Correlation between Pitch Impregnation Pressure and Pore Sizes of Graphite Block

This study aimed to investigate the effect of impregnation pressure on the decrease in porosity of impregnated bulk graphite. The correlation between pitch impregnation behavior and the pore sizes of the bulk graphite block was studied to determine the optimal impregnation pressure. The densities and porosities of the bulk graphite before and after pitch impregnation under various pressures between 10 and 50 bar were evaluated based on the Archimedes method and a mercury porosimeter. The density increased rates increased by 1.93–2.44%, whereas the impregnation rate calculated from the rate of open porosity decreased by 15.15–24.48%. The density increase rate and impregnation rate were significantly high when the impregnation pressures were 40 and 50 bar. Compared with impregnation pressures of 10, 20, and 30 bar, the minimum impregnatable pore sizes with impregnation pressures of 40 and 50 bar were 30–39 and 24–31 nm, respectively. The mercury intrusion porosimeter analysis results demonstrated that the pressure-sensitive pore sizes of the graphite blocks were in the range of 100–4500 nm. Furthermore, the ink-bottle-type pores in this range contributed predominantly to the effect of impregnation under pressure, given that the pitch-impregnated-into-ink-bottle-type pores were difficult to elute during carbonization.

Study of Thermally Expanded Graphite for Rehabilitation of Oil-Polluted Water Ecosystems

The properties of sorbent on the basis of thermoexplite (STRG) obtained from the engineering center of IngSU "Development of modified sorbation materials" have been investigated. This sorbent is proposed to be used in the elimination of oil spills and products of its processing from the water surface. The porosity of the STGR was analyzed using a mercury porosimeter Pascal 140 and 240 Evo. It is shown that the investigated sample is a volumetric porous tool with a specific pore volume of 35.5 cm3/g. It is found that the available porosity is more than 97.2%. The pore size distribution was studied. Based on the data of the porous system, research on the sorption of oil and oil products by this sorbent. Shown is the high efficiency of STRG in cleaning the water mirror from oil and oil products. The main properties of oil sorbents have been investigated.

Improvement of stability for cellulose polymer by calcium oxide for application to porous materials

In this study, calcium oxide (CaO) was used as an additive to form pores in a cellulose acetate (CA) membrane and at the same time improve the thermal stability of the cellulose acetate membrane. When the CA/CaO membrane was exposed to water pressure, the solvent was removed from the CA matrix area plasticized by the CaO particle size and water channels were formed. In addition, the high melting point of CaO and its bonding with the carbonyl group of CA caused a crosslinking effect. We succeeded in membrane synthesis with a high porosity of 73.1% and flux data of 95.25 L/m2h at 8 bar, which was enhanced thermally with an increased decomposition temperature of 50°C on thermogravimetric analysis (TGA). The pores generated in the cellulose acetate film were confirmed using a scanning electron microscope machine (SEM) and mercury porosimeter. Thermal stability and interactions in materials were measured using TGA and Fourier transform infrared (FT-IR).

Synthesis and Characterization of Graphene Oxide/Chitosan Composite Aerogels with High Mechanical Performance

Chitosan, a semi-crystalline biomolecule, has attracted wide attention due to its high synthesis flexibility. In this study, to improve the mechanical properties of chitosan aerogels (CSAs), graphene oxide (GO) was extracted and introduced into chitosan aerogels as fillers. The porous CSAs/GO composite aerogels were fabricated by an environmentally friendly freeze-drying process with different GO contents (0, 0.5, 1.0, 1.5, wt.%). The characteristics of the CSAs/GO were investigated by scanning electron microscopy (SEM), mechanical measurements and mercury porosimeter. The crystallinity of samples was characterized by X-ray diffraction (XRD). The mechanism of the effect of graphene oxide on chitosan was studied by Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results show that the microstructure of the samples is developed in the network structure. The porosity of CSAs/GO aerogels is as high as 87.6%, and the tensile strength of the films increased from 6.60 MPa to 10.56 MPa with the recombination of graphene oxide. The crystallinity (CrI) of composite aerogels increased from 27% to 81%, which indicates that graphene oxide improves the mechanical properties of chitosan by chemical crosslinking.

Petrophysical parameters of the porous space of the “tight” type sandstones of the Skole Unit - Preliminary analysis

The scientific goal of the paper is the physical characteristics of pore space of the Inocereamian Sandstones located in the Skole Unit as a part of the Outer Carpathians – The Carpathian Flysch. Rock samples were tested using mercury porosimeter. Using this method, cumulative curves of effective porosity were obtained, as well as the pore geometry distribution and pore surface area distribution. geometry and distribution. In the article the authors determine the physical parameters of the pore space for 30 samples, such as porosity, permeability, size and distribution of pore diameter, specific surface area and geometry of a pore space. Preliminary analysis of rock samples is to answer the question of the existence of sandstones capable of forming "tight" type deposits of natural gas and determining their reservoir parameters.

Impact of porosity on calcination and sulfation of calcium sorbents

The focus of the study was on sorbents with a grain size of 125-250 μm. Examinations of reactivity were conducted in a reaction furnace under conditions required for reactivity testing of calcium sorbents. The tests were performed according to standard calcium sorbent tests (FW). Computation of reactivity indices and capacity index were performed according to formulae contained in previous publications [1]. The process of simultaneous calcination and sulfation of calcium sorbents is controlled by the speed of chemical processes and diffusion. Therefore, surface properties of sorbents, including porosity, play an important role in the flue gas desulphurization process. Examinations of sorbent porosity were performed using a mercury porosimeter. Based on porosimetric analysis, open porosity, the total surface area of sorbents and mean diameter of pores were evaluated for the sorbents studied.

Biological and chemical corrosion of cement materials modified with polymer

The article presents the effect of the addition of polymer to mortars with CEMI and its influence on durability under conditions of sulfuric acid or nitric and sulphur bacteria or nitrogen (nitrification and denitrification). Both acids corresponds to the products of metabolism of bacteriaAcidithiobacillus thiooxidansandThiobacillus denitrificans,Paracoccus denitrificansby the literature is about 0.15 mmol/dm3. The changes in tightness materials studied by determining moisture mass and absorption. Corrosion processes were identified by examination in a scanning microscope equipped with an X-ray microanalyzer and a mercury porosimeter. The research results presented showed that the solution has a significantly weaker effect on the composite cement and cement-polymer compared with the action of bacteria. The action of both environments caused two opposing processes: unsealing the structure and deposition of corrosion products.

Effects of Pore Former on Properties of Alumina Porous Ceramic for Application in Micro-Filtration Membrane Supports

Due to its excellent chemical stability, high temperature resistance and mechanical properties, alumina porous ceramic was the first choice of the production of microfiltration membrane support body material. In this paper, alumina porous ceramic was prepared by alumina as main materials and adding proper amount of adhesives and sintering additives. Effects of the kinds and addition of pore formers, such as starch, graphite and carbon-black, on properties of alumina porous ceramic was studied. The porosity of the fired samples was evaluated by Archimedes law. The fired samples were characterized by scanning electron microscopy (SEM), compressive strength and mercury porosimeter measurements. Alumina porous ceramic composition was prepared by mixing 100% alumina with different particle size and 8 % graphite pore former. The sample was pressured at 10 MPa and fired at 1650 °C for 2 h, and endowed with 6-8 μm of the average pore diameter, 37.65 % of the porosity and 40.33 MPa of the compressive strength, respectively. The influence law of the kinds and addition of graphite pore former on the performance of alumina porous ceramic was studied for application in micro-filtration mmembrane supports.

Fabrication of Silica Monoliths with Hierarchically Porous Structure from Freeze-Drying

This paper provides a novel route to prepare silica monoliths with hierarchical porous structure via freeze drying. In this method, macroporous silica monoliths were first produced by freeze-drying and calcination. By adjusting the concentration of cetyltrimethylammonium bromide in ethylsilicate, a layer of mesoporous thin film was attached on the macroporous silica monolith. The structural characterization of the hierarchical porous monoliths were studied by field emission scanning electron microscopy, mercury porosimeter and nitrogen adsorption-desorption techniques (BET). It turned out that the pore distribution of the obtained monoliths was ranged from 3.72 nm to 23.21nm and the maximum specific surface area calculated from BET was about 288 m2/g, which indicated the existence of hierarchical structure in the obtained material.