Recent Advances in Transition Metal-Based Catalysts for Ethylene Copolymerization with Polar Comonomer.

The synthesis of polar functionalized polyolefin (PFP) offers improvement in mixing properties, polymer surface, and rheological properties with the potential of upgraded polyolefins for modern and ingenious applications. The synthesis of PFP from metal-based catalyzed olefin (non-polar in nature) copolymerization with polar comonomers embodies energy-efficient, atom-efficient, and apparently an upfront methodology. Despite their outstanding success during conventional polymerization of olefin, 3rd and 4th group (early transition metal)-based catalysts, owing to their electrophilic nature, face challenges mainly due to Lewis basic sites of the polar monomers. On the contrary, late transition metal-based catalysts have also made progress, in recent years, for PFP synthesis. The recent past has also witnessed several advancements in the development of dominating palladium-based catalysts while their lower resistance towards ligand functional groups has limited the practical application of abundant and cheaper nickel-based catalysts. However, the relentless efforts of the scientific community, during the past half-decade, have indicated rigorous progress in the development of nickel-based catalysts for PFP synthesis. In this review, we have abridged the recent research trends in both early as well as late transition metal-based catalyst development. Furthermore, we have highlighted the role of transition metal-based catalysts in influencing the polymer properties.

Research Trends in Carbon Chain Polymers and Their Derivatives: Highlighting the Decade-Long Research.

Polyolefins include low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), polypropylene (PP), and polybutylene (PB). Polyolefins offer unique characteristics such as chemical resistance, smooth surface, re-shapability, and are lighter than glass and metal-based materials. The global plastics industry produces polyolefin as their major product and these polyolefins are mostly used as commercial commodity plastics. Moreover, the characteristics of polyolefin can be further improved by forming their blends and/or composites and incorporating fillers. This review highlights the role of various fillers such as titanium dioixde-based, nitride-based, and carbon-based nanomaterials, in influencing polyolefin composites. Moreover, the contribution of layered double hydroxide in olefin polymerization, and the impact of filler properties such as filler content, filler type, filler phase stability, and synergistic effect between the fillers and polymers on nanocomposites are discussed.

Synergetic effect of bismuth vanadate over copolymerized carbon nitride composites for highly efficient photocatalytic H2 and O2 generation.

The development of copolymerized carbon nitride (CN)-based photocatalysts may support advances in photocatalytic overall water splitting. However, the recombination of charge carriers is the main bottleneck that reduces its overall photocatalytic activity. To overcome this problem, the construction of heterojunction technology has emerged as an effective approach to reduce the charge carrier recombination, thereby improving charge separation and transport efficiency. In this work, an innovative heterojunction was prepared between Quinolinic acid (QA) modified CN (CN-QAx) and novel nanorod-shaped bismuth vanadate (BiVO4) (BiVO4/CN-QAx) for overall water splitting through a simple in-situ solvent evaporation technique. The obtained results show that the synthesized samples have efficient and improved activities for releasing H2 (862.1 µmol/h) and O2 (31.58 µmol/h) under visible light irradiation. Furthermore, an exceptional apparent quantum yield (AQY) of 64.52 % has been recorded for BiVO4/CN-QA7.0 at 420 nm, which might be due to the substantial isolation of photoinducedcharge carriers. Therefore, this work opens up a new channel toward efficient CN-based photocatalysts in the sustainable energy production processes.

Robust thermal performance of red-emitting phosphor composites for white light-emitting diodes: Energy transfer and oxygen-vacancy induced electronic localization.

Ce3+ ion can effectively sensitize Sm3+ ion via energy transfer, and this phenomenon can led to the development of white light-emitting diodes (WLED). However, interestingly, high correlated color temperature (CCT), poor color-rending index (CRI), poor thermal stability, and low efficacy of available red phosphor still pose immense challenges. Herein, we undertook a combined analysis: X-ray diffraction (XRD), crystal refinement, electron spin resonance (ESR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and diffuse reflection spectroscopy (DRS). We also observed the optical properties of the resulting samples. The Ce3+ and Sm3+ dopants on the Sr2+ and La3+ sites in the mixed cation borate Sr3LaAl3B4O15 (SLAB) phosphors were quantitatively evaluated. A cerium ion merged as a sensitizer, improving the red emission intensity by enhancing it 3.9 times. The energy transfer (ET) between Ce3+ and Sm3+ was examined experimentally and with theoretical models as a function of Ce3+ concentrations at ambient temperatures. Several theoretical models were employed to simulate the luminescence decays of Ce3+ and Sm3+ doped samples at different doping levels and their transfer mechanisms were studied depending on forced electric dipole at each ion. Notably, the electronic sites created by the oxygen vacancies around the Ln3+ ions can effectively justify the highly efficient bluish-red phosphor. Additionally, the SL0.95AB:0.02Ce3+,0.03Sm3+ exhibited outstanding thermal-quenching (TQ) resistance and has > 94.8% intensity at 425 K. WLEDs made with the use of SL0.95AB:0.02Ce3+,0.03Sm3+ furnished an exceptional CRI exceeding 88 and low at CCT 4503 K. These results are superior to the parameters of commercial WLED containing Y3Al5O12:Ce3+ phosphor and blue LED chip (CCT≈7746 K, CRI≈75), and they could be a cornerstone for the fabrication of warm WLEDs.

Nanosilver: new ageless and versatile biomedical therapeutic scaffold.

Silver nanotechnology has received tremendous attention in recent years, owing to its wide range of applications in various fields and its intrinsic therapeutic properties. In this review, an attempt is made to critically evaluate the chemical, physical, and biological synthesis of silver nanoparticles (AgNPs) as well as their efficacy in the field of theranostics including microbiology and parasitology. Moreover, an outlook is also provided regarding the performance of AgNPs against different biological systems such as bacteria, fungi, viruses, and parasites (leishmanial and malarial parasites) in curing certain fatal human diseases, with a special focus on cancer. The mechanism of action of AgNPs in different biological systems still remains enigmatic. Here, due to limited available literature, we only focused on AgNPs mechanism in biological systems including human (wound healing and apoptosis), bacteria, and viruses which may open new windows for future research to ensure the versatile application of AgNPs in cosmetics, electronics, and medical fields.