engleski

The impact of dextran sulfate on the radiolytic synthesis of magnetic iron oxide nanoparticles

Recently, the new synthesis route to delta-FeOOH nanodiscs based on the γ-irradiation of a deoxygenated iron(III) chloride alkaline aqueous colloidal solution in the presence of diethylaminoethyl-dextran hydrochloride (DEAE-dextran) has been reported by Jurkin et al. [1]. In that work we supposed that γ-irradiation produced reducing conditions and that delta-FeOOH nanoparticles were formed through oxidation of obtained white suspension characteristic of Fe(OH)2. In this work, we studied the impact of dextran sulfate polymer (DEX-sulfate) on the radiolytic synthesis of magnetic iron oxide nanoparticles. The syntheses started with γ-irradiation (130 kGy) of deoxygenated iron(III) chloride alkaline aqueous colloidal solution in the presence of 2-propanol and DEX-sulfate. The radiolytically synthesised samples were isolated by conventional process of sample isolation (centrifugation/washing with water or ethanol) or in the presence of glycerol. The XRD results showed that sample isolated in the presence of glycerol contained Fe(OH)2, hydroxysulfate green rust II (GR SO42-) and goethite (alfa-FeOOH). The Mössbauer results confirmed the presence of Fe(OH)2 and hydroxysulfate green rust II (GR SO42-) in this sample. The radiolytically synthesized samples that were isolated by centrifugation and washing with water or ethanol contained GR SO42- and alfa-Fe2O3. Therefore, the DEX-sulfate favoured the formation of alfa-FeOOH and/or alfa-Fe2O3 through GR-II (SO42-) intermediate product.

iron oxides ; gamma-irradiation ; dextran sulfate ; green rust ; iron(II) hydroxide ; feroxyhyte

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