Thiol diffusion and the role of humidity in "Dip Pen Nanolithography".
The radii of octadecanethiol spots deposited by an atomic force microscope tip onto a gold surface were studied as a function of contact time and humidity. The deposition is well described by two-dimensional diffusion from an annular source of constant concentration, with a surface diffusion coefficient of 8400 nm(2) s(-1), independent of humidity. Facile transfer is observed even after near continuous deposition for more than 24 h in a dry N2 environment, indicating that a water meniscus is not required.
Sheehan
P E
PE
Naval Research Laboratory, Washington, DC 20375, USA. psheehan@stm2.nrl.navy.mil
Whitman
L J
LJ
D015374:Biosensing Techniques; D006046:Gold / Q000737:chemistry; D006813:Humidity; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
D013438:Sulfhydryl Compounds; D006046:Gold