Chemistry Reference
In-Depth Information
Figure 6.18
Structural hierarchy of W/O-nanostructured emulsions. Represented by
various length scales.
the amount of dispersed phase (
); (3) temperature-induced nanostructural
interconversions (Guillot et al., 2006; Muller et al., 2010a); (4) particle size
(given by
R
H
) (Guillot et al., 2010; Salentinig et al., 2008); (5) the amount and
type of stabilizer (Guillot et al., 2009a, 2010; Muller et al., 2010a; Salonen
et al., 2010b); (6) the type of lipid (Muller et al., 2010b; Nguyen et al., 2010);
(7) pH (Muller et al., 2010a; Salentinig et al., 2010); (8) the amount and type
of additive [e.g., R (
ϕ
) limonene (Guillot et al., 2006) or oleic acid (Salentinig
et al., 2010)]; (9) pressure-induced behavioral changes (Yaghmur et al., 2010);
(10) the method of preparation (Salentinig et al., 2008), that is, ultrasonication
or shearing; and (11) intermixing of two differently structured ISAsomes
(Moitzi et al., 2007; Salonen et al., 2010a). Some of these aspects are described
in the second and third sections. These properties (among others) facilitate the
modulation of ISAsome systems for their potential applications in a wide
range of fi elds.
Interparticle transfer among mixed ISAsomes renders smart systems pos-
sible where the material transfer could be performed in a controlled manner
and the rate of transfer systematically modulated, as presented in Section 6.4.
Initial addition of hydrogelling agents reduces the diffusion dynamics of ISA-
somes, while further addition enables ISAsome entrapment followed by
immobilization upon drying, which is discussed in Section 6.5. ISAsome-
polymer matrix systems are good candidates for housing various functional
molecules for transport or storage under dry conditions in the form of loaded
hydrogel fi lms.
In the fi nal section of the chapter, we presented inverse (W/O) emulsions
prepared from LC phases (in contrast to ISAsome dispersions, which are O/W
emulsions). Both types presented here are good examples of hierarchically
ordered structures that originate from lyotropic LC phases. Hydrogelled
aqueous regions of these emulsions demonstrate further possibilities in terms
of tuning their properties and hence increasing their performance in applied
science and technology.
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