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Chemical and Structural Properties of Nickel Hydroxide Xerogels Obtained by the Sol‐Gel Procedure in the Presence of Acetic Acid
Author(s) -
Sharma Pramod K.,
Fischer Hannes,
Craievich Aldo F.
Publication year - 1999
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1999.tb01868.x
Subject(s) - acetic acid , differential scanning calorimetry , hydroxide , fourier transform infrared spectroscopy , hydrolysis , chemical engineering , small angle x ray scattering , materials science , porosity , nickel oxide , sol gel , acid strength , oxide , chemistry , inorganic chemistry , organic chemistry , catalysis , scattering , nanotechnology , physics , zeolite , optics , engineering , thermodynamics
The sol‐gel route to glasses and ceramics has attracted an increasing amount of scientific and technological interest recently. In this process, sols with different concentrations are used as precursors for xerogels and to produce materials that consist of fine oxide particles. In the present work, nickel hydroxide gels have been obtained via the hydrolysis of a molecular precursor in the presence of acetic acid. The chemical aspects of the material transformation have been studied by using Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) for different acetic acid contents and several heat‐treatment temperatures. The carboxylic acid acts as a ligand at a molecular level in the precursor, therefore modifying the entire hydrolysis and condensation process. Small‐angle X‐ray scattering (SAXS) studies and density measurements have been performed for the structural characterization of the xerogels. A denser, final oxide material is obtained when a higher acetic acid concentration is used. The porosity of the dry gels coarsens when they are heat‐treated up to a temperature of ∼400°C and its density decreases. The material that has been heat‐treated up to a temperature of 800°C densifies and exhibits a finer porosity. The chemical properties at a molecular level satisfactorily explain and are well correlated with the structural characteristics of the studied material.