Formation of solid organic nanoparticles from a volatile catanionic microemulsion

Katrin Margulis-Goshen, Bruno F.B. Silva, Eduardo F. Marques*, Shlomo Magdassi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


A novel volatile microemulsion formed by the catanionic surfactant hexadecyltrimethylammonium octylsulfonate (TA 16So 8), heptane and water has been explored as a template for producing nanoparticles of hydrophobic organic materials. Butylated hydroxytoluene (BHT) was employed as the model hydrophobic substance. First, the oil-in-water microemulsion was formed, containing TA 16So 8 as the single emulsifier and BHT dispersed in the volatile microphase. Microstructure characterization by self-diffusion NMR revealed that BHT was indeed incorporated into the oil droplets and that the mean diameter of the main droplet population was 30 nm, larger than in the BHT-free microemulsion. Next, a rapid solvent and water removal by freeze drying allowed converting the microemulsion droplets into nanoparticles in the form of a dry, fine powder. This powder was freely dispersible in water to yield a stable suspension of amorphous BHT particles with a mean size of 19 nm and ζ-potential of +37 mV. The solid nanoparticles in the aqueous dispersion were thus smaller than the initial microemulsion droplets. For comparison, a conventional o/w microemulsion composed of CTAB and sec-butanol was also tested as a template for BHT particle formation by the same process, and it was found that it yielded crystalline particles of micrometre size. On the basis of our results, we anticipate the catanionic microemulsion method to be an efficient one for producing size-controlled, water-dispersible nanoparticles of other hydrophobic organic materials.

Original languageAmerican English
Pages (from-to)9359-9365
Number of pages7
JournalSoft Matter
Issue number19
StatePublished - 7 Oct 2011


Dive into the research topics of 'Formation of solid organic nanoparticles from a volatile catanionic microemulsion'. Together they form a unique fingerprint.

Cite this