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Self-assembled monolayers of rigid thiols
A Ulman1, J F Kang, Y Shnidman
1Department of Chemical Engineering, Chemistry and Materials Science, Polytechnic University, Six Metrotech Center, Brooklyn, NY 11201, USA. aulman@duke.poly.edu
Journal of Biotechnology
|January 6, 2001
Summary
Self-assembled monolayers (SAMs) from rigid biphenyl thiols form stable, engineerable surfaces. Their structure and properties influence crystal nucleation and polymer adhesion through molecular interactions.
Area of Science:
- Surface science
- Materials chemistry
- Nanotechnology
Background:
- Self-assembled monolayers (SAMs) are crucial for surface engineering.
- Rigid biphenyl moieties introduce unique molecular dipole moments affecting SAM properties.
- Understanding SAMs is key for applications in crystal growth and adhesion.
Purpose of the Study:
- To review the preparation, structure, properties, and applications of SAMs based on rigid 4-mercapto-biphenyls.
- To explore the influence of molecular rigidity and dipole moments on SAM formation and behavior.
- To highlight the utility of these SAMs as stable, molecularly engineered surfaces.
Main Methods:
- Adsorption kinetics studies using a modified Ising model.
- Analysis of equilibrium structures of SAMs and mixed SAMs.
- Infrared spectroscopy to determine molecular tilt angles.
- Wetting studies to assess surface stability.
- Investigation of glycine crystal nucleation and PDMS adhesion.
Main Results:
- The Langmuir isotherm model is inadequate for biphenyl thiol adsorption kinetics; a new Ising model provides a better fit.
- SAM structure is influenced by solution polarity.
- Biphenyl moieties exhibit small tilt angles on gold surfaces.
- SAM surfaces demonstrate long-term stability (months).
- Glycine crystal morphology and PDMS adhesion are dependent on interfacial hydrogen bonding.
Conclusions:
- Rigid biphenyl SAMs offer stable, molecularly engineerable surfaces.
- Interfacial hydrogen bonding significantly impacts crystal nucleation and polymer adhesion.
- The collective effect of polymer chains influences adhesion properties.
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