Surface structure of size exclusion chromatography stationary phase

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Chromatography is a key separation technique for nanomaterials like proteins, quantum dots, and carbon nanotubes.
• Understanding the nanoscale properties of chromatographic stationary phases is crucial for process optimization and new material development.

Purpose of the Study:

• To characterize the chromatographic stationary phase in its swollen wet state.
• To investigate the nanoscale morphology of stationary phases using advanced microscopy techniques.

Main Methods:

• Utilized Environmental Scanning Electron Microscopy (ESEM) for initial observations.
• Employed Atomic Force Microscopy (AFM) in wet mode for high-resolution nanoscale characterization of stationary phases in both wet and dry states.

Main Results:

• ESEM provided micron-range resolution, while AFM achieved nanometric resolution.
• Microscale cracks were observed on the surface of swollen stationary phase beads.
• Surface structures suggest that micron-sized beads are composed of nanometric beads.

Conclusions:

• AFM is effective for nanoscale characterization of hydrated chromatographic stationary phases.
• Observed surface cracks may explain the high mass transfer rates and low back pressures of the stationary phase.
• The findings provide insights into the nanoscale architecture of stationary phases, facilitating improved chromatographic separations.