Polymer (PEO)-liquid crystal (LC E8) composites: The effect from the LC inclusion

Ion-Conducting Composites of Polymers and Nematic Liquid Crystals

“…The same trend obtained from complex AC conductivity analyses has been reported for various polymer-based ion-conducting dipolar systems . The cause for the decrease of the relaxation time is the same as for the increase in ionic conductivity, namely, the increase of molecular chain segmental dynamics with increasing temperature. , …”

“…Hence, this morphology strongly differs from the ordinary well-formed and well-separated (and in the perfect caseuniformly distributed) microdroplet structural organization of the NLC phase within the bulk of the PDLC materials obtained by thermally- or photoinduced phase-separation processes. ,, If viewed at lower magnification, the PNLCCs considered here may display a relatively homogeneous texture (Figure c). Upon heating, the morphology of PNLCCs can undergo significant change, especially above their glass-transition temperature and close to their melting point, which is reasonable.…”

“…Also, the eventual field-driven reorientation of the LC molecules within the nematic microdomains disposed in the bulk of PNLCCs (such as those seen in Figure b and c) is hampered because the two phases (polymer and LC nematic) are not fully separated in the considered PNLCCs (composed from molecular NLC materials) that have been simply prepared only by mixing of the monomer mass and NLCs without the application of a method for the alignment of NLC molecules. The lack of electroactive properties has been evidenced by optical polarization microscopy studies of PNLCCs under an electric field …”

“…In this case, however, the opposite trend was observedthe crystallinity index X C increases (Figure b). This paradox is related to the increased numbers of intermolecular structures formed from NLC molecules and the host polymer at higher NLC concentration, an effect that is reflected in the XRD patterns clearly showing the growth of an additional sharp peak of diffraction , (Figure a).…”

“…By the solution cast technique, the preparation of homogeneous thin composite films can be well controlled by the solvent evaporation rate. In this way, stable free-standing thin films with high flexibility and a thickness of 100–200 μm can be formed relatively easy, possessing desirable mechanical, conductive, dielectric, thermal, and other properties. − ,− , As an example, Figure illustrates the preparation of PEO/E8-based ion-conducting PNLCCs (following the works of Koduru et al). , Also, highly stretchable conductive materials based on PNLCCs can be manufactured following the well-developed PDLC technology …”