Preparation of Macroporous Titania Films by a Sol‐Gel Dip‐Coating Method from the System Containing Poly(ethylene glycol)

Abstract

Macroporous titania (TiO 2 ) films have been prepared via a sol‐gel dip‐coating method from a titanium tetraisopropoxide solution that contains poly(ethylene glycol) (PEG). The macroporous morphology‐i.e., the size, distribution, and shape of the macropores‐is controlled by varying the content and molecular weight of PEG, the withdrawal speed, and the temperature of the dipping solution. The morphology of the TiO 2 film is determined by competitive contributions of the following factors: (i) decrease in fluidity, because of the evaporation of solvent; (ii) network formation by polycondensation reactions; and (iii) domain formation during phase separation into gel phases and solvent phases.