TY - JOUR
T1 - Preparation of highly concentrated nanostructured dispersions of controlled size
AU - Salentinig, Stefan
AU - Yaghmur, Anan
AU - Guillot, Samuel
AU - Glatter, Otto
PY - 2008/10/1
Y1 - 2008/10/1
N2 - This article presents the use of a shearing procedure for the preparation of stable nanostructured dispersions of lipid mesophases. This new application of the shearing technique is compared with the well-established ultrasonication method for the emulsification of these mesophases in water in terms of particle size, particle size distribution and available concentration range. With a laboratory-built shear device based on a Couette cell, it was possible to produce high quantities of internally self-assembled emulsion particles of controlled size at concentrated hydrophobic phase contents (phi(o)) of up to 70 wt%. The concentration limit of 70 wt% could be reached however, the maximum attainable concentration depended on the internal structure type of the particles. The limit was thus easily attained for emulsified microemulsions (EME) as well as for the emulsified inverse hexagonal phase (H(2)), whereas it was found to be lower for emulsified discontinuous (Fd3m) and bicontinuous (Pn3m) cubic phases. Moreover, by shearing, it was possible to keep the size of the particles relatively constant when increasing phi(o), whereas the particle size significantly increased with phi(o) when ultrasonication was employed. By means of ultrasonication, the hydrodynamic radius of the particles could be tuned linearly between 85 to 180 nm as a function of phi(o) up to a maximum of 20 to 30 wt%. Below the maximum concentration limit, particles displayed a well-controlled size.
AB - This article presents the use of a shearing procedure for the preparation of stable nanostructured dispersions of lipid mesophases. This new application of the shearing technique is compared with the well-established ultrasonication method for the emulsification of these mesophases in water in terms of particle size, particle size distribution and available concentration range. With a laboratory-built shear device based on a Couette cell, it was possible to produce high quantities of internally self-assembled emulsion particles of controlled size at concentrated hydrophobic phase contents (phi(o)) of up to 70 wt%. The concentration limit of 70 wt% could be reached however, the maximum attainable concentration depended on the internal structure type of the particles. The limit was thus easily attained for emulsified microemulsions (EME) as well as for the emulsified inverse hexagonal phase (H(2)), whereas it was found to be lower for emulsified discontinuous (Fd3m) and bicontinuous (Pn3m) cubic phases. Moreover, by shearing, it was possible to keep the size of the particles relatively constant when increasing phi(o), whereas the particle size significantly increased with phi(o) when ultrasonication was employed. By means of ultrasonication, the hydrodynamic radius of the particles could be tuned linearly between 85 to 180 nm as a function of phi(o) up to a maximum of 20 to 30 wt%. Below the maximum concentration limit, particles displayed a well-controlled size.
U2 - 10.1016/j.jcis.2008.07.021
DO - 10.1016/j.jcis.2008.07.021
M3 - Journal article
C2 - 18687442
SN - 0021-9797
VL - 326
SP - 211
EP - 220
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
IS - 1
ER -