Soft Matter Electron Microscopy

Nitash Balsara, Program Leader

The program’s objective is to reshape the way electron scattering and microscopy are utilized to investigate structure, composition and transport properties of soft matter.  We focus on three dimensional (3D) characterization of systems ranging from molecularly thin membranes formed by phospholipids to 50 mm thick synthetic polymer membranes used in fuel cells.  The microscopy techniques under development attempt to maximize spatial and energetic resolution while minimizing radiation exposure and damage.  This is achieved by using novel techniques to manipulate and detect the incident, transmitted, and scattered electrons.  In addition, aberration-correctors, high brightness instruments, and novel 3D image reconstruction algorithms based on discrete tomography are employed.  In situ electron microscopy experiments for investigating the dynamic nature of soft materials on molecular and sub-molecular length scales have been designed. While the immediate objective is to determine the nanometer length scale structures in these systems, this will lay the foundation for achieving atomic resolution. This may provide the basis for a unique user facility for high-resolution electron microscopy at NCEM capable of quantifying the structure of soft materials in both dry and solvated states.   Research centers on the synthesis of new functional membranes for energy-related applications and the development of state-of-the-art electron microscopy techniques and instrumentation for determining the structure and morphology of the membranes. 

CURRENT PROJECTS

• Characterization of structure and morphology of fuel cell membranes above the normal boiling point of water. (N. Balsara, K. Downing, A. Minor)
  

• Detailed electron tomography to determine the 3D nature of ion transporting channels in fuel cell and battery membranes. (N. Balsara, K. Downing, A. Minor)
  

• Determination of the effect of block copolymer molecular weight on the sequestration of lithium salts. (N. Balsara, A. Minor)
  

• Quantification of the effect of shape-controlling proteins on the curvature of lipid membanes by electron tomography. (J. Groves, K. Downing)
  

• Synthesis of gold labeled shape-controlling proteins to enable determination of surface protein  concentration. (J. Groves, K. Downing)
  

• Implementation of discrete tomography. (C. Kisielowski)
  

• Use of electrostatic phase plate to enhance the signal-to-noise ratio of electron microscopy data obtained from soft materials. (C. Kisielowski, A. Minor)
  Imaging of soft materials by exit wave reconstruction. (C. Kisielowski)
  

• Study of the effect of electric fields on block copolymer membranes by in-situ electron microscopy. (A. Minor, N. Balsara)