Table 7.

Difference between oleic acid and ricinoleic acid [98].

oleic acid	ricinoleic acid
1. Is a C18 FA with one double bond between C9 and C10	Is isostructural with oleic acid but has a hydroxyl group at C12 in the C18 tail
2. The double bond in the middle of its carbon chain forms a ‘kink’ believed to be effective at nanoparticle stabilization	Has a similar ‘kink’ for nanoparticle stabilization. Provides a functional group (OH) in addition to the steric repulsion: (i) the OH can be acetylated under mild conditions, (ii) the OH has low affinity for iron oxide surfaces, and (iii) the OH could initiate ring opening polymerization reactions
3. Only colloidal suspensions in non-polar organic media can be prepared (oleic acid-coated nanoparticles cannot be dispersed in organic media with a dielectric constant larger than 5)	Colloidal suspensions in more polar organic media can be prepared
4. Suitable for capping of monodispersed nanoparticles synthesized at very high temperatures	Not suitable for high-temperature synthesis due to possible oxidation of the OH groups to ketones