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13:57
Preparation and Friction Force Microscopy Measurements of Immiscible, Opposing Polymer Brushes
Published on: December 24, 2014
Molecular friction as a tool to identify functionalized alkanethiols
Joost te Riet1, Tim Smit, Jan W Gerritsen
1Department of Scanning Probe Microscopy, Institute for Molecules and Materials, Radboud University Nijmegen, P.O. Box 9010, 6500GL Nijmegen, The Netherlands.
Langmuir : the ACS Journal of Surfaces and Colloids
|March 16, 2010
Summary
Nanografting creates nanoscale patches of alkanethiols on gold surfaces. Friction measurements reveal these patches have fewer defects and can be used for molecular recognition based on thiol end groups.
Area of Science:
- Surface science
- Nanotechnology
- Materials chemistry
Background:
- Self-assembled monolayers (SAMs) are crucial in nanotechnology.
- Controlling SAM structure at the nanoscale is challenging.
- Atomic force microscopy (AFM) is a powerful tool for surface analysis.
Purpose of the Study:
- To construct and analyze nanoscale alkanethiol patches using nanografting.
- To investigate the relationship between molecular structure and friction in SAMs.
- To explore the potential of friction as a molecular recognition tool.
Main Methods:
- Nanografting technique to create well-defined alkanethiol patches on Au(111).
- Atomic force microscopy (AFM) for height measurements.
- Quantitative lateral friction measurements to analyze surface properties.
Main Results:
- Nanografted patches exhibited lower friction than the surrounding SAM matrix, indicating fewer defects.
- Friction increased with decreasing alkane chain length, with a subtle odd-even effect observed.
- Different thiol end groups (-CH(3), -CF(3), -OH, -SH, -COOH, -NH(2)) showed distinct friction behaviors, providing insights into molecular orientation and packing.
Conclusions:
- Nanografting is an effective method for creating defect-minimized SAMs.
- Lateral friction force is sensitive to molecular structure and end groups in alkanethiol SAMs.
- Friction measurements can serve as a molecular recognition tool for analyzing thiol-based SAMs.
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