Near-field infrared microscopy: a novel analytic mapping technique to nanocharacterize calcium silicate-based cement materials

Felipe Basquiroto de Souza, Changxi Zheng, Shujian Chen, Yanming Liu, Kwesi Sagoe-Crentsil, Wenhui Duan

Research output: Contribution to journalArticleResearchpeer-review

4 Citations (Scopus)

Abstract

Infrared imaging via scattering-type scanning near-field optical microscopy (s-SNOM) allows chemical mapping of organic and inorganic materials with nanoscale spatial resolution. However, its potential adaptation to the complex multiphase structure of Portland cement is yet to be explored. Here we demonstrate the successful implementation of s-SNOM to spatially resolve coexisting chemical phases in tricalcium silicate, Portland cement's main compound, with 20-nm resolution. We found that s-SNOM is sensitive to different anhydrous polymorphic phases, revealing nanoscale domains that are ‘invisible’ to other microscopic techniques. Furthermore, s-SNOM's ability to distinguish the unhydrated and hydrated phases signifies its great promise as an analytical tool to study the complex hydration process of cement. The key to s-SNOM's application was nano-modifying the surface roughness of the cement samples, allowing nanoscale infrared imaging without topographical artifacts. Our study opens a window for infrared spectral microscopy in cement and other porous inorganic materials.

Original languageEnglish
Article number106525
Number of pages9
JournalCement and Concrete Research
Volume147
DOIs
Publication statusPublished - Sep 2021

Keywords

  • Calcium silicate
  • Chemical mapping
  • Nano-characterization
  • Portland cement
  • S-SNOM

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