Fabrication of conjugated polymeric nanochannels from star-shaped supramolecular liquid crystals containing two different photoreactive groups

Abstract

New conjugated polymeric nanochannels were prepared via photopolymerisation and core extraction of starshaped supramolecular liquid crystals formed by simple hydrogen bonding between a phloroglucinol core and pyridine derivatives containing two different photoreactive groups. The polymerisable supramolecular liquid crystal exhibited a discotic columnar mesophase. Photopolymerisation of supramolecular liquid crystalline monomer provided cross-linked conjugated polymeric columns in which the diacetylene and acrylate moieties were selectively polymerised along the vertical and horizontal axes, respectively. Chemical treatment of the crosslinked conjugated columns with sodium hydroxide resulted in the removal of the phloroglucinol core to produce the cross-linked conjugated polymeric nanochannels with an estimated effective pore diameter of about 1 nm. The controlled methodology in the present study can be used to design and fabricate conjugated nanoporous organic materials with intriguing ordered structures.

Discotic Liquid Crystals

“…Lee et al also prepared phloroglucinol derivatives with two different photoreactive groups, i.e. the bisalkine and a terminal acrylate moiety for the fabrication of nanochannels. , …”

“…the bisalkine and a terminal acrylate moiety for the fabrication of nanochannels. 651,652 Tris(N-salicylideneaniline)s, so-called "hekates" were developed by the Yelamaggad group (Scheme 162). 653,654 Derivatives 352a and 352b with two alkoxy chains per ester possessed Col r and Col h phases, whereas 353a yielded only Col ob phase, and upon further increase of the chain lengths mesomorphism was completely lost.…”

Size-Selective Adsorption in Nanoporous Polymers from Coumarin Photo-Cross-Linked Columnar Liquid Crystals

“…Pioneering work on 1D nanoporous materials by Kim and co-workers has been followed by an increasing interest in these systems where a very common approach is based on the use of C 3 symmetric templates and pro-discotic mesogenic units connected by hydrogen bonding. − Cross-linking of such noncovalent LCs followed by template removal can yield materials with nanopores replicating the size of the molecular templates. The resultant pores are expected to incorporate guest molecules that resemble the original template.…”

Synthesis and characterisation of star-shaped liquid crystalline polymer with a POSS core

“…Indeed, the star-shaped (three-, four-, six-arm) LC polymers with different cores have been explored extensively and their mesogenic behaviour have also been studied. [35][36][37][38][39][40] The LC polymers containing mesogenic group of phenylbenzoate moiety have got more attention due to the higher thermal stability and easier arrangement into mesophase. [35,41] Employing phenylbenzoate moiety as mesogenic group to build the star-shaped POSS LC polymer should bring about the high thermal stability and the easier formation of liquid crystal phase.…”