Molecular Dynamics Simulations and Electric Field Poling of Covalently Bonded Chromophores at Poly(methyl
Nils M Denda1,2, Oguzhan Albayrak1,3, Henning Menzel1,3
1Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering - Innovation Across Disciplines), 30167 Hannover, Germany.
Abstract:
Embedding dipolar donor-acceptor molecules in polymer matrices is a promising route to novel optical materials. The noncentrosymmetric alignment of these chromophores is crucial for nonlinear optical activity in the application case. The present study proposes a novel simulation protocol, specifically designed to investigate the relaxation of chromophore alignment within a polymer matrix. This study contrasts two synthesis approaches: the first involves simple doped host-guest materials, and the second involves covalently bonded chromophores to the side chain of the host polymer. Covalent integration of chromophores results in higher glass transition values, thereby enhancing long-term alignment stability. The alignment stability of noncovalently bonded chromophore systems starts to decrease dramatically at 30 to 50 K above the observed glass transition. Covalently bonded chromophores show an enhanced alignment stability for the same temperature range above the observed glass transition. However, chromophore orientation is more constrained for chromophores that are covalently bonded to the polymer host compared to simple doped chromophore polymer systems. This study underscores the merits and limitations of covalent chromophore incorporation, delineating a paradigm for the exploration and development of novel, promising hybrid materials through simulation methods.
