Stability of binary SAMs formed by omega-acid and alcohol functionalized thiol mixtures.
A simple model is presented to describe the mixing process of acid- and alcohol-terminated thiol self-assembled monolayers (SAMs) on Au(111). It was found that the low-concentration acid-terminated SAMs are enriched in acid thiol compared with the original solution from which the SAM is made. Due to the relatively strong interaction between acid and alcohol head groups, homogeneously mixed SAMs showing alcohol/acid pairs are preferred when the acid-terminated thiol fraction in solution is below or equal to 50%. This particular behavior affecting the mixing process is explained using atomistic first-principle thermodynamics. The calculated phase diagram has been discussed and interpreted with the help of XPS.
Tielens
Frederik
F
UPMC Univ Paris 06, Laboratoire de Réactivité de Surface, Tour 54-55, 2èmeétage - Casier 178, Paris, France. frederik.tielens@upmc.fr
Humblot
Vincent
V
Pradier
Claire-Marie
CM
Calatayud
Monica
M
Illas
Francesc
F
D000143:Acids / Q000737:chemistry; D000327:Adsorption; D000438:Alcohols / Q000737:chemistry*; D002621:Chemistry / Q000379:methods; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D008968:Molecular Conformation; D015394:Molecular Structure; D013052:Spectrometry, X-Ray Emission / Q000379:methods; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D020349:Surface Plasmon Resonance; D013499:Surface Properties; D013816:Thermodynamics; D014965:X-Rays
D000143:Acids; D000438:Alcohols; D013438:Sulfhydryl Compounds; D006046:Gold