Wyniki wyszukiwania - BazTech

1

Zastosowanie mezoporowatych adsorbentów w procesie immobilizacji enzymów

Geszke-Moritz Małgorzata, Kamasa Karolina, Moritz Michał

Przemysł Chemiczny

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2025

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T. 104, nr 6

642--645

PL

Przegląd literaturowy dotyczący zastosowania mezoporowatych krzemionek, szkieletów metaloorganicznych oraz struktur organicznych jako nośników enzymów. Układy nośnik-unieruchomiony enzym znalazły zastosowanie w procesach technologicznych (reakcje hydrolizy, transestryfikacji), diagnostyce laboratoryjnej i neutralizacji substancji szkodliwych. Immobilizacja zazwyczaj zmniejsza aktywność enzymów, zwiększając jednocześnie ich stabilność termiczną oraz odporność na czynniki środowiskowe (pH).

EN

A review, with 25 refs., of use of mesoporous silicas, metal-org. framework and covalent org. framework as the enzyme support. The carrierimmobilized enzyme systems used in technol. processes (hydrolysis, transesterification), laboratory diagnostics and toxic substance neutralization were described. Immobilization decreased the enzyme activity and simultaneously increased their thermal stability to environmental factors (pH).

2

Recent achievements and applications of silsesquioxane-based hybrid materials - an overview

Piórecka Kinga, Kurjata Jan, Stańczyk Włodzimierz A.

Polimery

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2025

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Vol. 70, nr 3

151--165

EN

Based on a literature review from the last 3 years, potential applications of hybrid materials based on silsesquoxanes in engineering, catalysis, biomedicine, and drug delivery systems are presented. Methods of synthesis of such materials are also discussed, considering publications from previous years. Silsesquioxanes are characterized by a defined stable three-dimensional structure consisting of an inorganic core (Si-O-Si) and organic substituents. The rigid core and multifunctionality of substituents make silsesquioxanes ideal candidates for use in the synthesis of innovative materials in the areas of chemistry and biomedicine.

PL

Na podstawie przeglądu literaturowego z ostatnich 3 lat przedstawiono potencjalne zastosowania materiałów hybrydowych na bazie silseskwioksanów w inżynierii, katalizie, biomedycynie i systemach podawania leków. Omówiono również metody syntezy tego typu materiałów, biorąc pod uwagę publikacje z wcześniejszych lat. Silseskwioksany charakteryzują się zdefiniowaną stabilną trójwymiarowa strukturą składającą się z nieorganicznego rdzenia (Si-O-Si) oraz organicznych podstawników. Sztywny rdzeń i wielofunkcyjność podstawników czynią silseskwioksany idealnymi kandydatami do stosowania w syntezie innowacyjnych materiałów w obszarach chemii i biomedycyny.

3

Od mofów „w pigułce” do pigułek w mofie : przewodnik teoretyczno-praktyczny

Pander Marzena, Skałecka Natalia, Prus Julia, Stani Oliwia, Bury Wojciech

Wiadomości Chemiczne

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2024

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[Z] 78, 11-12

1697--1729

EN

The design, synthesis, and characterization of novel materials with unique properties represent an important field of modern chemistry. Metal-Organic Frameworks (MOFs) [1], a class of porous coordination polymers, exemplify such innovative materials. Despite their initial discovery less than 30 years ago, the field of MOFs has expanded rapidly, and is represented now by over 100 000 different structures [2]. The precise design of organic and inorganic building blocks (metal nodes and organic linkers), which can be regarded as chemical Lego® bricks, enables the realization of an almost limitless array of structural architectures, limited only by the imagination of a chemist. This versatility offers the potential to create advanced materials with tailored properties for specific applications, which include sorption and separation processes [3], heterogenous catalysis [4], drug delivery [5], sensing [6] or energy storage [7]. The aim of this tutorial review is to explore and highlight key aspects of modern porous materials, with a particular focus on MOFs. Basic definitions and classification of this class of materials are provided, alongside an overview of its dynamic development in recent years. The structural composition of these materials is discussed in relation to the principles of reticular chemistry, including nomenclature and topological representations. The increasing complexity within this field and the evolution of MOFs is addressed through the introduction of their generations. The main part of this paper focuses on Zr-based MOFs, a distinctive group known for their unique stability and structural versatility, as well as the ability to endure various post-synthetic modifications. The broad spectrum of their applications, from controlled drug delivery to highly efficient heterogeneous catalysis, is presented to showcase the main achievements in this area. This review aims to highlight how advancements in MOF research are paving the way for new developments in material science, encouraging readers for further in-depth exploration of this compelling area of modern chemistry.

4

Kowalencyjne szkielety organiczne : otrzymywanie, właściwości, zastosowanie

Makowski Damian, Bajorowicz Beata

Wiadomości Chemiczne

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2024

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[Z] 78, 3-4

219--241

EN

Covalent organic frameworks (COFs) are a novel and unique crystalline porous organic polymers formed by the reversible condensation of building units containing light elements and linked by strong covalent bonds. Covalent organic frameworks consist of linkers (building units) and chemical bonds formed between two building units. By carefully selecting the appropriate linkers and bonds, it is possible to create covalent organic frameworks with distinct features. This work provides a concise overview of covalent organic frameworks, including their structural, surface, optical, and electronic properties. The preparation strategies most commonly employed for COFs are also presented, along with relevant examples. The potential applications of covalent frameworks in various fields such as: photocatalysis, medicine, gas separation and storage, photovoltaics and sensors are also discussed, highlighting the need for further development of this important class of materials.

5

Research of Hybrid Aluminium Castings with the Use of Porous Cores

Brůna M., Medňanský Martin, Oslanec P.

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 3

18--24

EN

The paper focuses on the research of hybrid aluminium castings produced by overcasting technology. This is an advanced technology for ensuring the lightness of castings by using the principle of overcasting a core with a porous cellular structure produced by foaming. Process parameters in the foaming phase of the material have a great influence on the resulting porous structure. The article focuses on controlling the influence of pressure during the foaming process on the resulting porosity and evaluating by X-ray tomograph and measuring the relative density. Variants using an initial pressure of 0.3 MPa appear to be the most satisfactory. The challenge of this technology is to ensure adequate bonding of the metals at the interface between the porous core and the solidified metal without penetrating the coating layer. For this reason, the surface treatment of foamed cores with various etchants has been proposed to disrupt the oxide layer on their surface. Macrographs of the uncoated sample and samples etched with 0.5% HF and 10% H3PO4 demonstrated the need for core surface treatment to prevent liquid metal penetration. EDX analysis confirmed the presence of AlPO4 at the core/casting interface in the treated sample.

6

Modelling the Acoustic Properties of Baffles Made of Porous and Fibrous Materials

Kosała Krzysztof

Archives of Acoustics

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2024

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Vol. 49, nr 3

345--357

EN

The research described in the article addresses the problem of measurement, prediction and practical use of the acoustic properties of materials determined in an impedance tube. The aim of the research was to develop a simple calculation model for the insertion loss of small machinery enclosures, based on the normal incidence sound transmission loss and the normal incidence sound absorption coefficient of porous and fibrous materials. Both experimental and model tests were carried out on materials such as mineral wool, melamine foam and rebonded polyurethane foam. Assessing the absorption properties of the tested porous and fibrous materials was performed using selected theoretical models, relating the calculations of the normal incidence sound absorption coefficient to measurements of this parameter conducted using an impedance tube. The application of the modified Allard and Champoux model brought the best results with the smallest discrepancies of the obtained results in relation to the experimental tests. Assessing the sound-insulating properties of the tested mineral wool was carried out using the proposed calculation model for the normal incidence sound transmission loss, relating the obtained results to measurements conducted using an impedance tube. The assessment of the sound-insulating properties of porous and fibrous materials was performed using the proposed calculation model for insertion loss, which was validated using two prototype test stands for determining the insertion loss of cubic enclosures, in this case with walls made of porous and fibrous materials. Satisfactory results were obtained for engineering applications in the calculation results using the proposed models with respect to measurements. The results may have practical applications in assessing the effectiveness of acoustic enclosures, in which the basic construction material is an appropriate porous or fibrous plate, selected to have both sound-absorbing and sound-insulating properties.

7

Potential of Indirect Regenerative Evaporative Cooling System (M-Cycle) for Electronic Applications

Olbrycht Robert, Kałuża Marcin, Felczak Mariusz, Levchenko Dmytro, Więcek Bogusław

Pomiary Automatyka Robotyka

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2023

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R. 27, nr 3

19--25

EN

The article presents a simple prototype system based on the concept of indirect regenerative evaporative cooling (IREC) thermodynamic cycle for electronics applications. The key problem of selecting porous capillary material is discussed and preliminary experimental results are presented using IR thermography. The presented research is an initial step towards the development of a laboratory-validated, fully operational IREC system for high-power electronics.

PL

W artykule przedstawiono prototypowy układ chłodzenia oparty na koncepcji cyklu termodynamicznego pośredniego regeneracyjnego chłodzenia wyparnego (IREC) do zastosowań w elektronice. Omówiono kluczowy problem doboru porowatego materiału kapilarnego i przedstawiono wstępne wyniki eksperymentów z wykorzystaniem termografii w podczerwieni. Przedstawione badania stanowią wstępny krok w kierunku opracowania zweryfikowanego laboratoryjnie, w pełni funkcjonalnego systemu IREC do odprowadzania ciepła w systemach elektronicznych dużej mocy.

8

Multiobjective optimiaztion of microstructure parameters in a thermoelastic porous material by means of differential evolution and elements of game theory

Długosz Adam, Schlieter Tomasz

Computer Methods in Materials Science

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2022

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Vol. 22, No. 3

117--124

EN

The paper is devoted to the optimization of the microstructure parameters of a porous medium under thermo-mechanical loading. Four different criteria related to the properties of the porous material have been proposed and numerically implemented. To solve a multiobjective problem, a novel method based on the coupling of differential evolution and elements of game theory is used. The proposed algorithm features an appropriate balance between exploration and exploitation of objective space, which is necessary for the successful optimization of these types of tasks with the use of numerical simulations. The model of the thermo-elastic porous material is composed of two-scale direct analysis based on a numerical homogenization. Direct thermoelastic analysis with representative volume element (RVE) and finite element method (FEM) is performed. Numerical example of the optimization illustrating the usefulness of the proposed method is included.

9

Free vibration analysis of sandwich beam with porous FGM core in thermal environment using mesh-free approach

Hung Tran Quang, Tu Tran Minh, Duc Do Minh

Archive of Mechanical Engineering

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2022

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LXIX, nr 3

471--496

EN

Thermally induced free vibration of sandwich beams with porous functionally graded material core embedded between two isotropic face sheets is investigated in this paper. The core, in which the porosity phase is evenly or unevenly distributed,has mechanical properties varying continuously along with the thickness according to the power-law distribution. Effects of shear deformation on the vibration behavior are taken into account based on both third-order and quasi-3D beam theories. Three typical temperature distributions, which are uniform, linear, and nonlinear temperature rises, are supposed. A mesh-free approach based on point interpolation technique and polynomial basis is utilized to solve the governing equations of motion. Examples for specific cases are given, and their results are compared with predictions available in the literature to validate the approach. Comprehensive studies are carried out to examine the effects of the beam theories, porosity distributions, porosity volume fraction, temperature rises, temperature change, span-to-height ratio, different boundary conditions, layer thickness ratio, volume fraction index on the vibration characteristics of the beam.

10

The characterization of scaffolds based on dialdehyde chitosan/ hyaluronic acid

Grabska-Zielińska Sylwia, Sosik Adrianna, Małkowska Anna, Olewnik-Kruszkowska Ewa, Stein-Brink Kerstin, Kleszczyński Konrad, Kaczmarek-Szczepańska Beata

Engineering of Biomaterials

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2021

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Vol. 24, no. 163

76

11

Effective removal of odors from air with polymer nonwoven structures doped by porous materials to use in respiratory protective devices

Brochocka Agnieszka, Nowak Aleksandra, Panek Rafał, Kozikowski Paweł, Franus Wojciech

Archives of Environmental Protection

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2021

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Vol. 47, no. 2

3--19

EN

Filtering Respiratory Protective Devices (FRPD) is not typically evaluated for exposure to volatile compounds, even though they significantly affect their protective performance. Such compounds are released into the atmosphere by industrial processes and pose serious health risks in people inhaling them. The adsorbent materials currently used to prevent those risks include activated carbon (AC). Zeolites and mesoporous silica materials (MCM) are very popular among the sorption materials. Due to their physical and chemical properties, they are able to adsorb significant amounts of volatile compounds from air. The melt-blown technology was used to produce filtering nonwovens with modifiers. As a result, polymer nonwoven structures with modifiers in the form of AC, zeolite (NaP1 type), molecular sieves (SM, SM 4Å) and mesoporous silica materials (MCM-41) were produced. The use of ACs (AC1 from Zgoda and AC2 from Pleisch) and their mixtures with others modifiers allowed to obtain satisfactory sorption, protective and utility properties. The longest breakthrough time against cyclohexane (approx. 53 min) was afforded by a variant containing AC, against ammonia (approx. 12 min) for the variant with AC2 and a mixture of AC2 and MCM-41. In the case of acetone vapor satisfactory breakthrough times were found for the variants with AC2 and AC1+SM (~20–25 min.). The present work deals with scientific research to improve workers’ and society’s health and safety by pursuing a better working life, and creating a safe social environment.

12

Free vibration and buckling analyses of FG porous sandwich curved microbeams in thermal environment under magnetic field based on modified couple stress theory

Arshid Ehsan, Arshid Hossein, Amir Saeed, Mousavi S. Behnam

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 1

89--111

EN

Porous sandwich structures include different numbers of layers and are capable of demonstrating higher values of strength to weight ratio in comparison with traditional sandwich structures. Free vibration and mechanical buckling responses of a three-layered curved microbeam was investigated under the Lorentz magnetic load in the current study. A viscoelastic substrate was considered and the effect of the thermal environment on its mechanical properties was assessed. The core was composed of the functionally graded porous materials whose properties changed across the thickness based on some given functions. The face sheets were FG-carbon nanotube-reinforced composites and the influence of the placement of CNTs was evaluated on the behavior of the faces. Using the extended rule of mixture, their effective properties were determined. Modified couple stress theory was used to predict the results in the micro-dimension. While the governing equations were derived based on the higher order shear deformation theory and energy method, and mathematically solved via Navier’s method. The results were validated with the previously published works, considering the effects of various parameters. As comprehensively explained in the results section, natural frequencies and critical buckling loads were reduced by enhancing the central opening angle. Moreover, an increase in the porosity coefficient declined the mentioned values, but increasing the CNTs content showed the opposite effect. The outcomes of this study may help in the design and manufacturing of various equipment using such smart structures, making high stiffness to weight ratios more accessible.

13

Identification of Physical Parameters of a Porous Material Located in a Duct by Inverse Methods

Kani Marwa, Makni Amine, Taktak Mohamed, Chaabane Mabrouk, Haddar Mohamed

Archives of Acoustics

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2021

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Vol. 46, No. 4

657--665

EN

Lined ducts with porous materials are found in many industrial applications. To understand and simulate the acoustic behaviour of these kinds of materials, their intrinsic physical parameters must be identified. Recent studies have shown the reliability of the inverse approach for the determination of these parameters. Therefore, in the present paper, two inverse techniques are proposed: the first is the multilevel identification method based on the simplex optimisation algorithm and the second one is based on the genetic algorithm. These methods are used of the physical parameters of a simulated case of a porous material located in a duct by the computation of its acoustic transfer, scattering, and power attenuation. The results obtained by these methods are compared and discussed to choose the more efficient one.

14

Zeolity jako nośniki leków

Musielak Ewelina, Feliczak-Guzik Agnieszka, Nowak Izabela

Przemysł Chemiczny

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2020

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T. 99, nr 6

949--952

PL

Przedstawiono przegląd literatury dotyczącej zastosowania zeolitów, krzemionkowych materiałów porowatych o uporządkowanej strukturze, w terapii chorób nowotworowych i bakteryjnych, chorobie Alzheimera oraz jako adiuwantów leków przeciwnowotworowych i środków kontrastowych w obrazowaniu metodą rezonansu magnetycznego.

EN

A review, with 60 refs., of structure and phys.-chem. properties of zeolites used in pharmacotherapy. The use of ordered porous silica materials in therapies for cancer and bacterial origin, in Alzheimer’s disease and as cancer adjuvants and contrast agents in magnetic resonance imaging was discussed.

15

Zastosowanie modelu gazu zapylonego do wyznaczania parametrów strukturalnych materiałów porowatych

Tabiś Bolesław, Boroń Dominika

Przemysł Chemiczny

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2020

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T. 99, nr 6

888--891

PL

Przedstawiono metodę jednoczesnego wyznaczania współczynników dyfuzji Knudsena i efektywnego współczynnika dyfuzji cząsteczkowej gazów w porowatych ciałach stałych. Omówiono sposób wyznaczania parametrów strukturalnych materiałów makroporowatych. Zastosowano do tego celu model gazu zapylonego. Przedstawiono algorytm postępowania, od wskazówek dotyczących sposobu uzyskania danych doświadczalnych, aż do ich interpretacji. Zagadnienie to zilustrowano na przykładzie dwuskładnikowego roztworu gazowego azot-metan, ale zaproponowana metoda ma znaczenie ogólne.

EN

A quant. description of the diffusive mass movement in porous materials with pores diam. above 100 nm was provided. The method for detg. construction parameters characterizing such materials was discussed. The method of simultaneous detn. of effective mol. diffusion coeffs. and Knudsen diffusion coeffs. was developed. The N2-CH4 binary gaseous mixt. was tested using the method.

16

Izobaryczna metoda stacjonarna wyznaczania współczynników dyfuzji w materiałach porowatych

Boroń Dominika

Przemysł Chemiczny

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2020

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T. 99, nr 5

785--788

PL

Przedstawiono podstawy teoretyczne i algorytm postępowania służący do doświadczalnego wyznaczania współczynników dyfuzji w makroporowatych ciałach stałych. Uwzględniono jednoczesną dyfuzję molekularną i dyfuzję Knudsena. Zaproponowano i przetestowano metodę estymacji skorelowanych współczynników dyfuzji. Ten sposób można zastosować do pomiarów prowadzonych w warunkach ustalonych pod ciśnieniem atmosferycznym, z użyciem dwuskładnikowych roztworów gazowych o zróżnicowanym składzie. Zilustrowano go na przykładach dwóch układów dyfuzyjnych różniących się stosunkiem mas cząsteczkowych składników: {H₂, N₂} oraz {CO₂, H₂}.

EN

Fundamentals and an algorithm for exptl. detn. of diffusion coeffs. in macroporous solids under steady state conditions and const. pressure were presented. Two binary gaseous mixts. of in mol. mass-differing compds. (H₂+N₂ and CO₂+H₂) were taken into consideration as examples.

17

Thermophysical properties of porous materials

Koshlak Hanna, Pavlenko Anatoliy

Journal of New Technologies in Environmental Science

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2020

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Vol. 4, nr 4

174--180

EN

The study of the porosity of thermal insulation made of refractory materials is an important task for the power industry, since the thermal conductivity of porous materials depends on the shape and especially the location of the pores. An analytical review of existing technologies shows that research in this area is not enough to simulate the process of heat and mass transfer in porous alumina material. Experimental determination of the characteristics of heat and mass transfer in porous materials during the formation of a porous structure is a pressing scientific problem. This article analyzes the influence of the composition of materials on the formation of pores, as well as the effect of various impurities and temperature on the thermal conductivity of the material.

18

On size-dependent large-amplitude free oscillations of FGPM nanoshells incorporating vibrational mode interactions

Yi Hongwei, Sahmani Saeid, Safaei Babak

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 2

257--279

EN

At nanoscale, surface free energies of the atoms located on the free surfaces of structures significantly affect their mechanical characteristics. In this study, nonlinear large-amplitude free vibration response of nanoshells prepared from functionally graded porous materials (FGPM) is investigated by taking into account surface stress size effects and vibrational mode interactions. Non-classical shell model is constructed on the basis of the Gurtin–Murdoch type of the surface theory of elasticity having the capability of capturing surface stress size dependency. The accuracy of nonlinear vibration analysis is improved by incorporating the interaction of the main vibration mode and the first, third and fifth symmetric oscillation modes. Moreover, the closed-cell Gaussian-Random field scheme is put to use to extract the mechanical characteristics of FGPM nanoshell. Multiple timescales technique is then applied to achieve surface stress elastic-based nonlinear frequency of FGPM nanoshell analytically for different interactions between vibrational modes. It is revealed that by incorporating the interactions of the main vibration mode and higher symmetric oscillation modes, the behavior of the backbone curves belongs to the nonlinear free oscillation response of FGPM nanoshells changes from hardening to softening schema. It is found that when only the main vibration mode is taken into account, surface elasticity effects makes an enhancement in the significance of the hardening schema. However, by considering the interactions of higher symmetric oscillation modes, surface elasticity effects makes a reduction in the significance of the softening schema.

19

Cement paste microporosity analysis: a comparison of different experimental techniques

Bednarska Dalia, Koniorczyk Marcin

Technical Transactions

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2019

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Vol. 116, iss. 9

71--80

EN

Microstructure defines almost all material physical properties of a substance. Thus, its proper identification is essential for the assessment of material durability. Porous materials constitute the vast majority of those applied in civil engineering. The most important parameters describing a porous structure are the specific surface area, the shape and volume of pores and the pore size distribution. There are several methods which provide such results; however, each of them has some drawbacks. The main purpose of this paper is to compare results obtained by means of various methods commonly applied to the investigation of microstructure. These methods are mercury intrusion porosimetry (MIP), low temperature sorption of nitrogen and thermoporometry (TPM). The experimental research is conducted on aluminium oxide, which is characterised by unimodal pore size distribution and hardened cement paste prepared using portland cement (CEM I 42.5R with water-cement ratio equal to 0.5. The results obtained by the above-mentioned methods are thoroughly described and compared in this paper. Each of the presented approaches has some limitations; therefore, in order to receive a reliable description of porous microstructure, one has to apply at least two different experimental methods.

PL

Wśród materiałów budowlanych przeważającą większość stanowią materiały porowate. Dokładna znajomość mikrostruktury jest kluczowa w ocenie ich wytrzymałości i trwałości. Istnieje wiele metod eksperymentalnych służących do analizy struktur porowatych. W niniejszym opracowaniu porównane zostały następujące techniki: porozymetria rtęciowa (MIP), niskotemperaturowa adsorpcja azotu oraz termoporometria (TPM). Badaniom eksperymentalnym poddano dwa materiały. Pierwszy z nich, tlenek glinu, jest materiałem referencyjnym o unimodalnym rozkładzie porów. Zgodnie z deklaracją producenta dominująca średnica porów wynosi 7.3 nm. Drugim zastosowanym materiałem jest zaczyn cementowy przygotowany na bazie cementu portlandzkiego CEM I 42,5R. Stwardniały zaczyn charakteryzuje się skomplikowanym rozkładem porów. Opisane techniki analizy mikrostruktury są komplementarne. Aby uzyskać wiarygodny opis struktury wewnętrznej materiałów o skomplikowanym rozkładzie porów należy zastosować co najmniej dwie metody badawcze.

20

Method of Formation of Thermophysical Properties of Porous Materials

Koshlak Hanna, Pavlenko Anatoliy

Rocznik Ochrona Środowiska

|

2019

|

Tom 21, cz. 2

1253--1262

EN

The study of the porosity of thermal insulation made of refractory materials is an important task for the power industry, since the thermal conductivity of porous materials depends on the shape and especially the location of the pores. An analytical review of existing technologies shows that research in this area is not enough to simulate the process of heat and mass transfer in porous alumina material. Experimental determination of the characteristics of heat and mass transfer in porous materials during the formation of a porous structure is a pressing scientific problem. This article analyzes the influence of the composition of materials on the formation of pores, as well as the effect of various impurities and temperature on the thermal conductivity of the material.

PL

Porowatość izolacji termicznej wykonanej z materiałów ogniotrwałych jest ważnym zadaniem dla energetyki, ponieważ przewodność cieplna materiałów porowatych zależy od kształtu, a zwłaszcza od lokalizacji porów. Analiza analityczna istniejących technologii pokazuje, że badania w tej dziedzinie nie są wystarczające do symulacji procesu przenoszenia ciepła i masy w porowatym materiale z tlenku glinu. Eksperymentalne określenie charakterystyki transferu ciepła i masy w materiałach porowatych podczas tworzenia struktury porowatej jest palącym problemem naukowym. W artykule przeanalizowano wpływ składu materiałów na powstawanie porów, a także wpływ różnych zanieczyszczeń i temperatury na przewodność cieplną materiału.