[T1] Powder Production

[15P-T1-07] Synthesis of Tubular Iron Oxide Pigments with Bright Red Color Deposited on Phosphorylated Cellulose Nanofibers

K. Suga¹, Y. Oshima¹, T. Okihara¹, *T. Fujii¹ (1.Okayama University, Japan)

Keywords:Al-doped hematite, Vivid Red color, Tubular structure

Hematite α-Fe₂O₃, called “bengara”, is widely used as a red pigment because it is abundant, economical and extremely low in toxicity. However, its redness is not so high at around a*=+30. In this study, we attempted to improve the redness by controlling the microstructure of iron oxide particles and adding the Al element. Tubular Al-doped hematite particles were synthesized by co-precipitation method on phosphorylated cellulose nanofibers (P-CNF). By heat-treating the precipitates, the P-CNF were burned, and at the same time, the hydroxide precipitates crystalized into hematite. The sample with 29% Al addition showed an excellent reddish-yellow color with a*=44 and b*=56.