Table 1.

A summary of recent advances in microemulsion-based synthesis of Re nanoparticles (NPs). DDAB—dimethyl dioctyl ammonium bromide; DDAI—dimethyl dioctyl ammonium iodide; AOT—dioctylsulfosuccinate sodium.

Metal NP Composition	Microemulsion Type	Surfactant	Particle Size	Highlight(s) of Synthetic Method	Ref
Re NPs	Reverse microemulsion (a/o)	DDAB or DDAI	2.2 nm	Useful for synthesizing oxidation-sensitive NPs. Needs very low temperature	[72]
Re NPs	Reverse microemulsion	AOT	1–18 nm (depends on the synthesis conditions)	Control of the particle size with varying γ-irradiation doses.	[73,74]
Re/Re oxide NPs	Reverse microemulsion	AOT	0.7–1.4 nm	Obtained very small sized particles with a narrow size distribution but metal NPs oxidation state was not studied. Reverse trend observed for W factor effect.	[75]
Pt-Re bimetallic NPs	Reverse microemulsion	Triton X-100	1.8–2.05 nm	Small bimetallic NPs obtained, Used a very low W value (=0.3)	[77]
Re6 cluster@SiO2 NPs	Reverse microemulsion	Brij 30	30 nm	NPs kept their luminescence properties in aqueous solutions (potential for biological applications) (need to form multinuclear Re cluster at high temperatures first)	[81]
Re sulfide NPs	Reverse microemulsion	NP5/NP10 or NP10/Triton X-45	-	Introduced a novel high-throughput microemulsion synthesis device	[82]