Phase Change Material Particles and Their Application in Heat Transfer Fluids - Low-cost Nanomaterials: Toward Greener and More Efficient Energy Applications - page 458

Fig. 8 TEM images (bright
field) and size distributions of
a the Field's metal
nanoparticles, and b Indium
nanoparticles, which were
fabricated using the
nanoemulsion method. The
scale bars in both TEM
images represent 200 nm [ 5 ]

governing how the dispersed phase can be ruptured in another immiscible liquid
under a shear stress is given simply by Taylor's formula [ 34 ]:

d 2 r
g c

c ;

ð 4 Þ

where d is the droplet diameter, r is the interfacial tension between the droplet and
continuous phase, g c is the viscosity of the continuous phase, and c is the shear
rate. Based on Taylor's formula, it is possible to estimate the shear rate required to
form PCM nanoparticles. The nanoparticle size may be effectively regulated by
changing the synthesis temperature in order to vary the viscosity of the continuous
phase.
The size distribution of the Field's metal and Indium nanoparticles was exam-
ined using transmission electron microscopy (TEM, JEOL 2100F). TEM bright
field (BF) images of Field's and Indium nanoparticles are shown in Fig. 8 a and b,
respectively. These nanoparticles are spherical because the liquid nanodroplets