Interfacial Mechanisms of Water Vapor Sorption into Cellulose Nanofibril Films as Revealed by Quantitative Models

Minna Hakalahti, Marco Faustini, Cedric Boissiere, Eero Kontturi, Tekla Tammelin

Research output: Contribution to journalArticleScientificpeer-review

20 Citations (Scopus)

Abstract

Humidity is an efficient instrument for facilitating changes in local architectures of two-dimensional surfaces assembled from nanoscaled biomaterials. Here, complementary surface-sensitive methods are used to collect explicit and precise experimental evidence on the water vapor sorption into (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) oxidized cellulose nano fibril (CNF) thin film over the relative humidity (RH) range from 0 to 97%. Changes in thickness and mass of the film due to water vapor uptake are tracked using spectroscopic ellipsometry and quartz crystal microbalance with dissipation monitoring, respectively. Experimental data is evaluated by the quantitative Langmuir/Flory Huggins/dustering model and the Brunauer-Emmett-Teller model. The isotherms coupled with the quantitative models unveil distinct regions of predominant sorption modes: specific sorption of water molecules below 10% RH, multilayer build-up between 10 to 75% RH, and clustering of water molecules above 75% RH. The study reveals the sorption mechanisms underlying the well-known water uptake behavior of TEMPO oxidized CNF directly at the gas-solid interface.

Original languageEnglish
Pages (from-to)2951-2958
Number of pages8
JournalBiomacromolecules
Volume18
Issue number9
DOIs
Publication statusPublished - Sep 2017
MoE publication typeA1 Journal article-refereed

Keywords

  • QUARTZ-CRYSTAL MICROBALANCE
  • ADSORPTION
  • POLYMERS
  • ISOTHERM
  • SURFACE
  • BET
  • NANOCRYSTALS
  • ELLIPSOMETRY
  • TRANSPORT
  • FEATURES

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