The effects of local stiffness disparity on the surface segregation from binary polymer blends

Journal Article · Fri Dec 15 04:00:00 EST 1995 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.469871· OSTI ID:132850

Kumar, S K ^[1]; Yethiraj, A ^[2]; Schweizer, K S ^[3]; Leermakers, F A.M. ^[4]

---

1. Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)
2. Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706 (United States)
3. Department of Materials Science and Engineering, Chemistry, and Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)
4. Department of Physical and Colloid Chemistry, Wageningen Agricultural University, Dreijenplein 6, 6703 HB Wageningen (Netherlands)

The segregation observed in the simulations, however, is both much smaller in magnitude and of the opposite sign to that seen in the field theoretic calculations. Coupled with results of independent work on the bulk behavior of these athermal mixtures, which {ital do} {ital not} capture the experimentally observed phase separation, we suggest that hydrocarbon blends, at least over the chain lengths examined, cannot be modeled in terms of purely entropic effects, but rather through the incorporation of energetics. Analytic wall-PRISM results for a thread like model of the polymer molecules are also presented, and show that the various approximations made in deriving analytical theories critically affect the magnitude and the sign of the predicted athermal segregation. The connections of our analytical work to recent field theoretic analyses is also discussed. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• OSTI ID: 132850
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 23 Vol. 103; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BINARY MIXTURES
CHAINS
COMPUTERIZED SIMULATION
CONFORMATIONAL CHANGES
ENTROPY
FLEXIBILITY
POLYMERS
SEGREGATION
SURFACE PROPERTIES