Formation of an iron-based inorganic polymer (geopolymer)

Jonathan L. Bell, Waltraud M. Kriven

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

High surface area (132 m2/g) Fe2O3· 2SiO2 powder was synthetically made using an organic steric entrapment method. The resultant powder was poorly crystalline and contained small grains of magnetite and/or maghemite, and a minor amount of hematite. An iron-based inorganic polymer analogue (K2O·Fe 2O3·4SiO2·13H2O) was fabricated by mixing the synthetic Fe2O3·2SiO 2 powder into potassium silicate solution and curing at 50°C for 24 h. The resultant material was a water-soluble, rubbery gel. However, by aging this gel for 361 days at room temperature in a sealed container, the crystalline phases slowly dissolved, and the gel further hardened and became partially insoluble in water. The water insoluble component was amorphous and of the composition 0.48K2O·1.38Fe2O 3·4SiO2 as determined from SEM-EDS analysis. X-ray analysis showed a broad amorphous peak centered near 25° 20, indicative of short range ordering. The microstructure consisted of 10-20 nm sized precipitates, similar to conventional Al-based geopolymers. X-ray pair distribution function (PDF) results suggest that the atomic structure was more disordered than equivalent Al-based geopolymers, and that iron was present in predominately octahedral coordination.

Original languageEnglish (US)
Title of host publicationMechanical Properties and Performance of Engineering Ceramics and Composites IV - A Collection of Papers Presented at the 33rd International Conference on Advanced Ceramics and Composites
Pages301-312
Number of pages12
Edition2
StatePublished - May 13 2010
EventMechanical Properties and Performance of Engineering Ceramics and Composites IV - 33rd International Conference on Advanced Ceramics and Composites - Daytona Beach, FL, United States
Duration: Jan 18 2009Jan 23 2009

Publication series

NameCeramic Engineering and Science Proceedings
Number2
Volume30
ISSN (Print)0196-6219

Other

OtherMechanical Properties and Performance of Engineering Ceramics and Composites IV - 33rd International Conference on Advanced Ceramics and Composites
Country/TerritoryUnited States
CityDaytona Beach, FL
Period1/18/091/23/09

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

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