Preparation and proton conduction in liquid crystals containing sulfonic acid moiety. Issue 4 (23rd October 2018)

• Record Type: Journal Article
• Authors: Yu, Qiannan; Zhao, Zhengshun; Tan, Shuai
• Is Part Of: Emerging materials research. Volume 7:Issue 4(2018)
• Page Start: 218
• Page End: 222
• Publication Date: 2018-10-23
• Subjects: ionic conductivity -- self-assembly; Materials -- Periodicals; 620.11
• DOI: 10.1680/jemmr.17.00071
• Languages: English
• ISSNs: 2046-0147

Abstract

Abstract : A series of novel biphenyl benzoate based liquid crystals (1 ) containing terminal sulfonic acid moieties have been prepared through the etherification reaction for anhydrous proton conduction. The chemical structures of1 were characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy and high-resolution mass spectrometry. Differential scanning calorimetry measurements and polarizing optical microscopic observations indicated that1 exhibited a thermotropic smectic A phase in a temperature range of 188–226°C. X-ray diffraction measurements suggested that the molecules of1 in the smectic phase formed bilayer nanostructures, wherein the sulfonic acid moieties were lamellar aggregated within the layers to form two-dimensional pathways for proton conduction. Electrochemical impedance spectroscopy measurements suggested that the lamellar assembly of the sulfonic acid moieties in the smectic phase benefited the anhydrous proton conduction of the sulfonic acid derivatives, and proton conductivities on the order of 10 −4 S/cm were achieved. The proton conductivity of1 in the smectic A phase is higher than that in the crystal state and isotropic liquid state.