Mesoscale dynamics and cooperativity of networking dendronized nonlinear optical molecular glasses.
First, molecular scale insight into the mobility of a novel class of organic materials for photonic applications with electro-optical activities larger than 300 pm/V is presented. A representative second order nonlinear optical (NLO) material of this class of self-assembling molecular glasses involving quadrupolar phenyl-perfluorophenyl (Ph-PhF) interactions is analyzed based on its molecular relaxation phenomena and phase behavior. Thereby, a new and straightforward nanoscale methodology, involving shear modulation force microscopy and intrinsic friction analysis is introduced. It provides both the submolecular enthalpic and entropic dynamics in nanoconstrained systems (e.g., ultrathin films), and thus, insight into local motion of single molecules due to dissociation of Ph-PhF pairs as well as the cooperative dynamics of the assembled network. This nanoscale model-independent thermomechanical methodology is shown to be very effective in fundamentally evaluating appropriate poling conditions of organic NLO materials. It promises to be a straightforward analysis tool to guide organic material synthesis from a molecular mobility perspective, particularly for applications that impose nanoscale constraints on the system.
Gray
Tomoko
T
Department of Chemical Engineering, University of Washington, Seattle, Washington 98195-1750, USA.
Kim
Tae-Dong
TD
Knorr
Daniel B
DB
Luo
Jingdong
J
Jen
Alex K-Y
AK
Overney
René M
RM
D003198:Computer Simulation; D050091:Dendrimers / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D008956:Models, Chemical; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D017711:Nonlinear Dynamics; D010316:Particle Size; D013696:Temperature
D050091:Dendrimers; D046911:Macromolecular Substances