Details

Project TitleSurface-Independent, Surface-Modifying, Multifunctional Coatings and Applications Thereof
Track Code2006-145
Short Description

Northwestern researchers have developed a substrate independent multifunctional surface modification affording adherent nanofilms on all natural and synthetic surfaces tested, including metals, oxides, semiconductors, polymers and ceramics. The nanofilm chemically combines with a wide range of organic and inorganic species producing a variety of functional coatings and metallized surfaces with broad commercial utility.

#chemical #coatings #materials #biomedical #adhesives

Abstract

Generally molecules for surface modification are bifunctional entities designed to anchor to a substrate at one end and afford chemical functionality at the other end. This approach requires coatings tailored to the specific surface, such as alkanethiol - Au systems. A binding agent universally effective on all surfaces would provide great simplification and offer the potential for a wide range of substrate-coating combinations for chemical, biological, medical and commercial applications.

Utilizing the adhesive motif of mussel glue, oxidative dopamine coating (ODC) generates a nanofilm adherent to virtually all natural and synthetic surfaces including metals (Au, stainless steel), alloys (NiTi), metal oxides (TiO2, SiO2, Al2O3), semiconductors (GaAs, Si3N4), polymers (PE, PS, PEEK, polyurethanes, PDMS, PET, PTFE, PC) and ceramics (glass, hydroxyapatite). (Figure 1). Furthermore the nanofilm is reactive to organic and heteroatom functionalities such as amines and thiols and also strongly binds to various metals (Fe, Cu, Hg, Zn). Thus addition of a monofunctional methoxy poly(ethylene glycol)-thiol or amine to precoated ODC substrates creates universal protein resistive surfaces, that exhibited excellent long-term protein foul resistance on a variety of coated materials (Figure 2).

Metal binding properties of ODC treated materials afford the simple metallization of a wide array of substrate surfaces. Silver has been directly deposited, in the absence of a reducing agent, on Si3N4, glass, Au, Ti and PEEK polymer. Copper metal deposition, under reducing conditions, was accomplished on nanofilm coated Si, Al2O3, Nb2O5, NiTi, PS, PC, PEEK, glass and Au substrates (Figure 3). In combination with lithographic techniques the ODC process provides surface independent electroless metal patterning valuable in electronic applications and devices.

This invention offers a simple process with great potential for directly coating virtually all substrate surfaces with a wide range of agents useful in medical and commercial applications.

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Figure 1. XPS characterization of ODC surfaces. The bar graph represents the intensity of substrate signal before (hatched) and after (solid) coating. Substrate N/C ratio after coating (blue circles).

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Figure 2. NIH 3T3 fibroblast cell adhesion to bare surface (black) and to ODC treated surfaces after grafting with mPEG-SH (red).

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Figure 3. SEM images of Ag on Si (E) and Cu on glass (F) after photoresist patterned electroless metallization by OCR.

 
TagsMATERIALS: adhesives, MATERIALS: biomedical, CHEMICAL: coatings
 
Posted DateApr 19, 2011 1:37 PM

Inventor(s)

Phillip Messersmith

Haeshin Lee

Advantages

  • Simple coating
  • Adhesive binding to virtually any substrate surface
  • Reactive coating with a vast array of organic functionalities and metals
  • Unlimited range of protective and functional surface films useful in chemical, biological, medical and commercial applications

Publications

IP Status

Issued US Patent Nos. 8,541,060 and 8,999,452

This technology has been exclusively licensed in the area of medical applications.

Contact Information

Vara Josyula, PhD

Invention Manager
(p) 847-491-4456
(e) vara.josyula@northwestern.edu