Preparation of dopamine super-hydrophobic coating in pipeline

• Super-hydrophobic coatings have great application potential in the fields of surface self-cleaning, fluid drag reduction, anti-fog and anti-icing, and microfluidic control. The controls of morphologies for the super-hydrophobic coating inside a circular tube have not been investigated. In this paper, the polydopamine (PDA) was coated on the inner wall of stainless-steel cylinder by electrochemical deposition under different values of shear stress, and n-dodecyl mercaptan (NDM) was used to modify the PDA surface. This PDA/NDM coating shows super-hydrophobic behavior. Scanning electron microscopy (SEM), contact angle tester (CA), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction tester (XRD) were used to analyze the characterization of the coating. The results show that PDA deposition can be divided into two stages under the effect of shear stress. The first stage is the agglomeration of PDA particles on the stainless steel substrate. The second stage is PDA in-situ growth based on PDA particles aggregate, and the growth process is controlled by shear stress. When the shear stress is 1.85 mPa, the coating surface shows coral shaped balls with about 15—24 μm. When the shear stress is 7.41 mPa, the coating surface has a flaky structure with a particle size of about 1—4 μm. The wetting angles of the prepared PDA/NDM coating are greater than 150°, belongs to super-hydrophobic properties. And the coating has good chemical stability and heat resistance wear resistance and corrosion resistance. The work has certain guiding for the regulation and control of the surface nano/microstructure during the preparation of the inner surface coating of the pipe.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Bearbetnings-, yt- och fogningsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Manufacturing, Surface and Joining Technology (hsv//eng)

Nyckelord

Contact angle

Dopamine

Pipe

Shear stress

Super-hydrophobic coating

Energiteknik

Energy Engineering

Publikations- och innehållstyp

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