Patterns of Hierarchical Molecular Self-Assemblies 2

• Applicant: Professor Dr. Motomu Tanaka
• Subject Area: Preparatory and Physical Chemistry of Polymers ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 258513149

• Final Report Year: 2020

Final Report Abstract

This Project unraveled how small molecules, such as semifluorinatedalkanes, self-organize and form hierarchical structures, ranging over several orders of lengthscales from short-range intermolecular correlation (~ Å), formation of highly uniform nanodomains (~ 10 nm), to long-range correlation over ~ 1 µm. To precisely determine the shape, size and correlation of such self-assembled nanostructures, we employed grazing incidence small-angle X-ray scattering (GTSAXS). One of our unique achievements is to fully calculate the form factor F(q) arid the structure factor S(q) of the scattering signal collected by a two-dimensional detector. This enables us to precisely determine how subtle changes in molecular structures influence the individual domains as well as their collective behavior. In addition to the structural characterization, we quantitatively determined the mechanical properties of such self-organized nanodomains as a function of molecular structures. Here, we found that self-organized nanodomains of semifluorinatedalkanes could form two-dimensional physical gels even at zero surface pressures. This is clearly different from commonly used surfactants and polymers, which form gels only uder high compressions. Intringuingly, the selforganized nanodomains also exhibited a very prominent nonlinear viscoelasticity, suggesting that the unique properties of small molecules, such as weak cohesion and dipole repulsion, results in highly unique material properties. Finally, we modeled how the control of self-organization can potentially be used to fme-adjust the stability of microbubbles used in ultrasound image diagnostics. The obtained results have demonstrated that the precise quantification of structure-mechanics relationships as a function of molecular structures allows for the rational design of small molecules with optimal functions by tailoring their self-organizing capability.

Publications

• Influence of Semifluorinated Alkane Surface Domains on Phase Behavior and Linear and Nonlinear Viscoelasticity of Phospholipid Monolayers. Langmuir
  S. Mielke, X. Liu, M.P. Krafft, M. Tanaka
  
• Size, Shape and Lateral Correlation of Highly Uniform, Mesoscopic, Self-Assembled Domains of Fluorocarbon-Hydrocarbon Diblocks at the Air/Water Interface: A GISAXS Study. ChemPhysChem, 18, 2791 (2017)
  M. Veschgini, W. Abuillan, S. Inoue, A. Yamamoto, S. Mielke, X. Liu, O. Konovalov, M.P. Krafft, M. Tanaka
  
• Two-Dimensional Physical Gels Can Exist even at Zero Surface Pressure at the Air/Water Interface - Rheology of Self-Assembled Domains of Small Molecules. Angew. Chem. Int. Edit 56, 12603 (2017)
  M. Veschgini, T. Habe, S. Mielke, S. Inoue, X. Liu, M.P. Krafft, M. Tanaka
  
• 2D Spherulites of a Semi-Fluorinated Alkaric: Controlled Access to Either Radial Or Ring-Banded Morphologies. ChemPhysChem 19, 29 (2018)
  X. Liu, S. Mielke, C. Contal, D. Favier, A. Yamamoto, M. Tanaka, M.P. Krafft
  
• Emergence of Strong Nonlinear Viscoelastic Response of Semifluorinated Alkane Monolayers. Langmuir 34, 2489 (2018)
  S. Mielke, T. Habe, M. Veschgini, X. Liu, K. Yoshikawa, M.P. Krafft, M. Tanaka
  
• Neutron Scattering Reveals Water Confined in a Watertight Bilayer Vesicle. J. Am. Chem. Soc. 140, 11261 (2018)
  W. Abuillan, A.S. Becker, B. Demé, T. Homma, H. Isobe, K. Harano, E. Nakamura, M. Tanaka
  
• “Nonlinear Viscoelasticity of Highly Ordered, Two-Dimensional Assemblies of Metal Nanoparticles Confined at the Air/Water Interface’" Langmuir 3A, 13025-13034 (2018)
  S. Masuda, S. Mielke, F. Amadei, A. Yamamoto, P. Wdaang, T. Taniguchi, K. Yoshikawa, K. Tama, M. Tanaka
  
• Influence of Perfluorohexane-Enriched Atmosphere on Viscoelasticity and Structural Order of Self-Assembled Semifluorinated Alkanes at the Air-Water Interface. ChemPhysChem 20, 1698-1705 (2019)
  S. Mielke, W. Abuillan, M. Veschgini, X. Liu, O. Konovalov, M.P. Krafft, M. Tanaka
  
• Long-Range Lateral Correlation between Self-Assembled Domains of Fluorocarbon-Hydrocarbon Tetrablocks by Quantitative GISAXS. ChemPhysChem 20, 898-904 (2019)
  W. Abuillan, M. Veschgini, S. Mielke, X. Liu, O. Konovalov, M.P. Krafft, M. Tanaka