Magnetic orientation of poly(.gamma.-methyl-D-glutamate) liquid crystals

Abstract

NMR was used to detect the magnetic orientation of a biphasic solution of poly(Y-methyl-D-glutamate) in dichloromethane. The observed triplet is interpreted in terms of an outer doublet produced by the direct

Stiff Chain Polymer Lyotropic Liquid Crystals

“…The thermodynamic results are consistent with NMR results on side chain mobility (48). An applied magnetic field has been shown to align PGA, PMLG, PMDG, and PELG (68,(137)(138)(139)(140)(141), indicating an anisotropy in the magnetic susceptibility. The anisotropy (138,139) as well as the critical magnetic field needed to untwist the cholesteric phase (140) has been determined, analogous to the previously quoted studies on PBLG.…”

Biomolecular Piezoelectric Materials: From Amino Acids to Living Tissues

“…As with other piezoelectric materials such as amino acids, or FF, unidirectional polarization alignment is a very important issue for practical piezoelectric device applications. Therefore, several efforts have been made to fabricate polarized polypeptides through the application of an external magnetic field or electric field 113–117. In 2004, the strong piezoelectric coefficient d 14 of 26 pC N −1 was found in the PBLG membrane which was oriented by the application of a strong magnetic field ( Figure a) 114.…”

“…Therefore, several efforts have been made to fabricate polarized polypeptides through the application of an external magnetic field or electric field. [113][114][115][116][117] In 2004, the strong piezoelectric coefficient d 14 of 26 pC N −1 was found in the PBLG membrane which was oriented by the application of a strong magnetic field (Figure 7a). [114] The piezoelectric coefficient was linearly increased with applied magnetic field, and it was not saturated at the magnetic field of 10 T. In addition, the fabrication of uniform and unidirectionally polarized PBLG-PMMA composite film by the application of external electric field through corona discharging and contact charging methods has been reported (Figure 7b).…”

Diffusional Behavior of Solvent in Polypeptide Liquid Crystalline and Gel States with Highly Oriented Chains As Studied by NMR Spectroscopy

“…As is well-known, PBLG forms the lyotropic liquid crystalline (LC) state in good solvents such as dichloromethane, dioxane, chloroform, and so on, − and when the PBLG liquid crystalline solution is placed in a strong magnetic field, the main chain can be oriented in the direction of the magnetic field. − The molecular motion of solvent and PBLG in the liquid crystalline solution is influenced considerably by intermolecular interactions. − By the reaction of highly oriented PBLG chains with a cross-linker in a strong magnetic field, cross-linked PBLG gel with the highly oriented α-helical chains is expected to be prepared. In the liquid crystalline and the gel states, the orientation of the PBLG chains can be determined by using high-resolution solid-state 13 C NMR.…”