As their name indicates, liquid crystals simultaneously exhibit some characteristics common to both ordinary isotropic liquids and solid crystals. This ambivalence is also found in the effects of surfaces on these systems which lead to a great diversity of phenomena. These phenomena are reviewed focusing on nematic liquid crystals which have the simplest structure among the many existing types and which have been the most extensively studied. Three main kinds of effects can be distinguished. The first concerns the perturbation of the liquid crystalline structure close to the surface. Beyond this transition region, the bulk liquid crystalline structure is recovered with an orientation which is fixed by the surface: this phenomenon of orientation of liquid crystals by surfaces is the so-called anchoring. Finally, close to bulk phase transitions, critical adsorption or wetting can occur at surfaces as is also seen in isotropic systems.

https://iopscience.iop.org/article/10.1088/0034-4885/54/3/002/pdf

Surface effects and anchoring in liquid crystals

If the potential for a boom in the global hydrogen economy is realized, there will be an increase in the need for accurate hydrogen thermodynamic property standards. Based on current and anticipated needs, new fundamental equations of state for parahydrogen, normal hydrogen, and orthohydrogen were developed to replace the existing property models. To accurately predict thermophysical properties near the critical region and in liquid states, the quantum law of corresponding states was applied to improve the normal hydrogen and orthohydrogen formulations in the absence of available experimental data. All three equations of state have the same maximum pressure of 2000MPa and upper temperature limit of 1000K. Uncertainty estimates in this paper can be considered to be estimates of a combined expanded uncertainty with a coverage factor of 2 for primary data sets. The uncertainty in density is 0.04% in the region between 250 and 450K and at pressures up to 300MPa. The uncertainties of vapor pressures and saturated liquid densities vary from 0.1% to 0.2%. Heat capacities are generally estimated to be accurate to within 1%, while speed-of-sound values are accurate to within 0.5% below 100MPa.

/pdf/fundamental-equations-of-state-for-parahydrogen-normal-jfrnkfiwco.pdf

Fundamental Equations of State for Parahydrogen, Normal Hydrogen, and Orthohydrogen

Developments in the foundations of statistical mechanics during the past ten years or so. The author discusses how statistical concepts enter the treatment of deterministic mechanical systems, with particular reference to trajectory instabilities and to the KAM theorem. Then he deals with large systems: the thermodynamic limit and the theory of infinite systems. Non-equilibrium statistical mechanics is covered but LC relativistic statistical mechanics is not.

https://iopscience.iop.org/article/10.1088/0034-4885/42/12/002/pdf

Foundations of statistical mechanics

Phase transitions in liquid crystals

Landau theory of the nematic-isotropic phase transition

At sufficiently low frequency and small amplitude the sound velocity W in a fluid can be regarded as a purely thermodynamic property related to the adiabatic compressibility β S = - 1/V(∂V/∂p)s and the density ρ = M/V by 

$$ {W^{2}} = \frac{1}{{\rho \beta s}} $$

(1)

or 

$$ {W^{2}} = k{\left( {\frac{{\partial p}}{{\partial \rho }}} \right)_{T}} $$

(2)

where k is the ratio of the specific heats C p /C v .

Properties of Some Cryogenic Liquids from Sound Velocity Data

The Velocity of Ultrasonic Pulses in Hydrogen Between 60 and 90°K as a Function of Pressure

Some liquid crystals exhibit mesophases between the isotropic phase and the chiral nematic (or cholesteric) phase. There may be up to three different spatial structures in a temperature interval as small as 1 K. These phases are optically not birefringent and they reflect preferentially short wavelengths: that is why they are called blue phases1.

W. Van Dael

Papers

Properties of Some Cryogenic Liquids from Sound Velocity Data

The Velocity of Ultrasonic Pulses in Hydrogen Between 60 and 90°K as a Function of Pressure

Optical Activity in the Isotropic and Blue Phases of a Chiral Liquid Crystal