Structural evolution of crystalline polymer latex films: Propagating and confined acoustic modes

Structural evolution of polytetrafluoroethylene latex polymer films has been studied by Brillouin light scattering and atomic force microscopy (AFM). Using a tunable sintering process, we have controlled the degree of particle connectivity yielding a crossover in the behavior of acoustic excitations ranging from confined modes to propagating phonons. This transition has been correlated also to the surface morphology by AFM. Fully sintered films are characterized by extended “fibrillar” crystalline regions embedded in a disordered matrix, which still retain features of the original particulate structure.

[1]  A. Bassi,et al.  Investigation of confined acoustic phonons of tin nanoparticles during melting , 2001 .

[2]  K.H.J. Buschow,et al.  Encyclopedia of Materials: Science and Technology , 2004 .

[3]  Forrest,et al.  Quantifying glass transition behavior in ultrathin free-standing polymer films , 2000, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[4]  S. Bauer,et al.  Dielectric and electret properties of nanoemulsion spin-on polytetrafluoroethylene films , 2000 .

[5]  M. Klein,et al.  Conformational and orientational order and disorder in solid polytetrafluoroethylene , 1999 .

[6]  P. Galtier,et al.  Surface-induced organization of linear molecules on nanostructured polytetrafluoroethylene: Crystalline state of poly[vinylidenefluoride-trifluoroethylene] , 1997 .

[7]  L. David,et al.  Molecular Mobility, Phase Transitions, Transformation Plasticity and Memory Effect in Poly (tetrafluoroethylene) (PTFE) , 1996 .

[8]  Forrest,et al.  Effect of Free Surfaces on the Glass Transition Temperature of Thin Polymer Films. , 1996, Physical review letters.

[9]  T. Bellini,et al.  Static and dynamic light scattering study of fluorinated polymer colloids with a crystalline internal structure , 1994 .

[10]  A. Maradudin,et al.  Dynamical properties of solids , 1985 .

[11]  Manuel Cardona,et al.  Light Scattering in Solids VII , 1982 .

[12]  H. Starkweather,et al.  Fluorine-containing polymers. II. Polytetrafluoroethylene , 1961 .