Local vibration assisted molecular configurations in poly(vinylidene fluoride) of ordered ferroelectric phase in N,N-dimethylformamide

• Published in: Journal of molecular liquids 2011-07, Vol.161 (3), p.132-138
• Main Authors: Susrutha, B., Ram, S., Tyagi, A.K.
• Format: Article
• Language: English
• Subjects: Configurations; Molecular interactions; N,N-dimethylformamide; Poly(vinylidene difluoride); Polymer liquids; Vibrational spectra
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2011.05.005

Amide-based polymer liquids are important for developing biological and optical colloids or nanofluids. Functionalized properties arise from specific molecular structures. In this investigation, we report model molecular configurations of a polymer liquid, 0.3 g/L poly(vinylidene fluoride) (PVF 2) dissolved in liquid N,N-dimethylformamide (DMF), based on the characteristic IR vibration bands. Peculiarly, a ferroelectric β-PVF 2 phase reorders on a linear configuration in support with the DMF molecules, showing a characteristic band 840 cm − 1 (CH 2 rocking and CF 2 asymmetric stretching) with the trans band at 1275 cm − 1 . Four C O stretching bands ν 1 0, ν 1 1, ν 1 2, and ν 1 3 of 1650, 1675, 1725, and 1760 cm − 1 (bandwidth Δν ½ = 180 cm − 1 in the four bands) arise in four major configurations of DMF–PVF 2 pairs (or derivatives). Only one prominent ν 1 0 band 1660 cm − 1 (Δν ½ = 75 cm − 1 ) incurs with a shoulder ν 1 1 of 1725 cm − 1 (Δν ½ = 25 cm − 1 ) in two DMF configurations. A ferroelectric field cased in presence of β-PVF 2 leads to enhance IR absorption by as much as an order of magnitude. It leads to converging non-bonding electron density on the amide moiety. [Display omitted] ► We report, model molecular configurations and vibrational structure of PVF 2 in DMF. ► IR bands of PVF 2 molecules in DMF and pure DMF are studied. ► H-bonding of CHO and CH 3 groups of DMF with PVF 2 forms stable molecular configurations. ► A ferroelectric β-PVF 2 phase reorders out of a linear configuration with DMF.