Preparation of SAMs

The high surface coverage and near-crystalline structure of SAMs has limited their application as stationary phases in RPLC. Wirth et al. [70,71] have described the preparation of SAM-based chromatographic materials with the use of mixed... 

Mixed SAMs The preparation of SAMs with more than one head groups and/or chain lengths is a prerequisite for many of their uses in the design and synthesis of interfaces with complex properties [32,60,82,83]. With the development of SPM... 

Preparation of SAMs. Freshly cleaned gold substrates (Arrande, Germany) were immersed into a 2 mM solution of MUAP in ethanol. After 24 h the substrates were rinsed with ethanol and dried in a nitrogen stream. 

In this contribution we have presented the synthesis of the new photoreactive thiol MUAP bearing a photoreactive phenyl ester. This molecule is well suited for the preparation of SAMs on gold substrates and can be photochemically modified by UV-illumination due to the photo-Fries rearrangement leading to the formation of hydroxyketones. By a subsequent post-modification reaction with a fluorinated compound low-energy surfaces are attainable. 

In certain cases, additional aspects have to be considered. For example, in the case of metals that are covered with an oxide layer under ambient conditions, the preparation of SAMs may require specific pretreatments aimed at eliminating or reducing the amount of metal oxides on the surface. 

In the following sections, gold films will be discussed according to the support material, using information taken only from studies concerned with the use of these substrates for the preparation of SAMs. 

Although SAM precursors are amphiphilic molecules, as in L-B films, SAMs are more stable due to the specific nature of chemisorption. Thus, the preparation of SAMs is much more facile and the resulting adlayers are more stable. Functionalities can also be introduced into the adlayer that allows for further modification of the interface. Therefore, SAMs are attractive as coatings in many applications. 

B. Facile Preparation of SAMs that Present Mercaptan, Charged, and Polar Groups... 

Chemical reaction provides a straightforward method for the preparation of SAMs that present a variety of functional groups — especially polar, charged, or structurally complex groups, such... 

Preparation of SAMs. SAMs for FT-IR analysis were self-assembled from 1 mM solutions of compounds 1, 2, or 3 in dichloromethane for 16 h onto evaporated gold as described in reference 18. SAMs for AFM experiments were prepared similarly at RT on annealed Au(l 11) substrates as described in reference 19. 

Dodecanethiol and 11-mercapto-l-undecanol were purchased from Aldrich Chemical Company, Inc. (Milwaukee, WI) and used as received. Glassware for the preparation of SAMs was cleaned with chromic acid cleaning solution (Fisher Scientific). Gold shots (99.99%) were purchased from D.F. Goldsmith. Glass beads (10-30 pm) from Polyscience were used for the normal force calibration. The faceted... 

SAMs can be considered as a form of insoluble, two-dimensional, and grafted polymers that is, the substrate surface is the backbone, and the attached alkaneth-iolate (RS ) groups are the sidechains. The backbone already exists before the SAM is formed the preparation of SAMs is more like postpolymerization modification than it is like polymerization. The packing of the alkyl chains is such that the alkyl chains are highly ordered and crystallize. In SAMs of n-alkanethio-... 

---