Acetaldehyde gas removal by a nylon film-TiO2 composite sheet prepared on a paper surface using interfacial polymerization and electrostatic interactions.

In this study, preparation of a nylon film-TiO2 composite sheet with both physical durability under UV irradiation and TiO2 photocatalysis functionality was investigated. First, a nylon film was directly prepared on paper by interfacial polymerization using ethylenediamine and terephthaloyl chloride in a cyclohexane-chloroform mixture (3:1, v/v). Next, the nylon-coated paper was treated with tetraethyl orthosilicate and 3-aminopropyltrimethoxysilane to prepare polysiloxane on its surface. This was followed by fixation of TiO2 powder via electrostatic interactions with the polysiloxane. Although nylon films on paper usually decompose under TiO2 photocatalysis, the nylon film-TiO2 composite sheets prepared using 0.5%-1.0% (w/v) TiO2 did not decompose under photocatalysis. The residual rate of strength of the sheet remained at almost 100% after 240 h, which could be attributed to protection of the sheet by the polysiloxane layer. The nylon film was fibrous and could effectively adsorb acetaldehyde gas. All of the nylon film-TiO2 composite sheets prepared using 0.5%-5.0% TiO2 photocatalytically removed acetaldehyde under UV irradiation and no acetaldehyde gas was detected after 240-300 min. These results show the nylon film-TiO2 composite sheet can effectively remove acetaldehyde gas by photocatalysis and adsorption and could be applied to removal of volatile organic compounds in indoor air.