Abstract
Discotic liquid crystalline polymers have been attracting a great deal of interest
recently due to their unusual combination of properties (self-assembly, mechanical and thermal stability as well as easy processability) as compared to conventional polymers. Due to their ability of self-organization and self-healing, these
polymers are used in a variety of applications. The self-assembling nature of
discotic mesogens (present in these polymers) into columnar phase helps in
unidirectional charge or ion transfer in these polymers. So, we put together this
entry as an overview on the recent advances in the chemistry of polymeric
discotic liquid crystals (DLCs) with a particular focus on their self-assembly
which is useful for the preparation of new functional soft materials. The properties of DLC polymers depend on the discotic core as well as on the polymer
backbone. It has been observed that a particular set of properties can be tuned by
changing core or backbone. We have categorized all the discotic polymers into six
categories, and each of the category is further subdivided based on the type of
core structure of the discotic molecules. The dependence of mesomorphism on
the influence of position of discotic mesogens and connectivity in determining the
supramolecular organization of these compounds has been discussed briefly.
Overall, this entry will serve as general overview of polymeric DLCs and their
structure-property relationship based on each core/backbone.
Keywords
Liquid crystals · Discotic polymers · Liquid crystalline polymers · Discotic
mesogens · Columnar · Self-assembly
Introduction
Discotic liquid crystals (DLC) represent a well-known class of liquid crystals,
consisting of rigid disc-shaped aromatic cores and disordered alkyl substituents,
which possess the ability to self-organize into highly ordered supramolecular structures such as columns wherein the self-assembly is driven by the π-stacking of
aromatic cores. Due to the very efficient drift of charge carriers along the stacking
axes of these highly organized columns, DLCs possess remarkable charge transport
properties (Sergeyev et al. 2007; Ohta et al. 2003; Kaafarani 2011). Not only this,
DLCs also promise an important capability of self-healing and hence can be used in
the formation of highly anisotropic materials. Such properties make DLCs suitable
for the development of new smart materials. However, highly ordered DLCs like
polycyclic aromatic hydrocarbons having high mobility are not processable. On the
other hand, processable organic materials like oligomers and polymers do not
display high mobility because of the lower order. So, the incorporation of selfassembling properties of discotic mesogens in polymers may generate materials
useful for many device applications. So, this combination of polymers and discotic
60
S. Setia et al.
Discotic liquid crystalline polymers have been attracting a great deal of interest
recently due to their unusual combination of properties (self-assembly, mechanical and thermal stability as well as easy processability) as compared to conventional polymers. Due to their ability of self-organization and self-healing, these
polymers are used in a variety of applications. The self-assembling nature of
discotic mesogens (present in these polymers) into columnar phase helps in
unidirectional charge or ion transfer in these polymers. So, we put together this
entry as an overview on the recent advances in the chemistry of polymeric
discotic liquid crystals (DLCs) with a particular focus on their self-assembly
which is useful for the preparation of new functional soft materials. The properties of DLC polymers depend on the discotic core as well as on the polymer
backbone. It has been observed that a particular set of properties can be tuned by
changing core or backbone. We have categorized all the discotic polymers into six
categories, and each of the category is further subdivided based on the type of
core structure of the discotic molecules. The dependence of mesomorphism on
the influence of position of discotic mesogens and connectivity in determining the
supramolecular organization of these compounds has been discussed briefly.
Overall, this entry will serve as general overview of polymeric DLCs and their
structure-property relationship based on each core/backbone.
Keywords
Liquid crystals · Discotic polymers · Liquid crystalline polymers · Discotic
mesogens · Columnar · Self-assembly
Introduction
Discotic liquid crystals (DLC) represent a well-known class of liquid crystals,
consisting of rigid disc-shaped aromatic cores and disordered alkyl substituents,
which possess the ability to self-organize into highly ordered supramolecular structures such as columns wherein the self-assembly is driven by the π-stacking of
aromatic cores. Due to the very efficient drift of charge carriers along the stacking
axes of these highly organized columns, DLCs possess remarkable charge transport
properties (Sergeyev et al. 2007; Ohta et al. 2003; Kaafarani 2011). Not only this,
DLCs also promise an important capability of self-healing and hence can be used in
the formation of highly anisotropic materials. Such properties make DLCs suitable
for the development of new smart materials. However, highly ordered DLCs like
polycyclic aromatic hydrocarbons having high mobility are not processable. On the
other hand, processable organic materials like oligomers and polymers do not
display high mobility because of the lower order. So, the incorporation of selfassembling properties of discotic mesogens in polymers may generate materials
useful for many device applications. So, this combination of polymers and discotic
60
S. Setia et al.