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Dynamics of interacting interphases in polymer bilayer thin films

Published online by Cambridge University Press:  17 October 2017

David D. Hsu ,
Wenjie Xia ,
Jake Song  and
Sinan Keten
David D. Hsu
Affiliation:
Department of Physics & Engineering, Wheaton College, 501 College Avenue, Wheaton, IL 60187, USA
Wenjie Xia
Affiliation:
Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, M/S 8550, Gaithersburg, MD 20899, USA Center for Hierarchical Materials Design, Northwestern University, Evanston, IL 60208, USA Department of Civil & Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
Jake Song
Affiliation:
Department of Materials Science & Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA Department of Materials Science & Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
Sinan Keten*
Affiliation:
Department of Civil & Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3109, USA
*
Address all correspondence to Sinan Keten at s-keten@northwestern.edu
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Abstract

We investigate how the local glass-transition temperature (T g) depends on film thickness in monolayer and bilayer thin films with a polystyrene (PS) upper-layer and a poly(methyl methacrylate) (PMMA) lower-layer using coarse-grained simulations. Interactions between overlapping interphases demonstrate a superposition principle for describing their glass-transition behaviors. For supported bilayer films, the free surface effect on a PS film upper-layer is effectively eliminated due to an enhanced local T g near the PS–PMMA interface, which cancels out depressed T g near the free surface. However, at very low PMMA lower-layer thicknesses, the PMMA-substrate effect can penetrate through the polymer–polymer interface, leading to enhanced T g in the PS upper-layer.

Type
Research Letters
Information
MRS Communications , Volume 7 , Issue 4 , December 2017 , pp. 832 - 839
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Copyright
Copyright © Materials Research Society 2017 

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References

1. Ediger, M. and Forrest, J.: Dynamics near free surfaces and the glass transition in thin polymer films: a view to the future. Macromol. 47, 471 (2013).Google Scholar
2. Ellison, C.J. and Torkelson, J.M.: The distribution of glass-transition temperatures in nanoscopically confined glass formers. Nat. Mater. 2, 695 (2003).CrossRefGoogle ScholarPubMed
3. Forrest, J., Dalnoki-Veress, K., Stevens, J., and Dutcher, J.: Effect of free surfaces on the glass transition temperature of thin polymer films. Phys. Rev. Lett. 77, 2002 (1996).Google Scholar
4. Hanakata, P.Z., Douglas, J.F., and Starr, F.W.: Interfacial mobility scale determines the scale of collective motion and relaxation rate in polymer films. Nat. Commun. 5, 4163 (2014).Google Scholar
5. Hsu, D.D., Xia, W., Song, J., and Keten, S.: Glass-transition and side-chain dynamics in thin films: explaining dissimilar free surface effects for polystyrene vs poly (methyl methacrylate). ACS Macro Lett. 5, 481 (2016).Google Scholar
6. Paeng, K. and Ediger, M.: Molecular motion in free-standing thin films of poly (methyl methacrylate), poly (4-tert-butylstyrene), poly (α-methylstyrene), and poly (2-vinylpyridine). Macromol. 44, 7034 (2011).CrossRefGoogle Scholar
7. Paeng, K., Richert, R., and Ediger, M.: Molecular mobility in supported thin films of polystyrene, poly (methyl methacrylate), and poly (2-vinyl pyridine) probed by dye reorientation. Soft Mat. 8, 819 (2012).Google Scholar
8. Xia, W., Mishra, S., and Keten, S.: Substrate vs. free surface: competing effects on the glass transition of polymer thin films. Polymer 54, 5942 (2013).CrossRefGoogle Scholar
9. Ye, C., Wiener, C.G., Tyagi, M., Uhrig, D., Orski, S.V., Soles, C.L., Vogt, B.D., and Simmons, D.S.: Understanding the decreased segmental dynamics of supported thin polymer films reported by incoherent neutron scattering. Macromol. 48, 801 (2015).Google Scholar
10. Roth, C.B., McNerny, K.L., Jager, W.F., and Torkelson, J.M.: Eliminating the enhanced mobility at the free surface of polystyrene: fluorescence studies of the glass transition temperature in thin bilayer films of immiscible polymers. Macromol. 40, 2568 (2007).CrossRefGoogle Scholar
11. Yoon, H., and McKenna, G.B.: Substrate effects on glass transition and free surface viscoelasticity of ultrathin polystyrene films. Macromol. 47, 8808 (2014).CrossRefGoogle Scholar
12. Tito, N.B., Lipson, J.E., and Milner, S.T.: Lattice model of mobility at interfaces: free surfaces, substrates, and bilayers. Soft Mat. 9, 9403 (2013).CrossRefGoogle Scholar
13. Roth, C.B., and Torkelson, J.M.: Selectively probing the glass transition temperature in multilayer polymer films: equivalence of block copolymers and multilayer films of different homopolymers. Macromol. 40, 3328 (2007).Google Scholar
14. Baglay, R.R., and Roth, C.B.: Communication: experimentally determined profile of local glass transition temperature across a glassy-rubbery polymer interface with a T g difference of 80 K. J. Chem. Phys. 143, 111101 (2015).CrossRefGoogle Scholar
15. Baglay, R.R., and Roth, C.B.: Local glass transition temperature T g(z) of polystyrene next to different polymers: hard vs. soft confinement. J. Chem. Phys. 146, 203307 (2017).CrossRefGoogle Scholar
16. Lang, R.J., Merling, W.L., and Simmons, D.S.: Combined dependence of nanoconfined T g on interfacial energy and softness of confinement. ACS Macro Lett. 3, 758 (2014).CrossRefGoogle Scholar
17. White, R.P., Price, C.C., and Lipson, J.E.: Effect of interfaces on the glass transition of supported and freestanding polymer thin films. Macromol. 48, 4132 (2015).Google Scholar
18. Hsu, D.D., Xia, W., Arturo, S.G., and Keten, S.: Systematic method for thermomechanically consistent coarse-graining: a universal model for methacrylate-based polymers. J. Chem. Theory Comput. 10, 2514 (2014).Google Scholar
19. Hsu, D.D., Xia, W., Arturo, S.G., and Keten, S.: Thermomechanically consistent and temperature transferable coarse-graining of atactic polystyrene. Macromol. 48, 3057 (2015).CrossRefGoogle Scholar
20. Payne, M.C., Teter, M.P., Allan, D.C., Arias, T., and Joannopoulos, J.: Iterative minimization techniques for ab initio total-energy calculations: molecular dynamics and conjugate gradients. Rev. Mod. Phys. 64, 1045 (1992).Google Scholar
21. Hoover, W.G.: Canonical dynamics: equilibrium phase-space distributions. Phys. Rev. A 31, 1695 (1985).CrossRefGoogle ScholarPubMed
22. Plimpton, S. and Hendrickson, B.: A new parallel method for molecular dynamics simulation of macromolecular systems. J. Comput. Chem. 17, 326 (1996).Google Scholar
23. Marvin, M., Lang, R., and Simmons, D.: Nanoconfinement effects on the fragility of glass formation of a model freestanding polymer film. Soft Mat. 10, 3166 (2014).Google Scholar
24. Zhou, Y. and Milner, S.T.: Short-time dynamics reveals T g suppression in simulated polystyrene thin films. Macromol. 50, 5599 (2017).CrossRefGoogle Scholar
25. DeFelice, J., Milner, S.T., and Lipson, J.E.G.: Simulating local T g reporting layers in glassy thin films. Macromol. 49, 1822 (2016).Google Scholar
26. Rissanou, A.N. and Harmandaris, V.: Structural and dynamical properties of polystyrene thin films supported by multiple graphene layers. Macromol. 48, 2761 (2015).Google Scholar
27. Xia, W., Song, J., Hsu, D.D., and Keten, S.: Side-group size effects on interfaces and glass formation in supported polymer thin films. J. Chem. Phys. 146, 203311 (2017).Google Scholar
28. Forrest, J.A. and Mattsson, J.: Reductions of the glass transition temperature in thin polymer films: probing the length scale of cooperative dynamics. Phys. Rev. E 61, R53 (2000).CrossRefGoogle ScholarPubMed
29. Ellingson, P., Strand, D., Cohen, A., Sammler, R., and Carriere, C.: Molecular weight dependence of polystyrene/poly (methyl methacrylate) interfacial tension probed by imbedded-fiber retraction. Macromol. 27, 1643 (1994).Google Scholar
30. Anastasiadis, S.H., Russell, T.P., Satija, S.K., and Majkrzak, C.F.: The morphology of symmetric diblock copolymers as revealed by neutron reflectivity. J. Chem. Phys. 92, 5677 (1990).Google Scholar
31. Fernandez, M., Higgins, J., Penfold, J., Ward, R., Shackleton, C., and Walsh, D.: Neutron reflection investigation of the interface between an immiscible polymer pair. Polymer 29, 1923 (1988).Google Scholar
32. Slimani, M.Z., Moreno, A.J., and Colmenero, J.: Heterogeneity of the segmental dynamics in lamellar phases of diblock copolymers. Macromol. 44, 6952 (2011).Google Scholar
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