Polymeric dopant effects of bent‐core covalent‐bonded and hydrogen‐bonded structures on banana‐shaped liquid crystalline complexes

Abstract

Two series of banana‐shaped liquid crystalline (LC) H‐bonded complexes HPm/CBn (i.e., bent‐core H‐bonded side‐chain homopolymer HP mixed with bent‐core covalent‐bonded small molecule CB) and CPm/HBn (i.e., bent‐core covalent‐bonded side‐chain homopolymer CP mixed with bent‐core H‐bonded small molecular complex HB) with various m/n molar ratios were developed. The bent‐core covalent‐ and H‐bonded structural moieties were homopolymerized in the banana‐shaped LC H‐bonded complexes HPm/CBn and CPm/HBn, respectively. The influences of m/n molar ratios (polymeric moieties vs. small molecular moieties) on the mesomorphic and electro‐optical properties of both banana‐shaped LC H‐bonded complexes HPm/CBn and CPm/HBn were investigated. The polar smectic phases could be achieved and stabilized by smaller contents of polymeric dopants in banana‐shaped LC H‐bonded complexes, such as HP1/CB10, HP1/CB15, CP1/HB10, and CP1/HB15, which possessed tunable spontaneous polarization (Ps) values according to the molar ratios of m/n, that is, lower Ps values obtained in H‐bonded complexes HPm /CBn and CPm / HBn with higher ratios of H‐bonded moieties (larger m/n molar ratios), respectively. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 764–774, 2010

Formation and properties of liquid crystalline supramolecules with anisotropic fluorescence emission

“…The polarized FTIR sample was the spin-coated lm on silica with a rubbing poly(vinyl alcohol) (PVA) layer. 1 H NMR spectra were recorded on a Varian Mercury Plus 400 MHz spectrometer using DMSO-d 6 or CDCl 3 as solvent at room temperature and the chemical shis were referenced relative to tetramethylsilane. Differential scanning calorimetry (DSC) was performed using a DSC Pyris 1 from TA Instruments with samples sealed in aluminium pans and a scanning rate of 10 C min À1 under a nitrogen atmosphere.…”

“…This kind of supramolecule is generally prepared through specic noncovalent interaction between the LC polymer matrix and small molecules, i.e. hydrogen bonding [1][2][3][4] or electrostatic interaction. [5][6][7] Various function tectonic units varying from metal ions, 4,8 quantum dots 3 to organic dyes 9 were reported to be employed to prepare materials with various functions.…”

Hydrogen-bonded effects on supramolecular blue phase liquid crystal dimeric complexes

“…This shoulder is the carbonyl group which is in a less associated state than the pure AF* (H-donor) with a weaker carboxylic acid groups C=O stretching vibration appeared at 1700 cm -1 . [39][40][41] This is attributed to a carboxylic acid groups C=O stretching vibration at 1700 cm -1 in pure H-donor AF* which shifts toward higher wavenumber and overlaps with the band of the ester carbonyl groups at 1726 cm -1 in the asymmetric heterodimers of AF*/P* (1:1 mol.). As cooling from the isotropic state to the blue phase I at 68°C, two broad O-H bands centered at 1920 cm -1 and 2500 cm -1 still persist (see Fig.…”

Switching performance of a polymer-stabilized antiferroelectric liquid crystal based on bent-core molecules

“…According to further developing the promising switching performance, recent attempts were made to stabilize also the phases of bent-core molecules by fabricating network structures. [24][25][26] Photo-reactive mesogenic monomers consisting of bent-core molecules were used to stabilize a conventional antiferroelectric calamitic liquid crystal. 24 Reactive mesogens were also used to form bent-core elastomers.…”

“…24 Reactive mesogens were also used to form bent-core elastomers. 25 Also composites forming bent-core structures through hydrogen bonds 26 have been investigated. However, there is a lack of investigations on polymer-stabilized liquid crystals, where both the non-reactive liquid crystal and reactive monomer consist of mesogenic molecules with a bent core.…”