Fluorine modification on titanium dioxide particles: Improving the anti-icing performance through a very hydrophobic surface

In this study, fluorine modification was successfully conducted on titanium dioxide (TiO2) to enhance the anti-icing property through fabricating a very hydrophobic surface. TiO2 was firstly modified with 3-methacrylox-ypropyl-trimethoxysilane (MPS) to introduce C=C bonds. Then, dodecafluoroheptyl methacrylate (DFHMA) monomers were successfully grafted on the TiO2 particles via C=C bonds introduced by MPS. Herein, azobisisobutyronitrile (AIBN) was used as initiator to initiate the reaction. The chemical components of the TiO2 particles were investigated by X-ray photoelectron spectroscopy (XPS). XPS analysis of fluorine-modified TiO2 revealed that the fluorine content reached a peak value of 7.3%, while the water contact angle enhanced to a maximum value of 146 degrees. This water contact angle value of 146 degrees was dramatically increased by 131 degrees in comparison with unmodified TiO2, indicating a very hydrophobic surface. The crystallization temperature of a water droplet on the corresponding fluorine-modified TiO2 decreased to -19.4 degrees C (10.3 degrees C decrease in comparison with that of a water droplet on unmodified TiO2 ). Also, the freezing delay time on the fluorine-modified TiO2 is more than 25 min under the testing temperature of - 10 degrees C, exhibiting excellent anti-icing property.