Internal Specific Surface Area Research Articles

Earthworm-Inspired Co/Co3O4/CoF2@NSC Nanofibrous Electrocatalyst with Confined Channels for Enhanced ORR/OER Performance.

The rational construction of highly active and durable oxygen-reactive electrocatalysts for oxygen reduction/evolution reaction (ORR/OER) plays a critical role in rechargeable metal-air batteries. It is pivotal to achieve optimal utilization of electrocatalytically active sites and valid control of the high specific internal surface area. Inspiration for designing electrocatalysts can come from nature, as it is full of precisely manipulated and highly efficient structures. Herein, inspired by earthworms fertilizing soil, a 3D carbon nanofibrous electrocatalyst with multiple interconnected nanoconfined channels, cobalt-based heterojunction active particles and enriched N, S heteroatoms (Co/Co3O4/CoF2@NSC with confined channels) is rationally designed, showing superior bifunctional electrocatalytic activity in alkaline electrolyte, even outperforming that of benchmark Pt/C-RuO2 catalyst. This work demonstrates a new method for porous structural regulation, in which the internal confined channels within the nanofibers are controllably formed by the spontaneous migration of cobalt-based nanoparticles under a CO2 atmosphere. Theoretical analysis reveals that constructing Co/Co3O4/CoF2@NSC electrocatalyst with confined channels can greatly adjust the electron distribution, effectively lower the reaction barrier of inter-mediate and reduce the OER/ORR overpotential. This work introduces a novel and nature-inspired strategy for designing efficient bifunctional electrocatalysts with well-designed architectures.

Amplified Performance of Charge Accumulation and Trapping Induced by Enhancing the Dielectric Constant via the Cyano Group of 3D-Structured Textile for a Triboelectric Multi-Modal Sensor.

To further improve the output performance of triboelectric devices, reducing charge attenuation and loss has become a hot research topic. Particularly, textiles have emerged as one of the promising research directions for triboelectric devices owing to their special internal structure and large specific surface area. In the present work, polyacrylonitrile fibers are fabricated with two distinct structures to provide a higher dielectric constant due to the strong polar properties brought about by higher dipole moment of the CN group. In addition, the complex and closely connected structure of the textile increases specific internal surface area. As a friction layer, the output voltage is shown to increase to 625% of the initial value (from 8 to 60V) after the application of friction for a short time due to accumulation property. When acting as a trapping layer, the charge loss after injection is effectively prevented due to excellent charge trapping effect. After 24h, the triboelectric output performance remains at ≈70% of the initial value (decreasing from 320 to 220V), which is more than 20 times that of the polytetrafluoroethylene film, which decreases from 125 to 19V. The device is realized for the advanced application of multi-modal sensors.

Characterization of Agnihotra ash

Agnihotra is a traditional domestic solemnity, performed to maintain harmony between living beings and nature, without harming and by giving respect. Agnihotra, the simplest forms of Yajnya performed at sunset/ sunrise in which cow dung is burned in the copper pot by using cow ghee and brown rice as oblations along with chanting of mantras of sun and fire. The ash produced after performance of Agnihotra yajnya has various applications in the agricultural sector, environmental pollution control, medical sector, etc. In the present study we have characterized the Agnihotra ash. Elemental analysis of Agnihotra ash was done with the help of Atomic Absorption Spectroscopy. Characterization of Agnihotra ash was done by using X-Ray Diffraction analysis and Fourier Transform Infrared analysis. Analysis of ash compounds was done by X-Ray Diffraction – Theta-2-Theta spectrum and Energy Dispersive X-Ray spectrum. Agnihotra ash mainly consists of silicon dioxide (SiO2) as major compound. The Agnihotra ash was a highly porous material with a large internal specific surface area.

Egg-derived porous plasma modified clay composite for wastewater remediation.

Clays are often envisaged as an alternative to activated carbon for wastewater pollutant adsorption. However, conclusive results have only been obtained for clays heavily chemically modified. In this study, a greener approach is proposed to improve the retention capacity of clays. It consists in mixing clay (C) with eggshell (ES) and calcine, and then exposing to gliding arc plasma (ESC-800/PL). The resulting materials were characterized by nitrogen physisorption, FTIR, XRD, TGA/DTG, and point of zero charge analyses. The preparation gives porous platelet agglomerates resulting from the kaolinite-metakaolinite transition, thereby increasing their internal specific surface area and capacity to retain pollutants. This granular distribution is kept stable by partial pozzolanic reactions avoiding deagglomeration. The specific surface area and total pore volume increased respectively from 14 m2g-1 and 0.049 cm3g-1 to 89 m2g-1 and 0.061 cm3g-1 leading to an enhanced removal efficiency of Fast Green and Orange G dyes from polluted water. The maximum adsorption capacity occurred at 298K attaining values of 32.34 and 14.78mgg-1 for OG and FG, respectively. The pH plays a crucial role in the maximum sorption of dyes, and the experimental data were successfully adjusted to pseudo-first-order kinetic and Liu isotherm model.

Experimental investigation on microstructure evolution and spontaneous combustion properties of aerobic heated coal

Since coal oxidation and heat accumulation are prerequisites for coal spontaneous combustion, it is of great significance to study the characteristics of coal oxidation and heat accumulation to grasp characteristics of spontaneous combustion of residual coal and to locate the area with coal spontaneous combustion in goaf. In this study, three types of lignite and bituminous coal with a strong spontaneous combustion tendency were selected to prepare raw coal samples and aerobic heated coal samples. Then ultimate and proximate test, core pore and surface area test, SEM test, TG test, FTIR test and temperature-programmed test were undertaken, respectively. After coal undergoes aerobic heated progress, its surface micro-cracks, internal pore volume and specific surface area surge, and the active functional groups vary significantly; the contents of C and H fall, and that of O rises. These changes are conducive to coal oxidation. The temperatures corresponding to the first peak points in the DTG curves for the aerobic heated coal samples are lower than those for the raw coal samples, which indicates that the aerobic heated coal samples enter the self-oxidation acceleration stage earlier. Besides, according to the results of the temperature-programmed experiment, the cross-point temperatures of CO generation for the aerobic heated coal samples and the raw coal samples are 91 °C, 82 °C and 76 °C, respectively. A comprehensive analysis discloses that the aerobic heated coal samples are more likely to combust spontaneously in the initial stage of oxidation and to generate more CO. The heat dissipation zone, oxidation zone and suffocation zone were divided by monitoring the oxygen concentration changes in goaf at different stages on 5–20101 working face. It is determined that the oxidation zone of the goaf is 71–152 m on the inlet side and 59–128 m on the return side.

Silver Foams with Hierarchical Porous Structures: From Manufacturing to Antibacterial Activity.

The development of porous materials with hierarchical porous structures is currently of great interest. These materials exhibit properties representative of different pore scales and thus open up the possibility of being used in new applications. In this paper, a method for the preparation of silver foams with hierarchical porous structures is discussed. Here, the replication method, which is typically used to produce coarse-pore foams, is merged with dealloying, which is commonly used to manufacture small-pore foams. For this purpose, packed NaCl particles (hard template) were infiltrated with 75%Al–25%Ag alloy (whose so-called soft template is the Al-rich phase). Both the hard and soft templates were removed by water dissolution and dealloying with HCl or NaOH solutions, respectively. Extensive characterization of the resulting materials revealed pores ranging from a few nanometers to hundreds of micrometers. The materials were characterized by their antibacterial performance against Gram-positive and Gram-negative bacteria and showed significantly higher activity than both silver foams prepared by sintering pure Ag particles and silver nanofoams produced by chemical dealloying. The combinations of pores of different sizes and the resulting high internal specific surface area have a decisive influence on the antibacterial capacity of these new materials.

Estimation of soil specific surface area from adsorbed soil water content

AbstractThe adsorbed water content is an attractive predictor for estimation of soil specific surface area (SSA) as its measurement is less laborious and more cost effective than standard laboratory techniques. We analysed the effects of total specific surface area (SSAtot), external specific surface area (SSAex) and internal specific surface area (SSAin) on water vapour sorption on 21 soil samples, and proposed models for estimating SSAex, SSAtot and SSAin from organic carbon content and the slope of soil water vapour sorption isotherm (SL0.5) and water content (WC0.5) at a water activity of 0.5. The results indicated that the variation of correlation coefficients between water content change at 0.05 water activity interval (WCC0.05) and SSAtot with water activity was mainly due to the differences in water vapour adsorption in interlayer spaces at different water activity levels. Furthermore, in the soil water content range from ~0.001 to ~0.03 g g−1 (within the water activity range from ~0.45 to ~0.75), water vapour adsorption was related closely to SSAex. Cross‐validation results on estimated SSAex, SSAtot and SSAin of the 21 samples produced root mean square error (RMSE) values less than 9.39 m2 g−1 and Nash‐Sutcliffe model efficiency coefficients (E) greater than 0.93, suggesting that the proposed models provided reasonable estimates of SSA components. Thus, soil water vapour adsorption data can be applied to simultaneously estimate SSAex, SSAtot and SSAin. Variation of correlation between WCC0.05 and SSAtot with water activity depended on SSAin. Soil water vapour sorption is related closely to SSAex at water activities from ~0.45 to ~0.75. The proposed models yield reasonable estimates of SSAtot, SSAex and SSAin. Adsorbed water content can be used as a predictor for SSA estimation.Highlights Variation of correlation between WCC0.05 and SSAtot with water activity depended on SSAin. Soil water vapor sorption relates closely to SSAex at water activities from ~0.45 to ~0.75. The proposed models yield reasonable estimates of SSAtot, SSAex, and SSAin. Adsorbed water content can be used as a predictor for SSA estimation.

Magnetic hollow bimetallic zinc/cobalt zeolitic imidazolate framework as sorbent for efficiently enriching aflatoxins combined with UHPLC-IT-MSn determination.

A novel magnetic hollow bimetallic zinc/cobalt-based zeolitic imidazolate framework (MHB-Zn/Co-ZIF-8) was prepared via a microwave-assisted chemical etching in methanol. The structure, morphology, and specific surface area were characterized by X-ray diffraction and FTIR spectroscopy, scanning and transmission electron microscopy, and N2 adsorption. The hollow nanostructures with high internal specific surface area, abundant active sites, and reduced aggregation of nanoparticles endow the hollow zeolitic imidazolate framework (ZIF) nanoparticle with high chemical stability, desirable durability, and excellent adsorption abilities. The MHB-Zn/Co-ZIF-8 nanoparticle was used as an effective sorbent for magnetic solid-phase extraction (MSPE) of trace aflatoxins B1, B2, G1, and G2 from fruit juice and fruit samples. The main parameters affecting the efficiency of MSPE procedures were investigated and optimized. The results show that, under optimized conditions, enrichment factors ranging from 67- to 355-fold are obtained for the target analytes. The method is linear in the range 1.0 to 100.0ngmL-1 with correlation coefficients (R2) from 0.9960 to 0.9992. The limits of detection of four aflatoxins are in the range 0.18 to 1.50ngmL-1 and the average recoveries range from 75.1 to 102.4%, with relative standard deviations (RSDs) less than 13.6%. This work presents the excellent extraction performance of aflatoxins B1, B2, G1, and G2 on MHB-Zn/Co-ZIF-8. In addition, the applicability of the MSPE coupling with ultrahigh-performance liquid chromatography-ion trap tandem mass spectrometry (UHPLC-IT-MSn) for trace analysis in complex matrices is shown. Graphical abstract Schematic presentation of magnetic hollow bimetallic zinc/cobalt zeolitic imidazolate framework as sorbent for efficiently enriching aflatoxins B1, B2, G1, and G2 from fruit juice samples prior to ultrahigh-performance liquid chromatography-ion trap tandem mass spectrometry (UHPLC-IT-MSn) determination.

Getting insight into the influence of coexisting airborne nanoparticles on gas adsorption performance over porous materials

Adsorption as one of the most important air cleaning methods has been extensively applied during which the coexisting airborne nanoparticles (NPs) with sizes close to adsorbent pore sizes could inevitably influence gas adsorption processes. In this work, the influence of sub-20 nm NPs on toluene adsorption on ZSM-5 zeolites exchanged with different cations (Li+, Na+ and K+) were studied based on gas-and-particle coexisting adsorption/filtration tests. Affinities for both toluene and NPs on adsorbents follow Li-ZSM-5 > Na-ZSM-5 > K-ZSM-5 regarding the orders of charge density, pore size, and internal and external specific surface areas. The toluene adsorption was shown to be impaired by coexisting NPs from perspectives of thermodynamics and kinetics. For Li-ZSM-5, Na-ZSM-5 and K-ZSM-5, significant relative reductions of 10.4 %, 10.5 % and 16.0 % in toluene adsorption capacity at the lower feed concentration, and of 20.3 %, 15.2 % and 2.3 % in mass transfer coefficient at the higher feed concentration were observed, respectively. The influential mechanisms regarding competitiveness between toluene and NPs in interaction with cationic and porous surfaces were accordingly proposed, which are of practical significance for selecting robust adsorbents under realistic harsh air conditions.

Effect of Ag on deNOx performance of SCR-C3H6 over Fe/Al-PILC catalysts

Silver has been used to modify the iron-based catalyst supported on alumina pillared montmorillonite to enhance its activity at lower temperature (<300°C). Bimetallic Ag-Fe/Al-PILC (Pillared interlayer clay) was prepared by the ultrasonic impregnation method and performance was tested on a fixed bed reactor. The experiment results showed that silver obviously improved the catalyst activity at a lower temperature. The NO conversion efficiency of Ag-Fe/Al-PILC at 250°C was 60%, which was higher than Fe/Al-PILC (20%). The maximum 82% NO conversion and 100% N2 selectivity were obtained by 2.1Ag-Fe/Al-PILC at 250°C. Moreover, Ag-Fe/Al-PILC revealed better resistance to H2O and SO2. The catalyst characterization was conducted by several techniques with respect to the microstructure and physicochemical properties. According to the effects of N2-adsorption and desorption tests, Ag-Fe/Al-PILC formed a stable overall structure and presented a large internal specific surface area. Besides, XRD and UV-vis proved that the Ag-Fe solid solution, Ag+ and Agδ+ n species formed on the surface of the catalyst were the key factors affecting its low temperature activity. XPS results suggested that there was electron transfer between Ag and Fe, which formed a synergistic effect of bimetals and changed the content of Ag and Fe and their valence state on the catalyst surface. The findings of H2-TPR indicated that the addition of Ag promoted the shift of the Fe/Al-PILC reduction peak toward low temperature, which boosted the low-temperature reduction capacity of the catalyst. The surface acidity analysis by Py-FTIR indicated that Lewis acid and Brönsted acid existed simultaneously and Ag enhanced the stability of Brönsted acid.

Experimental and Predictive Description of the Morphology of Wet-Spun Fibers

The prediction of the morphology of wet-spun fibers has so far been only possible by complex and experimentally-intensive approaches that include the construction of ternary phase diagrams. Ultimately, however, the available models give approximate information. Here we propose an alternative predictive approach that uses design principles based on the combination of (1) Relative Energy Difference (RED) of Hansen solubility and, (2) a kinetic parameter ‘T’ that considers mass transfer effects. Such model is applied and experimentally validated for a priori determination of the diameter and internal morphology of wet-spun fibers. Remarkably, only three variables relevant to wet-spinning are needed, namely, the choice of polymer, solvent, and non-solvent types. A combination of systems are tested and the morphology of the obtained fibers determined via electron microscopy. Aspects related to demixing, internal specific surface area (BET) and layer formation on the fibers are described qualitatively. The faci...

Direct ink writing of porous cordierite honeycomb ceramic

Abstract Herein, we fabricated honeycomb ceramics with different porosities and pore shapes via the layer-by-layer deposition of cordierite (2MgO·2Al2O3·5SiO2) particle ink, obtaining proper rheological properties using a direct-writing technology. No collapses as well as minimal cracking and bending were observed in the internal structure of the samples after calcination. We measured and compared the internal porosity and specific surface area of honeycomb ceramics with the same pore shape but different pore dimensions, as well as the same pore dimension but different pore shapes. The samples were both loaded with an γ-Al2O3 washcoat and Pd-based catalyst using the same method for the catalytic combustion of toluene. The different porosity and pore shape influenced the catalytic efficiency. This study may provide some useful guidelines for fabrication of honeycomb ceramics by direct writing technology, which could be used to remove volatile organic pollutants(VOCs).

Determination of Internal and External Surface Area of Atomistic Porous Carbons

In this work, we propose the computational algorithm to compute the temperature-independent specific surface area of atomistic models of porous carbons. Concisely, the method is to divide the simulation space into fine grid points, place the selected probe molecule on each grid point and then check whether that insertion is accessible or inaccessible regions based on molecular force field. Three models of porous carbon structures are chosen as examples for estimating internal and external specific surface areas and trend of surface curvature. By comparing the computational cost, our proposed technique significantly requires less time-consuming than the physisorption. Therefore, for atomistic models of porous carbons, we recommend that our proposed method be more efficient and accurate than the experimentally and computationally traditional physisorption.

The Relationship between Functional Groups and Gaseous Productions and Micropore Structures Development of Coal Oxidized at Low Temperature under Methane-Diluted Atmospheres

ABSTRACTAs coal reservoirs containing high methane content are more prone to spontaneous combustion, disasters caused by the combined effects of methane and coal spontaneous combustion have been increasingly prominent. Given that air flows in different zones in a goaf contain methane with different contents, the mechanism governing the changes of micropores and functional groups of left-over coal subjected to spontaneous combustion in a goaf with air flows containing methane were investigated by sufficiently considering the diluted influence of methane. The change of microscopic functional groups and variation of gaseous products from coal oxidized at low-temperature (i.e., 70°C< it < 230°C) under different oxidizing atmospheres were separately acquired by employing Fourier transform infrared spectroscopy (FTIR) and gas chromatography. By using the Brunauer, Emmett and Teller (BET) method, a low-temperature nitrogen adsorption experiment was carried out on coal samples taken from the Shigang coal mine in Shanxi province, China under different methane-diluted oxidizing atmospheres. The results showed that the content of aliphatic hydrocarbons (methyl and methylene) of the coal oxidized at low temperature decreased with rising oxidizing temperature and reached a maximum at the condition of a 25% methane concentration. Meanwhile, other oxygen-containing functional groups and corresponding gaseous products were generated. The aforementioned results indicated that the initial temperature for the generation of CO and the amount generated both showed delayed effects in oxidizing atmospheres with different methane concentrations. By carrying out a low-temperature nitrogen adsorption experiment, it was determined that the average sizes of the pores in coal decreased in an oxidizing atmosphere (i.e., < 15% methane concentrations at a high temperature). However, the specific surface area (SSA) and accumulative total internal surface area of the pores increased. Additionally, the pore structure in the coal tended to be microscopic and complex in the aforementioned oxidizing atmosphere, as determined by using the fractal dimension D. The pore structure in the coal was increasingly complex after being oxidized in an oxidizing atmosphere containing methane, which increased the likelihood of the coal oxidation reaction and increased the occurrence probability of coal spontaneous combustion.

Comparative adsorption–regeneration performance for newly developed carbonaceous adsorbent

A proprietary adsorbent material called Nyex 1000 was developed by the Arvia Technology Ltd. (UK based waste water treatment company). Nyex 1000 was being employed for a number of commercial applications dealing with the removal of organic contaminants from industrial effluents. This adsorbent material had small adsorptive capacity. With the aim to address small adsorptive capacity, a new graphite based adsorbent material was developed. The particle design was accomplished through successive chemical, thermal and mechanical treatments of raw graphite material (natural large flake graphite, to be called here as NLFG). The chemical treatment of the NLFG was carried out through electrochemical intercalation using dilute (50%) sulfuric acid in an electrochemical cell. Chemically treated NLFG then went through thermal treatment at 850°C and followed by mechanical treatments consisting of compression (4536kgfcm−2) and chopping at 18,000rpm for 30s. The developed adsorbent material, (exfoliated compacted graphite, to be called here as ECG) and NLFG were characterized using state of the art techniques including SEM, BET surface area, XRD, Zeta potential, Boehm surface titration, bed electrical conductivity and laser size analysis. The characterization results showed significant increase in internal specific surface area from 1 to 17m2g−1. It was attributed to the development of partially porous particle surface verified by SEM results. The XRD, Boehm surface titration, Zeta potential results endorsed the associated chemical and physical changes appeared in the composition of the NLFG as a result of chemical, thermal and mechanical treatments. Adsorption-regeneration studies were conducted using developed ECG and existing Nyex 1000 materials. The pollutants used for adsorption–regeneration studies were acid violet 17, phenol, humic acid, ethane thiol and methyl propane thiol dissolved in aqueous solution. The results were compared and it was found that ECG showed significantly improved adsorption capacity with many folds. Both adsorbent materials, ECG and Nyex 1000 delivered 100% electrochemical regeneration efficiencies.

New Pyrolysis Model for Biomass Particles in a Thermally Thick Regime

In order to get a deep understanding of biomass pyrolysis and gasification with particle size ranging from several millimeters to centimeters, detailed modeling of thermochemical conversion of thermally thick particles is required. In this paper, a new pyrolysis model for a large biomass particle is established, and the porous particle is modeled with two systems. In the continuous system, a uniform multiphase CFD algorithm is implemented to resolve both internal and external flow fields, and the solid temperature is solved by considering heat conduction, heat convection, and radiation. In the discrete system, the large particle is regarded as a porous media and discretized into a cluster of small virtual particles which are used to model the devolatilization and particle shrinkage. The evolutions of porosity and internal specific surface area during pyrolysis are also taken into account. The proposed model is first validated with the experiments in the literature, and good agreements have been obtained. ...

Adsorption of Ni2+ and Cu2+ using Bio-Mineral: Adsorption Isotherms and Mechanisms

ABSTRACTHeavy metal pollution has become one of the most serious environmental pollution problems. This study aimed to determine the adsorption and desorption characteristics of Ni2+ and Cu2+ by bio-mineral which was induced by Bacillus subtilis, and to explore the effect of pH on adsorption characteristics. The results showed that the Langmuir model gave a better fit to the experimental data than the Freundlich model, which demonstrated the adsorption was of a single-molecule layer form. The maximum adsorption capacities of the bio-mineral for Ni2+ and Cu2+ were determined as 67.114 mg/g and 69.930 mg/g, respectively. The desorption rates of Ni2+ and Cu2+ were very low, especially for Ni2+ which was almost 0. Besides, the bio-mineral maintained high adsorption capability for metals ions within a wide pH range (pH ≥ 3). It did not show any new phases after adsorption of Ni2+ and Cu2+ tested by FTIR, indicating that the bio-mineral and heavy metal ions might mainly physically be adsorbed. The bio-mineral has a larger internal and external specific surface area, pore volume and colloidal properties which are beneficial for the adsorption of metals ions, but shows limits in desorption. This study provides a theoretical basis for the utilization of bio-mineral and opens a new perspective for the remediation of heavy metals pollution.

Acid, alkali and peroxide pretreatments increase the cellulose accessibility and glucose yield of banana pseudostem

Lignocellulosic biomasses such as banana pseudostem are attractive cellulose sources for bioenergy production, and for the use in biorefinery processes. However, pretreatment of lignocellulosic material is required to remove hemicellulose and lignin, while increasing cellulose accessibility to enzymatic hydrolysis (i.e., decreasing biomass recalcitrance). The effect of different concentrations of acid (H2SO4), alkaline (NaOH) and peroxide (H2O2) pretreatments on the chemical composition, cellulose accessibility, and enzymatic digestibility of banana pseudostem were studied. The water insoluble solids (WIS) recovery was low (∼30%) for the severe pretreatment conditions applied, indicating high material solubilization. Acid pretreatment completely removed the hemicellulose content, whereas alkaline and peroxide pretreatments reduced its amount to 4.38 and 8.68%, respectively. In contrast, the lignin content increased (from 17.26 to 39.99%) after severe acid pretreatment, while alkaline and peroxide pretreatments reduced the lignin content to 7.65% and 7.17%, respectively. In line with hemicellulose and lignin removal, the cellulose content increased from 60.84 to 75.48 and 74.37%, respectively for alkaline and peroxide pretreatments, with no alteration for acid. Dye adsorption assays showed that alkaline and acid pretreatments resulted in high internal and external specific surface areas – indicative of high cellulose accessibility – when compared with peroxide pretreatments. Overall, alkaline and acid pretreatments resulted in the highest glucose yields from enzymatic hydrolysis of banana pseudostem, compared with peroxide pretreatment. In conclusion, concentrations of each pretreatment that led to the highest glucose yields was identified, confirming that the banana pseudostem is a great source of fermentable sugars, with high potential for biofuel production.

Neutron scattering study of vitrinite: Insights into sub-micrometer inclusions in North American Carboniferous coals of bituminous rank

Results of SANS and USANS measurements performed on a series of six vitrinite samples having vitrinite reflectance (Ro) values ranging from 0.55% (high volatile bituminous rank) to 1.28% (medium volatile bituminous rank) were analyzed. Experimental data were acquired for two sample forms: platelets cut parallel to the bedding and pellets made up of randomly oriented, nearly-monodisperse particles.Numerical analysis indicates the presence of sub-micron sized inclusions embedded in the organic matrix. For the lowest-rank vitrinites, the dominating inclusions are monodisperse are ~7–12nm in diameter, and have concentrations of the order of 1017cm−3. Their shape is anisotropic, with the surface-to-volume ratio about three times larger than for a solid sphere.The higher-rank vitrinites contain much larger monodisperse inclusions having diameters of ~50nm, concentrations of ~1014cm−3, large surface-to-volume ratios, and fuzzy interfaces with the organic matrix. Inclusions of a similar size and concentration are also present in the lowest-rank sample, but are much less frequent than the small inclusions. We provisionally interpret those objects as inclusions of mineral matter, most likely associated with original plant material. The internal specific surface area (SSA) calculated for the small mineral matter inclusions is ~100m2/cm3 and for the large inclusions ~2m2/cm3.

Verification of a capillary model for the electroosmotic transport of a free solvent in ion-exchange membranes of different natures

It has been shown that the transport of a free solvent through ion-exchange membranes of different structural types in NaCl solutions can be calculated within the framework of the capillary model for electroosmotic transport on the basis of data on pore-radius distribution, exchange capacity, internal specific surface area, and concentration dependences of membrane electrical conductivity. The electrolyte-solution concentration range has been determined in which the convergence is observed between the data calculated in terms of the model and the results of the independent experimental determination of the numbers of water transport through the membranes. The fraction of through pores in the structure of an ion-exchange membrane has been found, and it has been shown that this fraction depends on the structural type of a polymer film alone.