the Lab-Tools Peltier thermo-electrically cooled variable-temperature (V-T) probe is also discussed. This enables the NMRC measurement of pore-size distributions in porous materials, from sub-nano- to over 1 micron sized pores. These techniques are suitable for a wide range of porous materials and also polymers. This instrument comes with a Graphical User Interface (GUI) for control, which also enables both online and offline analysis of the measured data. This makes it is easy to use for material science studies both in the field and in university, research institute, company and even school laboratories. The Peltier cooling gives the precision temperature control and smoothness needed by NMR Cryoporometry, particularly near the probe liquid bulk melting point. Results from example NMR Relaxation and NMR Cryoporometric measurements are given.

Measurement of pore size distribution of building materials by thermal method

The present work focuses on the study of the thermophysical properties of low porous insulation materials. In peculiar, we investigate the pore structure of composite materials and cements by thermal method. This method, adapted for fragile materials, is based on an existing model which allows the determination of pore size distribution. Firstly, the existing analytical model is presented. The thermal conductivity is modeled by assimilating the studied medium to N fluid phases and one solid phase in series / parallel. Secondly, some extensions to this model are proposed. In particular, we show that in the case of a single pore size, it is possible to obtain a finer pore size distribution by means of a normal law. We also show for the first time that the normalization of the thermal conductivity is an interesting way to study the pore size distribution of a material without knowing the overall porosity rate (which strongly depends on the method used). Furthermore, this model and its extensions have been successfully applied to different kinds of materials (plant fiber composites and cements). Fibers reinforced composites have one class of pores around 30 – 60 μm. Chemical treatments do not affect this pore size. Cements show a macroporosity (around 20 μm) which is often underestimated.

Synthesis of highly deficient nano SrCoOx for the purification of lanthanides from monazite concentrate

Highly deficient strontium cobaltite (SrCoOx), as a new nanomaterial that is thermally treated at low temperature (400–500 °C), is prepared using facile green method. The different prepared powders are characterized using X-ray diffraction method for phase identification, Fourier transform infrared for functional group identification, differential thermal analysis–thermogravimetry for thermal analysis, electron spin resonance for oxygen vacancies evaluation, BET method for specific surface area and pore size distribution measurements and high resolution transmission electron microscope for microstructure analysis. The effectiveness of oxygen vacancies is followed to improve the adsorptive properties of the studied materials. The prepared materials are effective for the selective separation of industrial and nuclear elements (Th, Fe). The results reveal that a novel SrCoOx nanomaterial is promising for the purification and production of lanthanides from monazite ore processing.

Experimental methods in chemical engineering: specific surface area and pore size distribution measurements—BET, BJH, and DFT

AbstractGas physisorption is an experimental technique based on equilibrium Van der Waals interactions between gas molecules and solid particles, that quantifies the specific surface area (SSA), pore size distribution (PSD), and pore volume of solids and powders. The performance of catalysts, absorbents, chromatography column materials, and polymer resins depends on these morphological properties. Here we introduce the basic principles and procedures of physical adsorption, especially nitrogen physisorption, as a guide to students and researchers unfamiliar with the field. The Brunauer‐Emmett‐Teller theory (BET) is a common approach to estimate SSA that extends the Langmuir monolayer molecular adsorption model to multilayer layers. It relies on an equilibrium adsorption isotherm, measured at the normal boiling point of the adsorbate, eg, 77 K or 87 K for N2 and Ar, respectively. Web of Science indexed 45 400 articles in 2016 and 2017 that mentioned N2 adsorption porosimetry—BET and BJH (Barrett‐Joyner‐Halenda) keywords. The VOSViewer bibliometric tool grouped these articles into four research clusters: adsorption, activated carbon in aqueous solutions for removal of heavy metal ions; synthesis of nanoparticles and composites; catalysts performance in oxidation and reduction processes; and photocatalytic degradation with TiO2. According to the literature, the accuracy of the density function theory (DFT) method is higher than with the BJH theory and it is more reliable.

Effect of compression on pore size distribution and porosity of PEM fuel cell catalyst layers

In this study, effects of compression (up to 5 MPa) on pore size distribution (PSD) and porosity of catalyst layers (CL) are investigated using a developed model for deformation of CL under compression. The model is based on effective medium theory and uses a representative geometry (unit cell) to simplify the complex and random porous structure of CL. In this model, different sizes are found for unit cells which are based on CL PSD measurement; this means that unit cell size has distribution since PSD is used as an input to the model. The model has been validated with experimental data in our previous publications. Effect of compression on four different CL samples is studied using the developed model and change of pore diameter is found as function of compression. The change of pore size is different for each sample and dependents on CL initial porosity, PSD, and ink properties. PSD and porosity, which are the indications of microstructure of CL, are found after compression up to 5 MPa. Larger pores show the most change, which causes the void volume percentage of smaller pores to increase, even though the number of pores remain the same. It is also found that the diameter of secondary pores can be decreased by up to 50% depending on CL microstructure, which is significant.

Fabrication of Super Hydrophobic Gas Diffusion Layers

Gas diffusion layer (GDL) plays a significant role in water management and heat removal within the polymer electrolyte fuel cells (PEFCs). When the GDL is flooded with liquid water, PEFC undergoes mass transport losses due to pore blockage by water which leads to decreased cell performance. For this purpose, the fabrication of selective wetting pattern by spray coating on the GDL surface is reported in this study. The present study will investigate the surface morphology of the GDL determined by its pore geometry and hydrophobicity which can control the water transport in PEFCs. Commercial GDLs were selected as a substrate. Two different monomers were used and their emulsions of required concentration were spray coated and polymerised to achieve the hydrophobic coatings. Regardless to monomer’s viscosity, super hydrophobic coatings on Commercial GDLs were obtained via spray coating with a contact angle of 1590 or higher, while the base surface’s contact angle was in the range of 1000. The fabricated GDLs were further analysed by means of sliding angles and scanning electron microscopy. Fourier Transform Infrared Spectroscopy (FTIR) analysis confirmed the successful introduction of the functional groups in both the coatings. Pore size distribution and adhesion forces measurement were used to investigate the water droplet transport on the coated GDLs. In this presentation, the results of our study will be discussed with the aim of highlighting how these results will benefit the water management of next generation high-power PEFCs.

A new image-based technique for measuring pore size distribution of nonwoven geotextiles

The use of digital images to evaluate geotextile characteristics has appeared in the scientific literature, particularly for estimating the pore size distribution (PSD) of nonwoven geotextiles used for filtration purposes. While numerous image analysis techniques for PSD curve estimation have been proposed, automation of the analysis methods has received almost no attention. The goal of the present study is to quantify PSD curves from images of representative geotextile specimens using a fully automatic algorithm and considering the concept of largest inscribing opening size. These features are incorporated in a software program (GeotexInspector) developed by the second author. GeotexInspector is based on the concept of classification using the Support Vector Machine technique and digital image processing. These techniques are combined to develop a tool with a robust learning algorithm to identify geotextile fibers and pores. PSD curves from continuous filament and staple fiber nonwoven geotextiles are estimated using GeotexInspector and then compared with theoretical models that have appeared in the literature. The results indicate that the curves obtained from image analysis are in good agreement with model outcomes for models focused on the structure of geotextiles that are similar to the geotextiles used in this study.

Experimental verification of pore impedance theory: Drilled graphite electrodes with gradually more complex pore size distribution

In this work, electrochemical impedance spectroscopy (EIS) measurements were carried out on increasingly complex distribution of cylindrical pores with well-defined geometries. The complexity of the system was increased by stepping up from a single pore to multiple pores with uniform pore depth and radii followed by generating pore size distributions. The impedance response was interpreted using ZView fitting and a graphical approach and was found to be well-described by existing theory. We characterised the impedance response of the resulting porous electrodes with varying geometrical and electrochemical parameters - pore depth, pore radii, pore density, and electrolyte conductivity. The obtained results suggest a possibility to use measurements on drilled cylindrical pores to interpret more complex pore size distributions (PSDs) as measurements of PSDs were successfully modelled by adding the impedance response of single pores.