Research Interests

We examine problems associated with the structure, phase behavior and dynamics of bulk and thin film polymer and polymer-based nanocomposite systems.

Thin Films: A diverse range of applications, from organic electronic devices and sensors to coatings and patterning, rely on the properties and performance of polymers under various conditions of confinement, particularly thin film geometries. The size-scales of confinement may be comparable to nanometers or tens of nanometers, depending on the application. However, the influence of interactions between polymer chains and the interfaces (free surface or substrate) may be manifested at length scales far beyond the size of the chain and often have a profound influence on the properties of the polymer. To this end, our program on polymer thin films comprise problems in three general categories: (1) wetting, interfacial instabilities and pattern formation, and self-assembly; (2) the influence of confinement and interfacial interactions on the glass transition, diffusion and viscosity, as well as on the phase and ordering transition temperatures of polymer mixtures and block copolymers, respectively; (3) the organization of nanoparticles (C60 fullerenes, nanotubes, semiconductor and metallic nanoparticles) in thin films. Our goal is to develop new rules to design and to “tailor” properties of thin films for various applications.Bulk: The second aspect of our research encompasses bulk rheological and dynamic mechanical behavior of polymer-based nanocomposite (organoclays, metal oxides, nanotubes ect.) systems. We are interested in developing an understanding of the connection between the nano-scale organization, meso-scale structure and bulk properties in these systems.

Our program is interdisciplinary, cross-cutting different fields, from physical chemistry of surfaces, to the processing of polymers, to the physics of materials. We employ a range of experimental tools, including scanning force microscopy, transmission electron microscopy, neutron scattering, ellipsometry, DMA and rheology, and our group collaborates with a number of theoretical groups here and elsewhere.

Selected Publications

Yuan Li, Xiaochu Wang, Isaac C. Sanchez, Keith P. Johnston and Peter F. Green, "Ordering in Asymmetric Block Copolymer Films by a Compressible Fluid," Journal of Physical Chemistry, Vol. 11, Issue 1, pp. 16-25 (2007).

Besancon, B.M., Soles, C.S., Green P.F, "The Glass Transition of Miscible Binary Polymer-Polymer Thin Films," Phys. Rev. Lett., Vol. 97, pp. 57809 (2006).

Kropka, J. M.; Green, P. F., "Control of Interfacial Instabilities in Thin Polymer Films with the Addition of a Miscible Component," Macromolecules, Vol. 39, pp. 8758 (2006).

Li, Y.; Meli, L.; Lim, K. T.; Johnston, K. P.; Green, P. F., "Structural Inversion of Micellar Block Copolymer Thin Films," Macromolecules, Vol. 39, Issue 20, pp. 7044-7054 (2006).

P. F. Green, "Our Shared Responsibility for the Future and Health of Materials Research (Part III), What is MRS doing?," Materials Research Society Bulletin, Vol. April, pp. Letter form the President (2006).

P. F. Green, "The Next Generation of Materials Researchers and the Discipline of Materials Science and Engineering: MRS Membership Identity and Role," Materials Research Society Bulletin, Vol. November, pp. Letter form the President (2006).

P.F. Green, "Going Forward," Materials Research Society Bulletin, Vol. December, pp. Letter form the President (2006).

P.F. Green, "Our Shared Responsibility for the Future and Health of Materials Research Globally (Part I): With the help of our friends," Materials Research Society Bulletin, Vol. January, pp. Letter form the President (2006).

P.F. Green, "Our Shared Responsibility for the Future and Health of Materials Research Globally (Part II): A return on investment and the need for international cooperation," Materials Research Society Bulletin, Vol. February, pp. Presidents Letter (2006).

Arceo, A; Green, PF, "Ordering transition of block copolymer films," J. Phys. Chem. B, Vol. 109, Issue 15, pp. 6958 (2005).

Besancon, BM; Green, PF, "Polystyrene-based single-walled carbon nanotube nanocomposite thin films: Dynamics of structural instabilities," Macromolecules, Vol. 38, Issue 1, pp. 110 (2005).

Li, Y; Loo, YL; Register, RA; Green, PF, "Influence of interfacial constraints on the morphology of asymmetric crystalline-amorphous diblock copolymer films," Macromolecules, Vol. 38, Issue 18, pp. 7745 (2005).

Peter F. Green, "Book: Kinetics,Transport and Structure in Hard and Soft Materials," Publisher: CRC Press (Taylor and Francis Group), (2005).

Abramowitz, H; Shah, PS; Green, PF; Johnston, KP, "Welding colloidal crystals with carbon dioxide," Macromolecules, Vol. 37, Issue 19, pp. 7316 (2004).

Besancon, BM; Green, PF, "Moving fronts in entangled polymeric films - art. no. 051808," Phys. Rev. E, Vol. 7005, Issue 5, pp. 1808 (2004).

Meli, L; Pham, JQ; Johnston, KP; Green, PF, "Polystyrene thin films in CO2 - art. no. 051601," Phys. Rev. E, Vol. 6905, Issue 5, pp. 1601 (2004).

Pham, JQ; Johnston, KP; Green, PF, "Retrograde vitrification in CO2/polystyrene thin films," J. Phys. Chem. B, Vol. 108, Issue 11, pp. 3457 (2004).

Putz, K; Green, PF, "Fragility in mixed alkali tellurites," J. Non-Cryst. Solids, Vol. 337, Issue 3, pp. 254 (2004).

Putz, KW; Mitchell, CA; Krishnamoorti, R; Green, PF, "Elastic modulus of single-walled carbon nanotube/poly(methyl methacrylate) nanocomposites," J. Polym. Sci. Pt. B-Polym. Phys., Vol. 42, Issue 12, pp. 2286 (2004).

Sirard, SM; Castellanos, H; Green, PF; Johnston, KP, "Spectroscopic ellipsometry of grafted poly (dimethylsiloxane) brushes in carbon dioxide," J. Supercrit. Fluids, Vol. 32, Issue 1-3, pp. 265 (2004).

Zhang, XG; Pham, JQ; Ryza, N; Green, PF; Johnston, KP, "Chemical-mechanical photoresist drying in supercritical carbon dioxide with hydrocarbon surfactants," J. Vac. Sci. Technol. B, Vol. 22, Issue 2, pp. 818 (2004).

Green, PF, "Wetting and dynamics of structured liquid films," J. Polym. Sci. Pt. B-Polym. Phys., Vol. 41, Issue 19, pp. 2219 (2003).

Green, PF; Ganesan, V, "Dewetting of polymeric films: unresolved issues," Eur. Phys. J. E, Vol. 12, Issue 3, pp. 449 (2003).

Pham, JQ; Green, PF, "Effective T-g of confined polymer-polymer mixtures. influence of molecular size," Macromolecules, Vol. 36, Issue 5, pp. 1665 (2003).

Pham, JQ; Mitchell, CA; Bahr, JL; Tour, JM; Krishanamoorti, R; Green, PF, "Glass transition of polymer/single-walled carbon nanotube composite films," J. Polym. Sci. Pt. B-Polym. Phys., Vol. 41, Issue 24, pp. 3339 (2003).

Pham, JQ; Sirard, SM; Johnston, KP; Green, PF, "Pressure, temperature, and thickness dependence of CO2-induced devitrification of polymer films - art. no. 175503," Phys. Rev. Lett., Vol. 9117, Issue 17, pp. 5503 (2003).

Sirard, SM; Gupta, RR; Russell, TP; Watkins, JJ; Green, PF; Johnston, KP, "Structure of end-grafted polymer brushes in liquid and supercritical carbon dioxide: A neutron reflectivity study," Macromolecules, Vol. 36, Issue 9, pp. 3365 (2003).

Wind, JD; Sirard, SM; Paul, DR; Green, PF; Johnston, KP; Koros, WJ, "Relaxation dynamics of CO2 diffusion, sorption, and polymer swelling for plasticized polyimide membranes," Macromolecules, Vol. 36, Issue 17, pp. 6442 (2003).

Zhang, XG; Pham, JQ; Martinez, HJ; Wolf, PJ; Green, PF; Johnston, KP, "Water-in-carbon dioxide microemulsions for removing post-etch residues from patterned porous low-k dielectrics," J. Vac. Sci. Technol. B, Vol. 21, Issue 6, pp. 2590 (2003).

Limary, R; Green, PF, "An unstable structured liquid: Film thickness dependence of the early stage evolution," Macromolecules, Vol. 35, Issue 17, pp. 6486 (2002).

Limary, R; Green, PF, "Late-stage coarsening of an unstable structured liquid film - art. no. 021601," Phys. Rev. E, Vol. 6602, Issue 2, pp. 1601 (2002).

Limary, R; Green, PF; Shull, KR, "Influence of surface ordering on the wetting of structured liquids," Eur. Phys. J. E, Vol. 8, Issue 2, pp. 103 (2002).

Masson, JL; Green, PF, "Viscosity of entangled polystyrene thin film melts: Film thickness dependence - art. no. 031806," Phys. Rev. E, Vol. 6503, Issue 3, pp. 1806 (2002).

Masson, JL; Green, PF, "Hole formation in thin polymer films: A two-stage process - art. no. 205504," Phys. Rev. Lett., Vol. 8820, Issue 20, pp. 5504 (2002).

Masson, JL; Olufokunbi, O; Green, PF, "Flow instabilities in entangled polymer thin films," Macromolecules, Vol. 35, Issue 18, pp. 6992 (2002).

Pham, JQ; Green, PF, "The glass transition of thin film polymer/polymer blends: Interfacial interactions and confinement," J. Chem. Phys., Vol. 116, Issue 13, pp. 5801 (2002).

Sirard, SM; Ziegler, KJ; Sanchez, IC; Green, PF; Johnston, KP, "Anomalous properties of poly(methyl methaerylate) thin films in supercritical carbon dioxide," Macromolecules, Vol. 35, Issue 5, pp. 1928 (2002).

Green, PF; Limary, R, "Block copolymer thin films: pattern formation and phase behavior," Adv. Colloid Interface Sci., Vol. 94, Issue 1-3, pp. 53 (2001).

Masson, JL; Limary, R; Green, PF, "Pattern formation and evolution in diblock copolymer thin films above the order-disorder transition," J. Chem. Phys., Vol. 114, Issue 24, pp. 10963 (2001).

Sirard, SM; Green, PF; Johnston, KP, "Spectroscopic ellipsometry investigation of the swelling of poly(dimethylsiloxane) thin films with high pressure carbon dioxide," J. Phys. Chem. B, Vol. 105, Issue 4, pp. 766 (2001).

Limary, R; Swinnea, S; Green, PF, "Stability of diblock copolymer/layered silicate nanocomposite thin films," Macromolecules, Vol. 33, Issue 14, pp. 5227 (2000).

Green, PF, "Characterization and Consequences of the Mixed Alkali Effect in Glass - Selected Papers from the Symposium held in Conjunction with the Fall Meeting of the Glass and Optical Materials Division of the American Ceramic Society - Wheeling, WV, USA October 18," J. Non-Cryst. Solids, Vol. 255, Issue 1, pp. IX (1999).

Green, PF; Brown, EF; Brow, RK, "Dynamics of mixed alkali metaphosphate glasses and liquids," J. Non-Cryst. Solids, Vol. 255, Issue 1, pp. 87 (1999).
Limary, R; Green, PF, "Dewetting instabilities in thin block copolymer films: Nucleation and growth," Langmuir, Vol. 15, Issue 17, pp. 5617 (1999).

Orso, KA; Green, PF, "Phase behavior of thin film blends of block copolymers and homopolymers: Changes in domain dimensions," Macromolecules, Vol. 32, Issue 4, pp. 1087 (1999).

P.F. Green (Guest Editor), "Journal of Non-Crystalline Solids vol. 255, 1999, special issue: "Characterization and consequences of the Mixed Alkali Effect in Glass"," , (1999).

Segalman, RA; Green, PF, "Dynamics of rims and the onset of spinodal dewetting at liquid/liquid interfaces," Macromolecules, Vol. 32, Issue 3, pp. 801 (1999).

Sidebottom, DL; Green, PF; Brow, RK, "Brillouin scattering in alkali metaphosphate glasses and melts," J. Mol. Struct., Vol. 479, Issue 2-3, pp. 219 (1999).

Smith, MD; Green, PF; Saunders, R, "Anisochemical homopolymer/diblock copolymer thin film blends," Macromolecules, Vol. 32, Issue 25, pp. 8392 (1999).

Green, PF; Barbour, JC, "Effect of homopolymer host chain relaxations on the translational diffusion of a diblock copolymer," J. Non-Cryst. Solids, Vol. 235, pp. 640 (1998).

Green, PF; Brow, RK; Hudgens, JJ, "Specific heat and transport "anomalies" in mixed alkali glasses," J. Chem. Phys., Vol. 109, Issue 18, pp. 7907 (1998).

P. F. Green (Guest Editor), "Materials Research Society Bulletin vol. 23, (1998) "New Functionality in Glass"," , (1998).

Sidebottom, DL; Green, PF; Brow, RK, "Regarding the correlation of nuclear spin relaxation and electrical conductivity relaxation in ionic glasses," J. Chem. Phys., Vol. 108, Issue 14, pp. 5870 (1998).

Sidebottom, DL; Green, PF; Brow, RK, "Structural correlations in the ac conductivity of ion-containing glasses," J. Non-Cryst. Solids, Vol. 222, pp. 354 (1997).