Biomimetic strategies in colloidal-electrochemical deposition of functional materials and composites using chenodeoxycholic acid

For the first time thin films of chenodeoxycholic acid (CDCH) were electrodeposited from sodium chenodeoxycholate (CDCNa) solutions potentiodynamically and by constant voltage deposition. The proposed deposition method was based on pH-dependent gel-forming properties of CDCH. CDCNa was found to be an efficient anionic surfactant for electrophoretic deposition (EPD) of carbon materials, such as submicrometre diamond, nanodiamond, carbon nanotubes, as well as memory type Zr-doped hydrotalcite (MHT) and poly(tetrafluoroethylene) (PTFE). In this approach, bifacial amphipathic CDCNa acted as a compatibilizing agent between the hydrophobic material surface and water. This study enabled the fabrication of composite coatings using CDCNa as a co-dispersing surfactant. An important practical outcome of this work was the development of advanced coatings for corrosion protection. We present a conceptually new strategy which enhances the protective properties of polymer coatings. It is based on the memory properties of MHT, which are linked to its ability to restore the original structure and composition after thermal dehydration. The protection mechanism involves in-situ MHT reconstruction, which limits water diffusion in pores of coatings. Another new finding was that CDCNa facilitated solubilization and EPD of ibuprofen in water. This finding paves the way for the development of drug delivery technologies and deposition of various water insoluble organic functional materials. Particularly important for future applications is the possibility of EPD of various hydrophobic polymers and composites using a biomimetic approach based on the CDCNa mediated deposition.