Showing papers in "Molecular Crystals and Liquid Crystals in 2012"
TL;DR: In this article, a homologous series of 8-(4′-n-alkoxybenzoyloxy) quinolines were synthesized by established methods and evaluated by optical microscopy.
Abstract: A homologous series of 8-(4′-n-alkoxybenzoyloxy) quinolines were synthesized by established methods [5,6]. On evaluation by optical microscopy, none of the homologues were found to exhibit mesogenic behavior even in the monotropic condition. Then, each homologue (B) was mixed with a liquid crystal component (A) and binary systems were studied by optical microscopy. Solid–mesomorphic or isotropic–nematic transition temperatures of binary mixtures were determined and plotted to obtain the phase diagram for transition temperatures versus percentage composition of component (A). The nematic–isotropic transition curve was extrapolated to zero mole percentage of component (A) (100%B) to determine the latent transition temperature (LTT) of each nonmesomorphic homologue. The number of carbon atoms in the n-alkyl chain of each homologue versus LTT is plotted and a phase diagram is obtained. The isotropic–nematic transition curve behaves in a normal manner like a curve behaving for a typical nematogenic homologous ...
87 citations
TL;DR: In this article, the degradations of biodegradable poly(3-hydroxybutyrate) (PHB), polylactide (PLA) and their derivatives were explored by kinetic and structure methods at 37 and 70°C in phosphate buffer.
Abstract: Hydrolytic degradations of biodegradable poly(3-hydroxybutyrate) (PHB), polylactide (PLA) and their derivatives were explored by kinetic and structure methods at 37 and 70°C in phosphate buffer. It was revealed the kinetic profiles for copolymer PHBV (20% of 3-hydroxyvalerate) and the blend PHB-PLA (1:1 wt. ratio). The intensity of biopolymer hydrolysis depending on temperature is characterized by total weight loss and the viscosity-averaged molecular weight decrement (ΔMW) as well as by WAXS and AMF techniques. Characterization of PHB and PHBV includes both ΔMW and crystallinity evolution (x-ray diffraction) as well as the AFM analysis of PHB film surfaces before and after aggressive medium exposition. The degradation is enhanced in the series PHBV < PHB < PHB-PLA blend < PLA. The impact of MW on the biopolymer hydrolysis is shown.
69 citations
TL;DR: In this paper, the latent transition temperature (LTT) for the nonmesomorphic component (B) of a binary system by an extrapolation method was obtained for seven binary systems consisting of mesomorphs and nonmesomorphs.
Abstract: Eight binary systems consisting of mesomorphs and nonmesomorphs (A1 or A2, + B1, B2, … B7, B8) were studied with a view to determine the latent transition temperature (LTT) for the nonmesomorphic component (B) of a binary system by an extrapolation method. Encouraging results supporting earlier views and LTT values were obtained for seven binary systems. Instead of reporting a single value of LTT, the range of temperature or two or three values are reported herewith depending upon the possible paths of extrapolation. LTT reported earlier for nonmesomorphs lie within the range of temperature determined presently. Though the “group slope value” differs from the earlier reported value, the group efficiency order remains the same. Thus, the present investigation raises the credibility of an extrapolation method to determine LTT and group efficiency order for nematic mesophase. Component A1 and A2 are nematogenic, namely, p-(p′-n-propyloxy benzoyloxy) anisole (A1) (90.0 to 116.0) and p-(p′-n-butyloxy benzoylox...
64 citations
TL;DR: In this paper, a new homologous series viz. Isobutyl-p-(p′-nalkoxy cinnamoyloxy) is synthesized with an isobutyl cinnamate end group and a further cinnamic moiety as a linking group.
Abstract: A new homologous series viz. Isobutyl-p-(p′-n-alkoxy cinnamoyloxy) cinnamates consisting of 11 homologs has been synthesized with an isobutyl cinnamate end group and a further cinnamate moiety as a linking group. The methyl to butyl homologs are nonmesomorphic, and the pentyl to hexadecyl derivatives are enantiotropic nematogens without exhibition of any smectic phases. The average thermal stability for the nematic phase is 138.1°C with a middle ordered melting point. The structures of the novel materials were confirmed by spectroscopic techniques. The liquid crystal phase type was determined by optical polarizing microscopy and all textures are of the threaded type. The mesomorphic behavior of the series is compared with a structurally similar homologous series.
55 citations
TL;DR: Ionic conducting membranes of gelatin plasticized with glycerol and containing LiI/I2 have been obtained and characterized by X-ray diffraction measurements, UV-Vis-NIR spectroscopy, thermal analysis and impedance analysis.
Abstract: Ionic conducting membranes of gelatin plasticized with glycerol and containing LiI/I2 have been obtained and characterized by X-ray diffraction measurements, UV-Vis-NIR spectroscopy, thermal analysis and impedance spectroscopy. The transparent (80–90% in the visible range) membranes showed ionic conductivity value of 5 × 10−5 S/cm at room temperature, which increased to 3 × 10−3 S/cm at 80°C. All the ionic conductivity measurements as a function of temperature showed VTF dependence and activation energy of 8 kJ/mol. These samples also showed low glass transition temperature of −76°C. Moreover the samples were predominantly amorphous. The membranes applied to small electrochromic devices showed 20% of color change from colored to bleached states during more than 70 cronoamperometric cycles.
42 citations
TL;DR: In this paper, the ionic conductivity revealed the best result of 6.5 × 10−5 S/cm for the sample with 17 wt.% of LiClO4.
Abstract: Gel Polymer Electrolytes (GPE) based on agar and containing LiClO4 have been prepared, characterized and applied to electrochromic devices. The ionic conductivity revealed the best result of 6.5 × 10−5 S/cm for the sample with 17 wt.% of LiClO4, which increased to 5.4 × 10−4 S/cm at 72°C. The GPE have been used in electrochromic devices (ECD) with K-glass/WO3/GPE/CeO2-TiO2/K-glass configuration. The ECD changed transmittance values up to 30% between the colored and transparent states. The charge density measurements revealed an increase of 5.5 to 7.5 mC/cm2 from the first to 500th cycles and then a decrease to 4.4 mC/cm2 during the next 4500 cycles. Coloration efficiency (η) of 25 cm2/C was obtained.
36 citations
TL;DR: In this paper, Gellan-based polymer electrolytes (PEs), doped with lithium iodide (LiI), were prepared and their electrical properties were characterized, showing that they are thermally stable up to 234°C and exhibit ionic conductivity of 3.8 × 10−4 S/cm at room temperature.
Abstract: Gellan-based polymer electrolytes (PEs), doped with lithium iodide (LiI), were prepared and their electrical properties were characterized. The samples are thermally stable up to 234°C and exhibit ionic conductivity of 3.8 × 10−4 S/cm at room temperature for the sample doped with 40 wt% of LiI. Addition of 10 wt% of glycerol promotes an increase of the ionic conductivity to 1.5 × 10−3 S/cm, which remains stable up to 100°C. The activation energies of 2.4 to 12.4 kJ/mol were derived from the Arrhenius model. The repeated ionic conductivity measurements as a function of temperature show that these membranes can be reversibly used between the room temperature and 100°C.
34 citations
TL;DR: The collagen scaffold with 0.75% niflumic acid solved in laurel oil was optimal in terms of biodegradability, absorbability and fibroblast cells biocompatibility and could be used as wound dressings with absorbent, antibacterial and anti-inflammatory properties.
Abstract: The aim of this study was to develop modern wound dressings such as controlled drug delivery systems. These systems consist in collagen as release support and niflumic acid as drug. The scaffolds were prepared by lyophilization in order to obtain porous structures and were evaluated by release profile of niflumic acid, water absorption, collagenase degradation and biocompatibility with fibroblast cells. The collagen scaffold with 0.75% niflumic acid solved in laurel oil was optimal in terms of biodegradability, absorbability and fibroblast cells biocompatibility. Thus, the obtained collagen scaffolds could be used as wound dressings with absorbent, antibacterial and anti-inflammatory properties.
34 citations
TL;DR: In this paper, a water/n-heptane microemulsion stabilised by the nonionic Brij-30 surfactant was used to synthesize a nanorod-like structure made of spherical nanocrystals.
Abstract: Copper oxide (CuO) nanorod-like structures made of spherical nanocrystals were synthesized at moderate temperature (80°C) starting from CuCl2·2H2O crystals in a water/n-heptane microemulsion stabilised by the nonionic Brij-30 surfactant. Whole Powder Pattern Modelling of the X-ray diffraction pattern shows absence of linear and planar defects with crystalline domains in the range of 4–8 nm. A linear correlation between the average size of the particles and the quantity of water in the system was observed: all synthesised specimens show a large blue shift of the energy bandgap (up to 2.7 eV versus 1.2 eV of bulk CuO) resulting from quantum confinement effects. The mechanism of growth of the spherical nanoparticles into nanorod-like structures has been elucidated.
32 citations
TL;DR: In this paper, the optical and thermal properties of two nonmesogenic compounds, namely, tetradecyl trimethyl ammonium bromide (TTAB) and glacial acetic acid (GAA), were investigated.
Abstract: We report the results of our studies on the optical and thermal properties of two nonmesogenic compounds, namely, tetradecyl trimethyl ammonium bromide (TTAB) and glacial acetic acid (GAA). The mixture exhibits very interesting schilieren texture of micellar nematic lyophase, smectic A (SmA), and SmG phases for all concentrations of TTAB sequentially when the specimen is cooled from its isotropic phase. The order parameter (S) of the micellar nematic phase is estimated with the help of temperature dependence of optical anisotropy from the measured refractive index and density data. The temperature variation of order parameter of the experimental curve is very well fitted with the Mayer–Saupe theoretical curve. The temperature variation of electrical conductivity is also discussed. The formation of above phases has been confirmed by optical X-ray and differential scanning calorimetry studies.
31 citations
TL;DR: In this article, the authors investigated gel polymer electrolytes (GPEs) based on sodium alginate plasticized with glycerol containing either CH3COOH or LiClO4.
Abstract: The present study investigates gel polymer electrolytes (GPEs) based on sodium alginate plasticized with glycerol containing either CH3COOH or LiClO4. The membranes showed ionic conductivity results of 3.1 × 10−4 S/cm for the samples with LiClO4 and 8.7 × 10−5 S/cm for the samples with CH3COOH at room temperature. The samples also showed thermal stability up to 160°C, transparency of up to 90%, surface uniformity and adhesion to glass and steel. Moreover, Dynamic Mechanical Analysis revealed two relaxations for both samples and the Ea values were between 18 and 36 kJ/mol. All the results obtained indicate that alginate-based GPEs can be used as electrolytes in electrochemical devices.
TL;DR: In this paper, the effect of terminal groups on nematic and/or smectic mesomorphism was studied with a view to understand how terminal groups affect mesomorphisms.
Abstract: Three binary systems, each consisting of two nonmesogenic compounds, viz. p-tolual-p-phenetidine (M.P. 108.5°C) [A] as the common component, and Methyl p-(p′-n-butyloxy benzoyloxy) benzoate (M.P. 119.0°C) [B1], Ethyl-p-(p′-n-butyloxy benzoyloxy) benzoate (M.P. 94.0°C) [B2], and n-Butyl p-(p′-n-butyloxy benzoyloxy) benzoate (M.P. 130.0°C) [B3] as the second component, respectively, are studied with a view to understand the effect of terminal groups on nematic and/or smectic mesomorphism. Latent transition temperatures (LTT) of the constituent components A, B1, B2, and B3 were determined by extrapolation. Binary system (A + B1) induces a nematogenic mesophase while binary systems (A + B2) and (A + B3) both induce a smectic mesophase in addition to a nematic mesophase. Phase diagrams of the binary systems under investigation are plotted for the mole percent of component (A) versus the transition temperatures of each binary system as determined from polarizing optical microscopy. The texture of the nematic me...
TL;DR: In this article, a CZTS containing ink was prepared by a sonochemical method, and properties of thin films deposited by a spraying method were investigated, and X-ray diffraction (XRD) patterns from the thin films mainly exhibited the (112), (200), (220), and (312) planes of a kesterite structure, and a phase transition was not observed in the range of annealing temperatures (maximum 500°C).
Abstract: CZTS containing ink was prepared by a sonochemical method, and properties of CZTS thin films deposited by a spraying method were investigated. We used CuCl2, ZnCl, SnCl2 and thiourea as precursor materials, 2-methoxyethanol as a solvent, and monoethanolamine as a stabilizer. X-ray diffraction (XRD) patterns from the CZTS films mainly exhibited the (112), (200), (220), and (312) planes of a kesterite structure, and a phase transition was not observed in the range of annealing temperatures (maximum 500°C) investigated in this study. Full width at half maximum (FWHM) values of all the XRD peaks stay nearly constant up to the annealing temperature of 300°C, and suddenly decreases from 300°C to 450°C, and finally saturates above ∼450°C. The optical bandgap of CZTS films was ∼1.25 eV, and the atomic elemental ratio of Cu:Zn:Sn:S in CZTS films was approximately 2:1:0.9:3.5. These results demonstrate that the CZTS containing ink developed in this study has promising potential for the formation of high quality CZT...
TL;DR: In this paper, the role of the structural peculiarities of electrically conductive polymer composites is considered and different conceptions of the nature of the conductivity and the mechanisms of charge transfer in heterogeneous structures are presented.
Abstract: The role of the structural peculiarities of electrically conductive polymer composites is considered in this review. Different conceptions of the nature of the conductivity and the mechanisms of charge transfer in heterogeneous structures are presented. Experimental results obtained by different scientists are only partially in accord with existing theoretical models. It is suggested that lack of information on various physical and chemical factors influencing the processes of electrical current formation in polymer composites is one of the main reasons for the divergence between theory and experimental results, among which the rate of the inter- and intra-phase interactions in composites may be considered very important. The conductivity of systems with binary conducting fillers is also considered.
TL;DR: In this article, the thermal variation of thin films of deoxyribonucleic acid (DNA)-surfactant (CTMA) and doped DNA-CTMA-Nile Blue (NB) (5 w%) complexes are reported and discussed.
Abstract: Refractive index dispersion of thin films of deoxyribonucleic acid (DNA)-surfactant (CTMA) and doped DNA-CTMA-Nile Blue (NB) (5 w%) complexes are reported and discussed. The thermal variation of the thin film thickness was measured by ellipsometry. The DNA-CTMA complex exhibits a rarely observed negative thermal expansion between room temperature and ca. 85°C. Doping with NB decreases the temperature range of negative thermal expansion to between room temperature and ca. 70°C. The dopping by 5 w% of NB lowers the absolute value of negative thermal expansion of DNA-CTMA system from 5% to 2% within this temperature range.
TL;DR: In this article, the plasticization of chitosonium acetate with glycerol increased the ionic conductivity value from 3.0 × 10−7 S/cm to 1.1 × 10 −5 S/ cm.
Abstract: Plasticized natural macromolecules-based polymer electrolyte samples were prepared and characterized. The plasticization of chitosonium acetate with glycerol increased the ionic conductivity value from 3.0 × 10−7 S/cm to 1.1 × 10−5 S/cm. The conductivity temperature relationship of the samples exhibits either VTF or Arrhenius type depending on the glycerol concentration in the sample. The dielectric studies evidencing the relaxation process in the plasticized sample at low frequency region are due to the electric polarization effect. Moreover, the samples were transparent in the Vis region, showed thermal stability up to 160°C and good surface uniformity.
TL;DR: In this article, a novel homologous series of 11 ethylene derivatives has been synthesized and evaluated, and the average smectic and nematic thermal stabilities are 126.7°C and 148.6°C respectively.
Abstract: A novel homologous series of 11 ethylene derivatives has been synthesized and evaluated. The methoxy to pentyloxy homologues are nonmesomorphic, whereas the hexyloxy to dodecyloxy derivatives are enantiotropically smectogenic and enantiotropically nematogenic in character. The tetradecyloxy and hexadecyloxy homologues exhibit only nematogenic character without showing of any smectogenic character. An odd–even effect is not observed in either of the transition curves from a phase diagram. The average smectic and nematic thermal stabilities are 126.7°C and 148.6°C, respectively. The liquid crystal properties of the novel series are compared with other structurally similar compounds. The texture of the nematic phase is a threaded or Schlieren type, and that of smectic phase shows the smectic A type as determined by optical polarizing microscopy. Analytical data support the molecular structures in all cases. The novel series is predominantly nematogenic and partly smectogenic with mesophase temperature ranges...
TL;DR: In this paper, the results on liquid crystal investigations under unconventional, incident light powers were described under high power laser irradiation both in free space and inside laser resonators, and in single-photon source applications for quantum information technology.
Abstract: This paper describes some of my results on liquid crystal investigations under unconventional, incident light powers: (1) under high-power laser irradiation both in free space and inside laser resonators, and (2) in single-photon source applications for quantum information technology. Several effects under high-power, nanosecond laser irradiation are outlined: athermal helical pitch dilation and unwinding of cholesteric mirrors, showing the limits for using them in laser physics; some pitfalls in measurements of thermal-density refractive nonlinearity and the first observation of thermal lens effects in liquid crystals under several nanosecond, low-pulse-repetition rate (2–10 Hz) laser irradiation in the presence of two-photon absorption; feedback-free kaleidoscope of patterns (hexagons, stripes, etc.) in dye-doped liquid crystals. At the single-photon level, definite linear and circular polarizations of single (antibunched) photons for quantum communications were obtained using single-emitter fluorescenc...
TL;DR: In this paper, real-time observation of 2D-GIXD during growth of pentacene thin films was carried out using a newly home-built portable vacuum deposition chamber using synchrotron radiation at SPring-8.
Abstract: In situ and real-time observation of 2-dimensional grazing incidence x-ray diffraction (2D-GIXD) during growth of pentacene thin films were carried out using a newly home-built portable vacuum deposition chamber using synchrotron radiation at SPring-8. Crystal growth and successive polymorphic transformation from thin film phase to bulk phase are clearly observed at room temperature and 75°C. A distinct orientation of bulk phase characterized by tilted (001) plane is found in the grown thin films at room temperature.
TL;DR: In this paper, a flexible organic light-emitting diodes (OLEDs) was fabricated on a cellulose paper substrate, which exhibited a luminance of 620 cd/m2 at a driving voltage of 15 V and a current efficiency of 0.85 cd/A.
Abstract: Cellulose paper was fabricated and employed as a substrate for flexible organic light-emitting diodes (OLEDs). The performance of the cellulose paper satisfies the criteria for a substrate of an OLED. The visible light transmittance of the cellulose paper was greater than 95% in the visible light wavelength range. After the OLED was fabricated on the cellulose paper substrate through a thermal evaporation method, the OLED exhibited a luminance of 620 cd/m2 at a driving voltage of 15 V and a current efficiency of 0.85 cd/A. This work suggests that cellulose paper is an environmentally promising substrate material for flexible OLEDs.
TL;DR: In this article, the carboxylic acid is believed to assist intercalation of dodecyl sulfate by facilitating the elimination of the carbonate ions present in the anionic clay.
Abstract: The study investigates the intercalation of magnesium-aluminum layered double hydroxide with sodium dodecyl sulfate. Monolayer intercalation of the LDH-carbonate was achieved using an acetic acid-assisted ion exchange reaction. The carboxylic acid is believed to assist intercalation of dodecyl sulfate by facilitating the elimination of the carbonate ions present in the anionic clay. Bilayer intercalation was achieved by a coprecipitation method and this resulted in a highly crystalline product. However, in this case the interlayer contains a mixture of dodecyl sulfate anion, sodium dodecyl sulfate and the hydrolysis product dodecanol. The organic phase in the latter product shows an order-disorder transition between 100°C and 120°C, with thermal degradation and volatilization commencing above 170°C.
TL;DR: In this article, the authors observed a strong effect of surfactant structure on the aggregation of ferromagnetic nanoparticles in nematic liquid crystal (LC) hosts, and the colloidal stability and ordering of the resulting nematic matrix.
Abstract: We observe a strong effect of surfactant structure on the aggregation of ferromagnetic nanoparticles in nematic liquid crystal (LC) hosts, and the colloidal stability and ordering of the resulting nematic matrix. We find that ferromagnetic nanoparticles coated with surfactants that possess terminal mesogenic groups induce minimal aggregation of the nanoparticles, resulting in a 1.5 times reduction in the value of the Frederikscz transition field in comparison with the parent LC host.
TL;DR: In this paper, a series of linear supramolecular hydrogen bonded liquid crystals (SMHBLC) have been investigated, where complimentary hydrogen bonds are formed between nonyloxy benzoic acid and various p-n alkyloxy benzino acids whose carbon chain length varied from 5 to 12.
Abstract: A novel series of linear supramolecular hydrogen bonded liquid crystals (SMHBLC) have been investigated. Complimentary hydrogen bonds are formed between p-n nonyloxy benzoic acid and various p-n alkyloxy benzoic acids whose carbon chain length varied from 5 to 12. The formed mesogens are characterized by Fourier Transform Infrared (FTIR) Spectroscopy, Polarizing Optical Microscopy (POM) and Differential Scanning Calorimetry (DSC). Phase diagram has been constructed through POM and DSC data. An interesting finding is the observation of a new smectic ordering, labeled as smectic X, which has been characterized by various thermal and electrical techniques. Optical tilt angle in smectic C and X phases have been measured. The theoretical mean field value β deduced from the experimental tilt angle values is observed to be in good agreement with the predicted value. Dielectric studies revealed a low frequency relaxation mechanism in smectic C phase and the corresponding activation energy has been calculated from...
TL;DR: In this article, a super thin azo-dye molecular alignment layer for LC display cell without spin-coating and rubbing processes has been proposed for optical rewritable (ORW) liquid crystal alignment technology.
Abstract: A new method to increatse the operation speed for optical rewritable (ORW) liquid crystal alignment technology has been proposed. Conventionally, we prepared the azo dye layer by spin-coating solution of SD1 with different concentrations. The new method is to form a super thin azo-dye molecular alignment layer for LC display cell without spin-coating and rubbing processes. Compared to the conventional one, the new method provides much smaller azimuthal anchoring energy, and increases the rewriting speed a lot. Providing the advantages of conventional photoalignment methods, the use of super thin layer can obviously improve the operation speed of ORW technology for e-paper application.
TL;DR: In this paper, a stress controlled rheometer was used to evaluate the rheological properties of a 70/100 bitumen which has been doped by different percentage of polyphosphamide.
Abstract: Bitumens are currently modelled as a colloidal system and are the most used materials for road paving. Despite this large application, asphalts are still affected by some inconveniences that bring to road deterioration. This is prevalently due to temperature cycling which is related to the given local climate conditions and to the incident traffic load. In the last decades bitumen performances have been improved by means of different types of additives in order to match various expectations. This improvement is often the result of the indications given by traditional empirical standardized tests like penetration grade, temperature ductility and Fraas breaking point. The comprehension of the chemical mechanism that regulates the action of the used additives can greatly help in designing new and better performance materials. By means of a Stress Controlled Rheometer we present a laboratory evaluation of the rheological properties of a 70/100 bitumen which has been doped by different percentage of Polyphosph...
TL;DR: In this article, the authors present the level of production (35-40 million tons/year) contra man made fibres and special treatment of them like enzymatic, liquid ammonia, plasma, corona, and ultra sound.
Abstract: Natural fibers are very important and very useful fibers which compete and coexist together with man-made fibers especially in area of quality, sustainability and economy of their production. In this paper we present the level of production (35–40 million tons/year) contra man made fibres and special treatment of them like enzymatic, liquid ammonia, plasma, corona, and ultra sound. Natural fibres are characterised by air permeability, hygroscopicity and capability of giving up moisture, no release of substances harmful for health, no allergic effect, biodegrability and safer behaviour in fire conditions in comparison to man-made fibers. Natural fibers conduct heat, can be dyed well, resist mildew and have natural antibacterial properties, block UV and are easy to make them flame retardant. Genetic modification of lignocellulosic fibrous raw materials improve their performance and giving possibilites to obtain polyhydroxy-alcanate (PHA) “in statu nascendi” in plant. For this reason, United Nations and FAO ...
TL;DR: In this article, a biomimetic approach to the design of polymer nanocomposites and demonstrates structure-property relationships that are controllable via processing conditions was taken, where cellulose nanocrystals (CNCs) were isolated from cotton by sulfuric acid hydrolysis and were incorporated in an alginate fiber wet spinning dope solution.
Abstract: This research takes a biomimetic approach to the design of polymer nanocomposites and demonstrates structure-property relationships that are controllable via processing conditions. Cellulose nanocrystals (CNCs) measuring 130 nm (length) × 20.4 nm (width) × 6.8 nm (height) were isolated from cotton by sulfuric acid hydrolysis and were incorporated in an alginate fiber wet spinning dope solution. Incorporating CNCs within the alginate fiber enables a nearly two-fold increase in the apparent jet stretch (JA ), ratio of the linear draw speed to extrusion velocity. Fiber spinning at a constant JA resulted in an unexpected decrease in fiber modulus and increase in toughness. Alternatively, fiber spinning at the maximum JA resulted in modulus increases that are predicted by the Halpin-Tsai model and the Hui-Shia model. Wide-angle X-ray diffraction (WAXD) was used to elucidate the structure and orientation of cellulose nanocrystals (CNC) within the alginate nanocomposite fibers and provide correlations with mecha...
TL;DR: In this paper, the mesogen molecules were simulated by virtual rod-like molecules and their orientation was given by polar and azimuthal angles towards the directors of neighboring liquid crystal layers.
Abstract: The liquid crystals anchoring theory is considered on the molecular level. Earlier calculations of mesogenic molecules interaction energy with graphite and PE surface give results being one-two orders higher than experimentally obtained values. To explain the experimental values of anchoring energy we proposed its dependence on the interaction between liquid crystal layers. In our calculations we have simulated the mesogen molecules by virtual rod-like molecules. The molecules orientation was given by polar and azimuthal angles towards the directors of neighboring liquid crystal layers. Obtained values of polar and azimuthal anchoring energy as well as their dependences on the order parameter are in good agreement with experimental data.
TL;DR: In this paper, an active layer of Vanadyl 2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO) has been employed in surface type humidity sensor.
Abstract: In this study an active layer of Vanadyl 2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO) has been employed in surface type humidity sensor. On top of preliminary deposited asymmetric metal electrodes, a VOPcPhO thin film was spun cast to obtain a surface type Al/VOPcPhO/Au sensor. The gap between the electrodes was 40 um. A solution of 30 mg/ml was deposited at 3000 rpm. The thickness of the VOPcPhO film was 150 nm. The capacitive effect of the sample was evaluated in the relative humidity range 0–87%RH, at room temperature. It was observed that the capacitance of the sensor increases 10 times under the effect of entire humidity range in the relative humidity level. The optical properties of VOPcPhO thin film were also investigated. The humidity-dependent capacitive properties make the sensor suitable for the application in the instruments used for environmental monitoring of humidity.
TL;DR: In this article, the ITO films were deposited on polyethylenenaphthalate at the room temperature using dc magnetron sputtering system with Ar ion-beam assist.
Abstract: The ITO films were deposited on polyethylenenaphthalate at the room temperature using dc magnetron sputtering system with Ar ion-beam assist. The dc sputtering power was maintained at 200 W, and the Ar ion-beam power was varied from 20 to 70 W. The change in the resistance of the ITO films in the cyclic bending tests was significantly delayed with the Ar-ion-beam power 40 W. Also, the ITO film showed relatively low resistivity (5.39 × 10−4 Ωcm). Thus. the ITO film showed good mechanical and electrical properties attributable to the effect of Ar ion bombardment on the thin film formation.