Bubble Attachment to Cellulose and Silica Surfaces of Varied Surface Energies : Wetting Transition and Implications in Foam Forming

No Thumbnail Available

Access rights

openAccess
publishedVersion

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2020-07-07

Department

Department of Bioproducts and Biosystems

Major/Subject

Mcode

Degree programme

Language

en

Pages

13

Series

Langmuir, Volume 36, issue 26, pp. 7296-7308

Abstract

To better understand the complex system of wet foams in the presence of cellulosic fibers, we investigate bubble-surface interactions by following the effects of surface hydrophobicity and surface tension on the contact angle of captive bubbles. Bubbles are brought into contact with model silica and cellulose surfaces immersed in solutions of a foaming surfactant (sodium dodecyl sulfate) of different concentrations. It is observed that bubble attachment is controlled by surface wetting, but a significant scatter in the behavior occurs near the transition from partial to complete wetting. For chemically homogeneous silica surfaces, this transition during bubble attachment is described by the balance between the energy changes of the immersed surface and the frictional surface tension of the moving three-phase contact line. The situation is more complex with chemically heterogeneous, hydrophobic trimethylsilyl cellulose (TMSC). TMSC regeneration, which yields hydrophilic cellulose, causes a dramatic drop in the bubble contact angle. Moreover, a high interfacial tension is required to overcome the friction caused by microscopic (hydrophilic) pinning sites of the three-phase contact line during bubble attachment. A simple theoretical framework is introduced to explain our experimental observations.

Description

* Ack:ssa mutta ei silti mukaan raportointiin | openaire: EC/H2020/788489/EU//BioElCell

Keywords

Other note

Citation

Ketola, A E, Xiang, W, Hjelt, T, Pajari, H, Tammelin, T, Rojas, O J & Ketoja, J A 2020, ' Bubble Attachment to Cellulose and Silica Surfaces of Varied Surface Energies : Wetting Transition and Implications in Foam Forming ', Langmuir, vol. 36, no. 26, pp. 7296-7308 . https://doi.org/10.1021/acs.langmuir.0c00682