High Performing Biobased Ionic Liquid Crystal Electrolytes for Supercapacitors

Production and storage of energy in a highly efficient and environmentally sustainable way is a demand of the current century to meet the growing global energy requirement. Design and development of novel materials and processes that allow precise control over the electrochemical behavior and conductivity of electrolytes is necessary for acquiring such targets. Development of ionic liquid crystals with ordered domains endowed with enhanced ionic conductivity from renewable resources is receiving much interest in this respect. In this paper, we report a unique strategy for the preparation and utilization of ionic liquid crystalline electrolyte derived from a renewable resource: cashew nut shell liquid; an abundantly available waste byproduct from cashew industry. We have prepared imidazolium-based ionic liquid crystal (PMIMP) from cardanol and studied its structure and liquid crystalline phase formation by various techniques. The symmetrical supercapacitor fabricated with mesoporous carbon electrodes employing PMIMP as electrolyte measured a specific capacitance of 131.43 F/g at a current density of 0.37 A/g with excellent cycle stability and 80% capacitance retention after 2000 cycles. All these excellent properties of the prepared ionic liquid crystalline electrolyte suggest its application as an efficient, environmentally friendly and low-cost electrolyte for energy storage devices

Bio-based Ionic Liquid Crystalline Quaternary Ammonium Salts: Properties and Applications

In the present work, we describe the preparation, properties, and applications of novel ionic liquid crystalline quaternary ammonium salts (QSs) of 3-pentadecylphenol, a bio-based low-cost material derived from cashew nut shell liquid. Amphotropic liquid crystalline phase formation in QSs was characterized using a combination of techniques, such as DSC, PLM, XRD, SEM, and rheology, which revealed the formation of one, two, and three dimensionally ordered mesophases in different length scales. On the basis of these results, a plausible mechanism for the formation of specific modes of packing in various mesophases was proposed. Observation of anisotropic ionic conductivity and electrochemical stability suggests their application as a solid electrolyte

Design of Macroscopically Ordered Liquid Crystalline Hydrogel Columns Knitted with Nanosilver for Topical Applications

The design of liquid crystalline hydrogels knitted with silver nanoparticles in macroscopic ordering is becoming a subject of research interest due to their promising multifunctional applications in biomedical and optoelectronic applications. The present work describes the development of liquid crystalline Schiff-based hydrogel decorated with silver nanoparticles and the demonstration of its antifungal applications. Schiff base was prepared from polyglucanaldehyde and chitosan, and the former was prepared by the oxidation of amylose (polyglucopyranose) isolated from abundantly available unutilized jackfruit seed starch. Self-assembled silver columns decorated with macroscopically ordered networks were prepared in a single step of in situ condensation and a reduction/complexation process. The various noncovalent interactions among the −OH, −CO, and −NH impart rigidity and ordering for the formation of macroscopically ordered liquid crystalline hydrogel and the Ag­(I) complexation evidenced from the studies made by FT-IR spectroscopy in combination with rheology and microscopic techniques such as SEM, TEM, AFM, XRD, and PLM. The antifungal studies were screened using species of Candida by disc diffusion method. The MIC and MFC values, in vitro antifungal studies, reactive oxygen species (ROS) production, and propidium iodide (PI) uptake results suggest that the present macroscopically ordered liquid crystalline hydrogel system can be considered an excellent candidate for topical applications. All these results suggest that this design strategy can be exploited for the incorporation of biologically relevant metal nanoparticles for developing unique robust hydrogels for multifunctional applications

Facile Bioanchoring Strategy for the Preparation of Hierarchical Multiple Structured ZnO Crystals and Its Application as a Photoanode in Dye Sensitized Solar Cells

This paper demonstrates a facile bioanchoring strategy for controlling the crystal growth process of ZnO crystals during calcination to form hierarchical multiple structures. Crystalline phase and morphology of ZnO was investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. Results revealed the evolution of ZnO nanocrystallites from nanosize to hierarchical self-assembly of polydispersed microstructures of bars/sheets/spheres/hollow spheres in wurzite hexagonal phase. ZnO exhibited photoluminescence attributed to the presence of various defects which was further supported by Raman spectroscopy and energy-dispersive X-ray spectroscopy. On the basis of the various experimental results, a plausible growth mechanism for the formation of multiple structures of ZnO crystals is proposed. Further demonstrated is the application of the polydispersed submicrometer sized ZnO crystals as photoanode in dye sensitized solar cells for improving the power conversion efficiency (∼5.3%) through high dye loading and enhanced light absorption edge via inherent light reflection mechanism

Nanostructured Semiconducting PEDOT–TiO₂/ZnO Hybrid Composites for Nanodevice Applications

In this paper, we have developed a simple strategy for the preparation of hybrid nanocomposites of poly­(3,4-ethylenedioxythiophene)–TiO₂/ZnO (PZT) and demonstrated its application in a thermoelectric device. Hierarchical hetero-nanostructured TiO₂/ZnO (ZTO) was prepared by a facile sol–gel process in the presence of a biocapping agent. PZT was prepared by in situ polymerization of EDOT in the presence of ZTO. It was characterized by UV–visible, FT-IR, XRD, Raman, SEM, TEM, and AFM analyses. Results revealed homogeneous distribution of ZTO with a heterocrystalline phase of wurtzite ZnO/anatase TiO₂ having high density of various defects in the hybrid nanocomposite. Studies showed that ZTO is excellently interfaced with highly ordered self-assembled extended π-layers of PEDOT chains, which could enhance the charge carrier concentration (3.92 × 10²⁰ cm^–3) and charge carrier mobility (0.83 cm² V^–1 s^–1). Furthermore, we have demonstrated its application as a thermoelectric material by fabricating the device (Cu/PZT/Cu), which showed low thermal conductivity of 0.0495 Wm^–1K^–1, Seebeck coefficient of 19.05 μV K^–1, power factor of 1.28 μW m^–1K^–2, and figure of merit of 4.8 × 10^–3 at ambient temperature. All of these excellent material properties of PZT suggest its application as an active material for the fabrication of nanoelectronic devices with large area

Flexible Electrochemical Transducer Platform for Neurotransmitters

We have designed a flexible electrochemical transducer film based on PEDOT–titania–poly­(dimethylsiloxane) (PTS) for the simultaneous detection of neurotransmitters. PTS films were characterized using various techniques such as transmission electron microscopy, scanning electron microscopy, atomic force microscopy, four probe electrical conductivity, ac-impedance, and thermomechanical stability. The electrocatalytic behavior of the flexible PTS film toward the oxidation of neurotransmitters was investigated using cyclic voltammetry and differential pulse voltammetry. The fabricated transducer measured a limit of detection of 100 nm ± 5 with a response time of 15 s and a sensitivity of 63 μA mM^–1 cm^–2. The fabricated transducer film demonstrated for the simultaneous determination of epinephrine, dopamine, ascorbic acid, and uric acid with no interference between the analyte molecules. Further, transducer performance is validated by performing with real samples. The results suggested that the fabricated flexible PTS transducer with superior electrocatalytic activity, stability, and low response time can be explored for the sensing of neurotransmitters and hence can be exploited at in vitro and in vivo conditions for the early detection of the various diseases