RESUMEN
The real-time shape evolution of nanoimprinted polymer patterns is measured as a function of annealing time and temperature using critical dimension small-angle X-ray scattering (CD-SAXS). Periodicity, line width, line height, and sidewall angle are reported with nanometer resolution for parallel line/space patterns in poly(methyl methacrylate) (PMMA) both below and above the bulk glass transition temperature (T(G)). Heating these patterns below T(G) does not produce significant thermal expansion, at least to within the resolution of the measurement. However, above T(G) the fast rate of loss in pattern size at early times transitions to a reduced rate in longer time regimes. The time-dependent rate of polymer flow from the pattern into the underlying layer, termed pattern "melting", is consistent with a model of elastic recovery from stresses induced by the molding process.
Asunto(s)
Cristalización/métodos , Calor , Modelos Químicos , Modelos Moleculares , Nanoestructuras/química , Nanoestructuras/ultraestructura , Polimetil Metacrilato/química , Simulación por Computador , Sistemas de Computación , Dureza , Conformación Molecular , Transición de Fase , Polimetil Metacrilato/análisis , Propiedades de Superficie , Difracción de Rayos X/métodosRESUMEN
A novel soluble aryl amide-bridged ladderlike polymethylsiloxane (A-LPMS) was synthesized by stepwise coupling polymerization on the basis of amido H-bonding self-assembling template from monomer N,N'-bis(3-methyldiethoxylsilylpropyl)-[4,4'-oxybis(benzyl amide)]. The monomer was prepared in a high yield by the hydrosilylation reaction of template agent N,N'-diallyl-[4,4'-oxybis(benzyl amide)] with methyldiethoxysilane in the presence of dicyclopentadienylplatinum dichloride (Cp(2)PtCl(2)) as catalyst. A variety of techniques including (1)H NMR, (13)C NMR, (29)Si NMR, FTIR, XRD, DSC, and, especially, static and dynamic light scattering and viscosimetry were combined to confirm the presence of the ordered ladderlike structure of polymer A-LPMS.
