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Bio-waste-based porous carbon nanoparticles (PCNPs) were synthesized using green synthesis and investigated their doping effect on the optical and electrical properties of polymer-dispersed ferroelectric liquid crystals (PDFLCs) composites. Here we employed the polymerization-induced phase separation (PIPS) approach for constructing the PDFLCs. Our results indicate that the dispersion of PCNPs into the PDFLC material results in an alteration to several physical parameters, including morphology, dielectric permittivity, conductivity and optical band gap. A decrease in the ac conductivity of the doped samples was seen. Additionally, UV-Visible study reveals that inclusion of PCNPs resulted in a decrease in the optical band gap of PDFLC, with a value of approximately 3.1 eV. These findings demonstrate the potential of using PCNPs as dopants in PDFLCs for various applications, including sensing, energy storage and optoelectronics. [ABSTRACT FROM AUTHOR]

Polymer-stabilized cholesteric liquid crystal is one of the most coveted systems in the ever-expanding field of liquid crystal due to its wider potential application in smart windows, optical shutters, tunable lenses, etc. The dispersion of polymer into liquid crystal by introducing a small amount of chiral dopant prepared polymer-stabilized cholesteric liquid crystal. In this work, two samples of polymer- cholesteric liquid crystal were prepared. Surface treatment is applied on one composite while another sample is prepared without any treatment on the indium tin-oxide coated glass substrates. Frequency and temperature-dependent dielectric parameters are observed for both samples. The dielectric studies revealed that after surface treatment, the permittivity of the sample significantly increased. AC conductivity of the sample also increased. The photoluminescence spectra also show improvement in the intensity with the surface-treated sample. [ABSTRACT FROM AUTHOR]

Ferroelectric liquid crystals(FLCs), an exciting class of liquid crystals(LCs), found potential applications in the display as well as non-display regimes due to their fast response, low driving voltage and nonvolatile memory. The amalgamation of nanoparticles into FLCs has opened up new avenues in the LCs research field by alterations/modification of the existing properties of LCs. In this work, porous carbon nanoparticles (PCNPs) were dispersed into FLC mixture (W206E) and investigated their doping effect on FLC's textural, phase transition temperatures and dielectric studies in planar-aligned cells. Dielectric spectroscopy was carried out in the frequency range of 20 Hz to 10 MHz to explore the frequency as well as the temperature dependent of FLC in the entire SmC* region. The transition temperature of FLC mixture is increased by 4 °C in PCNPs doped FLC sample then undoped FLC sample. Nearly 8.42% increase in permittivity is observed. A Gold stone relaxation mode at ∼627 Hz was observed at lower frequency. [ABSTRACT FROM AUTHOR]

Liquid crystals are self-organized anisotropic fluids which exhibit ordered states ranging from nematics to smectics/hexatics. Hybridized liquid crystals with nanoparticles broaden the research area in finding the novel functional devices. Reported herein, the study of highly stable room temperature nematic liquid crystal E7 and carbon-coated cobalt (Co) nanoparticles. Dispersion of 0.50 wt.% Co into E7 has been introduced to tailor the physical parameters of host E7. Dielectric studies have been performed in planar as well as homeotropic cells in the frequency range of 20 Hz–10MHz while photoluminescence spectra have been recorded at excitation wavelength of 325 nm in planar cells. Dielectric studies reveal the change in phase transition temperature and molecular dynamics associated with magnetic nanoparticles doped liquid crystals. Quenching in photoluminescence intensity has been observed with the inclusion of Co nanoparticles due to the formation of non-radiative channels in the composite system. The intercalation of Co nanoparticles into E7 studies manifests the strong correlation between liquid crystals and nanoparticles. Allocation of magnetic attributes onto liquid crystal molecules finds potential applications in advanced magnetic materials, information devices and optical devices. [ABSTRACT FROM AUTHOR]

The changes in physical properties obtained by dispersing hydrophilic carboxylated graphene quantum dots (GQDs, <10 nm), which are non-toxic, biocompatible, and eco-friendly, into a room-temperature nematic liquid crystal, 5CB (4-pentyl-4ˈ- biphenylcarbonitrile) are described. Nematic–isotropic transition temperatures, polarising microscopy, electro-optic, photoluminescence, and dielectric investigations are reported for two composites having concentrations of GQDs of 0.25 and 1.0 wt.% in 5CB and compared to pristine 5CB. At the lower concentration (0.25%) of GQDs there is an enhancement in the order parameter by 5.49%, the birefringence by 1.28%, and the activation energy for dielectric relaxation by 4.4% compared to pure 5CB. However, at the higher concentration (1%), aggregation of GQDs occurs. This is apparent in optical textures and resulted in the deterioration of optical and electrical properties compared to 5CB. The photoluminescence spectrum of both concentrations of GQDs are centred at the same wavelength; however, the 1% GQD-5CB mixture exhibits significant quenching and may be suitable for some optical devices. Overall, our results support that, in addition to promoting sustainable, heavy-metal-free, and environmentally safe technologies, a low concentration of GQDs in LCs produces composites that have superior electrical and optical properties; thus, making them suitable for a variety of photonics and display applications. [ABSTRACT FROM AUTHOR]

In the present work, coefficient of volume expansion is estimated using ultrasonic velocity and density of 8CB, 8CB + 0.5% ZnO, 8CB + 2.0% ZnO and 8CB + 5.0% ZnO mixtures in the temperature range of 283.15K–318.15K. The coefficient of volume expansion is used to evaluate numerous thermo-acoustic parameters viz; Moelwyn-Hughes parameter (C1), Beyer's nonlinear parameter (B/A), reduced volume (V*), reduced bulk modulus (B*), isochoric acoustical parameter (Δ), fractional free volume (f), repulsive exponent (n), isobaric (Γ), isochoric (Γ′′), and isothermal (Γ′) Gruneisen parameters, Anderson-Gruneisen parameter (δ) and Sharma's constant (S0). Present study reveals that Sharma constant can be treated as molecular constant for 8CB and ZnO dispersed 8CB mixtures. A relationship between Δ≅B* +0.1 and C1≅δ +1 has been established for all the samples under investigation. The effect of increase of ZnO NPs concentration on the intermolecular interactions has been explained in terms of temperature variation of thermo-acoustical parameters. [ABSTRACT FROM AUTHOR]

Research on the solvent extraction of ruthenium from hydrochloric acid media has been carried out using N,N'-dimethyl-N,N'-dicyclohexylmalonamide (DMDCHMA) dissolved in 1,2-dichloroethane. Ruthenium extraction percentages (%E) ranging from 50% to 80% have been achieved for HCl concentrations between 5 M and 7 M. Extraction curves exhibiting the dependence of the %E ruthenium on HCl concentration in the aqueous phases are presented, the latter solutions being obtained by dissolution of either Ru(III) or Ru(IV) salts. The influence of some experimental parameters on the %E Ru, such as the equilibration time, extractant concentrations, and hydrogen-ion activities, has been thoroughly investigated. Additionally, DMDCHMA is also adequate for extracting Pd(II) from 5 M to 7 M HCl solutions and under similar experimental conditions, %E Rh(III) is below 5%, and Pt(IV), Ir(III), and Ir(IV) cause the formation of third phases. Both Ru and Pd(II) can be successfully stripped from the loaded organic phases with water. A partition scheme to isolate Ru from a number of some associated elements has also been attempted. [ABSTRACT FROM AUTHOR]

Abstract: Solvent extraction studies for platinum recovery from chloride media have been carried out using N,N'-dimethyl-N,N'-diphenyltetradecylmalonamide (DMDPHTDMA). Platinum can be effectively extracted by DMDPHTDMA in the presence of tin and can also be successfully stripped by an aqueous mixture of 4M HCl + 0.05M NaClO3. The influence of different Sn:Pt feed ratios on the extraction system has been considered. Experimental parameters such as equilibration time, diluent, and temperature effects, extractant and hydrogen ion concentrations have been thoroughly investigated. The loading capacity of DMDPHTDMA for platinum has also been evaluated. Platinum extraction is proposed to occur via an ion-pair association. [ABSTRACT FROM AUTHOR]

Solvent extraction studies for rhodium (III) in chloride medium have been carried out with N,N'-dimethyl-N,N'-diphenyltetradecylmalonamide (DMDPHTDMA). Rhodium can be effectively extracted by DMDPHTDMA in the presence of tin and can also be successfully stripped by an aqueous mixture of 4 M HCl+0.05 M NaClO3. The influence of different Sn:Rh feed ratios on the extraction system has been taken into account. Some experimental parameters like equilibration time, extractant concentration and hydrogen and chloride ions concentrations have been investigated in detail. The loading capacity of DMDPHTDMA for rhodium has been determined. An ion-pair association is proposed to explain rhodium extraction. [ABSTRACT FROM AUTHOR]