B07 Semicrystalline Homopolymers and Block Copolymers at the Air/Water Interface and in Langmuir-Blodgett Films on Solid Supports

Friday 19. May 2023
Kreßler

 

We developed a fundamental understanding of the crystallization mechanism of synthetic polymers at air/liquid interfaces in contrast to their behavior when crystallized in thin films on solid supports or in bulk. This yielded thermodynamic and kinetic models different from existing models for crystallization in bulk and in thin films on solid supports. The experimental focus lay on the crystallization behavior of precision polyphosphoester and poly(ethylene oxide)s with well-defined point defects in Langmuir films at the air/liquid interface by microscopic and X-ray scattering techniques. These films were also transferred to solid supports (Langmuir-Blodgett films) and studied by X-ray scattering as well as atomic force microscopy. The influence of tacticity (atactic, isotactic, syndiotactic) and pH-value of the aqueous subphase on the crystallization behavior of poly(methacrylic acid) was investigated. Furthermore, the influence of Hofmeister salts on the crystallization of poly(vinyl alcohol) on the surface of the salt solutions was considered. Details on the crystallography and chain orientation of the polymers with respect to the subphase surface were obtained by grazing incidence wide angle X-ray scattering (GI-WAXS) and infrared reflection absorption spectroscopy (IRRAS) for all polymers under investigation. Thermodynamic and kinetic models were developed which compared the crystallization of the respective polymers in bulk, in thin films on solid supports (Langmuir-Blodgett films), and in thin films on aqueous surfaces (Langmuir films).

Highlighted Publications:
  1. Yury Golitsyn, Martin Pulst, Muhammad Haris Samiullah, Karsten Busse, Jörg Kressler, and Detlef Reichert, Crystallization in PEG networks: The importance of network topology and chain tilt in crystals. Polymer 165, 72-82 (2019) 
  2. K. Busse, C. Fuchs, N. Hasan, M. Pulst, and J. Kressler, Crystallization of Poly(ethylene oxide) on the Surface of Aqueous Salt Solutions Studied by Grazing Incidence Wide-Angle X-ray Scattering Langmuir 34, 12759 (2018) 

  3. Martin Pulst, Muhammad H Samiullah, Ute Baumeister, Marko Prehm, Jens Balko, Thomas Thurn-Albrecht, Karsten Busse, Yury Golitsyn, Detlef Reichert, and Jörg Kressler, Crystallization of Poly(ethylene oxide) with a Well-Defined Point Defect in the Middle of the Polymer ChainMacromolecules 49, 6609-6620 (2016)