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Topic Review
Chemical Depolymerization Methods of Poly(ethylene terephthalate)
The significant amount of waste generated by poly(ethylene terephthalate) (PET) requires the development of a recycling process chain in which chemical recycling plays an important role. On the one hand, it allows the depolymerization of degraded plastics that do not meet the quality requirements to be used in mechanical recycling, and on the other hand, provides an opportunity to process cheap waste and obtain products with greater added value. It can be widely used in the recycling of both packaging plastics and textiles, or other waste generated with PET.
  • 814
  • 12 Oct 2023
Topic Review
Chemical Recycling for Plastic Waste
Plastics play an integral role in shaping our modern society and are ubiquitous in our daily lives. Their superior material characteristics, performance, and low production cost make them desirable for vast consumer and industrial applications. Chemical or feedstock recycling refers to any reprocessing technology directly affecting the formulation of polymeric waste or the polymer itself.  The recycling plastic waste through chemical means are explored.
  • 385
  • 23 May 2023
Topic Review
Chemical Treatment for Textile Waste
Trends in the textile industry show a continuous increase in the production and sale of textile materials, which in turn generates a huge amount of discarded clothing every year. This has a negative impact on the environment, on one side, by consuming resources—some of them non-renewables (to produce synthetic polymers)—and on the other side, by polluting the environment through the emission of GHGs (greenhouse gases), the generation of microplastics, and the release of toxic chemicals in the environment (dyes, chemical reagents, etc.). When natural polymers (e.g., cellulose, protein fibers) are used for the manufacturing of clothes, the negative impact is transferred to soil pollution (e.g., by using pesticides, fertilizers). In addition, for the manufacture of clothes from natural fibers, large amounts of water are consumed for irrigation. According to the European Environment Agency (EEA), the consumption of clothing is expected to increase by 63%, from 62 million tonnes in 2019 to 102 million tonnes in 2030.
  • 1.1K
  • 14 Oct 2022
Topic Review
Chiral Porous Organic Frameworks
Organocatalysis, the use of chiral organic molecules as catalysts, has emerged as a highly efficient alternative to traditional asymmetric catalysis methods. Chiral porous organic frameworks have emerged as candidates for heterogeneous asymmetric organocatalysis.
  • 257
  • 20 Jul 2023
Topic Review
Chitin and Chitosan
Chitin and its derivative chitosan are highly abundant polymers in nature, appearing in both the shells and exoskeletons of various marine and non-marine species. Since they possess favorable properties, such as biocompatibility, biodegradability, non-toxicity, and non-immunogenicity, they have gained recent attention due to their enormous potential biomedical applications. The polycationic surface of chitosan enables it to form hydrogenic and ionic bonds with drug molecules, which is one of its most useful properties. Because chitosan is biocompatible, it can therefore be used in drug delivery systems. The development of chitosan-based nanoparticles has also contributed to the significance of chitin as a drug delivery system that can deliver drugs topically. Furthermore, chitin can be used in cancer treatment as a vehicle for delivering cancer drugs to a specific site and has an antiproliferative effect by reducing the viability of cells. Finally, chitosan can be used as a wound dressing in order to promote the faster regeneration of skin epithelial cells and collagen production by fibroblasts.
  • 1.2K
  • 01 Aug 2022
Topic Review
Chitosan and Chitosan Modified by Functionalization
The biomedical and therapeutic importance of chitosan and chitosan derivatives is the subject of interdisciplinary research. In this entry, researchers intended to consolidate some of the recent discoveries regarding the potential of chitosan and its derivatives to be used for biomedical and other purposes. Why chitosan? Because chitosan is a natural biopolymer that can be obtained from one of the most abundant polysaccharides in nature, which is chitin. Compared to other biopolymers, chitosan presents some advantages, such as accessibility, biocompatibility, biodegradability, and no toxicity, expressing significant antibacterial potential. In addition, through chemical processes, a high number of chitosan derivatives can be obtained with many possibilities for use. 
  • 1.4K
  • 02 Apr 2022
Topic Review
Chitosan and its Derivatives
Chitosan (CS) is a hemi-synthetic cationic linear polysaccharide produced by the deacetylation of chitin. CS is non-toxic, highly biocompatible, and biodegradable, and it has a low immunogenicity. Additionally, CS has inherent antibacterial properties and a mucoadhesive character and can disrupt epithelial tight junctions, thus acting as a permeability enhancer. As such, CS and its derivatives are well-suited for the challenging field of ocular drug delivery. In the present review article, we will discuss the properties of CS that contribute to its successful application in ocular delivery before reviewing the latest advances in the use of CS for the development of novel ophthalmic delivery systems. Colloidal nanocarriers (nanoparticles, micelles, liposomes) will be presented, followed by CS gels and lenses and ocular inserts. Finally, instances of CS coatings, aiming at conferring mucoadhesiveness to other matrixes, will be presented.
  • 1.0K
  • 31 Jul 2020
Topic Review
Chitosan in Fish Biotechnology
Chitosan is increasingly used for safe drug and nucleic acid delivery due to well-known properties such as bioadhesion, low toxicity, biodegradability and biocompatibility. Furthermore, chitosan derivatization can be easily performed to improve solubility and stability of chitosan-nucleic acid polyplexes, and enhance efficient target cell drug delivery, cell uptake, intracellular endosomal escape, unpacking and nuclear import of expression plasmids. This review focus attention on recent advances in chitosan-mediated gene delivery for fish biotechnology applications such as fish vaccination against bacterial and viral infection, control of gonadal development, and gene overexpression and silencing for overcoming metabolic limitations such as dependence on protein-rich diets and low glucose tolerance of farmed fish.
  • 2.2K
  • 27 Oct 2020
Topic Review
Chitosan-based Flame-Retardant Systems
During the last decade, the utilization of chitin, and in particular its deacetylated form, i.e. chitosan, for flame retardant purposes, has represented quite a novel and interesting application, very far from the established uses of this bio-sourced material. In this entry, chitosan is a carbon source that can be successfully exploited, often in combination with intumescent products, in order to provide different polymer systems (namely, bulky materials, fabrics and foams) with high flame retardant (FR) features. Besides, this specific use of chitosan in flame retardance is well suited to a green and sustainable approach.
  • 1.5K
  • 22 Oct 2020
Topic Review
Chitosan-Based Polyurethane Flexible Foams
Polyurethane (PUR) foam is a synthetic polymer.
  • 794
  • 14 Sep 2021
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