Biomedical Engineering Reference
In-Depth Information
size (0.91 um) less the middle diameter of the network holes (2-3 um) are fixed on the one
side of the network wall by means of plaque (Figure 3 a).
The binding of the particles takes place by formation of plaques connecting particles with
the
reactive charged groups
of the SC-DSS network, indicated by arrow in Fig 3 a. The
same ESEM images were obtained for SC enriched phase the same system containing smaller
(0.21 um) particles. (Data are not shown).
Figure 2. Photography's of semidilute two phase W-SC(1.6 wt%)-SA(0.29 wt %)-DSS systems without
particles ( a ) and with 3 um particles of sulfate latex( b), as well as microphotography's of the same
system containing 3 um particles (c), and its SC enriched phase (d). DSS/SC weight ratio, q=0.14.
In the later system, formation of plaques connecting particles with the active sites of the
SC-DSS network may be seen especially distinctly. Another type of the structure was
observed for the relatively large (5 um) particles dispersed into the demixed system (Figure 3
c). These particles has diameter larger than sizes of the holes inside the network. Their
incorporation into the network leads to significant damage and destructions of the latter as it
can be seen in Figure 3 c.
The most interesting structure was observed in the case of the system incorporating
particles having 3 um in diameter. These particles are similar in size with that of the network
holes (2-3 um). As can be seen in Figure 3 b the particles of CLM-Sfn latex build ideally into
the network without damage of the later. The same result was obtained for 3 um sulfate latex.
Incorporation of these particles inside the network has one interesting feature. Small
structural elements of these charged particles inside the network develop perfect orientation
from the center in to direction of periphery.
Width of these small structural elements (about
10 nm) is comparable with the distance between sulfate groups in polysaccharide
molecules[20]. Therefore we can reliably assume that incorporation of the particles inside the
network leads to the total polarization of their structure elements including negatively charged
sulfate groups.
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