Effect of hydrostatic pressure on closed-loop phase behavior of block copolymers
SCIE
SCOPUS
- Title
- Effect of hydrostatic pressure on closed-loop phase behavior of block copolymers
- Authors
- Ryu, DY; Lee, DJ; Kim, JK; Lavery, KA; Russell, TP; Han, YS; Seong, BS; Lee, CH; Thiyagarajan, P
- Date Issued
- 2003-06-13
- Publisher
- AMERICAN PHYSICAL SOC
- Abstract
- The effect of hydrostatic pressure (P) on closed-loop phase behavior of deuterated polystyrene-block-poly(n-pentyl methacrylate) copolymers [dPS-PnPMA] was investigated by using small-angle neutron scattering and birefringence. For P<20.7 bar, dPS-PnPMA exhibited a lower disorder-to-order transition temperature (T-LDOT) at 175 degrees C, and then an upper order-to-disorder transition temperature (T-UODT) at 255 degrees C. With increasing pressure both T-LDOT and T-UODT were markedly changed, where dT(LDOT)/dP was 725 degrees C/kbar and dT(UODT)/dP was -725 degrees C/kbar. These are consistent with predictions by the Clausius-Clapeyron equation using measured values of the volume and enthalpy changes of both transitions. The large pressure coefficients imply that the closed-loop phase behavior observed for PS-PnPMA is an entropic-driven phase transition.
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/12423
- DOI
- 10.1103/PhysRevLett.90.235501
- ISSN
- 0031-9007
- Article Type
- Article
- Citation
- PHYSICAL REVIEW LETTERS, vol. 90, no. 23, 2003-06-13
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