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Matrix Assisted Formation of Ferrihydrite Nanoparticles in a Siloxane/Poly(Oxyethylene) Nanohybrid

Nuno J. O. Silva·Vitor S. Amaral·Veronica de Zea Bermudez·Silvia C. Nunes·Denis Ostrovskii·Joao Rocha·Luis D. Carlos
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Abstract

Matrix-assisted formation of ferrihydrite, an iron oxide hydroxide analogue of the protein ferritin-core, in a sol-gel derived organic-inorganic hybrid is reported. The hybrid network (named di-ureasil) is composed of poly(oxyethylene) chains of different average polymer molecular weights grafted to siloxane domains by means of urea cross-linkages and accommodates ferrihydrite nanoparticles. Magnetic measurements, Fourier transform infrared and nuclear magnetic resonance spectroscopy reveal that the controlled modification of the polymer molecular weight allows the fine-tuning of the ability of the hybrid matrix to assist and promote iron coordination at the organic-inorganic interface and subsequent nucleation and growth of the ferrihydrite nanoparticles whose core size (2-4 nm) is tuned by the amount of iron incorporated. The polymer chain length, its arrangement and crystallinity, are key factors on the anchoring and formation of the ferrihydrite particles.

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Nuno J. O. Silva, Vitor S. Amaral, Veronica de Zea Bermudez, Silvia C. Nunes, Denis Ostrovskii, Joao Rocha, Luis D. Carlos. 2004-10-27. Matrix Assisted Formation of Ferrihydrite Nanoparticles in a Siloxane/Poly(Oxyethylene) Nanohybrid. https://arxiv.org/abs/cond-mat/0410695

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