Porous polydimethylsiloxane membranes loaded with low-temperature crystallized TiO.sub.2 NPs for detachable antibacterial films

• Published in: Journal of materials science Vol. 54; no. 2; pp. 1665 - 1676
• Main Authors: Alberti, Stefano, Ferretti, Maurizio, Vicini, Silvia, Castellano, Maila, Caratto, Valentina
• Format: Journal Article
• Language: English
• Published: Springer 01.01.2019
• Subjects: Antibacterial agents; Dimethylpolysiloxane
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-018-2881-4

TiO.sub.2 was prepared via sol-gel synthesis, and in order to obtain crystallized anatase in a colloidal suspension, it was subjected to a hydrothermal process in the presence of a minimum amount of nanoparticles, which acted as nucleation seeds. Concurrently, high-pH sol-gel syntheses were performed with the increase in NH.sub.3 solutions as a comparison for the samples' activity. Polydimethylsiloxane was chosen as supporting material for the TiO.sub.2 nanoparticles for its high surface area and its stability against catalyst's photoactivity. They were both processed with the electrospinning technique: It was possible to disperse titania among PDMS fibers and to obtain detachable polymeric membranes with the appearance of white soft sheets. These membranes show antibacterial activity under fluorescent light, and thus, they may be used as a film for several kinds of surfaces. The synthesized samples were controlled and characterized by means of rheological measurements, scanning electron microscopy images together with EDS maps, differential scanning calorimetry analyses, diffuse reflectance spectra for energy gap (E.sub.gap) calculations and recycling photocatalytic experiments, while Escherichia Coli inactivation gave evidence of the antibacterial activity.