N Sukumar - New Group IV Chemical Motifs for Improved Dielectric Permittivity of Polyethylene

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      Publication Details (including relevant citation   information):



    1.      J. Chem. Inf.   Model.    53(4):879–886 (2013)   DOI:10.1021/ci400033h


      An enhanced dielectric permittivity of polyethylene and related   polymers, while not overly sacrificing their excellent insulating   properties, is highly desirable for various electrical energy   storage applications. In this computational study, we use density   functional theory (DFT) in combination with modified group   additivity based high throughput techniques to identify promising   chemical motifs that can increase the dielectric permittivity of   polyethylene. We consider isolated polyethylene chains and allow   the CH2 units in the backbone to be replaced by a number of Group   IV halides (viz., SiF2, SiCl2, GeF2, GeCl2, SnF2, or SnCl2 units)   in a systematic, progressive, and exhaustive manner. The   dielectric permittivity of the chemically modified polyethylene   chains is determined by employing DFT computations in combination   with the effective medium theory for a limited set of   compositions and configurations. The underlying chemical trends   in the DFT data are first rationalized in terms of various   tabulated atomic properties of the constituent
      atoms. Next, by parametrizing a modified group contribution   expansion using the DFT data set, we are able to predict the   dielectric permittivity and bandgap of nearly 30 000 systems   spanning a much larger part of the configurational and
      compositional space. Promising motifs which lead to   simultaneously large dielectric constant and band gap in the   modified polyethylene chains have been identified. Our   theoretical work is expected to serve as a possible motivation   for future experimental efforts.

      Address (URL): http://www.doi.org/10.1021/ci400033h