XTTc Tc

which accounts for the temperature distance from both the © temperature and Tc In terms ofx', Eq. 17 may be represented as [12]:

where the amplitude £(©) is given by Eq.(8). In the case of the dynamic correlation length no theoretical interpretation for d *(©) has yet been developed. However, one may suggest phenomenologically that d* should follow the same scaling as Eq.19, writing

where "t^ *(®) is the experimental value of the dynamic correlation length at T=© (Fig.11). As is seen in Fig.12, the reduced correlation lengths d*/£, d*(0) for various polymers in different solvents fall on the same master curve when plotted vs. the reduced temperature x '. This is the first demonstration of the universality for the dynamic behavior of solutions of polymers in organic liquids and supercritical fluids.

Figure 11. £d*(&) for several polymer solutions. Figure 12 Master plot for \ J^d*(®) vs. de Gennes'

The symbols are spelled out in the insets.

scalingvariable (Eq.18).

Figure 11. £d*(&) for several polymer solutions. Figure 12 Master plot for \ J^d*(®) vs. de Gennes'

The symbols are spelled out in the insets.

scalingvariable (Eq.18).

0 0

Post a comment