Preparation of Novel Blue Turquoise-imitated Phosphate Pigments using Aluminum Hydroxide

EasyChair Preprint 1937

Abstract

Recently, the use of harmful metals is restricted around world. However, because suitable substitutes have not been obtained, some materials containing harmful metals have been used in many fields. Therefore, novel inorganic pigments are required with suitable properties and without difficult production methods. As novel blue pigment, various copper aluminum phosphate hydroxides imitated with Turquoise, CuAl₆(PO₄)₄(OH)₈•4H₂O, were prepared by the mixing of copper nitrate solution, aluminum hydroxide solution, phosphoric acid, and sodium hydroxide solution.The obtained powders were estimated with X-ray diffraction (XRD), Infrared (IR) spectra, ultraviolet–visible (UV–Vis.)reflectance spectra, and L*a*b* color space. Furthermore, the other related compositions with Turquoise were also investigated. The color of phosphate pigment changed from light blue to green by heating at 500ºC. Samples prepared at pH 9 were easy to be green powder. Sample prepared at Cu/Al=2/3 and then heated at 300ºC became dark green powder. The phosphate pigments from light blue to dark green were obtained in this preparation system.

Keyphrases: Phosphates, Turquoise, blue pigment

@booklet{EasyChair:1937,
  author    = {Hiroaki Onoda and Ryota Sasaki},
  title     = {Preparation of Novel Blue Turquoise-imitated Phosphate Pigments using Aluminum Hydroxide},
  howpublished = {EasyChair Preprint 1937},
  year      = {EasyChair, 2019}}