Elasticity-controlled molecular dynamics of 9,9′-bifluorenyldene as a function of temperature and force

Abstract

Medium elasticity is an important coupling parameter that influences the molecular motions that occur in solids. In this work, the light-induced twisting motion of 9,9′-bifluorenyldene (BF) was investigated in an elastic polymer, ultra low density polyethylene (ULDPE), as a function of temperature and applied force. Analysis of the BF fluorescence lifetime in accordance with the modulus change of the ULDPE showed that temperature and force significantly affected the excited-state molecular dynamics in the elasticity-controlled regime.