Effect of lamellar nanostructures on the second harmonic generation of polymethylmethacrylate films doped with 4-(4-nitrophenylazo)aniline chromophores

TL;DR

This study investigates how lamellar nanostructures influence second harmonic generation in PMMA films doped with azo chromophores, focusing on molecular orientation dynamics under electrostatic poling and nanostructure formation.

Contribution

It introduces a method to enhance second harmonic generation in PMMA films by incorporating lamellar nanostructures via surfactant-induced nanostructuring.

Findings

Lamellar nanostructures were successfully incorporated into PMMA films.

Second harmonic generation efficiency depends on nanostructure presence and poling conditions.

Molecular orientation dynamics were characterized by in-situ SHG measurements.

Abstract

The kinetics of the orientation of Disperse Orange 3 molecules embedded in amorphous and nanostructured Polymethylmethacrylate films was studied under the effect of an intense electrostatic poling field. Non-centrosymmetric chromophore distributions were obtained in Polymethylmethacrylate films by Corona poling technique. These distributions depends on the Corona poling time. The changes in the orientation of the Disperse Orange 3 molecules were followed by in-situ transmitted Second Harmonic Generation measurements. The Second Harmonic Generation signal was recorded as function of time at several temperatures; it was fitted as function of the Corona poling time, considering matrix-chromophore interactions. The Polymethylmethacrylate films were nanostructured by the incorporation of an anionic surfactant, the Sodium Dodecyl Sulfate. The lamellar nanostructures in the films were identified by X-ray diffraction measurements.