Molecular model for nematic polymers in liquid crystal solvents

Abstract

A theory for the nematic-isotropic phase transition in semirigid polymer/liquid crystal solutions is proposed. The polymer is described by an elastic chain and van der Waals and steric intermolecular interactions are included in a mean field approximation. It is shown that these interactions orient the liquid crystal molecules and the polymer chains in the solution. The order parameter of the liquid crystal molecules and of the polymer are calculated as a function of temperature and concentration and the phase diagram for the first order phase transition is given. The effects of chain length and chain flexibility are discussed.

Nematic Phase Transition in Systems of Polymer Chains with Mesogenic Groups

“…. dijp+, fi K(iji, 5 i + l ) , i = l where K ( s i , G i + 1 ) = JJ exp ( -f i i /~)~[ c i ( q ) ] ,(12)w and Hi is defined by Equation(9). Owing to the spherical approximation the integralI2 can be reduced to the well-known functional integral for the harmonic oscillator12 and so can be calculated exactly.…”

Phase transitions in lyotropic colloidal and polymer liquid crystals

“…behaviour at higher densities, with attractive interactions and for bidisperse systems), they do not lead to the exact result of Onsager for infinitely thin hard rods. There are also some other models based on the wormlike chain which we can only mention here: an extension of the Flory theory to wormlike chains (Ronca and Yoon 1982, 1985 and theories using a Maier-Saupe potential (Ten Bosch et al 1983, \torner et al 1985. As a last point we want to draw attention to some monographs and review papers on liquid crystals (De Gennes 1974, Stephen and Straley 1974, Chandrasekhar 1977, Luckhurst and Gray 1979, Vertogen and De Jeu 1988, Frenkel 1991 and liquid crystalline polymers (Straley 1973a, Blumstein 1978, Grosberg and Khokhlov 1981, Ciferri et al 1982, Miller 1982, Samulski and DuPré 1983, Gordon and Plate 1984, Khokhlov and Semenov 1985, Ciferri and Marsano 1987, Semenov and Khokhlov 1988, DuPré and Yang 1991, which might be helpful for the reader.…”

Interaction of mono-carboxylic acids in benzene studied by small-angle neutron scattering

“…The closest to the experimental data is the case of the random phase approximation (RPA) model for the straight rigid rod-like particles [9]. This model considers in a standard way [31][32][33]9] the excluded volume interaction between such particles as a sum of isotropic and orientation dependent contributions. Below, the second contribution is referred as nematic attraction.…”