Fabrication Of Paraffin And Polypropylene Superhydrophobic Surfaces

Superhydrophobic materials have a lot of applications in many areas, scientists prepared superhydrophobic materials with all kinds of methods, as known, much of the methods invovle at last two kinds of materials, and the fabrication process is always complicated with a high cost, some even may damage the environment, which limit the industrial application of the superhydrophobic materials.Because of the easy fabrication process, good flexibility, transparency, conductivity and other functions, polymers drive the attention of superhydrophobic scientists. Polyolefin with a low price and surface energy is easy to process, in our work, we fabricate superhydrophobic polyolefin surfaces with three kinds of facile green physical methods.We employed two kinds of wax to make superhydrophobic wax mixture powder: the paraffin wax with a low melting point and the carnauba wax with a high melting point, with the rising content of the paraffin wax content in the mixture, we produced the most superhydrophobic wax powder, which consisits of 70%(Wt) paraffin wax and 30%(Wt) carnauba wax showing a water contact angle (WCA) of 164.5°. We also developed an application for the wax powder to adsorb the leaked petroleum, which is meaningful to the environment protection. The wax powder consisting a paraffin wax content of 70% showed a adsorption mass ratio reaching a level of 10.The superhydrophobicity of the fracture surfaces of paraffin was first discovered, the water contact angle (WCA) reaches 152.4±3°, which is higher than the contact angles of the other surfaces of the paraffin. It is the high roughness which leads to the good superhydrophobicity of the fracture surface, and from the differential scanning calorimetry (DSC) and X-ray Diffraction (XRD) spectra we conclude that it is the crystals inside the paraffin that result in the high roughness of the fracture surfaces. And we employed a sheet of copper mesh to replicate the morphology of the fracture surfaces. Each grid of the copper mesh produces a small fracture surface, and with this facile method we fabricated superhydrophobic surfaces with a WCA of 162.4±3°nd a sliding angle (SA) lower than 3°, this method is convenient for us to fabricate large-area superhydrophobic surfaces fast and environmentally. The WCA of HDPE fracture surface reaches 152.4° because of the micro-nano structures of the HDPE fracture surfaces, which also denotes the superhydrophobicity, while the LDPE fracture surface and the PS fracture surface is not superhydrophobic due to the smooth morphologies. Also, using the carbon nanotubes (CNTs) and PP (Polypropylene) we made the superhydrophobic conductive fracture surface of CNTs, the WCA of the composites with a CNTs proportion of 20% is 162± 3° and the conductivity reaches 5 S/cm.Micro-size copper mesh was applied to make superhydrophobic surfaces on the PP substrates. Firstly, the copper mesh was etched by the FeCl3 solution, with proper etching time, nano-size structures were made on the copper mesh, which showed an increase of the hydrophobicity, then this etched copper mesh was pressed on the PP substrate at 110℃ for 10 min, then cooled down to the room temperature, at last, the copper mesh was peeled off. The WCA of the obtained PP substrate surface is 162°, and the SA is lower than 3°.