Journal Article

FZJ-2022-06226

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Effects of Surface Chemical Modification by Ethoxysilanes on the Evolution of 3D Structure and Composition of Porous Monoliths Consisting of Alumina Hydroxide Nanofibrils in the Temperature Range 25–1700 °C

Khodan, A. (Corresponding author) ; Kanaev, A. ; Esaulkov, M. ; Kiselev, M. ; Nadtochenko, V.

2022
MDPI Basel

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Please use a persistent id in citations: http://hdl.handle.net/2128/33544  doi:10.3390/nano12203591

Abstract: Bulk nanomaterials with an open porosity offer exciting prospects for creating new functional materials for various applications in photonics, IR-THz optics, metamaterials, heterogeneous photocatalysis, monitoring and cleaning toxic impurities in the environment. However, their availability is limited by the complexity of controlling the process of synthesis of bulk 3D nanostructures with desired physicochemical and functional properties. In this paper, we performed a detailed analysis of influence of a silica monolayer chemically deposited on the surface of a monolithic ultraporous nanostructure, consisting of a 3D nanofibril network of aluminum oxyhydroxide, on the evolution of structure and morphology, chemical composition and phase transformations after heat treatment in the temperature range of 20−1700 °C. The experimental results are interpreted in the framework of a physical model taking into account surface and volume mass transport and sintering kinetics of nanofibrils, which made it possible to estimate activation energies of the surface diffusion and sintering processes. It is shown that the presence of a surface silica monolayer on the surface affects the kinetics of aluminum oxyhydroxide dehydration and inhibits diffusion mass transfer and structural phase transformations. As a result, the overall evolution of the 3D nanostructure significantly differs from that of nanomaterials without surface chemical modification.

Keyword(s): Chemical Reactions and Advanced Materials (1st) ; Chemistry (2nd)

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Contributing Institute(s):

1. JCNS-4 (JCNS-4)
2. JCNS-FRM-II (JCNS-FRM-II)
3. Heinz Maier-Leibnitz Zentrum (MLZ)

Research Program(s):

1. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)

Experiment(s):

1. KWS-3: Very small angle scattering diffractometer with focusing mirror (NL3auS)
2. KWS-2: Small angle scattering diffractometer (NL3ao)

Appears in the scientific report 2022

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Database coverage:
; ; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DOAJ Seal ; Ebsco Academic Search ; IF >= 5 ; JCR ; SCOPUS ; Web of Science Core Collection

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