Preparation of Acid-Resisting Ultramarine Blue by Novel Two-Step Silica Coating Process

Abstract

Acid-resisting ultramarine blue pigment was prepared by a novel two-step silica coating process which is dense liquid coating followed by a sol-gel process. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and BET surface area analysis were used to characterize the composition of elements, surface structure, and morphology on the coating films. Uniform, smooth, and dense silica films on the irregular particles of ultramarine pigment were obtained via novel two-step coatings. Acid resistance of the silica-coated ultramarine blue was evaluated by immersing the pigment in 10 wt % hydrochloric acid. The silica-coated ultramarine blue prepared by the novel two-step process shows the 10th grade of acid resistance, which exhibits much higher acid resistance than that by dense liquid, sol-gel, and conventional two-step coatings. Furthermore, leaching experiments indicated that no sulfur was leached out for the sample prepared by novel two-step coatings, while hydrogen sulfide concentrations from 0.018 to 0.34 mg/L were detected in the leaching solutions for the samples prepared by the conventional two-step coating, dense liquid coating, and sol-gel process.Fujian Pucheng Max Pigment Co

Extra-Framework Content in Sodalite-Group Minerals: Complexity and New Aspects of Its Study Using Infrared and Raman Spectroscopy

“…Characteristic IR bands of S-bearing groups in the sodalite-group minerals are observed in the ranges 1124-1142 cm −1 (asymmetric stretching vibrations of the SO 4 2group, the F 2 (ν 3 ) mode), 614-637 cm −1 (bending vibrations of the SO 4 2group, the F 2 (ν 4 ) mode) and 575-585 cm −1 (antisymmetric stretching vibrations of the S 3 − radical anion, the ν 3 mode-A weak band) [26][27][28][29][30].…”

Spectroscopic and Crystal-Chemical Features of Sodalite-Group Minerals from Gem Lazurite Deposits

“…(bending vibrations of the SO 4 2− group, the F 2 (ν 4 ) mode), 583-587 cm −1 (antisymmetric stretching vibrations of the cis-conformer (C 2v ) of the chain-like S 4•− radical anion, the B 1 mode), 655-659 (antisymmetric stretching vibrations of the cis-conformer (C 2v ) of the linear S 4 molecule, the B 1 mode; shifts towards lower values in the presence of Cl − ), and 575-585 cm −1 (antisymmetric stretching vibrations of the S 3•− radical anion, the ν 3 mode-a weak band)[21,32,[37][38][39][40]. .2 wt.% of H2O which corresponds to 0.72 H2O molecules per formula unit.…”

Facile preparation of acid-resistant magnetite particles for removal of Sb(Ⅲ) from strong acidic solution

“…However, silica gel-coated Fe 3 O 4 particles still cannot be applied in strong acid conditions because Fe 3 O 4 cores are vulnerable to corrosion. Li et al [10] and Liu et al [11] prevented Fe 3 O 4 cores from acid corrosion by employing dense liquid coating which required the reaction temperature to be maintained at 90°C. It is not convenient for coating Fe 3 O 4 particles though, as nano-sized Fe 3 O 4 particles are prone to conversion into Fe 2 O 3 at high temperature when exposed to the atmosphere [12–14].…”