Optimization of Polydopamine Coatings

Polydopamine coatings were fabricated onto the surfaces of glass slides, silicon wafers, and Teflon pieces. A method to change surface properties was optimized, providing a new way of using substrates by means of make-over surface properties. The technology has a wide range of potential approaches including high performance coatings and biomedical surfaces. The experiments can be conducted with various types of surface modifications to make surfaces hydrophilic, hydrophobic, conductive, or magnetic. The changes of film thickness and surface energy as functions of incubation time were quantified by means of ellipsometry, profilometry, and contact angle measurements. The use of primer polydopamine serves as a starting point for additional exterior layer fabrication including PEG and silver particles. Polydopamine coatings can be applied to many different materials which gives it a great potential for expansion in the future. Testing a new, simpler method of creating these coatings is expected to be a significant contribution for many biomedical applications such as wound healing and tissue engineering. Surface modification will be able to be done with greater ease and be applied to many types of material with complex shape and multiple uses at lower costs. Glass slides, silicon wafers, and Teflon pieces were soaked in a polydopamine solution to determine the optimum incubation time, when the thickness on the substrate plateaus. The glass and silicon have very similar surfaces properties and both result in an optimum incubation time of 24 hours with a coating of about 40 nm. The optimum incubation time for Teflon is also about 24 hours and results in a polydopamine coating of 16 nm. The methods are described below for cleaning and dip-coating the substrates to provide uniform and stable coatings.