Local Direction of Optomechanical Stress in Azobenzene Containing Polymers During Surface Relief Grating Formation. Issue 8 (7th March 2022)

• Record Type: Journal Article
• Authors: Loebner, Sarah; Yadav, Bharti; Lomadze, Nino; Tverdokhleb, Nina; Donner, Hendrik; Saphiannikova, Marina; Santer, Svetlana
• Is Part Of: Macromolecular materials and engineering. Volume 307:Issue 8(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-07
• Subjects: azobenzene containing polymers -- colloidal particles -- direction of optomechanical stress -- orientation approaches; Plastics -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1002/mame.202100990
• Languages: English
• ISSNs: 1438-7492

Abstract

Abstract: In this work, it is revealed how the photoinduced deformation of azobenzene containing polymers relates to the local direction of optomechanical stresses generated during irradiation with interference patterns (IPs). It can be substantiated by the modeling approach proposed by Saphiannikova et al., which describes the directional photodeformations in glassy side‐chain azobenzene polymers, and proves that these deformations arise from the reorientation of rigid backbone segments along the light polarization direction. In experiments and modeling, surface relief gratings in pre‐elongated photosensitive colloids of few micrometers length are inscribed using different IPs such as SS, PP, ±45, SP, RL, and LR. The deformation of colloidal particles is studied in situ, whereby the local variation of polymer topography is assigned to the local distribution of the electrical field vector for all IPs. Experimentally observed shapes are reproduced exactly with modeling azopolymer samples as visco‐plastic bodies in the finite element software ANSYS. Orientation approach correctly predicts local variations of the main axis of light‐induced stress in each interference pattern for both initially isotropic and highly oriented materials. With this work, it is suggested that the orientation approach implements a self‐sufficient and convincing mechanism to describe photoinduced deformation in azopolymer films that in principle does not require auxiliary assumptions. Abstract : The photoinduced deformation in glassy azobenzene containing polymers during irradiation with modulated light is comprehensively described by orientation approach proposed by Saphiannikova et al. Experimentally observed topographies formed under irradiation with different interference pattern are exactly reproduced with modeling the azo‐polymer samples as visco‐plastic bodies in the finite element software ANSYS.