Combining laser ablation and Sol-Gel techniques for the synthesis of nanostructured organic-inorganic matrices

In this work we report a new and simple method that combines the pulsed laser ablation in liquids (PLAL) and the Sol-Gel techniques to obtain nanocomposite glasses and gelatins. Gold nanoparticles (Au-NPs) are generated by PLAL using the corresponding target. The target is submerged in a transparent liquid solution made previously with tetraetylorthosilicate (TEOS) adding diluted hydrochloric acid as catalyzer. In the case of gelatins commercial gelatin and tap water are used. The laser source is a Nd:YAG laser emitting at 1064 nm, with an energy of 100 mJ and 8 ns pulse duration at 10 Hz repetition rate focused on the target in a 2 mm diameter laser spot. The ablation time is 10 min for the glasses and gelatins. The Au-NPs are uniformly dispersed in the solution. After the ablation process the gels are sealed and stored at room temperature for several days. The samples are characterized by UV-Vis spectroscopy, HRTEM, ellipsometry and AFM microscopy, these measurements reveal optical transparency and a refractive index near 1.45 for the pure glass, whereas a colorful aspect, a refractive index of 1.42, and a small surface roughness of 1.92 nm for the glass containing Au-NPs. In the case of gelatins self-sustained flexible films are obtained.