Topical preparations like cream, ointment have many limitations like less spreading coefficient
, less penetration through stratum corneum, less patient compliance due to stickiness or need to apply with rubbing etc.
Both the spreading coefficient
and minimal free energy surface models have been used extensively to predict the morphology of ternary and quaternary blends (23-37).
It is generally desirable to have the surface tension of the ink less than that of the surface energy of the substrate, to provide a positive spreading coefficient
and lead to good printability.
c] and we see that a high value of the spreading coefficient
is concomitant with a large intrinsic work of adhesion.
32) used the concept of spreading coefficient
to predict the morphology of ternary blends.
12) explained the morphological observation for ternary polymer blends on the basis of spreading coefficient
by modifying the Harkin's equation, in which two dissimilar phases are dispersed in the third phase (matrix).
The positive spreading coefficient
of the systems with high enough [W.
The morphology of the ternary blends studies here can be predicted by the calculation of the interfacial tension and the spreading coefficient
as shown in (2) where [[gamma].
This concept is based on the spreading coefficient
, [lambda], and is found to be transferable to a blend system consisting of two immiscible polymers A(m1) and B(m2), and a filler (f) that replaces the third polymer C.
mf]), and spreading coefficient
(coefficient of wetting) ([S.
BA] is the spreading coefficient
of phase B onto phase A in a matrix C, and the [[gamma].
2) extended the spreading coefficient
approach to take into account the surface free energy by including the interfacial area of each component.