Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-10T16:45:45.693Z Has data issue: false hasContentIssue false

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

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