Bioinspired fabrication of conducting SnO2 film on polymeric substrates
IFREMER, LDCM, Departement of research and technological developments
When a sensor or underwater cameras are immersed in sea water, they are quickly covered with marine growth. The proliferation of these marine fouling can cause shift measurement To protect the sensors, our group has developed a very innovative method based on localized sea water electro-chlorination on the optical window which is coated by a transparent and conducting SnO2 film (1). The SnO2 film is deposited by conventional vapor deposition technique which requires a high temperature resistant substrate. Therefore bio-inspired methods for the fabrication of inorganic coating have been developed in recent years which can be applied at room temperature (2). In this work we have used spermine, a naturally occurring polyamine which is grafted to the surface in order to obtain the fast growth of a homogenous, thin and transparent SnO2 on polymer surfaces. The Polymethyl Methacrylate (PMMA) surfaces were treated by the plasma oxygen in order to graft the epoxysilane on the surface. In the second step, the spemrine was grafted on the surface by the reaction amine and epoxy group; finally the spermine functionalized surfaces were incubated with aqueous solution of sodium hexafluorostannate to promote the SnO2 coating. Each step of the functionalization was characterized by FTIR and X-Ray Photoelectron Spectroscopy (XPS). Moreover the morphology of the SnO2 film was characterized by Scanning Electron Microscopy (SEM). The Sno2 film on the surface was confirmed by the presence of Sn3d and O1s sates with binding energies (BE) at 486, 495 and 530 eV respectively. The BE peaks observed for Sn 3d5/2 clearly shows Sn+4 is present in the film. The homogeneous and thin film obtained by this bio-inspired method will be used to perform localized sea water electro-chlorination on different substrates (glass and polymer) in order to protect them against biofouling growth.
1- Electrochemical treatments using tin oxide anode to prevent biofouling, C.Debiemme-Chouvy, Y.Hua, J.-L.Duval, D.Festy, H.Cachet. Electrochemica Acta. 2011, 56, 10364-10370.
2- Self-Assembly of Highly Phosphorylated Silaffins and Their Function in Biosilica Morphogenesis. N.Kroger, S.Lorenz, E.Brunner, M.Sumper. Science 2002, 298, 584-586