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Wyszukujesz frazę "adsorption layer" wg kryterium: Temat


Tytuł:
Dynamic nanostructures at the surface of rising bubbles in amphiphile solutions: Comparison of low-molecular-weight surfactants and proteins
Autorzy:
Wiertel-Pochopien, Agata
Witkowski, Łukasz
Kosior, Dominik
Fuller, Gerald G.
Warszynski, Piotr
Gochev, Georgi G.
Zawala, Jan
Wydawca:
Elsevier B.V.
Cytata wydawnicza:
Ł. Witkowski, A. Wiertel-Pochopien, D. Kosior, G. Gochev, P. Warszynski, G.G. Fuller, J. Zawala, Dynamic nanostructures at the surface of rising bubbles in amphiphile solutions: Comparison of low-molecular-weight surfactants and proteins, Advances in Colloid and Interface Science, 340 (2025) 103447. https://doi.org/10.1016/j.cis.2025.103447
Opis:
Partial financial support from the Polish National Science Centre (NCN grant no. 2021/43/B/ST8/00053) and statutory research fund of ICSC PAS is acknowledged with gratitude. J.Z. expresses gratitude to Kazimierz Malysa and Reinhard Miller for the opportunity to witness their numerous insightful discussions on LVPs in protein solutions, which served as an inspiration for this work.
The formation, stability, and decay of foams occur under dynamic conditions. Given their inherent complexity, an accurate description of these subprocesses necessitates an analysis of multiple factors, with a particular focus on the formation and structure of the adsorption layer. Single rising bubble techniques facilitate a deeper comprehension of the dynamics of diverse phenomena in foams, as they yield experimental data under dynamic conditions. This review examines the subtle differences in the dynamic adsorption structures of low-molecular-weight surfactants and proteins at the liquid/gas interface. These differences can significantly impact interfacial properties and potentially alter our understanding of the mechanisms behind the formation of the Dynamic Adsorption Layer (DAL). The primary techniques under consideration are local velocity profiles (LVPs) of single rising bubbles and dynamic fluid-film interferometry (DFI) of the thin liquid film formed at the collision of a bubble with a free liquid surface. We provide a summary of recent findings on the topic. Due to the limited availability of comprehensive datasets on proteins, our discussion is partially supplemented by newly obtained unpublished data. We highlight key differences in the behavior of bubbles in low-molecular-weight surfactant solutions versus protein solutions that have previously been overlooked in the literature. We explore their potential origins in the context of DAL dynamics and architecture.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Monitoring of contamination of coal processing plants and environmental waters using bubble velocity measurements – advantages and limitations
Autorzy:
Zawala, J.
Malysa, E.
Krzan, M.
Malysa, K.
Tematy:
bubble velocity
water purity
surface active contaminants
method detection
adsorption layer
Pokaż więcej
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/110915.pdf  Link otwiera się w nowym oknie
Opis:
The paper presents fundamentals of a simple physicochemical method (SPMD) and analysis of results obtained when the method was applied for detection of organic contaminations (surface-active substances SAS) in samples of environmental and industrial waters. The method is based on measurements of variations of air bubble local velocities, which can be significantly changed in presence of surface-active contaminants. Lowering of the bubble velocity is a consequence of a motion induced dynamic adsorption layer (DAL) formed over surface of the rising bubble. The DAL formation retards the surface fluidity and the bubble rising velocity can be lowered by over 50% when the bubble surface is completely immobilized. We showed that the SPMD is a very sensitive tool (detection limit even below 1 ppm) for detection of various kinds of surface-active substances (ionic, non-ionic) in water samples. On the basis of results obtained using precise laboratory set-up, an accuracy of the SPMD is discussed. Moreover, effect of inert electrolyte addition on the bubble velocity lowering and value of detection limit of the SPMD is discussed. Simple approach, enabling quantitative analysis of the surface-active contaminants in samples collected, based on “equivalent concentrations” determination, is proposed. Results obtained for industrial (Jankowice and Knurow coal processing plants, Jaslo Refinery channel) and environmental waters (Wisloka and Ropa river) are used for detailed analysis and critical discussion of advantages and limitations of the SPMD.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of dynamic adsorption layer formation on bubble attachment to quartz and mica surfaces in solutions of pure and mixed surface-active substances
Autorzy:
Wiertel-Pochopień, A.
Zawala, J.
Tematy:
quartz
bubble
mica
dynamic adsorption layer
wetting film
three-phase contact
Pokaż więcej
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/109361.pdf  Link otwiera się w nowym oknie
Opis:
The paper presents systematic studies on influence of state of dynamic adsorption layer (DAL) induced at the rising bubble interface on time-scale of the bubble attachment to quartz and mica surfaces immersed in pure n-cetyl-trimethylammonium bromide (CTAB) and mixed octanol/CTAB solutions of different concentrations. It was found that in the case of pure CTAB solutions, the influence of DAL on time of bubble attachment and the three-phase contact (TPC) formation (tTPC) strongly depends on solution concentration. Generally, two solution concentration regimes were distinguished – low and high - for which different degree of solid surfaces hydrophobization was observed. It was determined that for low concentration regime the solid surface is only slightly hydrophobized while for high regime, hydrophobicity of the solid surface is much higher. Consequently, wetting film rupture for low concentration regime is governed by electrostatic interactions while for high concentration regime significance of these interactions is much smaller. As a result, the DAL influenced the film rupture in these two regimes in a quite different manner. For mixed n-octanol/CTAB solutions it was found that CTAB molecules presence is necessary condition for wetting film destabilization. Moreover, thanks to the developed approach, allowing control of initial adsorption coverage over the bubble surface (independently on concentration), it was proved that constant adsorption degree of CTAB molecules at the bubble surface in the mixture, leads to identical times of the TPC formation.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coalescence of surface bubbles: The crucial role of motion-induced dynamic adsorption layer
Autorzy:
Scheid, Benoit
Miguet, Jonas
Fuller, Gerald G.
Borkowski, Mariusz
Zawała, Jan
Rastogi, Preetika
Atasi, Omer
Wydawca:
Elsevier
Cytata wydawnicza:
Advances in Colloid and Interface Science 317 (2023) 102916. https://doi.org/10.1016/j.cis.2023.102916
Opis:
The formation of motion-induced dynamic adsorption layers of surfactants at the surface of rising bubbles is a widely accepted phenomenon. Although their existence and formation kinetics have been theoretically postulated and confirmed in many experimental reports, the investigations primarily remain qualitative in nature. In this paper we present results that, to the best of our knowledge, provide a first quantitative proof of the influence of the dynamic adsorption layer on drainage dynamics of a single foam film formed under dynamic conditions. This is achieved by measuring the drainage dynamics of single foam films, formed by air bubbles of millimetric size colliding against the interface between n-octanol solutions and air. This was repeated for a total of five different surfactant concentrations and two different liquid column heights. All three steps preceding foam film rupture, namely the rising, bouncing and drainage steps, were sequentially examined. In particular, the morphology of the single film formed during the drainage step was analyzed considering the rising and bouncing history of the bubble. It was found that, depending on the motion-induced state of adsorption layer at the bubble surface during the rising and the bouncing steps, single foam film drainage dynamics can be spectacularly different. Using Direct Numerical Simulations (DNS), it was revealed that surfactant redistribution can occur at the bubble surface as a result of the bouncing dynamics (approach-bounce cycles), strongly affecting the interfacial mobility, and leading to slower rates of foam film drainage. Since the bouncing amplitude directly depends on the rising velocity, which correlates in turn with the adsorption layer of surfactants at the bubble surface during the rising step, it is demonstrated that the lifetime of surface bubbles should intimately be related to the history of their formation.
Polish National Agency for Academic Exchange (PPN/BEK/2020/1/00025/DEC/1) National Science Centre (project No. 2020/38/E/ST8/00173) United States-India Education Foundation (USIEF) F.R.S.-FNRS
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Bubble Formation and Motion in Liquids—A Review
Autorzy:
Kowalczuk, Przemyslaw B.
Kosior, Dominik
Wiertel-Pochopień, Agata
Zawała, Jan
Wydawca:
MDPI
Cytata wydawnicza:
D. Kosior, A. Wiertel-Pochopien, P. B. Kowalczuk, J. Zawala "Bubble Formation and Motion in Liquids—A Review", Minerals, 13(9) (2023) 1130, DOI: 10.3390/min13091130
Opis:
Partial financial support from the Polish National Science Centre (NCN grant no. 2021/43/B/ST8/00053) is acknowledged with gratitude.
In flotation, a bubble acts as a carrier for attached particles. The properties of the gas–liquid interface of the bubble are one of the main factors determining the bubble motion and flotation efficiency. Monitoring of the bubble motion may deliver interesting information about the state of the gas–liquid interface. In the case of pure liquids, a bubble surface is fully mobile, while the presence of surface-active substances (e.g., surfactants) causes diminishing bubble velocity due to the retardation of the interface fluidity. The theoretical prediction of the terminal velocity value for the bubble has been investigated for over a century, delivering a number of various models describing bubble motion in a liquid. This narrative review is devoted to the motion of the bubble in stagnant liquids and is divided into three main sections describing: (i) experimental techniques for tracking bubble motion, (ii) bubble motion and shape deformation in clean water, and (iii) bubble motion in solutions of surface-active substances.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Ruch pęcherzyka w cieczach i fizykochemiczna metoda detekcji zanieczyszczeń powierzchniowo-aktywnych w wodzie
Bubble motion in liquids and physocochemcal method of detection of surface-active pollutants in water
Autorzy:
Zawała, Jan
Kosior, Dominik
Małysa, kazimierz
Tematy:
surfaktanty
micelizacja
krytyczne stężenie micelarne
ultrafiltracja micelarna
bubble
velocity
surfactant
drag coefficient
dynamic adsorption layer
Pokaż więcej
Wydawca:
Polskie Towarzystwo Chemiczne
Powiązania:
https://bibliotekanauki.pl/articles/1853755.pdf  Link otwiera się w nowym oknie
Opis:
Motion of gas bubbles in aqueous phase (either clean water or solutions of surface-active substances) is a phenomenon of great practical importance. Gas/liquid contacting is one of the most common operations in the chemical and petrochemical industry and mineral processing In particular in mineral industry, for all kind of flotation processes it is the main act responsible for the success of the entire technology As a result, properties of the liquid/gas interfaces are considered as a one of the most important parameters, determining the outcome of industrial applications and engineering processes. These properties can be modified by surfactants which adsorption (molecules accumulation) at the interfaces leads to the decrease in the interfacial tension and modification of the hydrodynamic boundary conditions. Description of a single bubble motion in wide range of flow magnitude (Reynolds numbers) is not trivial and many attempts have been undertaken to quantify a bubble behavior in liquids. This paper presents a short overview of the current “state of arts” on physics of the bubble motion in liquids and the elaborated models, describing motion of the bubble formed in liquid phase. The comparison of the theoretical models predictions with the available experimental data is presented. It is shown, moreover, that the bubble velocity can be used as a very sensitive tool for detection of organic contaminations in environmental water samples.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badanie tworzenia warstwy adsorpcyjnej białek na powierzchni nanocząstek tlenkowych
Formation of adsorption layer of proteins on the surface of oxygen nanoparticles
Autorzy:
Bratoń, Lena
Opis:
Badania prowadzone w ostatnich latach wskazują na rosnące zainteresowanie strukturami, które można zaliczyć do szeroko rozumianej nanotechnologii. Wykorzystywane związki, kwalifikowane jako nanomateriały są podmiotem licznych analiz pod kątem możliwości ich zastosowania, a w wyniku tego nanotechnologia jest od wielu lat prężenie rozwijającą się dziedziną nauki. Nanomateriały ze względu na swoje specyficzne właściwości, które odróżniają je od struktur występujących w większej skali, zyskują na popularności w wielu dziedzinach przemysłu, a dzięki zdolnościom do przenikania przez bariery biologiczne, znajdują zastosowanie także w medycynie i biologii. Wykazują również zdolność do interakcji z biomolekułami, a podczas kontaktu z białkami mogą prowadzić do ich fibrylacji oraz otaczają się powłoką określaną jako „korona białkowa”. Przeanalizowanie mechanizmu tworzenia się struktur na powierzchni nanocząstek jest istotne podczas opracowywania dalszych możliwości zastosowań nanomateriałów, a także ich wykorzystania w celach terapeutycznych. Celem niniejszej pracy było przeanalizowanie możliwości tworzenia się warstw adsorpcyjnych na powierzchni nanocząstek tlenkowych oraz ich wpływ na fibrylację białek osocza.
Research done in recent years indicates a growing interest in structures that can be categorized as nanotechnology in the broadest sense. The compounds, qualified as nanomaterials, are the subject of numerous analyses for their applicability, and as a result, nanotechnology has been a thriving scientific field for many years. Nanomaterials, due to their specific properties that distinguish them from structures on a larger scale, are gaining popularity in many industrial fields, and due to their ability to penetrate biological barriers, they are also used in medicine and biology. They also show the ability to interact with biomolecules, and when in contact with proteins can lead to their fibrillation and surround themselves with a coating referred to as a "protein corona." Analyzing the mechanism of the formation of such structures on the surface of nanoparticles is crucial when developing applications of nanomaterials, as well as their use for therapeutic purposes. The purpose of this study was to analyze the adsorption layers on the surface of oxide nanoparticles and their effect on the fibrillation of plasma proteins.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Inne
Tytuł:
Badania właściwości fizykochemicznych adsorbentów adenozyny otrzymanych metodą warstwa po warstwie
Studies on the physicochemical properties of adenosine adsorbents obtained using the layer-by-layer method
Autorzy:
Mostowska, Justyna
Opis:
The thesis presents a way of the synthesis using layer-by-layer deposition method of molecularly imprinted polymeric materials, which selectively bind adenosine, which is a potential cancer biomarker. Silica gel particles were synthesized via Stöber method, which were coated with an ultrathin layers of a different polymers containing thymine moieties. Molecularly imprinted materials were prepared by UV irradiation of the microspheres coated with a polymer layer which caused photodimerization of thymine chromophores in the presence of adenine or adenosine templates. Subsequent removal of the templates resulted in the formation of the cavities of appropriate shape and size. Molecularly imprinted adsorbents show much higher adsorption and selectivity capacity for adenosine than for other nucleosides. In the final step of the research I have attempted the synthesis of polymeric materials based on natural polysacharides – thymine-functionalized chitosan and cytosine-functionalized κ-carrageenan, which may be used to obtain molecularly imprinted adsorbents.
W pracy przedstawiono sposób otrzymywania metodą warstwa po warstwie materiałów polimerowych drukowanych molekularnie, wiążących selektywnie adenozynę, będącą biomarkerem niektórych typów nowotworów. Zsyntetyzowane mikrosfery Stöbera pokryto ultracienkimi warstwami różnych polimerów zawierających w swojej strukturze reszty tyminy. Adsorbenty drukowane molekularnie otrzymano przez naświetlanie mikrosfer pokrytych warstwą polimerową promieniowaniem UV powodującym fotodimeryzację reszt tyminy, w obecności cząsteczki szablonowej, którą stanowiła adenina lub adenozyna, a następnie jej usunięcie z pozostawieniem w ten sposób wnęk o odpowiednim kształcie i rozmiarze. Drukowane molekularnie adsorbenty wykazały większą niż materiały referencyjne zdolność adsorpcyjną i selektywność adsorpcji adenozyny w porównaniu do pozostałych nukleozydów. W ostatnim etapie badań podjęto próbę otrzymania materiałów polimerowych na bazie polisacharydów naturalnych – chitozanu funkcjonalizowanego tyminą oraz κ-karagenanu funkcjonalizowanego cytozyną, które mogą posłużyć do otrzymywania adsorbentów drukowanych molekularnie.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Inne
Tytuł:
Electrical Characteristics of Tin Oxide Films Grown by Thermal Atomic Layer Deposition
Autorzy:
Yoon, Seong Yu
Choi, Byung Joon
Tematy:
atomic layer deposition
tin oxide
electrical property
oxygen adsorption
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/352926.pdf  Link otwiera się w nowym oknie
Opis:
Tin dioxide (SnO2 ) is an n-type semiconductor and has useful characteristics of high transmittance, excellent electrical properties, and chemical stability. Accordingly, it is widely used in a variety of fields, such as a gas sensor, photocatalyst, optoelectronics, and solar cell. In this study, SnO2 films are deposited by thermal atomic layer deposition (ALD) at 180°C using Tetrakis(dimethylamino)tin and water. A couple of 5.9, 7.4 and 10.1nm-thick SnO2 films are grown on SiO2 /Si substrate and then each film is annealed at 400°C in oxygen atmosphere. Current transport of SnO2 films are analyzed by measuring current – voltage characteristics from room temperature to 150°C. It is concluded that electrical property of SnO2 film is concurrently affected by its semiconducting nature and oxidative adsorption on the surface.
Dostawca treści:
Biblioteka Nauki
Artykuł

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