Chemistry Aspects and Designing Strategies of Flexible Materials for High-Performance Flexible Lithium-Ion Batteries

In recent years, flexible and wearable electronics such as smart cards, smart fabrics, bio-sensors, soft robotics, and internet-linked electronics have impacted our lives. In order to meet the requirements of more flexible and adaptable paradigm shifts, wearable products may need to be seamlessly integrated. A great deal of effort has been made in the last two decades to develop flexible lithium-ion batteries (FLIBs). The selection of suitable flexible materials is important for the development of flexible electrolytes self-supported and supported electrodes. This review is focused on the critical discussion of the factors that evaluate the flexibility of the materials and their potential path toward achieving the FLIBs. Following this analysis, we present how to evaluate the flexibility of the battery materials and FLIBs. We describe the chemistry of carbon-based materials, covalent-organic frameworks (COFs), metal-organic frameworks (MOFs), and MXene-based materials and their flexible cell design that represented excellent electrochemical performances during bending. Furthermore, the application of state-of-the-art solid polymer and solid electrolytes to accelerate the development of FLIBs is introduced. Analyzing the contributions and developments of different countries has also been highlighted in the past decade. In addition, the prospects and potential of flexible materials and their engineering are also discussed, providing the roadmap for further developments in this fast-evolving field of FLIB research.     

Functionalization of carbon nanofibers with elastomeric block copolymer using carbodiimide chemistry

Surface functionalization of carbon nanofibers (CNFs) with aminopropyl terminated polydimethylsiloxane [(PDMS-NH₂)] and other organic diamines was achieved using carbodiimide chemistry. The carbodiimide chemistry provides faster reaction rate so that the reaction occurs at lower temperature compared to amidation and acylation-amidation chemistry. CNF functionalized with PDMS-NH₂ fibers were further functionalized with oligomer of polyimide (6FDA-BisP) using imidization reaction. The formation of block copolymer on the surface of CNF is proposed as an effective method to engineer the interphase between the fiber and the polymer, which is essential to modulate and enhance the properties of the nanocomposite. The efficiency of the carbodiimide chemistry to functionalize amine terminated groups on CNF and the functionalization of block copolymer was characterized using thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy.     

A facile synthesis of melatonergic antidepressant agomelatine

Agomelatine was synthesized from 8-aminonaphthalen-2-ol by diazotization-iodination, formylation, C–C bond formation by nitroaldol and Pd/C hydrogenation of β-nitrovinylnaphthalene followed by N-acetylation. The route reported employs readily and commercially viable starting materials and reagents, and can potentially be utilized for process synthesis of agomelatine.     

Design and development of an optical beam splitter assembly and high precision colinearity measurements of laser beams

Laser beams with extremely high colinearity are often required where precision position monitoring is important. In order to achieve the said objective, a special type of Laser Beam Splitter Assembly (BSA) has been designed and fabricated in a very small volume due to space constraints. The main features and details of such a system are described here. This type of beam splitter assembly coupled with a diode laser through fibers can be remotely used for alignment or position monitoring of different medium to large size structures with a reconstruction accuracy of 10 μm. In this way, BSA generates two counter propagating laser beams from a single diode laser coupled to an optical fiber. In the present work, the colinearity between two beams within 1 mrad with the variation of 50 μrad has been achieved. The laser's power in the two arms may be controlled precisely, which is an important feature of this BSA. The BSA has been tested to work over a temperature range between ?20 °C to +40 °C. It has also been exposed to 1.0 MeV neutrons at a flux of ～5.0×10¹⁰ n/cm²/s and found compatible.     

Cobalt(II) Complex Catalysed Epoxidation with Molecular Oxygen

Cobalt(II) complexes 1 or 2, catalyses the epoxidation of alkenes in the presence of molecular oxygen and 2-methylpropanal in high yields.     

Stability-Indicating HPTLC Method of Carteolol in Bulk Drug and in Pharmaceutical Dosage Forms

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive, selective, precise and stability-indicating high-performance thin-layer chromatography (HPTLC) method was developed...     

Complexation behavior of gelatin with amphiphilic drug imipramine hydrochloride as studied by conductimetry,surface tensiometry and circular dichroism studies

Herein we report our studies carried out on the interaction between IMP and gelatin in aqueous medium at 25 °C using conductimetry, surface tensiometry and circular dichroism (CD) techniques. Both surface tensiometry and conductimetry results indicate that the drug interacts with the gelatin in a surfactant-like manner, i.e., both critical aggregation (cac) and polymer saturation points (psp) were observed. The interaction starts with the formation of a highly surface-active complex as revealed by the lowering of surface tension on the addition of drug to the macromolecule. The decrease in cac on increasing gelatin concentration is an indication of the strong interaction between gelatin and IMP. However, at low concentration of gelatin the interaction was not much strong as exposed by surface tension study, i.e., the cac was not very clear (as with higher gelatin concentrations). As usual, the psp increased on increasing the gelatin concentration and was always higher than the critical micelle concentration of the drug in pure aqueous medium. Using CD measurements the influence of IMP on the secondary structure of gelatin in aqueous solutions was also investigated. CD studies (performed at very low drug concentrations) illustrated that the random coil content of gelatin increases with increasing drug concentration. Free energies of aggregation (ΔG_agg) and micellization (ΔG_mic) were computed with the help of degrees of micelle ionization obtained from the specific conductivity – [IMP] plots.     

Determination of zirconium and hafnium in solution by X-ray fluorescence spectrometry

The samples were introduced into the XRF spectrometer in ordinary flat bottom polyethylene bottles for the estimation of Zr or Hf in presence of one another in solution. By using high voltage (50 kV) and high current (50 mA) least limits of detection obtained were an order of magnitude better than other conventional analytical techniques. Relations of intensity to concentration in various concentration ranges have been determined and the results are compared with those of other analytical techniques.     

Isolation of a flavonoid from Feronia limonia

The roots and leaves of Feronia limonia yielded a flavonoid characterized as 5-hydroxy-2-(4-hydroxyphenyl)-7-methoxy-6-(3-methylbut-2-enyl)chroman-4-one along with known imperatorin, bergapten and xanthotoxin. These isolated compounds were characterized by UV, IR, NMR and mass spectral studies.