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Mechanical Contact Spectroscopy: Characterizing Nanoscale Adhesive Contacts via Thermal Forces

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    SYSNO ASEP0508143
    Document TypeJ - Journal Article
    R&D Document TypeJournal Article
    Subsidiary JČlánek ve WOS
    TitleMechanical Contact Spectroscopy: Characterizing Nanoscale Adhesive Contacts via Thermal Forces
    Author(s) Jonáš, Alexandr (UPT-D) RID, SAI, ORCID
    Kochanczyk, M.D. (US)
    Ramirez, A.D. (US)
    Speidel, M. (DE)
    Florin, E. L. (DE)
    Number of authors5
    Source TitleLangmuir. - : AMER CHEMICAL SOC - ISSN 0743-7463
    Roč. 35, č. 17 (2019), s. 5809-5820
    Number of pages12 s.
    Publication formPrint - P
    Languageeng - English
    CountryUS - United States
    Keywordsmodel porous-media ; colloid detachment ; surface-roughness
    Subject RIVBH - Optics, Masers, Lasers
    OBOR OECDFluids and plasma physics (including surface physics)
    Způsob publikováníOmezený přístup
    Institutional supportUPT-D - RVO:68081731
    UT WOS000466816900017
    EID SCOPUS85065148201
    AnnotationThe adhesion of micro- and nanoparticles to solid substrates immersed in liquids is a problem of great scientific and technological importance. However, the quantitative characterization of such nanoscale adhesive contacts without rupturing them still presents a major experimental challenge. In this article, we introduce mechanical contact spectroscopy (MCS), an experimental technique for the nondestructive probing of particle adhesion in liquid environments. With MCS, the strength of adhesive contacts is inferred from residual position fluctuations of adherent particles excited by thermal forces. In particular, the strength of adhesion is correlated with the standard deviation of the particle lateral position x, with smaller position standard deviations xi = root <Delta x(2)> indicating higher adhesive strength. For a given combination of particles, substrate, and immersion medium, the adhesion is characterized by the mechanical contact spectrum, which is a histogram of xi values obtained from tracking an ensemble of adherent particles. Because the energy of thermal excitation at room temperature is very small in comparison to the typical total energy of adhesive contacts, the studied contacts remain in equilibrium during the measurement. Using MCS, we study the adhesion of micrometer-sized particles to planar solid substrates under a wide range of environmental conditions, including liquid immersion media of varying ionic strength and adhesion substrates with different chemical functionality of their surfaces. These experiments provide evidence that MCS is capable of reproducibly detecting minute changes in the particle-substrate work of adhesion while at the same time covering the range of adhesive contact strength relevant in the context of surface chemistry, biology, and microfabrication.
    WorkplaceInstitute of Scientific Instruments
    ContactJan Slaměník,, Tel.: 541 514 205 ; Miluše Langová,
    Year of Publishing2020
    Electronic address
Number of the records: 1