相关论文: Hydrogen-bonded Silica Gels Dispersed in a Smectic…
Comprehensive x-ray scattering studies have characterized the smectic ordering of octylcyanobiphenyl (8CB) confined in the hydrogen-bonded silica gels formed by aerosil dispersions. For all densities of aerosil and all measurement…
We report a high-resolution x-ray scattering study of the smectic liquid crystal octylcyanobiphenyl (8CB) confined to aligned colloidal aerosil gels. The aligned gels introduce orientational fields that promote long-range nematic order…
The effects of dispersed aerosil nanoparticles on two of the phase transitions of the thermotropic liquid crystal material 4-n-pentylphenylthiol-4'-n-octyloxybenzoate 8barS5 have been studied using high-resolution x-ray diffraction…
We have studied the effects of quenched random disorder created by dispersed aerosil nanoparticle gels on the nematic to smectic-A (N-SmA) and smectic-A to reentrant nematic (SmA- RN) phase transitions of thermotropic liquid crystal…
High-resolution ac-calorimetry has been carried out on dispersions of aerosils in the liquid crystal octyloxycyanobiphenyl (8OCB) as a function of aerosil concentration and temperature spanning the crystal to isotropic phases. The…
The short-range order which remains when the isotropic to smectic-A transition is perturbed by a gel of silica nanoparticles (aerosils) has been studied using high-resolution synchrotron x-ray diffraction. The gels have been created…
We present a neutron scattering analysis of the structure of the smectic liquid crystal octylcyanobiphenyl (8CB) confined in one-dimensional nanopores of porous silicon films (PS). The smectic transition is completely suppressed, leading to…
High-resolution X-ray scattering studies of the nonpolar thermotropic liquid crystal 4-n-pentylphenylthiol-4'-n-octyloxybenzoate (\bar{8}S5) in aerosil gel nano-networks reveal that the aerosil-induced disorder significantly alters both the…
Liquid crystals offer many unique opportunities to study various phase transitions with continuous symmetry in the presence of quenched random disorder (QRD). The QRD arises from the presence of porous solids in the form of a random gel…
We report studies of the frequency dependent shear modulus, $G^*(\omega)=G'(\omega)+iG''(\omega)$, of the liquid crystal octylcyanobiphenyl (8CB) confined in a colloidal aerosil gel. With the onset of smectic order, $G'$ grows approximately…
A high-resolution calorimetric study has been carried out on nano-colloidal dispersions of aerosils in the liquid crystal 4-\textit{n}-pentylphenylthiol-4'-\textit{n}-octyloxybenzoate ($\bar{8}$S5) as a function of aerosil concentration and…
Confinement in the nanochannels of porous silicon strongly affects the phase behavior of the archetype liquid-crystal 4-n-octyl-4-cyanobiphenyl (8CB). A very striking phenom- enon is the development of a short-range smectic order, which…
The liquid crystal octylcyanobiphenyl (8CB) was doped with the chiral agent CB15 and spin-coated onto a substrate treated for planar alignment of the director, resulting in a film of thickness several hundred nm in the smectic-A phase. In…
We report combined optical birefringence and neutron scattering measurements on the liquid crystal 12CB nanoconfined in mesoporous silicon layers. This liquid crystal exhibits strong nematic-smectic coupling responsible for a discontinuous…
Optical birefringence measurements on a rod-like liquid crystal (8OCB), imbibed in silica channels (7 nm diameter), are presented and compared to the thermotropic bulk behavior. The orientational and positional order of the confined liquid…
We have studied the quenched random disorder (QRD) effects created by aerosil dispersion in octylcyanobiphenyl (8CB) liquid crystal (LC) using Atomic Force Microscopy (AFM) technique. Gelation process in the 8CB+aerosil gels yields a QRD…
The continuous nematic to smectic-A (N-SmA) phase transition has been studied by high-resolution ac-calorimetry in binary mixtures of the liquid crystal octylcyanobiphenyl(8CB) and a non-mesogenic, low-molecular weight, solvent…
4-n-octyl-4-cyanobiphenyl (8CB) has been recently shown to display an unusual sequence of phases when confined into porous silicon (PSi). The gradual increase of oriented short-range smectic (SRS) correlations in place of a phase transition…
We study the smectic AC transition in anisotropic and uniaxial disordered environments, e.g., aerogel with an external field. We find very strange behavior of translational correlations: the low-temperature, lower-symmetry Smectic C phase…
The effect of a rigid, non-polar and nonmesogenic solute biphenyl ((C_{6}H_{5}-C_{6}H_{5})) on the divergence of the bend elastic constant K_{33} of (4,4^{\prime}) -n-octyl-cyanobiphenyl (8CB) near the smecticA-nematic transition is…