Andrzej Żywociński - Academia.edu (original) (raw)

Papers by Andrzej Żywociński

Physical review, 1985

High-resolution volumetric study of the smectic-Asmectic-C transition in 4-(n-pentyl)phenylthio-4... more High-resolution volumetric study of the smectic-Asmectic-C transition in 4-(n-pentyl)phenylthio-4'-(n-octyl)oxybenzoate (8S5)

The Journal of Chemical Thermodynamics, Apr 1, 1983

... of the excess molar volumes of (cyclohexane +benzene) between 293.15 and 308.15 K by use of a... more ... of the excess molar volumes of (cyclohexane +benzene) between 293.15 and 308.15 K by use of a continuousdilution dilatometer STEFAN A. WIECZOREK ... plots for ((1x)C6H6+xcC6H,z1 at 298.15 K. SVm = VmVm(298.15 K)1: curve 1, Stokes, Levien, and Marsh;(' 2, Kumaran ...

Physical review, Aug 1, 1987

High-resolution volumetric study of the smectic-Atonematic transition in 4-(n-pentyl)phenylthiol-... more High-resolution volumetric study of the smectic-Atonematic transition in 4-(n-pentyl)phenylthiol-4'-(n-octyloxy)benzoate (SSS) and octyloxycyanobiphenyl (SOCB)

Philosophical Magazine Letters, 2004

Physical Review E, Jun 6, 2008

We propose a new surface treatment allowing to obtain a sliding planar anchoring of nematic (or c... more We propose a new surface treatment allowing to obtain a sliding planar anchoring of nematic (or cholesteric) liquid crystals. It consists of depositing a thin layer of the polymercaptan hardener of an epoxy resin on an isotropic substrate (bare or ITO-coated glass plates). Microscopic observations of defect annihilations and capacitance measurements show that the molecules align parallel to the surface and slide viscously on it when they change orientation, which implies a zero (or extremely small) azimuthal anchoring energy. By contrast, the zenithal anchoring energy W θ is found to be larger than 3 × 10 −5 J/m 2. We also measured the liquid crystal rotational surface viscosity γS by a new thermo-optical method using the large temperature variation of the pitch of a compensated cholesteric mixture. We found that the sliding length γS/γ1 (where γ1 is the bulk rotational viscosity) is very large in comparison with the length of a liquid crystal molecule. This result is explained by a simple model which takes into account the diffusion of the liquid crystal within the polymer layer.

Вестник Санкт-Петербургского университета. Серия 4. Физика. Химия, 2013

ABSTRACT 2013 ФИЗИКА Выпуск 2 Июнь ХИМИЯ НАУЧНО-ТЕОРЕТИЧЕСКИЙ ЖУРНАЛ. ИЗДАЁТСЯ С АВГУСТА 1946 ГОД... more ABSTRACT 2013 ФИЗИКА Выпуск 2 Июнь ХИМИЯ НАУЧНО-ТЕОРЕТИЧЕСКИЙ ЖУРНАЛ. ИЗДАЁТСЯ С АВГУСТА 1946 ГОДА СОДЕРЖАНИЕ ФИЗИКА Крылов И. Р., Охинченко И. А., Шапочкин П. Ю. Аппаратная асимметрия резо-нансов насыщения поглощения на примере резонансов SiF 4 /CO 2 .

Journal of Polymer Science Part B, Mar 1, 1995

SYNOPSIS Liquid-liquid demixing, following spinodal quenches of poly-2-chlorostyrene/polystyrene ... more SYNOPSIS Liquid-liquid demixing, following spinodal quenches of poly-2-chlorostyrene/polystyrene blends, was followed by light scattering at 632.8 nm. The dependences of demixing on H/ D substitution and molecular weight of the polystyrene, and on pressure, are reported. In the region of interest, the phase diagram is of the lower critical solution (LCS) type, and demixing is induced by raising the temperature. The transition temperature is lowered by deuterium substitution. At constant quench depth the transition proceeds more rapidly a t elevated pressure.

Journal of Physical Chemistry C, Mar 13, 2007

We investigate possible usage of single-walled carbon nanotubes (SWNTs) as an efficient storage a... more We investigate possible usage of single-walled carbon nanotubes (SWNTs) as an efficient storage and separation device of hydrogen-methane mixtures at room temperature. The study has been done using Grand Canonical Monte Carlo simulations for modeling storage and separation of hydrogen-methane mixtures in idealized SWNTs bundles. These mixtures have been studied at several pressures, up to 12 MPa. We have found that the values of the stored volumetric energy and equilibrium selectivity greatly depend on the chiral vector (i.e., pore diameter) of the nanotubes. The bundle formed by [5,4] SWNTs (nanotube diameter of 6.2 Å) can be regarded as a threshold value. Below that value the densification of hydrogen or methane is negligible. Bundles with wider nanotube diameter (i.e., 12.2, 13.6, 24.4 Å) seem to be promising nanomaterials for hydrogen-methane storage and separation at 293 K. SWNTs with pore diameters greater than 24.4 Å (i.e., [18,18]) are less efficient for both on-board vehicle energy storage and separation of hydrogen-methane mixture at 293 K with pressures up to 12 MPa. SWNTs comprised of cylindrical pores of 8.2 and 6.8 Å in diameter (equivalent chiral vector [6,6] and [5,5], respectively) are the most promising for separation of the hydrogen-methane mixture at room temperature, with the former selectively adsorbing methane and the latter selectively adsorbing hydrogen. We observed that inside the pores of [6,6] nanotubes absorbed methane forms a quasi-one-dimensional crystal when the system has thermalized. The average intermolecular distance of such a crystal is smaller than the one of liquid methane in bulk at 111.5 K, therefore exhibiting the quasione-dimensional system clear compression characteristics. On the other hand, for a smaller nanotube diameter of 6.8 Å the hydrogen can enter into the tubes and methane remaining in bulk. We found that in the interior of [5,5] nanotubes adsorbed/compressed hydrogen forms a quasi-one-dimensional crystal.

HAL (Le Centre pour la Communication Scientifique Directe), Dec 1, 2000

The line tension of a dislocation is measured in a vertical smectic-A film as a function of tempe... more The line tension of a dislocation is measured in a vertical smectic-A film as a function of temperature and film thickness. There are two contributions to the line tension: a bulk contribution that corresponds to the energy of the dislocation in an infinite medium and a surface correction that accounts for interactions with the two free surfaces. Both terms are measured in pure 8CB ͑octylcyanobiphenyl͒ as a function of temperature when the bulk nematic-smectic-A transition temperature T c is approached.

Thermochimica Acta, Mar 1, 1992

Abstract Long-term calorimetric measurements of energy production during the electrolysis of LiOD... more Abstract Long-term calorimetric measurements of energy production during the electrolysis of LiOD solutions with palladium or titanium electrodes were carried out using an automated diathermal calorimeter. No excess energy attributable to “cold fusion” was detected.

Journal of Physical Chemistry B, Oct 16, 2002

Journal of Physical Chemistry B, Aug 13, 2003

High-resolution molar volume data for 4-cyano-4'-n-octylbiphenyl (8CB) are presented as a fun... more High-resolution molar volume data for 4-cyano-4'-n-octylbiphenyl (8CB) are presented as a function of temperature near the nematic to isotropic (NI) phase transition. Close to the NI transition the volume was measured at 10 mK temperature steps and at two different pressures. From the data an isobaric thermal expansion coefficient, α p (T), and isothermal compressibility coefficient, β T (T), were calculated. Fitting the V(T) and β T (T) data according to a tricritical hypothesis with the critical exponents a = α'= allowed one to find the spinodal temperatures, T* and T**, on both sides of the first-order phase transition. A universal ratio (T N I - T*)/(T** - T N I ) is compared with the theoretical mean field value. The measured volume jump at the transition, ΔV N I , is related to the enthalpy jump, ΔH N I , which was obtained from the very precise calorimetric measurements by other authors.

Physical review, Dec 1, 2000

HAL (Le Centre pour la Communication Scientifique Directe), 2003

International audienc

Journal of Molecular Liquids, 2021

Kh2004000029, 1989

ściśliwości w funkcji temperatury • • • • • • • • • • • 9.4.5. Dyskusja wykładników krytycznych d... more ściśliwości w funkcji temperatury • • • • • • • • • • • 9.4.5. Dyskusja wykładników krytycznych dla przejścia fazowego smektyk-A-nematyk • 9.5. Przejście fazowe nematyk-faza izotropowa w 8CB •

Molecular Crystals and Liquid Crystals Incorporating Nonlinear Optics, 1987

Abstract High resolution measurements of molar volume V(T) and isothermal compressibility coeffic... more Abstract High resolution measurements of molar volume V(T) and isothermal compressibility coefficient were made on pure 10S5. The molar-volume variations show a classical second order smectic-A-smectic-C transition. These data are very well described by a mean—field Landau model. The isobaric thermal—expansion coefficient has been calculated. The data of the compressibility at the SmA—SmC transition do not show any singularity.

Journal de Physique, 1982

2014 Les densités des mélanges binaires de 4,4'-dipentylazoxybenzène (DPAB) et 4-éthyl-4'-pentyla... more 2014 Les densités des mélanges binaires de 4,4'-dipentylazoxybenzène (DPAB) et 4-éthyl-4'-pentylazoxybenzène (EPAB) avec 4-pentyl-4'-cyanobiphényle (PCB) pour les concentrations moyennes et dans l'intervalle des températures 25-80 °C sont mesurées. Les volumes isothermes de mélange des solutions Vs (égaux aux volumes d'excès VE, en cas d'existence des deux composants dans la même phase que la solution) sont aussi calculés à partir des interpolations de volumes molaires. Les coefficients isobares de dilatation thermique, pour un mélange de EPAB + PCB sont aussi calculés. La présence de complexes molaires de type A-B est confirmée. Abstract.-Densities of binary mixtures of 4,4'-dipentylazoxybenzene (DPAB) and 4-ethyl-4'-pentylazoxybenzene (EPAB) with 4-pentyl-4'-cyanobiphenyl (PCB) were measured over the temperature range of 25 to 80 °C and in the middle area of concentrations. Isothermal volumes of mixing Vs (equal to the excess volume VE when both pure components and solution are in the same phase) were also calculated from interpolated molar volumes. Isobaric thermal expansion coefficients were also calculated for one of the mixture concentrations EPAB + PCB. The presence of a molecular A-B complex has been confirmed.

Journal de Physique, 1986

2014 Des études de l'influence du rapport r des épaisseurs des couches smectiques des composants ... more 2014 Des études de l'influence du rapport r des épaisseurs des couches smectiques des composants d'un mélange binaire sur l'allure du diagramme de phase ont été effectuées. Les mélanges de 80CB (smectique Ad) et d'un des composés de la série homologue des 5-n-alkyl-2-(4-isothiocyanatophenylo) dioxane-1,3 (DBT-smectiques A1) ont été pris comme exemples. Quand r augmente la stabilité de la phase smectique en mélange diminue et pour r ~ 1,4 on observe un intervalle nématique séparant les régions des smectiques A1 et Ad. Pour le système binaire particulier 80CB-4DBT on a examiné les densités, les viscosités et les données de la diffusion des rayons X en fonction de la composition et température. Enfin les enthalpies des transitions de phase ont été mesurées. Le nematique séparant les smectiques présente une viscosité et structure interne caractéristiques des nématiques typiques. Le volume molaire du système binaire dépasse ceux des composants; l'excès est maximal pour des concentrations en 80CB inférieures à 0,2. Abstract 2014 The effect is tested of the smectic layer spacing ratio, r, on the phase diagram for the binary systems consisting of 80CB (smectic Ad) and one of the twelve compounds of the 5-n-alkyl-2-(4'-isothiocyanatophenyl) dioxane-1,3 homologous series (DBT compounds-smectics A1) has been studied The stability of the smectic phase in the mixture decreases with increasing r, and for r ~ 1.4 a nematic gap separating the smectics A1 and Ad is observed The density, viscosity and scattering of X-rays as a function of temperature are measured and the enthalpy of the phase transitions is determined for the binary system 80CB-4DBT. The nematic phase reveals in the nematic gap a viscosity and structure characteristic for typical nematics. The binary system increases its molar volume as a result of mixing and assumes a maximum in the concentration range x8OCB 0.2.

Physical Review A, 1983

Sensitive volumetric measurements show a classical second-order 2-C transition in mixtures of 8S5... more Sensitive volumetric measurements show a classical second-order 2-C transition in mixtures of 8S5 with 755 in agreement with findings of Schantz and Johnson for pure 8S5, and apparently a first-order A-K transition (although an extremely weak one) for 30 and 37 mole %% of 7S 5; thus an earlier suggestion of a (critical) end point where a second-order A-C line meets the border of a first-order region, X-A and then 2V-C, is corroborated. I. INTRQI3UCTION Besides the indication of tricritical behavior other interesting multicritical phenomena have been studied in liquid crystals and their mixtures. An interesting case has been studied by Johnson et al. In this binary mixture one pure compound, 8S5, displays the smectic-C, smectic-A, and nematic phases whereas the other, 7S5, shows no smectic-A phase. Thus the smectic-A phase gets squeezed out and hence on the temperature-mole fraction (T,x) phase diagram three lines of phase transitions, A-C, N-A, and C N, meet-at what was called the NAC point. In reality a first-order transition line in a mixture remains a line only in field variables, whereas it becomes a two-phase region, often narrow, bounded by two lines when T xvariables areused. The meeting of three first-order transitions results in a triple point just as is obtained in every pure substance when vapor, liquid, and crystal coex