Tuning the Surface Free Energy of Polybenzoxazine Thin Films

A novel approach to manipulate the surface free energy and wettability on polybenzoxazine thin films can be achieved simply by varying the time of thermal treatment or UV exposure. A fraction of the intramolecular hydrogen bonding of the as-cured sample will convert into intermolecular hydrogen bonding upon thermal treatment or UV exposure and, thus, results in an increase in the hydrophilicity and wettability. This UV approach provides a simple method to generate wettability patterns or wettability gradients on the surface of a polybenzoxazine film. In addition, we have applied this technique to the preparation of a large-area periodic array of CdTe colloidal nanocrystals on polybenzoxazine thin films.