Future Directions
Although columnar phases are not always associated with discotics, discoticscontaining polymers may play a major role in future directions of columnar phaseforming polymers, largely thanks to their attractive potential applications in the field
of optoelectronics, arising from π-stacked discotic cores. It has been shown that the
attachment of triphenylene units to a macromolecule may give rise to a π-stacked
columnar mesophase featuring an order (Mu et al. 2017) and/or molecular mobility
(Kranig et al. 1990) supporting charge transport even better than the small molecule
counterpart in a highly ordered columnar mesophase (Mu et al. 2017), which makes
such polymers particularly appealing. Therefore, it is of great interest to extend such
advantageous phase structures to those polymers containing discotic units that are
more capable of supporting high carrier mobility. Considering that there are no
reports on columnar phase-forming polymers covalently bearing hexabenzo[bc,ef,
hi,kl,no,qr]coronene, phthalocyanine, or porphyrin as the side-groups, this necessitates a deeper understanding on the polymer structure-phase relationship.
References
Adam D, Schuhmacher P, Simmerer J, Häussling L, Siemensmeyer K, Etzbachi KH, Ringsorf H,
Haarer D (1994) Fast photoconduction in the highly ordered columnar phase of a discotic liquid
crystal. Nature 371:141–143
Allcock HR, Connolly MS, Sisko JT, Al-Shali S (1988) Effects of organic side group structures on
the properties of poly(organophosphazenes). Macromolecules 21:323–334
Allegra G, Meille SV (2004) Mesomorphic phases of flexible polymers: the self-compacting chain
model. Macromolecules 37:3487–3496
Allen G, Lewis CJ, Todd SM (1970) Polyphosphazenes. 2. Characterization. Polymer 11:44–60
Antipov EM, Kulichikhin VG, Plate NA (1992) Mesophase structure of some flexible chain
polymers. Polym Eng Sci 32:1188–1203
Ban J, Chen S, Li C, Wan X, Zhang H (2014) Influence of the spacer and molecular weight on the
phase behavior of side-chain liquid crystalline polymers containing triphenylene discotic
mesogen units as side groups. Polym Chem 5:6558–6568
M
R
PcHA
HH
PcHMA
HH
PcCuMA
Cu
HBCV1
HBCV2A
HBCV2MA
CuTAPA3
CuTAPB3
R
(CH 2 ) 3 N 3
R
Chart 13 Monomers of cross-linked columnar LC phase-forming polymers
5 Columnar Phase-Forming Polymers
141
Although columnar phases are not always associated with discotics, discoticscontaining polymers may play a major role in future directions of columnar phaseforming polymers, largely thanks to their attractive potential applications in the field
of optoelectronics, arising from π-stacked discotic cores. It has been shown that the
attachment of triphenylene units to a macromolecule may give rise to a π-stacked
columnar mesophase featuring an order (Mu et al. 2017) and/or molecular mobility
(Kranig et al. 1990) supporting charge transport even better than the small molecule
counterpart in a highly ordered columnar mesophase (Mu et al. 2017), which makes
such polymers particularly appealing. Therefore, it is of great interest to extend such
advantageous phase structures to those polymers containing discotic units that are
more capable of supporting high carrier mobility. Considering that there are no
reports on columnar phase-forming polymers covalently bearing hexabenzo[bc,ef,
hi,kl,no,qr]coronene, phthalocyanine, or porphyrin as the side-groups, this necessitates a deeper understanding on the polymer structure-phase relationship.
References
Adam D, Schuhmacher P, Simmerer J, Häussling L, Siemensmeyer K, Etzbachi KH, Ringsorf H,
Haarer D (1994) Fast photoconduction in the highly ordered columnar phase of a discotic liquid
crystal. Nature 371:141–143
Allcock HR, Connolly MS, Sisko JT, Al-Shali S (1988) Effects of organic side group structures on
the properties of poly(organophosphazenes). Macromolecules 21:323–334
Allegra G, Meille SV (2004) Mesomorphic phases of flexible polymers: the self-compacting chain
model. Macromolecules 37:3487–3496
Allen G, Lewis CJ, Todd SM (1970) Polyphosphazenes. 2. Characterization. Polymer 11:44–60
Antipov EM, Kulichikhin VG, Plate NA (1992) Mesophase structure of some flexible chain
polymers. Polym Eng Sci 32:1188–1203
Ban J, Chen S, Li C, Wan X, Zhang H (2014) Influence of the spacer and molecular weight on the
phase behavior of side-chain liquid crystalline polymers containing triphenylene discotic
mesogen units as side groups. Polym Chem 5:6558–6568
M
R
PcHA
HH
PcHMA
HH
PcCuMA
Cu
HBCV1
HBCV2A
HBCV2MA
CuTAPA3
CuTAPB3
R
(CH 2 ) 3 N 3
R
Chart 13 Monomers of cross-linked columnar LC phase-forming polymers
5 Columnar Phase-Forming Polymers
141