Alkyl chains in a nematic field. 2. Temperature and chain length dependence of orientation ordering

Journal Article · Thu May 31 04:00:00 EDT 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100374a059· OSTI ID:6379059

Photinos, D J; Samulski, E T; Toriumi, Hirokazu ^[1]

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1. Univ. of North Carolina, Chapel Hill (USA)

A model of flexible solutes which explicitly includes molecular shape anisotropy and flexibility (Photinos et al., preceding paper in this issue) exhibits quantitative agreement with observed temperature and chain-length dependence of deuterium NMR segmental order profiles of alkanes dissolved in a nematic solvent. A generalized order parameter for flexible chains is proposed and the average properties of the constrained chain are contrasted with the same properties calculated for chains in an isotropic medium. Conformer probabilities (corrected for inertial effects) are similar to those computed for isotopic (liquid) alkanes. The picture of these flexible solutes in the anisotropic mean field that emerges from our quantitative modeling of NMR data suggests that, although the alkanes may acquiesce and conform to the nematic constraints, they retain considerable conformational freedom and exhibit (average) properties that are only slightly perturbed from those found in the isotropic state.

• OSTI ID: 6379059
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 94:11; ISSN JPCHA; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
BONDING
CALCULATION METHODS
CRYSTALS
FABRICATION
FLUIDS
HYDROCARBONS
INTERACTIONS
JOINING
LIQUID CRYSTALS
LIQUIDS
MATHEMATICAL MODELS
ORGANIC COMPOUNDS
ORIENTATION
TEMPERATURE DEPENDENCE