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  1. Article: Editorial Overview: Hot Topic: COVID-19: Colloid and Interface Aspects of COVID-19.

    Liggieri, Libero / Miller, Reinhard

    Current opinion in colloid & interface science

    2021  Volume 56, Page(s) 101525

    Language English
    Publishing date 2021-10-16
    Publishing country England
    Document type Editorial
    ZDB-ID 2019683-0
    ISSN 1359-0294
    ISSN 1359-0294
    DOI 10.1016/j.cocis.2021.101525
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Influence of Surfactant Concentration on Spontaneous Emulsification Kinetics.

    Toor, Ritu / Denoyel, Renaud / Liggieri, Libero / Schmitt, Murielle / Antoni, Mickaël

    Langmuir : the ACS journal of surfaces and colloids

    2022  Volume 38, Issue 38, Page(s) 11521–11528

    Abstract: The kinetics of spontaneous emulsification is investigated on aqueous pendant drops in paraffin oil. Optical microscopy in transmission mode is used for high-spatial-resolution image recording. The influence of a lipophilic surfactant (Span 80) and two ... ...

    Abstract The kinetics of spontaneous emulsification is investigated on aqueous pendant drops in paraffin oil. Optical microscopy in transmission mode is used for high-spatial-resolution image recording. The influence of a lipophilic surfactant (Span 80) and two water-soluble surfactants (CTAB and SDS) is investigated. As time runs, the drop interface turns opaque due to the formation of microstructures associated with spontaneous emulsification. The time evolution of this phenomenon is shown to depend upon temperature and surfactant concentration, which leads to an overall shrinkage due to gradual water uptake and transport into paraffin oil. Spontaneous emulsification kinetics depends upon the chemical composition. Higher concentrations of Span 80 and CTAB (resp. SDS) are shown to promote (resp. hinder) water transport. This work provides new insights into the understanding of spontaneous emulsification when combining the properties of non-ionic and ionic surfactants.
    Language English
    Publishing date 2022-09-12
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2005937-1
    ISSN 1520-5827 ; 0743-7463
    ISSN (online) 1520-5827
    ISSN 0743-7463
    DOI 10.1021/acs.langmuir.1c03443
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Evaluating the Impact of Hydrophobic Silicon Dioxide in the Interfacial Properties of Lung Surfactant Films.

    Guzmán, Eduardo / Santini, Eva / Ferrari, Michele / Liggieri, Libero / Ravera, Francesca

    Environmental science & technology

    2022  Volume 56, Issue 11, Page(s) 7308–7318

    Abstract: The interaction of hydrophobic silicon dioxide particles (fumed silicon dioxide), as model air pollutants, and Langmuir monolayers of a porcine lung surfactant extract has been studied in order to try to shed light on the physicochemical bases underlying ...

    Abstract The interaction of hydrophobic silicon dioxide particles (fumed silicon dioxide), as model air pollutants, and Langmuir monolayers of a porcine lung surfactant extract has been studied in order to try to shed light on the physicochemical bases underlying the potential adverse effects associated with pollutant inhalation. The surface pressure-area isotherms of lung surfactant (LS) films including increasing amounts of particles revealed that particle incorporation into LS monolayers modifies the organization of the molecules at the water/vapor interface, which alters the mechanical resistance of the interfacial films, hindering the ability of LS layers for reducing the surface tension, and reestablishing the interface upon compression. This influences the normal physiological function of LS as is inferred from the analysis of the response of the Langmuir films upon the incorporation of particles against harmonic changes of the interfacial area (successive compression-expansion cycles). These experiments evidenced that particles alter the relaxation mechanisms of LS films, which may be correlated to a modification of the transport of material within the interface and between the interface and the adjacent fluid during the respiratory cycle.
    MeSH term(s) Animals ; Lung ; Pressure ; Pulmonary Surfactants/chemistry ; Pulmonary Surfactants/metabolism ; Silicon Dioxide ; Surface Properties ; Surface Tension ; Surface-Active Agents/metabolism ; Swine
    Chemical Substances Pulmonary Surfactants ; Surface-Active Agents ; Silicon Dioxide (7631-86-9)
    Language English
    Publishing date 2022-01-25
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1520-5851
    ISSN (online) 1520-5851
    DOI 10.1021/acs.est.1c06885
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Book: Surface analysis techniques optical methods

    Liggieri, Libero

    (Current opinion in colloid and interface science ; 19.2014,3)

    2014  

    Author's details ed. by Libero Liggieri
    Series title Current opinion in colloid and interface science ; 19.2014,3
    Language English
    Size S. 175 - 252
    Publisher Elsevier
    Publishing place Amsterdam u.a.
    Document type Book
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  5. Article ; Online: Monolayers of Cholesterol and Cholesteryl Stearate at the Water/Vapor Interface

    Ramón G. Rubio / Eduardo Guzmán / Francisco Ortega / Libero Liggieri

    Colloids and Interfaces, Vol 5, Iss 30, p

    A Physico-Chemical Study of Components of the Meibum Layer

    2021  Volume 30

    Abstract: Langmuir monolayers containing different amounts of cholesterol and cholesteryl stearate were studied at two different temperatures (24 °C and 35 °C). The main goal was to contribute towards the understanding of how the variations in the chemical ... ...

    Abstract Langmuir monolayers containing different amounts of cholesterol and cholesteryl stearate were studied at two different temperatures (24 °C and 35 °C). The main goal was to contribute towards the understanding of how the variations in the chemical composition may affect the physico-chemical properties of these specific lipid monolayers. The model mixture was chosen considering that cholesteryl esters are present in cell membranes and some other biological systems, including human tear lipids. Therefore, an investigation into the effect of the lipid monolayer composition on their interfacial properties may elucidate some of the fundamental reasons for the deficiencies in cell membranes and tear film functioning in vivo. The experimental results have shown that the molar ratio of the mixture plays a crucial role in the modulation of the Langmuir film properties. The condensing effects of the cholesterol and the interactions between the lipids in the monolayer were the main factors altering the monolayer response to dilatational deformation. The modification of the mixture compositions leads to significant changes in the Langmuir films and the mechanical performance, altering the ability of the monolayer to reduce the surface tension and the viscoelastic properties of the monolayers. This suggests that subtle modifications of the biomembrane composition may significantly alter its physiological function.
    Keywords Langmuir monolayers ; dilational rheology ; cholesterol ; cholesteryl stearate ; Chemistry ; QD1-999
    Subject code 540
    Language English
    Publishing date 2021-05-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Emulsification and emulsion stability: The role of the interfacial properties.

    Ravera, Francesca / Dziza, Katarzyna / Santini, Eva / Cristofolini, Luigi / Liggieri, Libero

    Advances in colloid and interface science

    2020  Volume 288, Page(s) 102344

    Abstract: In this review, we highlight and discuss the effects of interfacial properties on the major mechanisms governing the aging of emulsions: flocculation, coalescence and Ostwald ripening. The process of emulsification is also addressed, as it is well ... ...

    Abstract In this review, we highlight and discuss the effects of interfacial properties on the major mechanisms governing the aging of emulsions: flocculation, coalescence and Ostwald ripening. The process of emulsification is also addressed, as it is well recognized that the adsorption properties of emulsifiers play an important role on it. The consolidated background on these phenomena is briefly summarised based on selected literature, reporting relevant findings and results, and discussing some criticalities. The typical experimental approaches adopted to investigate the above effects are also summarised, underlining in particular the role of adsorption at the droplet interface. Attention is paid to different types of surface-active species involved with emulsion production, including solid particles. The latter being of increasing interest in a wide variety of emulsions-related products and technologies in various fields. The possibility to stop the long term aging caused by Ostwald ripening in emulsions is also discussed, quantifying under which conditions it may occur in practice.
    Language English
    Publishing date 2020-12-14
    Publishing country Netherlands
    Document type Journal Article ; Review
    ZDB-ID 210507-x
    ISSN 1873-3727 ; 0001-8686
    ISSN (online) 1873-3727
    ISSN 0001-8686
    DOI 10.1016/j.cis.2020.102344
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Influence of Surfactant Concentration on Spontaneous Emulsification Kinetics

    Toor, Ritu / Denoyel, Renaud / Liggieri, Libero / Schmitt, Murielle / Antoni, Mickaël

    Langmuir. 2022 Sept. 12, v. 38, no. 38

    2022  

    Abstract: The kinetics of spontaneous emulsification is investigated on aqueous pendant drops in paraffin oil. Optical microscopy in transmission mode is used for high-spatial-resolution image recording. The influence of a lipophilic surfactant (Span 80) and two ... ...

    Abstract The kinetics of spontaneous emulsification is investigated on aqueous pendant drops in paraffin oil. Optical microscopy in transmission mode is used for high-spatial-resolution image recording. The influence of a lipophilic surfactant (Span 80) and two water-soluble surfactants (CTAB and SDS) is investigated. As time runs, the drop interface turns opaque due to the formation of microstructures associated with spontaneous emulsification. The time evolution of this phenomenon is shown to depend upon temperature and surfactant concentration, which leads to an overall shrinkage due to gradual water uptake and transport into paraffin oil. Spontaneous emulsification kinetics depends upon the chemical composition. Higher concentrations of Span 80 and CTAB (resp. SDS) are shown to promote (resp. hinder) water transport. This work provides new insights into the understanding of spontaneous emulsification when combining the properties of non-ionic and ionic surfactants.
    Keywords chemical composition ; emulsifying ; light microscopy ; lipophilicity ; oils ; shrinkage ; surfactants ; temperature ; water solubility ; water uptake
    Language English
    Dates of publication 2022-0912
    Size p. 11521-11528.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 2005937-1
    ISSN 1520-5827 ; 0743-7463
    ISSN (online) 1520-5827
    ISSN 0743-7463
    DOI 10.1021/acs.langmuir.1c03443
    Database NAL-Catalogue (AGRICOLA)

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  8. Article: Evaluating the Impact of Hydrophobic Silicon Dioxide in the Interfacial Properties of Lung Surfactant Films

    Guzmán, Eduardo / Santini, Eva / Ferrari, Michele / Liggieri, Libero / Ravera, Francesca

    Environmental science & technology. 2022 Jan. 26, v. 56, no. 11

    2022  

    Abstract: The interaction of hydrophobic silicon dioxide particles (fumed silicon dioxide), as model air pollutants, and Langmuir monolayers of a porcine lung surfactant extract has been studied in order to try to shed light on the physicochemical bases underlying ...

    Abstract The interaction of hydrophobic silicon dioxide particles (fumed silicon dioxide), as model air pollutants, and Langmuir monolayers of a porcine lung surfactant extract has been studied in order to try to shed light on the physicochemical bases underlying the potential adverse effects associated with pollutant inhalation. The surface pressure–area isotherms of lung surfactant (LS) films including increasing amounts of particles revealed that particle incorporation into LS monolayers modifies the organization of the molecules at the water/vapor interface, which alters the mechanical resistance of the interfacial films, hindering the ability of LS layers for reducing the surface tension, and reestablishing the interface upon compression. This influences the normal physiological function of LS as is inferred from the analysis of the response of the Langmuir films upon the incorporation of particles against harmonic changes of the interfacial area (successive compression–expansion cycles). These experiments evidenced that particles alter the relaxation mechanisms of LS films, which may be correlated to a modification of the transport of material within the interface and between the interface and the adjacent fluid during the respiratory cycle.
    Keywords air ; breathing ; hydrophobicity ; lungs ; mechanical properties ; silica ; surface tension ; surfactants ; swine ; technology ; vapors
    Language English
    Dates of publication 2022-0126
    Size p. 7308-7318.
    Publishing place American Chemical Society
    Document type Article
    ISSN 1520-5851
    DOI 10.1021/acs.est.1c06885
    Database NAL-Catalogue (AGRICOLA)

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  9. Article: Evaluation of the impact of carbonaceous particles in the mechanical performance of lipid Langmuir monolayers

    Guzmán, Eduardo / Santini, Eva / Ferrari, Michele / Liggieri, Libero / Ravera, Francesca

    Colloids and surfaces. 2022 Feb. 05, v. 634

    2022  

    Abstract: Carbonaceous particles are accounted among the most common environmental pollutants. This makes necessary a careful examination of their potential impact on the physico-chemical properties of different biological films, e.g. tear film, skin, or lung ... ...

    Abstract Carbonaceous particles are accounted among the most common environmental pollutants. This makes necessary a careful examination of their potential impact on the physico-chemical properties of different biological films, e.g. tear film, skin, or lung surfactant. This work analyzes the interaction of three different types of carbonaceous particles with Langmuir monolayers of 1,2-Dipalmitoyl-sn-glycerol-3-phosphocholine (DPPC) spread at the water/vapor interface. This type of studies can be exploited as preliminary in vitro tests for evaluating the potential risks and hazards of this type of pollutants for human health, which requires to study the effect of the particles on the ability of lipid layers for reducing the surface tension under static and dynamics conditions. The obtained results have shown that the insertion of particles into lipid films leads to the emergence of excluded area-like effects which modify the interfacial cohesion and packing. This hinders partially the ability of the lipid films for reducing the surface tension, which may present important adverse effects for the normal physiological performance of lipid membranes, and in particular for the performance of lung surfactant layers. Furthermore, the analysis of the response of lipid layers including carbonaceous particles against mechanical stresses also evidenced that particle incorporation worsens the mechanical performance of lipid layers, which may alter both their functional and structural roles.
    Keywords cohesion ; human health ; lipids ; lungs ; surface tension ; surfactants ; vapors
    Language English
    Dates of publication 2022-0205
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 1500517-3
    ISSN 0927-7757
    ISSN 0927-7757
    DOI 10.1016/j.colsurfa.2021.127974
    Database NAL-Catalogue (AGRICOLA)

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  10. Article ; Online: Hydrophobisation of Silica Nanoparticles Using Lauroyl Ethyl Arginate and Chitosan Mixtures to Induce the Foaming Process.

    Krzan, Marcel / Jarek, Ewelina / Petkova, Hristina / Santini, Eva / Szyk-Warszynska, Lilianna / Ravera, Francesca / Liggieri, Libero / Mileva, Elena / Warszynski, Piotr

    Polymers

    2022  Volume 14, Issue 19

    Abstract: We studied silica suspensions with chitosan and biodegradable synthetic surfactant lauroyl ethyl arginate (LAE). Hydrophilic and negatively charged silica nanoparticles were neutralised due to the coating with chitosan. That presence of LAE led to the ... ...

    Abstract We studied silica suspensions with chitosan and biodegradable synthetic surfactant lauroyl ethyl arginate (LAE). Hydrophilic and negatively charged silica nanoparticles were neutralised due to the coating with chitosan. That presence of LAE led to the partial hydrophobisation of their surface, which favoured their attachment to the surface of a thin foam film. It was found that the presence of small and medium-sized (6-9 nm) hydrophobic particles in the interfacial layer of lamella foam film inhibited the coalescence and coarsening processes, which prolonged the life of the foam. Furthermore, hydrophobising of 30 nm particles allowed the formation of large aggregates precipitating from the mixture under steady-state conditions. These aggregates, however, under the conditions of the dynamic froth flotation process in the foam column, were floated into the foam layer. As a result, they were trapped in the foam film and Plateau borders, effectively preventing liquid leakage out of the foam. These results demonstrate the efficiency of using chitosan-LAE mixtures to remove silica nanoparticles from aqueous phase by foaming and flotation.
    Language English
    Publishing date 2022-09-28
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527146-5
    ISSN 2073-4360 ; 2073-4360
    ISSN (online) 2073-4360
    ISSN 2073-4360
    DOI 10.3390/polym14194076
    Database MEDical Literature Analysis and Retrieval System OnLINE

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