Structure-dependent thermochromism of PAZO thin films: theory and experiment

• Georgi Mateev,
• Dean Dimov,
• Nataliya Berberova-Buhova,
• Nikoleta Kircheva,
• Todor Dudev,
• Ludmila Nikolova,
• Elena Stoykova,
• Keehoon Hong,
• Dimana Nazarova,
• Silvia Angelova and
• Lian Nedelchev

Beilstein J. Nanotechnol. 2026, 17, 186–199, doi:10.3762/bjnano.17.12

• ]-1,2-ethanediyl, sodium salt] (PAZO) exhibits a range of unique physical properties that are critical for its diverse applications in photonics, optoelectronics, memory devices, and sensing technologies. In this study, we investigate the thermochromic behavior of PAZO thin films, focusing on the

• relationship between the structural organization of the polymer side chains and temperature-induced optical changes. By combining experimental spectroscopic techniques with theoretical modeling, we demonstrate that the thermochromic response of PAZO films is strongly influenced by molecular aggregation, film

• in azopolymer thin films and offer valuable guidelines for the design of thermally responsive photonic materials. Keywords: aggregate; azopolymer; birefringence; PAZO; thermochromism; Introduction Functionalization of polymers with different photo- and bioactive groups to achieve novel