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Topic Review
Chitin
       Chitin, being the second most abundant biopolymer after next to cellulose, has been gaining popularity since its initial first discovery by Braconot in 1811. However, fundamental knowledge and literature on about chitin and its derivatives from insects are difficult to obtain. The most common and sought-after sources of chitin are shellfishes (especially crustaceans) and other aquatic invertebrates. The amount of shellfishes available is obviously restricted by the amount of food waste that is allowed; hence, it is a limited resource. Therefore,Hence, insects are the best choices since, out of 1.3 million species in the world, 900,000 are insects, making them the most abundant species in the world. In this review, a total of 82 samples from shellfishes—crustaceans and mollusks (n = 46), insects (n = 23), and others (n = 13)—have been collected and studied for their chemical extraction of chitin and its derivatives. The aim of this paper is to review the extraction method of chitin and chitosan for a comparison of the optimal demineralization and deproteinization processes with, so as to consideration of insects as alternative sources of chitin. The methods employed in this review are based on comprehensive bibliographic research. Based on previous data, chitin and chitosan yield contents of insects in their study favorably compares and competes with those of commercial chitin and chitosan—for example, 45% in Bombyx eri, 36.6% in Periostracum cicadae (cicada sloughs), and 26.2% in Chyrysomya megacephala. Therefore, according to the data reported by previous researchers, with comparable yield values to those of against crustacean chitin and the great interests of in insects as alternative sources, efforts towards comprehensive knowledge in this field are relevant.
  • 2.4K
  • 30 Oct 2020
Topic Review
Hole-Transporting Layer in Perovskite Solar Cells
Organic-inorganic halide perovskite solar cells (PSCs) have received particular attention because of the high-power conversion efficiencies (PCEs), facile fabrication route and low cost. The hole-transporting layer (HTL) play an important role in PSCs to effectively extract holes from the perovskite film and to transport holes to the metal electrode in normal PSCs. 
  • 2.4K
  • 09 Aug 2022
Topic Review
Propylene Synthesis
Propylene is one of the most important feedstocks in the chemical industry, as it is used in the production of widely diffused materials such as polypropylene. Conventionally, propylene is obtained by cracking petroleum-derived naphtha and is a by-product of ethylene production. To ensure adequate propylene production, an alternative is needed, and propane dehydrogenation is considered the most interesting process.
  • 2.4K
  • 25 Oct 2021
Topic Review
Transition Metal Dichalcogenides
In recent years, the material characteristics and properties of transition metal dichalcogenide (TMDCs) have gained research interest in various fields, such as electronics, catalytic, energy storage. In particular, many researchers have been focusing on the applications of TMDCs in dealing with environmental pollution. TMDCs provide a unique opportunity to develop higher-value applications related to environmental matters. This work highlights the applications of TMDCs contributing to pollution reduction in (i) gas sensing technology, (ii) gas adsorption and removal, (iii) wastewater treatment, (iv) fuel cleaning, and (v) carbon dioxide valorisation and conversion. Overall, the applications of TMDCs have successfully demonstrated the advantages of contributing to environmental conversation due to their special properties. The challenges and bottlenecks of implementing TMDCs in the actual industry are also highlighted. More efforts need to be devoted to overcoming the hurdles to maximize the potential of TMDCs implementation in the industry.
  • 2.4K
  • 27 Oct 2020
Topic Review
Epoxide Synthesis and Ring-Opening Reactions
This entry concentrates on some examples of success stories from the synthesis of approved medicines and drug candidates using epoxide chemistry in the development of robust and efficient syntheses at large scale. The focus is on those parts of each synthesis related to the substrate-controlled/diastereoselective and catalytic asymmetric synthesis of epoxide intermediates and their subsequent ring-opening reactions with various nucleophiles. These are described in the form of case studies of high profile pharmaceuticals spanning a diverse range of indications and molecular scaffolds such as heterocycles, terpenes, steroids, peptidomimetics, alkaloids and main stream small molecules. Representative examples include, but are not limited to the antihypertensive diltiazem, the antidepressant reboxetine, the HIV protease inhibitors atazanavir and indinavir, efinaconazole and related triazole antifungals, tasimelteon for sleep disorders, the anticancer agent carfilzomib, the anticoagulant rivaroxaban the antibiotic linezolid and the antiviral oseltamivir. Emphasis is given on aspects of catalytic asymmetric epoxidation employing metals with chiral ligands particularly with the Sharpless and Jacobsen–Katsuki methods as well as organocatalysts such as the chiral ketones of Shi and Yang, Pages's chiral iminium salts and typical chiral phase transfer agents.
  • 2.4K
  • 09 Oct 2020
Topic Review
AgNPs
Elementary silver nanoparticles (AgNPs) are of great interest because of their various probable medical application. Due to their antimicrobial activity, low toxicity and inexpensive cost, the mechanism of silver nanoparticles biosynthesis in bacterial, fungal and plant cells is extremely exciting from the point of view of the different cellular compounds participation in it: proteins, enzymes, acids, etc.
  • 2.3K
  • 15 Dec 2020
Topic Review
Electrochemical Glucose Sensing
The research field of glucose biosensing has shown remarkable growth and development since the first reported enzyme electrode in 1962. Extensive research on various immobilization methods and the improvement of electron transfer efficiency between the enzyme and the electrode have led to the development of various sensing platforms that have been constantly evolving with the invention of advanced nanostructures and their nano-composites. Examples of such nanomaterials or composites include gold nanoparticles, carbon nanotubes, carbon/graphene quantum dots and chitosan hydrogel composites, all of which have been exploited due to their contributions as components of a biosensor either for improving the immobilization process or for their electrocatalytic activity towards glucose. This review aims to summarize the evolution of the biosensing aspect of these glucose sensors in terms of the various generations and recent trends based on the use of applied nanostructures for glucose detection in the presence and absence of the enzyme.
  • 2.3K
  • 13 Nov 2020
Topic Review
Polystyrene vs. Polylactide
Polystyrene (PS) is a thermoplastic polymer made of aromatic hydrocarbon monomer styrene that is derived from fossil-fuels. The synthesis of PS is based on the free radical polymerization of styrene using free-radical initiators. It is mostly used in solid (high impact and general purpose PS), foam and expanded PS forms. The main advantages of PS are low-cost, easy processing ability, and resistance to ethylene oxide, as well as radiation sterilization. Polylactide (PLA)—biodegradable and compostable aliphatic polyester—is one of the key biopolymers with the largest market significance. 
  • 2.3K
  • 28 Dec 2022
Topic Review
Metal Oxides for CO2 Capture and Conversion
Metal oxides are essential in determining the overpotential and product selectivity in the CO2reduction reactions (CO2RR). In contrast, developing efficient and stable metal oxides is a significant challenge that must be achieved to lower the production cost of fuels in the practical implementation of CO2RR technologies. 
  • 2.3K
  • 14 Apr 2022
Topic Review
Li7La3Zr2O12 (LLZO): An Overview
Li7La3Zr2O12 (LLZO) is an inorganic garnet type solid electrolyte which has proven to be one of the most promising electrolytes because of its high ionic conductivity at room temperature, low activation energy, good chemical and electrochemical stability, and wide potential window.
  • 2.3K
  • 03 Aug 2021
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