Self-Assembled Monolayers on Engineering Metals:  Structure, Derivatization, and Utility

Abstract

A methodology for the formation and derivatization of self-assembled monolayers (SAMs) of alkyl phosphonic acids on common engineering metals such as steel, stainless steel, aluminum, copper, and brass is described. This methodology is shown to be a versatile route for surface modification of such substrates. α,ω-Metal bisphosphonate SAMs are shown to be receptive to complexation by organic acids and acid-containing polymers such as fluoropolymers and ethylene-co-methacrylic acid. This latter attribute is exploited in the construction of polymer/SAM/metal interfaces of surprising durability. The durability of the interface is a strong function of the SAM chain length.

Bisphosphonate-mediated gene vector delivery from the metal surfaces of stents

“…Bisphosphonates are known to demonstrate high-affinity binding to both mineral and metallic surfaces through phosphonate-metal coordination (16). It was therefore hypothesized that a metallic surface could be modified through an aminobisphosphonate exposure, thereby attaching to the metallic surface a derivatizable polybisphosphonate molecule that could, in turn, be covalently conjugated with vector-binding agents; this modification could, hypothetically, enable local gene delivery from metal surfaces exposed to the aqueous bisphosphonate.…”

Organic corrosion inhibitors: where are we now? A review. Part IV. Passivation and the role of mono- and diphosphonates

“…In the following work [44], studies were carried out on oxidized Al, and APhC 8 was studied instead of APhC 10 F 17 . After treatment of the sample surface by a 0.1% APhC 8 solution in THF,  was < 105°, although in the case of similar treatment with APhC 10 or APhC 18 solution with the same concentration,  was >115°. In addition, the SAM formed by APhC 18 gave the lowest coefficient of friction on Al, while the surface itself had the highest one.…”

“…For example, Van Alsten [10] found a good correlation between the length of the SAM main chain and the characteristics of the "coated metal/SAM/polymer" system, and also considered the effect of treatment time when self-assembly occurs directly from the binder polymer phase. He came to the conclusion that the procedure for the production of SAM using alkylphosphonic acids on conventional engineering metals is a versatile way for modifying their surface.…”

“…Recently, in another work [28] the influence of the processing time of 304L stainless steel by ethanol solutions of 5.0 mM APhC 4 , APhC 8 , APhC 10 or APhC 16 was studied in order to determine the optimal conditions for the formation of SAM. It was found that the best results, judging from the cyclic voltammetry curves recorded in an aqueous solution containing 0.2 M Na 2 SO 4 and 5 mM K 4 [Fe(CN) 6 ], were obtained at 8 h in APh solutions.…”

“…In this function, phosphonates are of great interest not only as an anticorrosive means, but also as adhesion promoters for polymer coatings [8][9][10]. It should be noted that the widespread practical use of SAMs for the passivation of metals was apparently hampered by the long time of their formation and the frequent need for the use of inflammable solvents.…”