Investigation on the impact of thermal performance of fluid due to hybrid nano-structures

Journal of Thermal Analysis and Calorimetry - This article explores the role of hybrid nano-particles in enhancing the thermal performance of Sutterby fluid over a two-dimensional body of variable...     

Preparation of Hierarchical Porous Activated Carbon from Banana Leaves for High-performance Supercapacitor: Effect of Type of Electrolytes on Performance

We demonstrate a facile efficient way to fabricate activated carbon nanosheets (ACNSs) consisting of hierarchical porous carbon materials. Simply heating banana leaves with K₂CO₃ produce ACNSs having a unique combination of macro-, meso- and micropores with a high specific surface area of ∼1459 m² g⁻¹. The effects of different electrolytes on the electrochemical supercapacitor performance and stability of the ACNSs are tested using a two-electrode system. The specific capacitance (C_sp) values are 55, 114, and 190 F g⁻¹ in aqueous 0.5 M sodium sulfate, organic 1 M tetraethylammonium tetrafluoroborate in acetonitrile, and pure ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF₆]) electrolytes, respectively. The ACNSs also shows the largest potential window of 3.0 V, the highest specific energy (59 Wh kg⁻¹) and specific power (750 W kg⁻¹) in [BMIM][PF₆]. A mini-prototype device is prepared to demonstrate the practicality of the ACNSs.     

Emission-Color Control in Polymer Films by Memorized Fluorescence Solvatochromism in a New Class of Totally Organic Fluorescent Nanogel Particles

In this work, a new class of totally organic fluorescent nanogel particles and their exceptionally specific behaviors based on their unique structures are introduced, which draws a sharp line from conventional fluorophore-doped and fluorophore-branched-type particles. The nanogel particles, the diameter of which could be controlled by adjusting reaction conditions, such as the solvent system, were spontaneously fabricated with a spherical shape by direct polymerization of non-heterocyclic aromatic compounds, such as 2,6-dihydroxyanthracene, 2,6-dihydroxynaphthalene, and 9,9-bis(4-hydroxyphenyl)fluorene with triazinane as the cross-linker. A fluorophoric moiety formed from a polymer main chain was realized in the particle, and consequently, the resultant content of the fluorophoric moiety was around 70–80 wt % per particle. The uniqueness and versatility of the particles can be emphasized by their good compatibility with various solvents due to their amphiphilic and ampholytic swelling properties, but also by their remarkable fluorescent solvatochromism in the dispersion state. Furthermore, these behaviors were preserved even in their polymer composite system. This study also demonstrates that various fluorescent polymer films can be fabricated with emission color control due to memorization of the solvatochromism phenomenon of the dispersed fluorescent nanoparticles.     

Energy transfer and excited state lifetime of some anthracene laser dyes

The lifetimes of some anthrathene derivatives in different solvents have been determined using the phase modulation method. The lifetime of 10-phenyl-2-methyl-9-acetoxyanthracene and 10-(4-acetoxyphenyl)-2-methyl-9-acetoxyanthracene were found to equal 11 and 11 ns in methanol, respectively. Energy transfer from 10-phenyl-2-methyl-9-acetoxyanthracene and 10-(4-acetoxyphenyl)-2-methyl-9-acetoxyanthracene to rhodamine B and rhodamine 110 in different solvents has been studied by using steady-state emission measurements. The large values of the critical transfer distance R₀ and the rate constant of energy transfer k_ET suggest that the mechanism is long-range dipole–dipole energy transfer as described by Förster.     

DABCO–PEG ionic liquid-based synthesis of acridine analogous and its inhibitory activity on alkaline phosphatase

In world, many people struggle with viral, parasitic, bacterial, cancer, and other diseases. Therefore, numerous chemists seek to develop less toxic, more selective, and effective medicines. Most therapeutic medicines are based on inhibition of specific enzymes. Acridines are interesting heterocyclic structures that are much sought after targets attributed to their wide biological activities and feature to display potent enzymes inhibitory effects. Their approach of action is owing to DNA interaction and subsequent effects on the biological functions linked to DNA and associated enzymes. In this regards, we synthesized acridine analogous through 1,4-diazabicyclo[2.2.2]octane (DABCO)–polyethylene glycol-400 (PEG-400) mediated ionic liquid approach. DABCO–PEG-400-mediated IL was prepared through the DABCO alkylation using 1-bromopentane followed by mixing with PEG-400. The synthesized analogous were investigated as inhibitors of alkaline phosphatase, which is a nonspecific phosphomonoester hydrolase that catalyzes the hydrolysis of broad spectrum of organic monophosphates. Analogue viz. 3,3,6,6-tetramethyl-9-(4-nitrophenyl)-2,3,4,5,6,7,9,10-octahydroacridine-1,8-dione was found to be potent alkaline phosphatase inhibitor.     

Three novel tetracyclic triterpenoids of biogenetic interest from the leaves of Azadirachta indica

From the methanolic extract of Azadirachta indica leaves, we have isolated three new tetracyclic triterpenoids of biogenetic interest, namely, melianol 1, desfurano-desacetylnimbin-17-one 2 and meliatetraone 3. The structure elucidation is based on extensive spectral studies including ¹H–¹H-COSY, NOESY, HMQC, and HMBC experiments.     

Copper Schiff base functionalized polyaniline (Cu‐SB/PANI): A highly efficient polymer based organometallic catalyst for the synthesis of 2‐amino chromene derivatives

Copper Schiff Base functionalized Polyaniline (Cu‐SB/PANI) has been synthesized as an efficient, recyclable and heterogeneous polymer based organometallic catalyst by simple method. The catalyst has been well characterized with different spectroscopic techniques such as FTIR, SEM/EDX, elemental mapping, XRD, TEM, TG, XPS, EPR and ICP‐AES analyses. The catalytic potential of the catalyst has been explored by synthesizing 2‐amino chromene derivatives. The catalyst efficiently catalyzed the reaction affording excellent yield of the products (95–97%) in very short reaction time period (6–8 min). The catalyst could be reused for five times with insignificant loss in catalytic activity.