Enhanced polyethylene wetting properties by a simple dipping process

Functional surfaces with special wettability have drawn the researchers’ attention in recent years due to the numerous benefits they present in their various applications, especially in the field of polymeric materials. Several works were published concerning various kinds of polymers, but data on polyolefins, specifically polyethylene, are rather scarce, and all are involved and onerous processes. Herein we report a simple dipping method in a suspension of TiO2 nanoparticles combined with a silane coupling agent. The main result reported is the obtainment of superhydrophobicity in polyethylene with the addition of n-hexadecane to the suspension. A systematic study aiming at the increase in surface hydrophobicity was carried out on the most commercially used types of polyethylene. The surfaces were coated with titanium dioxide nanoparticles functionalized with an organosilane in order to obtain a superhydrophobic material. The main variation regarding the published data dwelled in the addition of an alkane to the treatment solution. The technique consisted of a single layer immersion (dip-coating) of the polymer in the treatment solution, at an optimally defined working temperature, and with variations in the parameters time of immersion and concentration of the alkane additive. The treated surfaces were analyzed and characterized by static contact angle measurement (WCA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Raman spectroscopy, and optical profilometry. A progressive increase in hydrophobicity was found with increasing alkane concentration, reaching WCA values higher than 150° for all types of polyethylene used, characterizing superhydrophobic behavior.