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HRTEM study of freeze-dried and untreated synthetic ferrihydrites: consequences of sample processing

Published online by Cambridge University Press:  09 July 2018

C. Greffié*
Affiliation:
BRGM, Ressources Minérales, B.P. 6009, 45060 Orléans Cedex 02
M. Amouric
Affiliation:
CRMCC, Campus de Luminy, 13288, Marseille
C. Parron
Affiliation:
CEREGE, UMR CNRS 6635, B.P. 80, 13545 Aix en Provence Cedex 04, France
*

Abstract

Two-line ferrihydrite samples were synthesized following conventional procedure. Detailed characterizations of freeze-dried and untreated samples – prepared from direct inclusion of the fresh precipitates in hydrophilic resin – were made by high resolution transmission electron microscopy to investigate in detail their structural organization and to compare the two types of preparations.

Only highly disordered chain-like aggregates of 2 5 nm diameter size nano-particles were revealed within the untreated samples. Conversely, in freeze-dried samples, domains with different degrees of order were recognized, from poorly ordered 2-line ferrihydrite to 3-line ferrihydrite particle aggregates that revealed lattice fringes. Associated with these aggregates, a goethite phase with a modified crystal morphology was also observed.

These HRTEM observations revealed that freeze-drying techniques induce artifacts by disturbing ferrihydrite aggregates while direct inclusion in hydrophilic resin preserves the primary organization of such poorly ordered phases.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2001

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References

Bachhuber, K. & Frösch, H. (1983) Melanine resins, a new class of water-soluble embedding media for electron microscopy. J. Microsc. 130, 1–9.Google Scholar
Carlson, L. & Schwertmann, U. (1981) Natural ferrihydrites in surface deposits from Finland and their association with silica. Geochim. Cosmochim. Acta, 45, 421–429.Google Scholar
Chukhrov, F.V., Zvyagin, B.B., Gorshkov, A.I., Yermilova, L. P. & Balashova, V.V. (1973) Ferrihydrite. I. Akad. Nauk SSSR. Ser. Geol. 4, 23–33.Google Scholar
Cornell, R.M. & Giovanoli, R. (1987) Influence of silicate species on the morphology of goethite grown from ferrihydrites. J. Chem. Soc., Chem. Comm. 1517, 413–414.Google Scholar
Drits, V.A., Sakharov, B.A., Salyn, A.L. & Manceau, A. (1993) Structural model for ferrihydrite. Clay Miner. 28, 185–207.Google Scholar
Eggleton, R.A. & Fitzpatrick, R.W. (1988) New data and a revised structural model for ferrihydrite. Clays Clay Miner. 36, 111–124.Google Scholar
Feitknecht, W., Giovanoli, R., Michaelis, W. & Muller, M. (1973) Die Hydrolyse der Lösungen von Eisen (III)- chlorid. Helv. Chim. Acta, 56, 2847–2856.Google Scholar
Fischer, W.R. & Schwertman, U. (1975) The formation of hematite from amorphous iron (III) hydroxide. Clays Clay Miner. 23, 33–37.CrossRefGoogle Scholar
Greffié, C., Parron, C., Benedetti, M. & Hiemstra, T. (1996) Influence de l’or sur la cristallisation des oxyhydroxydes de fer. C.R. Acad. Sci. Paris, 322, 197–204.Google Scholar
He, Q.H., Leppard, G.G., Paige, C.R. & Snodgrass, W.J. (1996) Transmission electron microscopy of a phosphate effect on the colloid structure of iron hydroxide. Wat. Res. 30, 1345–1352.CrossRefGoogle Scholar
Janney, D.E., Cowley, J.M. & Buseck, P.R. (2000) Transmission electron microscopy of synthetic 2- and 6-line ferrihydrite. Clays Clay Miner. 48, 111–119.Google Scholar
Leppard, G.G., Burnison, B.K. & Buffle, J. (1990) Transmission electron microscopy of the natural organic matter of surface waters. Anal. Chim. Acta, 232, 107–121.Google Scholar
Manceau, A. & Drits, V.A. (1993) Local structure of ferrihydrite and feroxyhite by EXAFS spectroscopy. Clay Miner. 28, 165–184.CrossRefGoogle Scholar
Manceau, A. & Gates, W.P. (1997) Surface structural model for ferrihydrite. Clays Clay Miner. 45, 448–460.Google Scholar
Perret, D., Leppard, G.G., Müller, M., Belzile, N., De Vitre, R. & Buffle, J. (1991) Electron microscopy of aquatic colloids non perturbing preparation of specimens in the field. Wat. Res. 25, 1333–1343.Google Scholar
Schwertmann, U. & Cornell, R.M. (1991) Iron Oxides in the Laboratory. VCH, Weinheim, Germany.Google Scholar
Schwertmann, U. & Fisher, W.R. (1973) Natural amorphous ferric hydroxi de. Geoderma, 10, 237–247.Google Scholar
Schwertmann, U. & Murad, E. (1983) Effect of pH on the formation of goethite and hematite from ferrihydrite. Clays Clay Miner. 31, 277–284.Google Scholar
Shinoda, K., Matsubara, E., Muramatsu, A. & Waseda, Y. (1994) Local structure of ferric hydroxide Fe(OH)3 in aqueous solution by the anomalous X-ray scattering and EXAFS methods. Materials Trans. 35, 394–398.Google Scholar
Waychunas, G.A., Fuller, C.C., Rea, B.A. & Davis, J.A. (1996) Wide angle X-ray scattering study of two-line ferrihydrite structure: effect of arsenate sorption and counterion variation and comparison with EXAFS results. Geochim. Cosmochim. Acta, 60, 1765–1781 Google Scholar