Sol–gel–xerogel transformations in the thin layer at the salt solution–gaseous reagent interface and the synthesis of new materials with microtubular morphology
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In this report, we consider the peculiarities of sol–gel–xerogel transformations, which occurs in the thin layer at the FeCl2/FeCl3 water solution and gaseous NH3 interface. A thin layer consisting of nanoparticles of Fe(OH)3 and Fe3O4 is formed as a result of interfacial reaction. Depending on the time of treatment with gaseous ammonia, it was possible to obtain either a freestanding layer with a thickness of 1 μm or microtubular structures (scrolls). Synthetic conditions, under which a large number of preferentially oriented microtubes are formed with diameters of about 10 and up to 200-μm long, were determined. The synthesized structures consisted of crystalline Fe3O4 nanoparticles with an average diameter of about 5–10 nm incorporated in an amorphous matrix. Layers and tubes were characterized by X-ray diffraction analysis, scanning and transmission electron microscopy (SEM and TEM), and X-ray photoelectron spectroscopy. The model, concerning sol–gel–xerogel transformations in the thin layer, formed after interaction at the salt solution–gaseous reagent interface, was suggested. The magnetic properties of the products were studied.
A sol–gel–xerogel transformation in the thin layer at the gas–solution interface has been studied.
Tubular or planar morphology of the products depended on synthesis conditions.
The opportunity to obtain an array of oriented microtubes was demonstrated for the first time.
The layers and tubes based on Fe3O4 demonstrated superparamagnetic properties.
KeywordsSol–gel process Interface Thin films Microtubes Magnetite
This work was supported by the Russian Science Foundation (grant No. 16-13-10223). We are grateful to the Research Park of St. Petersburg State University for assistance in studies of our samples: Nanotechnology Center, Centre for Innovative Technologies of Composite Nanomaterials, and Centre for X-Ray Diffraction Studies.
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Conflict of interest
The authors declare that they have no conflict of interest.
- 2.Castellón E, Zayat M, Levy D (2018) Sol-gel materials for electro-optical and optically active humidity-sensitive devices. J Sol-Gel Sci Technol. https://doi.org/10.1007/s10971-018-4852-2
- 24.Mori T, Tanaka H, Dalui A, Mitoma N, Suzuki K, Matsumoto M, Aggarwal N, Patnaik A, Acharya S, Shrestha LK, Sakamoto H, Itami K, Ariga K (2018) Carbon nanosheets by morphology-retained carbonization of two-dimensional assembled anisotropic carbon nanorings. Angew Chem Int Ed 57:9679–9683CrossRefGoogle Scholar
- 27.Gulina L, Tolstoy V (2011) In: Vyvenko OF (ed) State-of-the-art trends of scientific researches of artificial and natural nanoobjects. Saint-Petersburg State University, Saint-Petersburg, RussiaGoogle Scholar
- 38.Tolstoy VP, Gulina LB (2013) New way of As2S3 microtubules preparation by roll up thin films synthesized at the air-solution interface. J Nano Electron Phys 5:01003Google Scholar
- 40.Farimani MHR, Shahtahmasebi N, Rezaee Roknabadi M, Ghows N, Kazemi A (2013) Study of structural and magnetic properties of superparamagnetic Fe3O4/SiO2 core-shell nanocomposites synthesized with hydrophilic citrate-modified Fe3O4 seeds via a sol-gel approach. Phys E: Low-Dimens Syst Nanostruct 53:207–216CrossRefGoogle Scholar
- 41.Ko Y, Kwon M, Song Y, Lee SW, Cho J (2018) Thin-film electrode design for high volumetric electrochemical performance using metal sputtering-combined ligand exchange layer-by-layer assembly. Adv Funct Mater. https://doi.org/10.1002/adfm.201804926
- 47.John F, Moulder WFS, Peter ES, Kenneth DB (1995) Handbook of X-ray photoelectron spectroscopy. Physical Electronics, Inc, Minnesota, USAGoogle Scholar
- 48.Thermo scientific data system for XPS. https://xpssimplified.com. Accessed 29 Nov 2018.
- 52.Lee J, Lee Y, Youn JK, Na HB, Yu T, Kim H, Lee SM, Koo YM, Kwak JH, Park HG, Chang HN, Hwang M, Park JG, Kim J, Hyeon T (2008) Simple synthesis of functionalized superparamagnetic magnetite/silica core/shell nanoparticles and their application as magnetically separable high-performance biocatalysts. Small 4:143–152CrossRefGoogle Scholar