One of the most remarkable features of polymeric materials is the phenomeno
n of surface segregation in polymer blends whose components surface energie
s are similar in magnitude. Herein, we contribute to this field by consider
ing (i) surface phase behavior in stereochemically asymmetric polymer blend
s and (ii) determination of the sign and magnitude of surface energy (gamma
) difference for a pair of polymers differing only slightly in their gamma
values. Specifically, we present experimental results obtained on the blend
s of isotactic and syndiotactic poly(methyl methacrylate) (i-PMMA/s-PMMA bl
ends), revealing that the syndiotactic macromolecules segregate to both the
polymer-air and polymer-solid (glass) interface, expelling their isotactic
counterparts. Also, the contact angle results and their analysis by the us
e of Lifshitz-van der Waals/acid-base approach are presented for PMMA and p
olystyrene (PS), which reveal that the surface free energy of PS is 1.5 +/-
1.1 mJ/m(2) higher than that of PMMA.