Orientational Ordering of the Near-Surface Layers of Nitrobenzene

Kuznetsova, A. A.; Mikhailenko, V. I.; Popovskii, A. Yu.

doi:10.1023/b:japs.0000049622.74381.ca

Cited by 4 publications

(8 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The spectra were recorded in the region of the atmospheric UV range: in the frequency interval 34000-42000 cm -1 for anisole and 30000-50000 cm -1 for nitrobenzene. In the indicated frequency range for anisole there is a band connected with one vibronic transition, and for nitrobenzene we observe a number of overlapping bands due to several vibronic transitions [3].…”

Section: Introductionmentioning

confidence: 72%

Effect of a solid substrate on orientational ordering and the process of associate formation in thin interlayers of solutions of some organic compounds

2006

Self Cite

View full text Add to dashboard Cite

We have studied the vibronic absorption spectra of thin submicron interlayers of anisole and nitrobenzene solutions as a function of the concentration and thickness of the interlayer. We have observed isosbestic points in a series of spectra obtained for different concentrations and thicknesses. This in turn is due to the existence in the system of two types of absorbing centers, which we connect with monomers and molecular associates (dimers). We discuss the relative contribution of different types of interactions leading to dimer formation.Introduction. Wall layers of organic liquids consisting of polar anisometric molecules are orientationally ordered like nematic liquid crystals under the action of the field of a lyophilic solid substrate. Therefore in these systems, as previously in nematics [1], we should expect the appearance of an associate formation effect due to dipole-dipole molecular interaction. The results of an experimental study of this effect in interlayers of nonmesogens by spectroscopy and dielectric constant measurements have been reported in [2]. Obviously the appearance of an associate formation effect is due to the action of an asymmetric surface force field and intermolecular dispersion interaction between monomer-dimer and dimer-dimer pairs, and also dipole interaction between monomer-monomer pairs.It is of interest to estimate the relative contribution of each of these interactions to the observed effects. In other words, we need to determine whether only one intermolecular interaction between liquid particles is sufficient to form dimers, or if a major role is played in the dimerization process by the surface force field.Experiment. The associate formation effect has been studied for nonmesogenic preparations such as polar monosubstituted benzene-nitrobenzene (C 6 H 5 -NO 2 ) and anisole (C 6 H 5 -O-CH 3 ), the dipole moments of which are equal to 4.2 D and 1.35 D respectively. In order to study the relative contribution of each type of interaction, they must be varied independently. By varying the thickness of the liquid interlayer, we can vary the contribution from the surface force field; and by varying the concentration of the solution of the test preparation, we can affect the contribution of the second factor.The characteristic features of the molecular structure of the wall layers were studied by investigating the shape of the bands in the electronic absorption spectra for submicron interlayers of solutions of the samples. The spectra were recorded in the region of the atmospheric UV range: in the frequency interval 34000-42000 cm -1 for anisole and 30000-50000 cm -1 for nitrobenzene. In the indicated frequency range for anisole there is a band connected with one vibronic transition, and for nitrobenzene we observe a number of overlapping bands due to several vibronic transitions [3].In the low concentration range, the spectra were recorded in standard cuvets for a planar layer with variable

show abstract

Section: Introductionmentioning

confidence: 72%

Effect of a solid substrate on orientational ordering and the process of associate formation in thin interlayers of solutions of some organic compounds

2006

Self Cite

View full text Add to dashboard Cite

show abstract

“…Изучение свойств полимолекулярного ориентаци-онно упорядоченного приповерхностного эпитропно 1 -жидкокристаллического (ЭЖК [1-3]) слоя необходимо для развития теоретических представлений о природе этого состояния [3][4][5][6], усовершенствования его количе-ственной физической модели [7] и, в частности ЭЖК слоев н-алканов как основ минеральных смазочных ма-сел [8][9][10], для решения практической задачи управления процессами трения в механизмах [11,12].…”

Section: Introductionunclassified

“…Ввиду малой (∼ 4 µm и менее) толщины d s ЭЖК слоев прямое их изучение затруднительно, поэтому в оптических [2,3,5,6,12,13] и реологических [12,[14][15][16] экспериментах обычно исследовались гетерофазные (со-держащие ЭЖК слои и пространственно отделенную от них " объемную" жидкость) прослойки толщиной D ∼ 1.5−10 µm, а для установления характеристик сло-ев использовалась определенная структурная модель прослойки, в которой заложены параметры слоя d s и вязкость µ. При расчете последних в реологических опы-тах измерялась " эффективная" вязкость η eff прослойки и применялись дополнительно различные гидродинамиче-ские модели слоя с постоянной вязкостью, зависящей от расстояния до подложки, от интенсивности течения и др., но собственно структура ЭЖК слоя при этом не рассматривалась. Предлагаемые [3][4][5][6] механизмы орга-низации ЭЖК фазы в должной степени не описывали экспериментально установленные ее свойства.…”

Section: Introductionunclassified

See 1 more Smart Citation

Эпитропно-Жидкокристаллический Слой Гексадекана В Реологической Модели Гетерофазной Прослойки

Алтоиз¹,

Бутенко²,

Кириян³

2018

Журнал Технической Физики

View full text Add to dashboard Cite

“…The brightest experimental results were connected with measurements and the further processing of series of intrinsic electronic-vibrational absorption spectra [11]. These spectra were measured for ultrathin liquid interlayers in wide ranges of their thicknesses, temperatures, and concentrations [13,14]. The statistical analysis of spectral results showed the existence of two types of absorption centers in this system.…”

Section: Introductionmentioning

confidence: 99%

Properties of Wall-Adjacent Epitropic Liquid Crystalline Layers

Popovskii

Mikhailenko

2012

Ukr. J. Phys.

View full text Add to dashboard Cite

A two-component theoretical model of orientational ordering in wall-adjacent layers of a nonmesogenic liquid (consisting of monomers and dimers) with anisotropic intermolecular interaction has been developed. In the framework of the model, a number of experimental results such as the isotherms of disjoing pressure and some peculiarities in the behavior of heat capacity and dielectric permittivity of the liquid interlayers have been explained.

show abstract

Orientational Ordering of the Near-Surface Layers of Nitrobenzene

Cited by 4 publications

References 6 publications

Effect of a solid substrate on orientational ordering and the process of associate formation in thin interlayers of solutions of some organic compounds

Effect of a solid substrate on orientational ordering and the process of associate formation in thin interlayers of solutions of some organic compounds

Эпитропно-Жидкокристаллический Слой Гексадекана В Реологической Модели Гетерофазной Прослойки

Properties of Wall-Adjacent Epitropic Liquid Crystalline Layers

Contact Info

Product

Resources

About