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Topic Review
Unraveling Physical and Chemical Effects of Textile Microfibers
Microfibers are the most prevalent microplastics in most terrestrial, freshwater, and marine biota as well as in human tissues and have been collected from environmental compartments across most ecosystems and species sampled worldwide. These materials, made of diverse compound types, range from semi-synthetic and treated natural fibers to synthetic microfibers. Microfibers expose organisms across diverse taxa to an array of chemicals, both from the manufacturing process and from environmental adsorption, with effects on organisms at subcellular to population levels. Untangling the physical versus chemical effects of these compounds on organisms is challenging and requires further investigations that tease apart these mechanisms. 
  • 581
  • 27 Dec 2022
Topic Review
Single-Crystal Nickel-Cobalt-Manganese Cathode Research
The booming electric vehicle industry continues to place higher requirements on power batteries related to economic-cost, power density and safety. The positive electrode materials play an important role in the energy storage performance of the battery. The nickel-rich NCM (LiNixCoyMnzO2 with x + y + z = 1) materials have received increasing attention due to their high energy density, which can satisfy the demand of commercial-grade power batteries. Prominently, single-crystal nickel-rich electrodes with s unique micron-scale single-crystal structure possess excellent electrochemical and mechanical performance, even when tested at high rates, high cut-off voltages and high temperatures.
  • 1.4K
  • 27 Dec 2022
Topic Review
Polyethyleneimine-Based Drug Delivery Systems for Cancer Theranostics
With the development of nanotechnology, various types of polymer-based drug delivery systems have been designed for biomedical applications. Polymer-based drug delivery systems with desirable biocompatibility can be efficiently delivered to tumor sites with passive or targeted effects and combined with other therapeutic and imaging agents for cancer theranostics. As an effective vehicle for drug and gene delivery, polyethyleneimine (PEI) has been extensively studied due to its rich surface amines and excellent water solubility.
  • 379
  • 27 Dec 2022
Topic Review
Bulk Preparation Technologies in Food Packaging Applications
Active packaging has played a significant role in consumers’ health and green environment. Synthetic polymers, such as poly(ethylene terephthalate) (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS), poly(vinyl chloride) (PVC), polycarbonate (PC), poly(lactic acid) (PLA), etc., and naturally derived ones, such as cellulose, starch, chitosan, etc., are extensively used as packaging materials due to their broad range of desired properties (transparence, processability, gas barrier properties, mechanical strength, etc.). The food packaging field has been challenged to deliver food products free from microbes that cause health hazards. However, most of the used polymers lack such properties. Owing to this, active agents such as antimicrobial agents and antioxidants have been broadly used as potential additives in food packaging substrates, to increase the shelf life, the quality and the safety of food products. Both synthetic active agents, such as Ag, Cu, ZnO, TiO2, nanoclays, and natural active agents, such as essential oils, catechin, curcumin, tannin, gallic acid, etc., exhibit a broad spectrum of antimicrobial and antioxidant effects, while restricting the growth of harmful microbes. Various bulk processing techniques have been developed to produce appropriate food packaging products and to add active agents on polymer matrices or on their surface. Among these techniques, extrusion molding is the most used method for mass production of food packaging with incorporated active agents into polymer substrates, while injection molding, thermoforming, blow molding, electrospinning, etc., are used to a lower extent.
  • 606
  • 27 Dec 2022
Topic Review
Hydrogen Evolution Reaction and MXenes
Green hydrogen production via electrocatalytic water splitting paves the way for renewable, clean, and sustainable hydrogen (H2) generation. H2 gas is produced from the cathodic hydrogen evolution reaction (HER), where the reaction is catalyzed primarily from Pt-based catalysts under both acidic and alkaline environments. MXene is a 2D nanomaterial based on transition-metal carbide or nitride, having the general formula of Mn+1XnTx, where M = transition metal, X = C and/or N and Tx = surface termination groups such as F, O, OH and Cl.
  • 759
  • 26 Dec 2022
Topic Review
Preparation of ZnO Nanocomposites for Improved Photocatalytic Activity
There are many methods of fabricating ZnO nanostructured materials, including solution-based and vapour-phase methods. However, some of the challenges with most solution-based preparation procedures are: (i) reproducibility due to the constraint of using metal salts of variable purity, (ii) the slow rate of crystal growth, and (iii) the necessity of shaping agents for well-regulated morphologies. Most synthetic strategies for Vis/solar light-responsive semiconductors aim for a reduction in the band gap energy and the effective separation of the photogenerated (e−/h+) charge carriers. These two properties rely on the particle dimension of the semiconductor, its crystal phase, and degree of crystallinity, hence, the need for shaping agents that produce increased specific surface areas for self-assembled nanoporous materials. Controlling synthesis conditions ensures the fabrication of semiconductors with the desired photocatalytic properties.
  • 372
  • 26 Dec 2022
Topic Review
Iron-Series Electrocatalysts for Water Splitting
The development of non-noble metal-based electrocatalysts with high performance for hydrogen evolution reaction and oxygen evolution reaction is highly desirable in advancing electrocatalytic water-splitting technology but proves to be challenging. One promising way to improve the catalytic activity is to tailor the d-band center. This approach can facilitate the adsorption of intermediates and promote the formation of active species on surfaces.
  • 693
  • 26 Dec 2022
Topic Review
Structure and Bonding in Planar Hypercoordinate Carbon Compounds
The term hypercoordination refers to the extent of the coordination of an element by its normal value. In the hypercoordination sphere, the element can achieve planar and/or non-planar molecular shape. Hence, planar hypercoordinate carbon species violate two structural rules: (i) The highest coordination number of carbon is four and (ii) the tetrahedral orientation by the connected elements and/or groups. The unusual planar orientations are mostly stabilized by the electronic interactions of the central atom with the surrounding ligands. Primary knowledge of the planar hypercoordinate chemistry will lead to its forthcoming expansion. Experimental and theoretical interests in planar tetracoordinate carbon (ptC), planar pentacoordinate carbon (ppC), and planar hexacoordinate carbon (phC) are continued. The proposed electronic and mechanical strategies are helpful for the designing of the ptC compounds. Moreover, the 18-valence electron rule can guide the design of new ptC clusters computationally as well as experimentally. However, the counting of 18-valence electrons is not a requisite condition to contain a ptC in a cluster. Furthermore, this ptC idea is expanded to the probability of a greater coordination number of carbon in planar orientations. Unfortunately, until now, there are no such logical approaches to designing ppC, phC, or higher-coordinate carbon molecules/ions. There exist a few global minimum structures of phC clusters identified computationally, but none have been detected experimentally. All planar hypercoordinate carbon species in the global minima may be feasible in the gas phase.
  • 2.1K
  • 26 Dec 2022
Topic Review
Structure, Properties, and Synthesis of SnWO4
Stannous tungstate (SnWO4), which is a potential catalyst due to its narrow band gap, suitable band position, and nontoxicity.
  • 802
  • 23 Dec 2022
Topic Review
Nanostructured Materials for COVID-19 Prevention
The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has raised great concerns about human health globally. Prevention and vaccination are still the most efficient ways to slow down the pandemic and to treat SARS-CoV-2 in various aspects.
  • 459
  • 23 Dec 2022
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