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Topic Review
ABC-Type Linear Triblock Terpolymers
This entry aims to cover the most recent advances regarding the synthesis of linear ABC-type triblock terpolymers by RAFT polymerization, as well as their self-assembly properties in aqueous solutions. RAFT polymerization has received extensive attention, as it is a versatile technique, compatible with a great variety of functional monomers and reaction conditions, while providing exceptional and precise control over the final structure, with well-defined side-groups and post-polymerization engineering potential. Linear triblock terpolymers synthesis can lead to very interesting novel ideas, since there are countless combinations of stimuli/non-stimuli and hydrophilic/hydrophobic monomers that someone can use. One of their most interesting features is their ubiquitous ability to self-assemble in different nanostructures depending on their degree of polymerization (DP), block composition, solubilization protocol, internal and external stimuli. 
  • 1.1K
  • 26 May 2021
Topic Review
Effect of Nano-Additives on PLA/Nanocomposite Properties
Poly(lactic acid) (PLA) is considered the most promising biobased substitute for fossil-derived polymers due to its compostability, biocompatibility, renewability, and good thermomechanical properties. However, PLA suffers from several shortcomings, such as low heat distortion temperature, thermal resistance, and rate of crystallization, whereas some other specific properties, i.e., flame retardancy, anti-UV, antibacterial or barrier properties, antistatic to conductive electrical characteristics, etc., are required by different end-use sectors. The addition of different nanofillers represents an attractive way to develop and enhance the properties of neat PLA. Numerous nanofillers with different architectures and properties have been investigated, with satisfactory achievements, in the design of PLA nanocomposites.
  • 1.1K
  • 21 Mar 2023
Topic Review
Antimicrobial Peptides and Proteins (AMPs)
Mycotoxins are toxic secondary metabolites produced by filamentous fungi in crops or during storage, transport and processing of food and feed commodities, which pose serious health risks for both humans and animals. The trend of mycotoxin contamination in food and feed has reached alarming levels. Antimicrobial peptides and proteins (AMPs) with antifungal activity are gaining much interest as natural antifungal compounds due to their properties such as structure diversity and function, antifungal spectrum, mechanism of action, high stability and the availability of biotechnological production methods. 
  • 1.1K
  • 14 Jan 2022
Topic Review
Electrospun Nanofiber Mats
Air pollution is one of the biggest health and environmental problems in the world and a huge threat to human health on a global scale. Due to the great impact of respiratory viral infections, chronic obstructive pulmonary disease, asthma, emphysema, lung disease, and heart disease, respiratory allergies are increasing significantly every year. Because of the special properties of electrospun nanofiber mats, e.g., large surface-to-volume ratio and low basis weight, uniform size, and nanoporous structure, nanofiber mats are the preferred choice for use in large-scale air filtration applications. 
  • 1.1K
  • 07 May 2021
Topic Review
General Synthesis Methods of Poly (ε-caprolactone)-Based Graft Copolymers
Synthetic biopolymers are attractive alternatives to biobased polymers, especially because they rarely induce an immune response in a living organism. Poly ε-caprolactone (PCL) is a well-known synthetic aliphatic polyester universally used for many applications, including biomedical and environmental ones.  To expand the range of applications for PCL, researchers have investigated the possibility of grafting polymer chains onto the PCL backbone. As the PCL backbone is not functionalized, it must be first functionalized in order to be able to graft reactive groups onto the PCL chain. These reactive groups will then allow the grafting of new reagents and especially new polymer chains. Grafting of polymer chains is mainly carried out by “grafting from” or “grafting onto” methods.
  • 1.1K
  • 29 Nov 2022
Topic Review
Structural and Thermal Characterization of Resins
The synthesis of poly(vinylbenzyl pyridinium salts) fabricated through poly(vinylbenzyl halogene-co-divinylbenzene) quaternization of N-decyloxy-1-(pyridin-3- or -4-yl)ethaneimine was verified by the FTIR spectra of the final quaternized products, in comparison with the spectra of the initial copolymers.
  • 1.1K
  • 17 Mar 2022
Topic Review
Reprocessable Photodeformable Azobenzene Polymers
Photodeformable azobenzene (azo) polymers are a class of smart polymers that can efficiently convert light energy into mechanical power, holding great promise in various photoactuating applications. They are typically of crosslinked polymer networks with highly oriented azo mesogens embedded inside. Upon exposure to the light of appropriate wavelength, they experience dramatic order parameter change following the configuration change of the azo units. This could result in the generation and accumulation of the gradient microscopic photomechanical force in the crosslinked polymer networks, thus leading to their macroscopic deformation. Most of the presently developed photodeformable azo polymers have stable chemically crosslinked networks, which make their reprocessing impossible, thus limiting their large scale applications. To solve this problem, reprocessable photodeformable azo polymers have been recently developed by introducing dynamic crosslinking networks (including physically crosslinked and dynamic covalent bond-crosslinked ones) into their structures. In addition, some uncrosslinked photodeformable azo polymers have also been reported and constitute one special type of reprocessable photodeformable azo polymers, whose photodeformation behaviors are mainly induced by the selective reorientation of the azo moieties (become perpendicular to the polarization direction of the polarized light) under the irradiation of either polarized blue light or interfering polarized light.
  • 1.1K
  • 30 Aug 2021
Topic Review
Versatile Polyaniline-Based Polymers in Food Industry
Intrinsically conducting polymers (ICPs) have been widely studied in various applications, such as sensors, tissue engineering, drug delivery, and semiconductors. Specifically, polyaniline (PANI) stands out in food industry applications due to its advantageous reversible redox properties, electrical conductivity, and simple modification. The rising concerns about food safety and security have encouraged the development of PANI as an antioxidant, antimicrobial agent, food freshness indicator, and electronic nose. At the same time, it plays an important role in food safety control to ensure the quality of food.
  • 1.1K
  • 14 Dec 2022
Topic Review
Recent Advances in PLA/TiO2 Composites
Polylactic acid/titanium oxide (PLA/TiO2) composites as multifunctional materials havebeen studied extensively by couple of  research groups owing to their outstanding mechanical, thermal, photocatalytic, and antimicrobial properties. This review describes the experimental approaches used to improve the compatibility of PLA/TiO2 composites. The mechanical, thermal, photocatalytic,  and antimicrobial properties of PLA/TiO2 composites are discussed. The potential applications arising from the structural and functional properties of PLA/TiO2 composites were also reviewed. Finally,  it is concluded that a deep understanding of the impacts of TiO2 filler with available improvement approaches in the dispersibility of this filler in the PLA matrix would be the key for the effective usage of PLA/TiO2 composites and to expand their suitability with worldwide application requirements.
  • 1.1K
  • 06 Apr 2021
Topic Review
Aerogels for the Removal of Heavy Metal Ions
Aerogel is a general term referring to novel nanostructured materials characterized by very high porosity and tunable physicochemical properties that are obtained following a sol–gel process and an appropriate drying method. Such novel materials are entering the market in everyday products and a wide portfolio of properties usable for applications in health care, foods, agriculture, energy, and environmental remediation. Bio-based aerogels obtained from renewable resources and biomass are biodegradable and biocompatible due to the natural origin of the polymers, and for this reason, they greatly contribute to the sustainable concept of the bio-economy, offering promising commodities for environmental remediation.
  • 1.1K
  • 22 Jan 2024
Biography
Mahmoud A. Hussein
M.A. Hussein is a professor of Polymer Chemistry, Polymer Chemistry Lab, Chemistry Department, Faculty of Science, Assiut University (AU), Egypt. He obtained his PhD in Organic Polymer Synthesis from Assiut University, Egypt in 2007. He got a position at Chemistry Department, King Abdulaziz University (KAU), Jeddah, Saudi Arabia from 2010 – till now. He got a postdoctoral position in the Unive
  • 1.1K
  • 13 Mar 2023
Topic Review
Fluoropolymer Membranes for Membrane Distillation and Membrane Crystallization
Fluoropolymer membranes are applied in membrane operations such as membrane distillation and membrane crystallization where hydrophobic porous membranes act as a physical barrier separating two phases. Due to their hydrophobic nature, only gaseous molecules are allowed to pass through the membrane and are collected on the permeate side, while the aqueous solution cannot penetrate. However, these two processes suffer problems such as membrane wetting, fouling or scaling. Membrane wetting is a common and undesired phenomenon, which is caused by the loss of hydrophobicity of the porous membrane employed. This greatly affects the mass transfer efficiency and separation efficiency. Simultaneously, membrane fouling occurs, along with membrane wetting and scaling, which greatly reduces the lifespan of the membranes. Therefore, strategies to improve the hydrophobicity of membranes have been widely investigated by researchers. In this direction, hydrophobic fluoropolymer membrane materials are employed more and more for membrane distillation and membrane crystallization thanks to their high chemical and thermal resistance. 
  • 1.1K
  • 03 Jan 2023
Topic Review
Fiber–Hydrogel Composites for Wound Healing
The structural resemblance of fiber–hydrogel composites to natural tissues has been a driving force for the optimization and exploration of these systems in biomedicine. Indeed, the combination of hydrogel-forming techniques and fiber spinning approaches has been crucial in the development of scaffolding systems with improved mechanical strength and medicinal properties.
  • 1.1K
  • 11 Mar 2021
Topic Review
COF-Based Photocatalysts for Enhanced Synthesis of Hydrogen Peroxide
Photocatalytic synthesis of H2O2 has emerged as a compelling alternative, offering the prospect of harnessing solar energy directly to drive chemical reactions, thereby circumventing the need for energy-intensive processes and deleterious chemicals.
  • 1.1K
  • 11 Mar 2024
Topic Review
Sulfonimide-Based Dendrimers
Dendrimers are multifunctional polymer compounds with a tree-like shape and a high branching degree. 
  • 1.1K
  • 25 Feb 2021
Topic Review
Bioactive Polymers via the Biginelli Reaction
Multicomponent reactions (MCRs) have been used to prepare polymers with appealing functions. The Biginelli reaction, one of the oldest and most famous MCRs, has sparked new scientific discoveries in polymer chemistry since 2013. The applications of the Biginelli reaction in developing functional polymers are mainly focusing on polymers that can be used in the biomedical area as antioxidants, anticancer agents, and bioimaging probes.
  • 1.1K
  • 22 Nov 2022
Topic Review
Recycling of High-Molecular-Weight Organosilicon Compounds in Supercritical Fluids
The main known patterns of thermal and/or catalytic destruction of high-molecular-weight organosilicon compounds are considered from the viewpoint of the prospects for processing their wastes. The advantages of using supercritical fluids in plastic recycling are outlined in this entry. They are related to a high diffusion rate, efficient extraction of degradation products, the dependence of solvent properties on pressure and temperature, etc. A promising area for further research is described concerning the application of supercritical fluids for processing the wastes of organosilicon macromolecular compounds.
  • 1.1K
  • 14 Dec 2022
Topic Review
Stimulus-Responsive Polymers and Polypeptoid Skeletons
Polypeptoids have low cytotoxicity and good biocompatibility because of their structural similarity to polypeptides. Different from polypeptides, however, polypeptoids show thermal transformation similar to synthetic thermoplastics, making them suitable for various heat treatment methods. Polypeptoids combine the properties of natural macromolecules and synthetic polymers, and become great candidates as stimulus-responsive biopolymers.
  • 1.1K
  • 05 Aug 2021
Topic Review
Solid State Nuclear Magnetic Resonance Investigating Cellulose-Based Materials
Solid state nuclear magnetic resonance (ssNMR) is a powerful and attractive characterization method for obtaining insights into the chemical structure and dynamics of a wide range of materials. Current interest in cellulose-based materials, as sustainable and renewable natural polymer products, requires deep investigation and analysis of the chemical structure, molecular packing, end chain motion, functional modification, and solvent–matrix interactions, which strongly dictate the final product properties and tailor their end applications. In comparison to other spectroscopic techniques, on an atomic level, ssNMR is considered more advanced, especially in the structural analysis of cellulose-based materials
  • 1.1K
  • 15 Apr 2022
Topic Review
Natural and Modified Cyclodextrins as Packaging Additives
Cyclodextrins (CDs) have been used by the pharmaceutical and food industries since the 1970s. Their cavities allow the accommodation of several hydrophobic molecules, leading to the formation of inclusion complexes (ICs) increasing the guest molecules’ stability, allowing their controlled release, enhancing their water solubility and biodisponibility.
  • 1.1K
  • 18 Nov 2021
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