Functional group effects on the enthalpy of adsorption for self-assembly at the solution/graphite interface

Area of Science:

• Physical Chemistry
• Surface Science
• Thermodynamics

Background:

• Self-assembly processes are crucial in various scientific fields.
• Traditional experimental and theoretical methods often fail to capture all factors influencing self-assembly.
• Understanding interfacial thermodynamics is key to controlling self-assembly.

Purpose of the Study:

• To investigate the thermodynamics of self-assembly at a liquid/solid interface.
• To measure the enthalpy of adsorption, including all relevant interactions.
• To compare experimental data with theoretical lattice energies.

Main Methods:

• Utilized flow microcalorimetry to measure adsorption enthalpy.
• Analyzed interactions including analyte-analyte, analyte-solvent, analyte-substrate, and solvent-substrate.
• Computed lattice energies for aliphatic analyte monolayers.

Main Results:

• Experimental data and computed lattice energies showed similar trends for most aliphatic analytes.
• Discrepancies were observed for fatty acid and bromoalkane adsorbates.
• These differences suggest the importance of analyte-analyte interactions in solution.

Conclusions:

• Flow microcalorimetry offers a comprehensive thermodynamic view of interfacial self-assembly.
• Solution-phase interactions significantly impact self-assembly thermodynamics at interfaces.
• Accurate thermodynamic models must account for both interfacial and solution phenomena.