Wang Qiang
Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, Colorado 80523-1370, USA.
J Chem Phys. 2008 Aug 7;129(5):054904. doi: 10.1063/1.2962978.
Using the random-phase approximation and self-consistent field calculations, we have investigated the effects of finite interaction range and compressibility on the order-disorder transition (ODT) and the lamellar structure of symmetric diblock copolymers. While the compressibility does not affect the ODT, both the values of chiN and bulk lamellar period at the ODT increase with increasing interaction range. On the other hand, both the free-energy density and bulk period of the lamellae increase with either increasing interaction range or decreasing compressibility. Even with a finite compressibility, the mean-field ODT is still a second-order phase transition. The scaling exponent of bulk lamellar period with chiN, however, decreases with increasing compressibility. Our mean-field analysis provides a well understood reference for the study of fluctuation effects in diblock copolymers with finite interaction range and compressibility.
利用随机相位近似和自洽场计算，我们研究了有限相互作用范围和压缩性对对称二嵌段共聚物的有序-无序转变（ODT）和层状结构的影响。虽然压缩性不影响ODT，但ODT处的χN值和本体层状周期都随着相互作用范围的增加而增大。另一方面，层状结构的自由能密度和本体周期都随着相互作用范围的增加或压缩性的降低而增大。即使具有有限的压缩性，平均场ODT仍然是二级相变。然而，本体层状周期随χN的标度指数随着压缩性的增加而减小。我们的平均场分析为研究具有有限相互作用范围和压缩性的二嵌段共聚物中的涨落效应提供了一个易于理解的参考。
