Spin Casting, Electric Field Poling, and Lattice Hardening

Spin Casting, Electric Field Poling, and Lattice Hardening 

We can prepare functionalized chromophore and crosslinking reagents in a thermosetting composition that is, the chromophores and crosslinking reagents can react to form a three-dimensional crosslinked polymer matrix. Thermosetting polyurethane, sol-gel, or epoxy chemistries are frequently used. Many variations on the above themes can be and have been executed for example, 

A uniform electric field distribution across the sample is extremely important for achieving device quality materials. Unfortunately, real chromophore materials do not always behave as uniform insulator materials. We have already demonstrated that ionic impurities can dramatically reduce the effective electric field felt by chromophores. The presence of spatially and temporally varying nonuniform space charge distributions leads to nonuniform poling fields. The resulting nonuniform chromophore order can lead to light scattering. 

Kaino and co-workers [255] have investigated the effect of polymer polydis-persity on electro-optic materials properties. No dependence on polydispersity was observed for guest host materials but for Disperse Red chromophores covalently attached to monodisperse polystyrene weaker absorption tails were observed. This result suggests that chromophore-chromophore interactions are modified by the polymer host. 

In Fig. 19, uncrosslinked refers to the situation where only one end of the chromophore is attached to the polymer backbone (prescursor polymer) while crosslinked refers to the situation where both ends of the chromophore are attached to the polymer backbone (final hardened polymer) [138]. The double-end crosslinking results in improvement in the dynamic thermal stability by more 

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