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Tytuł:
O siłach napędowych w przyrodzie : koncepcje, interpretacje, nieporozumienia
About driving forces in nature : concepts, interpretations and misunderstandings
Autorzy:
Orlik, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2200428.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
termodynamika chemiczna
entropia
entalpia swobodna
energia swobodna Helmholtza
współrzędna reakcji
reguła Le Chateliera-Brauna
chemical thermodynamics
entropy
free Gibbs energy
free Helmholtz energy
reaction coordinate
Le Chatelier-Braun principle
Opis:
Prepared for presentation within the Didactic Section of Polish Chemical Society, the study summarizes selected problems and concepts of teaching the basics of chemical reaction energetics as part of chemical undergraduate studies. The following problems are discussed: 1) indication of misunderstandings related to the definition of standard states in thermodynamics, with particular emphasis on the unfortunate assignment of the temperature of 298.15 K as "standard temperature", 2) problems with the interpretation of entropy as a "measure of disorder", with a recommendation regarding for understanding entropy as a measure of the number of ways to distribute the total energy of the system between the available degrees of freedom of motions, in terms of the quantum representation, i.e. the energy characteristics of a substance through sequences of energy levels, 3) a proposal to introduce the issue of thermodynamic driving forces of a chemical reaction based on the characteristics of the water evaporation process under different conditions, which favors the distinction of any reaction driving force from its standard driving force, as well as the distinction of such forces for isochoric and isobaric systems, both one- and multi-component, (4) the necessity to take into account the entropy of mixing of reagents to deepen the understanding of changes in the driving force of the reaction on the way to the state of chemical equilibrium, and 5) various interpretations of the influence of temperature on the equilibrium composition of the reacting system (Le Chatelier-Braun rule), with a recommendation for molecular interpretation, showing the role of differences in energies and sequences of energy levels of reactants and products for the value and direction of changes of the equilibrium constants of the reaction with temperature, taking into account also the principles of statistical thermodynamics. An additional aim of the article is to emphasize the importance of elementary mathematical education for mastering the basic laws governing the course of physicochemical processes, as well as for true understanding of chemistry, in general.
Źródło:
Wiadomości Chemiczne; 2023, 77, 1-2; 1--34
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the Ozonation Process for Shaping the Energy Properties of the Surface Layer of Polymer Construction Materials
Autorzy:
Kłonica, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/2027827.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
surface layer
ozone
polymer material
surface free energy
Opis:
The properties of the surface layer of construction materials are very important for making adhesive bonds. The article presents the test results for surface free energy in PA6 polyamide subjected to surface layer modification using the ozonation process. To develop the surface geometrically, the samples were subjected to mechanical processing. The comparison of results demonstrated that ozonation is an efficient and eco-friendly method of modifying the surface layer. The article also presents the comparison results for measurements of selected surface roughness parameters.
Źródło:
Journal of Ecological Engineering; 2022, 23, 2; 212-219
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control of glass surface wettability via esterification with n-alkyl alcohols
Autorzy:
Kruszelnicki, Mateusz
Polowczyk, Izabela
Kowalczuk, Przemyslaw B.
Powiązania:
https://bibliotekanauki.pl/articles/2146948.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hydrophobicity
surface free energy
contact angle
zeta potential
roughness
Opis:
Surface wettability plays an essential role in many processes and materials applications. It depends mainly on the surface roughness and chemical composition, thus through a controlled modification of these parameters, the wettability can be restrained. Glass is an inorganic solid material, composed mainly of amorphous silica, which surface, due to the presence of reactive hydroxyl groups, can be quite easily chemically modified. This feature can be used to control the wettability of glass by reaction with organic compounds. In this study, the esterification of glass silanol groups with n-alkyl alcohols (Cn/H2n+1/OH, n=3, 4, 6, 8, 10) was employed to modify its wettability. The effect of such modification on the physicochemical properties of glass surface was comprehensively investigated and characterised by the water contact angle, surface free energy, zeta potential, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) measurements. We demonstrate that the wettability of the esterified glass surface is strongly dependent on both the chain length of used alcohol and modification time. The alcohol molecule binds to the glass surface through a Si-O-C bond, leading to the formation of a monolayer that does not significantly affect the surface morphology and zeta potential. Conducted studies provided a broader view of the influence of this technique for modifying surface wettability on its physicochemical properties.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 2; art. no. 145147
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Does Physics Forbid Libertarian Freedom?
Autorzy:
Koperski, Jeffrey
Powiązania:
https://bibliotekanauki.pl/articles/2083941.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Instytut Filozofii
Tematy:
libertarianism
free will
conservation of energy
dualism
emergentism
Opis:
Three well-known physicists have recently argued that libertarian freedom is impossible. In their view, free will is incompatible with what we know about science at the most fundamental level. Here I show that their arguments presuppose a naïve version of reductionism and consider two alternatives, one appealing to mind–body dualism and the other to emergentism. The former says that free will is a capacity of one’s mind, an immaterial entity not subject to the laws of nature. The latter says that free will is an emergent capacity that cannot be reduced to the properties of an agent’s constitutive atoms. These alternatives, however, face the same problem: They seem to violate a fundamental law, namely the conservation of energy. I show how the libertarian can respond to this objection.
Źródło:
Filozoficzne Aspekty Genezy; 2022, 19, 1; 111-132
2299-0356
Pojawia się w:
Filozoficzne Aspekty Genezy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrokinetic and surface properties of some methacrylate-based copolymers
Autorzy:
Ersoy, Bahri
Çiftçi, Hakan
Evcin, Atilla
Merdivenci, Yılmaz
Powiązania:
https://bibliotekanauki.pl/articles/2146940.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
methacrylate copolymer
zeta potential
contact angle
hydrophobicity
surface free energy
Opis:
In this study, some electrokinetic and surface properties of MBAOM-GMA copolymers synthesized from 2-[(methoxy-1,3-benzothiazole-2-yl) amino]-2oxoethyl methacrylate (MBAOM) and glycidyl methacrylate (GMA) monomers were investigated. Accordingly, (i) pH-dependent zeta (ζ) potential changes of the copolymers were investigated under a constant ionic strength (in 1.10-3mol/dm3 NaCl) and the corresponding isoelectric points (iep) were determined, (ii) zeta potential changes depending on the salt concentration in the presence of mono-, di- and tri-valent metal salts were examined, (iii) contact angles (θ) of the copolymers with water were measured and their wetting behavior was assessed, and (iv) surface free energies (SFE) of the copolymers were determined by Acid-Base approach using Van Oss-Chaudhury-Good method. The compositions of the copolymers were 77% MBAOM - 23% GMA, 45% MBAOM - 55% GMA, and 19% MBAOM - 81% GMA. FeCl3, CaCl2, and KCl salts were used for the salt solutions for the zeta potential measurements. As a result, (i) it was determined that the chemical structure of methacrylate copolymers showed a decisive effect on both electrokinetic and surface properties, (ii) the hydrophobic character of copolymer increased with the increase of the GMA ratio, and correspondingly, the SFE decreased, and (iii) the iep of the copolymers varied between pH 3.1-3.7 depending on composition.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 5; art. no. 152162
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free vibration of composite cylindrical shells with orthogonal stiffeners
Autorzy:
Wu, Yongfu
Zhao, Chen
Liang, Haofeng
Yao, Sishi
Xue, Jianghong
Xu, Peng
Powiązania:
https://bibliotekanauki.pl/articles/2086971.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
free vibration
laminated cylindrical shells
stiffener
energy method
Opis:
This paper proposes theoretical and numerical approaches to scrutinize the free vibration of orthogonal stiffened cylindrical shells. According to K´arman-Donnell shell theory, the total energy of the stiffened cylindrical shells is derived. Based on the principle of minimum potential energy, the eigenfunction related to the frequency is established and solved by developing a Matlab program. Analytical solutions of the natural frequency for free vibraion of the stiffened cylindrical shells are calculated and are verified against the finite element results from ABAQUS software. On account of the observations from the parametric study, an optimization scheme of the stiffeners is proposed.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 2; 239--252
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Key factors governing fibril formation of proteins: insights from simulations and experiments
Autorzy:
Co, N. T.
Viet, M. H.
Truong, P. M.
Kouza, M.
Li, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/1954243.pdf
Data publikacji:
2022-02-01
Wydawca:
Politechnika Gdańska
Tematy:
tworzenie włókienek
swobodna energia wiązania
fibre formation
binding free energy
Opis:
Fibril formation of proteins and peptides is associated with a large group of major human diseases, including Alzheimer’s disease, prion disorders, amyotrophic lateral sclerosis, type 2 diabetes, etc. Therefore, understanding the key factors that govern this process is of paramount importance. The fibrillogenesis of polypeptide chains depends on their intrinsic properties as well as on the external conditions. In this mini-review we discuss the relationship between fibril formation kinetics and the sequence, aromaticity, hydrophobicity, charge and population of the so called fibril-prone conformation in a monomer state. The higher the population, the faster is the fibril elongation and this dependence may be described by a single exponential function. This observation opens up a new way to understand the fibrillogenesis of bio-molecules at the monomer level. We will also discuss the influence of the environment with focus on the recently observed dual effect of crowders on the aggregation rat es of polypeptide chains.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2014, 18, 3; 245--254
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure and surface free energy of light-cured dental composites after their modification with liquid rubber
Autorzy:
Sowa, Monika
Przekora, Agata
Pałka, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/2058402.pdf
Data publikacji:
2022
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
dental composite
solubility
liquid rubber
wettability
surface free energy
Opis:
The use of liquid rubber as a component of light-cured dental composites is one of the methods of increasing their fracture toughness. It also reduces polymerization shrinkage and offers the potential to lower water sorption. The aim of the study was to evaluate the miscibility of liquid rubber in composite matrix resins as well as changes in the wettability and surface free energy (SFE) values of commercial lightcuring composites after their modification with liquid rubber. The research materials were Flow Art and Boston (Arkona) light-cured composites and resin mixtures used in their production. Liquid rubber Hypro 2000X168LC VTB (Huntsman Int.) was used as a modifier. The solubility of liquid rubber was assessed under light microscopy. The contact angle and SFE measurements were made on a DSA30 goniometer (Kruss) using water and diiodomethane. It was found that the liquid rubber solubility depended mainly on the viscosity of the resin, which was related to the amount of BisGMA. The resulting mixture showed good temporal stability without larger domains. The curing process released the liquid rubber as a separate phase formed as spherical domains. The morphology of these domains was homogeneous and their size did not exceed 50 µm in diameter. The presence of liquid rubber in modified composites increased their hydrophobicity and reduced the surface free energy value. The obtained properties might help to reduce the formation of bacterial biofilm on dental fillings.
Źródło:
Engineering of Biomaterials; 2022, 25, 164; 9--15
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of chitosan and lipid layers deposited onto polyethylene terephthalate (pet) on its wetting properties
Autorzy:
Szafran, Klaudia
Jurak, Małgorzata
Wiącek, Agnieszka Ewa
Powiązania:
https://bibliotekanauki.pl/articles/2131531.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
chitosan
surface free energy
wettability
Opis:
The wetting properties of chitosan (Ch) and single 1,2-dipalmitoylsn-glycero-3-phosphocholine (DPPC), cholesterol (Chol) and binary DPPC-Chol layers deposited onto polyethylene terephthalate activated by low-temperature air plasma (PETair) were examined. PET is widely used in tissue engineering, but its low hydrophilicity limits its integration with the surrounding tissues. Ch is a biocompatible polysaccharide, distinguished by its antimicrobial properties, widely distributed in medicine. DPPC and Chol are the major building components of cell membrane, so they can perfectly mimic membrane behaviour during contact with the Ch layer. Monolayers of lipids were deposited onto PETair with or without the Ch layer using the Langmuir-Blodgett technique. The total surface free energy (SFE) and its components changes were calculated from theoretical approaches. Wettability strongly depended on the monolayer composition as well as the Ch layer. The Ch film decreased the contact angle and increased SFE of the PET surface with the lipid monolayers due to specific organisation of molecules within the chitosan scaffold. The most promising combination of surface modification for tissue engineering applications seems to be the PETair/Ch/DPPC-Chol system.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2021, 26; 210-221
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spór o ciągłość życia i umysłu. Argumenty na rzecz kognitywizmu
Autorzy:
Piekarski, Michał
Powiązania:
https://bibliotekanauki.pl/articles/2188173.pdf
Data publikacji:
2021-11-30
Wydawca:
Uniwersytet Pedagogiczny im. Komisji Edukacji Narodowej w Krakowie. Instytut Filozofii i Socjologii
Tematy:
life
mind
semantic information
syntactic information
free energy principle
normativity
body
content
Markov blankets
Opis:
The dispute over the continuity of life and mind. Arguments for cognitivism: The purpose of this paper is to discuss the position of non-cognitivism on the issue of the so-called dispute over the continuity / discontinuity of life and mind. In discussing the views of Michael Kirchhoff and Tom Froese, I will point out some difficulties related to their position. Next, I will formulate three arguments in favor of the cognitive alternative, emphasizing the need to resort to semantic information in explaining these phenomena. According to noncognitivist position, there is a continuity in the life-mind line, which can be justified by referring to the concept of Shannon’s syntactic information. Opponents of this thesis, i.e. supporters of cognitivism, claim that the explanation of cognition requires the use of other tools than those used to explanation of life, because, first, the notion of syntactic information does not exhaust the complexity of these phenomena, and, second, the non-cognitive position raises many problems and ambiguities. According to cognitivists, when explaining life and mind, one should refer to the concept of semantic information that is rejected by noncognitivists. In the Conclusion I will analyze the ambiguities and assumptions related to the thesis about the continuity or discontinuity between life and cognitive processes.
Źródło:
ARGUMENT: Biannual Philosophical Journal; 2021, 11, 1; 71-91
2083-6635
2084-1043
Pojawia się w:
ARGUMENT: Biannual Philosophical Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ działania plazmy niskotemperaturowej na zmiany zwilżalności wybranych polimerów
Effect of low-temperature plasma on changes in wettability of selected polymers
Autorzy:
Hołysz, Lucyna
Kamela (Rymuszka), Diana
Terpiłowski, Konrad
Chibowski, Emil
Powiązania:
https://bibliotekanauki.pl/articles/1853718.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
polimer
plazma niskotemperaturowa
zwilżalność
kąt zwilżania
swobodna energia powierzchniowa
adhezja
polymer
low-temperature plasma
wettability
contact angle
surface free energy
adhesion
Opis:
The effects of air, oxygen and argon plasma treatment on wetting and energetic properties of polymers: polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), polyoxymethylene (POM), polyamide (PA6G), polycarbonate (PC) and polypropylene (PP) were studied. The changes in surface properties of PMMA, PEEK, POM, PA6G polymers after the air plasma treatment, and PP and PC polymers after the Ar or O2 plasma treatment were determined via the measurement of advancing and receding contact angles of three liquids having different polarity, i.e. water, formamide and diiodomethane. Having the determined contact angles the surface free energy and its components of the polymers were calculated using three different theoretical approaches, namely: acid-base Lifsthitz-van der Waals (LWAB), contact angle hysteresis (CAH) and Owens and Wendt (O-W). The effects of plasma treatment were further determined by calculations of the adhesion work and work of spreading of water on modified polymer and compared to values calculated for the unmodified surfaces. Then for the PEEK and POM modified with the air plasma, their surface wettability was determined after 14 days from the exposure to the plasma. It was found that plasma treatment caused better wettability what reflected in a decreased contact angles measured on the modified polymer surfaces. The greatest changes appeared for polar liquids, i.e. water and formamide. It pointed to an increased the surface hydrophilicity after the plasma treatment. The changes correlated also with the increased polar interactions due to appearance polar groups on the surface. For the studied polymer surfaces, generally the dispersive interactions practically did not change, regardless the treatment time and plasma type. The total surface free energy values calculated for the polymers from three different approaches to interfacial interactions are similar. However, the energy values are apparent because they depend s upon the kind of liquid used for the contact angles measurement. Irrespectively of the plasma type, for all polymers an increase of the adhesion work of water in reference to the unmodified surfaces was observed. The most appropriate time to improve the adhesion between the polymer surface and liquid was found to be 25 or 60 s. However, the effects of plasma treatment are not permanent. With the storage time the contact angles have increased. This can be due to the structure reorganization within a few nm thick the surface layer.
Źródło:
Wiadomości Chemiczne; 2021, 75, 9-10; 1270-1295
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption of sodium/calcium poly(acrylic acid) salts on anatase: effect of the polyelectrolyte molecular weight and neutralization
Autorzy:
Jacquemet, Christian
Powiązania:
https://bibliotekanauki.pl/articles/1449765.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorption
free energy
Langmuir isotherm
sodium-calcium poly(acrylic acid) salts
anatase
Opis:
Abstract: Interactions of poly(acrylic acid)s (PAAs) of two different molecular weights (Mw = 9,560 g×$mol^{-1}$ and 4,220 g×$mol^{-1}$) with surfaces of an untreated anatase $TiO_2$ were assessed through adsorption isotherm measurements. Those dispersants were tested under different sodium-calcium neutralization states (molar ratio $r = Ca^{2+}$ / $CO_{2-}$ varying from 0 to 0.35). Their behavior towards the $TiO_2$ surfaces can be described by the Langmuir adsorption model. For both polymers, surface coverage ($Γ_max$) evolves linearly with the molar ratio $r$. For a given r value, a lower surface coverage was observed with the polymer having the highest molecular weight. The free energy of adsorption ($/DeltaG_{ads}$) of PAAs was estimated from adsorption experiment data. This calculation indicates that sorption occurs spontaneously and is unlikely to be of chemical nature. The absolute values of $/DeltaG_{ads}$ are higher for the highest molecular weight polymers suggesting that they are more strongly adsorbed to anatase surfaces. The absolute values of $/DeltaG_{ads}$ per mole of sodium-calcium macromolecules are found to be lower than those calculated for their homologues 100% sodium neutralized suggesting that they are bound with the solid by a fewer number of segments.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 1; 113-123
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ritz method for large deflection of orthotropic thin plates with mixed boundary conditions
Autorzy:
Al-Shugaa, Madyan A.
Al-Gahtani, Husain J.
Musa, Abubakr E.S.
Powiązania:
https://bibliotekanauki.pl/articles/1839813.pdf
Data publikacji:
2020
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
Ritz method
energy method
orthotropic plate bending
mixed boundary conditions
free edges
large deflection
metoda Ritza
metoda energetyczna
duże ugięcie
mieszane warunki brzegowe
gięcie blach
gięcie blach ortotropowe
Opis:
In this paper, the Ritz method is developed for the analysis of thin rectangular orthotropic plates undergoing large deflection. The trial functions approximating the plate lateral and in-plane displacements are represented by simple polynomials. The nonlinear algebraic equations resulting from the application of the concept of minimum potential energy of the orthotropic plate are cast in a matrix form. The developed matrix form equations are then implemented in a Mathematica code that allows for the automation of the solution for an arbitrary number of the trial polynomials. The developed code is tested through several numerical examples involving rectangular plates with different aspect ratios and boundary conditions. The results of all examples demonstrate the efficiency and accuracy of the proposed method.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2020, 19, 2; 5--16
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of methods of surface treatment of metal elements on their surface free energy, with a view to the formation of polymer–metal hybrid elements
Wpływ metod przygotowania powierzchni elementów metalowych na ich swobodną energię powierzchniową w aspekcie wytwarzania elementów hybrydowych typu polimer-metal
Autorzy:
Trzaska, Oliwia
Wróblewski, Roman
Czekaj, Alina
Czyż, Joanna
Kaczmar, Jacek W.
Powiązania:
https://bibliotekanauki.pl/articles/947435.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
surface free energy (SFE)
polymer–metal hybrid elements
polymer–metal interface
injection
molding
swobodna energia powierzchniowa (SEP)
hybrydowe elementy polimer-metal
powierzchnia międzyfazowa polimer-metal
technologia wtryskiwania
Opis:
An analysis was made of methods of chemical surface treatment of metal elements made of DC04 steel and Al6061 alloy, for the formation of polymer–metal joints in injection molding technology. The surface characterization included determination of surface free energy (SFE) by the OWRK (Owens–Wendt–Rabel–Kaelble) method, and determination of its polar and dispersive components. Depending on the chemical treatment applied, the highest values of the polar constant for DC04 and Al6061 sheets were 26.4 and 39.2 mJ/m2, respectively, the highest values of the dispersion constant were 55.6 and 53.5 mJ/m2, respectively, for DC04 and Al6061 sheets. In the case of the surfaces of sheets made of the Al6061 alloy, the increase in the polar component value was most favorably influenced by the etching with 15% NaOH solution for 5 minutes, and the increase in the dispersive component – by the etching with 15% NaOH solution with the addition of thiourea for 2 minutes. In the case of the surface of DC04 sheets, the increase of the polar component was most favorably influenced by chemical cleaning for 10 minutes (in a solution with the composition: Na2CO3 50 g/mol, Na3PO4 × 12 H2O 50 g/mol, NaOH 50 g/mol). The highest value of the dispersive component of the surface DC04 sheets was obtained after etching with 15% HCl solution with the addition of thiourea for 5 minutes.
Analizowano wpływ sposobu obróbki chemicznej powierzchni na właściwości adhezyjne elementów metalowych (blach) wykonanych ze stali DC04 oraz ze stopu Al6061, przeznaczonych do wytwarzania połączeń polimer-metal w technologii wtryskiwania. Charakterystyka powierzchni obejmowała wyznaczenie swobodnej energii powierzchniowej (SEP) metodą OWRK (Owens-WendtRabel i Kaelble) oraz jej składowych polarnej i dyspersyjnej. W zależności od zastosowanej obróbki chemicznej największe wartości składowej polarnej SEP blach wykonanych ze stali DC04 oraz stopu Al6061 wyniosły, odpowiednio, 26,4 oraz 39,2 mJ/m2, natomiast największe wartości składowej dyspersyjnej, odpowiednio, 55,6 oraz 53,5 mJ/m2. W wypadku powierzchni blach ze stopu Al6061 na zwiększenie wartości stałej polarnej najkorzystniej wpłynęło trawienie 15% roztworem NaOH przez 5 minut, natomiast na zwiększenie stałej dyspersyjnej – trawienie 15% roztworem NaOH z dodatkiem tiomocznika przez 2 minuty. W wypadku powierzchni blach wykonanych ze stali DC04 na zwiększenie stałej polarnej najwyraźniej wpłynęło oczyszczanie chemiczne przez 10 minut (w roztworze o składzie: Na2CO3 50 g/mol, Na3PO4 × 12 H2O 50 g/mol, NaOH 50 g/mol). Największą wartość stałej dyspersyjnej powierzchni blach ze stali DC04 uzyskano po trawieniu 15% roztworem HCl z dodatkiem tiomocznika przez 5 minut.
Źródło:
Polimery; 2020, 65, 11-12; 816-821
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanism and Synthesis of Yttrium Iron (Y-Fe) Alloy by Low Temperature Process Using Calcium as Reductant
Autorzy:
Ilayaraja, Marimuthu
Berchmans, L. John
Sankaranarayan, Sankara Raman
Powiązania:
https://bibliotekanauki.pl/articles/355144.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Gibbs free energy
reaction kinetics
VSM
XRD
SEM
Opis:
In this paper, study the preparation of Y-Fe alloy by reduction-diffusion process, which is novel technique for producing an alloy from its ores directly at different temperatures. From this work, investigates the particles size and morphology structure of alloy by X-Ray Diffraction (XRD), Energy dispersive-X-ray analyzer (EDAX) and Scanning Electron Microscope (SEM) respectively. Here study the thermodynamics of property of system such as Gibbs free energy and reaction kinetics of system respectively. The Vibrating Sample magnetometer (VSM) is used to study the magnetic properties of alloy such as cocerviety, saturation magnetization and retentivity.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1593-1596
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 97

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