Table 3: Physical and chemical properties of α-Fe2O3 nanoparticles prepared using microemulsion method.

Physical and chemical propertiesFe2O3 pigment prepared using
0.2 M Fe2(SO4)30.4 M Fe2(SO4)30.6 M Fe2(SO4)3

Average particles size91419
Sp. Gr.5.165.14.99
SolubilityInsolubleInsolubleInsoluble
Oil abs.272624
Hiding power4.54.34.1
Resistance against heating at (700°C)ExcellentExcellentExcellent

Fastness properties against
Sulfuric acid 5%ExcellentExcellentExcellent
Hydrochloric acid 5%V. GoodV. GoodV. Good
Sod. Hyroxide, 2%ExcellentExcellentExcellent
Sod, Carbonate, 5%ExcellentExcellentExcellent
Cal. Hydroxide (Saturated Solution)V. GoodV. GoodV. Good
Organic Solvents*InsolubleInsolubleInsoluble
Linseed OilInsolubleInsolubleInsoluble
Oleic AcidInsolubleInsolubleInsoluble

*Water, ethanol, acetone, chloroform, carbon tetrachloride, toluene, xylene, and tetrahydrofuran.