Cobalt Chromium (Co-Cr) alloys has been widely used in the biomedical arena for cardiovascular, orthopedic and dental applications. Surface modification of the alloy allows us to tailor the interfacial properties to address critical challenges of Co-Cr alloy in medical applications. Self assembled monolayers (SAMs) of Octadecylphosphonic acid (ODPA) have been used to form thin films on the oxide layer of the Co-Cr alloy surface by solution deposition technique. The SAMs formed were investigated for their stability to oxidative conditions of ambient laboratory environment over periods of 1, 3, 7 and 14 days. The samples were then characterized for their stability using X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM) and Contact Angle Measurements. Detailed high energy XPS elemental scans confirmed the presence of the phosphonic monolayer after oxidative exposure which suggested that the SAMs were firmly attached to the oxide layer of Co-Cr alloy. AFM images gave topographical data of the surface and showed islands of SAMs on Co-Cr alloy surface, before and after SAM formation and also over the duration of the oxidative exposure. Contact angle measurements confirmed the hydrophobicity of the surface over 14 days. Thus the SAMs were found to be stable for the duration of the study. These SAMs could be subsequently tailored by modifying the terminal functional groups and could be used for various potential biomedical applications such as drug delivery, biocompatibility and tissue integration

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Metals and their alloys have been widely used in all aspects of science and engineering. However the science of nanotechnology is driving newer demands and requirements for better performance of existing materials and also at a higher level of precision. This is naturally presenting complicated demands on the surface of these metals with a need for surface modification. Self Assembled Monolayers (SAMs) are nanosized coatings that present the most efficient method of carrying out surface modification. Alkylsilanes are silicon based SAMs which are compatible with the majority of metals and alloys. These nanocoatings can serve primary functions such as surface coverage, etch protection and anti corrosion, along with a host of other secondary chemical functions because of their amphiphilic nature. We present a brief introduction to surface modification of metals and alloys followed by a detailed description of silane based nanocoatings and their applications in technology. Then a look at the engineering aspects of these coatings in terms of patterning techniques is presented along with a discussion of the applications of patterned SAMs.

To address critical challenges with the use of Co-Cr alloy, a common metal alloy used in biomedical applications we demonstrated the formation of phosphonic acid organic nanosized thins films on Co-Cr alloy. X-ray photoelectron spectroscopy (XPS) determined the surface atomic composition before and after film deposition. The presence of phosphorous 'P' after deposition indicated presence of organic film formation. Similarly, changes in surface hydrophobicity as indicated by contact angle measurements suggested organic thin film formation.