Synthesis of nano CoAl2O4 pigment for ink-jet printing to decorate porcelain

Abstract

The CoAl 2 O 4 pigment commonly used for coloring ceramic products was synthesized by microwave hydrothermal processing (M-H), and ink-jet printing with this aqueous pigment ink was performed to decorate porcelain. First, a precursor was prepared by adjusting the solution to pH 12. Then, M-H reaction was applied to this precursor at 240°C for 2 h, yielding particles of CoAl 2 O 4 . In addition, the precursor concentration of the suspension was shown to greatly affect the color tone of the resulting particles. As the precursor concentration increased, the synthesized particles that were bluish-green at lower concentrations took on a darker blue color. The synthesized CoAl 2 O 4 particles were regular octahedrons measuring approximately 70 nm. The particles synthesized by M-H reaction were used to prepare an aqueous suspension, which was then used for printing on tiles by an ink-jet printing system. The synthesized particles were well dispersed in the prepared aqueous suspension, as little sediment was formed in this suspension left for 1 week. The printing system experienced no clogging and the printed image was of good quality.

Microwave-Assisted Preparation of Inorganic Nanostructures in Liquid Phase

“…254 In contrast, the analogous conventional hydrothermal approach failed to generate phasepure products with homogeneously distributed morphologies, indicating the advantages of the microwave-hydrothermal synthesis over the conventional hydrothermal technique in terms of shorter reaction time and homogeneous products. Obata et al 263 prepared CoAl 2 O 4 octahedral nanocrystals with sizes of ∼70 nm by a microwave-hydrothermal process at 240 °C for 2 h, and inkjet printing with as-prepared aqueous pigment ink was performed to decorate porcelain. The nanoparticles were well dispersed in the aqueous suspension with a high stability.…”

Synthesis of cobalt aluminate spinel by sol-gel process: Investigation of starting reagents and precursors obtained after pyrolysis

“…The inverse or mixed structure can exhibit different colours, and it changes from dark green and turquoise to blue depending on the replacement amount of Co 2+ , Al 3+ and Co 3+ in the tetrahedral and octahedral sites [1][2][3]. The blue spinel of cobalt has attracted significant attention as a colouring agent in glaze and bulk tile compositions due to its superior properties, such as chemical and thermal stability as well as colour stability [4][5][6][7][8]. Furthermore, CoAl2O4 nanoparticles exhibit good photocatalytic activity for the degradation of textile dyes [9,10].…”

Effect of Ce Doping of a Co/Al2O3 Catalyst on Hydrogen Production via Propane Steam Reforming

“…The crystallinities and phase purities of the as-prepared 30Co x Ce y /70γ-Al 2 O 3 catalysts were determined by XRD analysis, as shown in Figure 1A [25]. However, in the case of the 30Co x Ce y /70γ-Al 2 O 3 catalyst, the amount of Ce in the sample was insufficient to yield diffraction peaks corresponding to CeO 2 , even though Ce had been added.…”