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Topic Review
The Ubiquity of Microplastics in the Environment
Plastic is an indispensable material in modern society; however, high production rates combined with inadequate waste management and disposal have resulted in enormous stress on ecosystems. In addition, plastics can become smaller particles known as microplastics (MPs) due to physical, chemical, and biological drivers. MP pollution has become a significant environmental problem affecting terrestrial and aquatic ecosystems worldwide.
  • 750
  • 28 Aug 2023
Topic Review
Methods of Making Lithium-Ion Batteries Membrane
Due to the growing demand for eco-friendly products, lithium-ion batteries (LIBs) have gained widespread attention as an energy storage solution. With the global demand for clean and sustainable energy, the social, economic, and environmental significance of LIBs is becoming more widely recognized. LIBs are composed of cathode and anode electrodes, electrolytes, and separators. Notably, the separator, a pivotal and indispensable component in LIBs that primarily consists of a porous membrane material, warrants significant research attention. 
  • 749
  • 22 Sep 2023
Topic Review
Carrageenan-Based Hard Capsules: Review
Carrageenan is used as a gelling agent in products, such as frozen foods, jellies and yogurt. Commercially, carrageenan has been produced in six different types based on their structures. Among the six polymers, κ-carrageenan is the most produced due to its high gelling ability caused by the C4 conformation on the 3,6-anhydro-D-galactopyranosyl that forms a helix-like structure. The formation of the helix structure is supported by the enormous number of –OH groups that form many hydrogen bonds.
  • 746
  • 28 Sep 2021
Topic Review
Types of Micellar Assemblies
Amphiphilic block copolymers (with a variety of hydrophobic blocks and hydrophilic blocks; often polyethylene oxide) self-assemble in water to micelles/niosomes similar to conventional nonionic surfactants with high drug loading capacity.
  • 744
  • 08 Nov 2022
Topic Review
Permeation Enhancers of Hormones Penetration through the Skin
Hormones have attracted considerable interest in recent years due to their potential use in treatment of many diseases. Their ability to have a multidirectional effect leads to searching for new and increasingly effective drugs and therapies. Limitations in formulating drug forms containing hormones are mainly due to their low enzymatic stability, short half-life and limited bioavailability. One of the solutions may be to develop a hydrogel as a potential hormone carrier, for epidermal and transdermal application. 
  • 741
  • 01 Sep 2022
Topic Review
Hybrid Materials Based on Polyhydroxyalkanoates
Polyhydroxyalkanoates (PHAs) constitute a family of biopolyesters that are synthesized and accumulate within the cellular structure of prokaryotic cells by bacteria, and they act as carbon and energy reserve materials under conditions of limited nutrient, such as nitrogen, oxygen, phosphorous or magnesium. As naturally derived materials, PHAs have been used for multiple cell and tissue engineering applications; however, their widespread biomedical applications are limited due to their lack of toughness, elasticity, hydrophilicity and bioactivity. To overcome this challenge combination of PHA with different polymers and inorganic materials are used to form hybrid composites with improved structural and functional properties.
  • 737
  • 07 Jun 2021
Topic Review
Enhancing Weathering Resistance of Wood
Although weathering is primarily a surface phenomenon, it is an important issue for wood products as it affects their appearance, service life, and wood-coating performance. To encourage the use of wood as a material for joinery and other building components, the results of research into increasing the weathering resistance of wood are extremely significant. The development of weathering protection methods is of great importance to reduce the maintenance requirements for wood exposed outdoors and can have a major environmental impact.
  • 736
  • 30 Jun 2021
Topic Review
Properties and Bioactivity of Chitosan
Chitosan (CS) is a natural biopolymer derived by deacetylation (N-acetyl-D-glucosamine to D-glucosamine unit) of chitin.
  • 730
  • 11 Jun 2021
Topic Review
Polymer-Based Thermal Management Material
The thermally conductive polymer is usually categorized into the intrinsic thermally conductive polymers and the thermally conductive polymer composites.
  • 726
  • 09 Sep 2021
Topic Review
Hydrogels as Biomaterials for Wound Dressings
Wound management remains a challenging issue around the world, although a lot of wound dressing materials have been produced for the treatment of chronic and acute wounds. Wound healing is a highly dynamic and complex regulatory process that involves four principal integrated phases, including hemostasis, inflammation, proliferation, and remodeling. Chronic non-healing wounds are wounds that heal significantly more slowly, fail to progress to all the phases of the normal wound healing process, and are usually stalled at the inflammatory phase. These wounds cause a lot of challenges to patients, such as severe emotional and physical stress and generate a considerable financial burden on patients and the general public healthcare system. It has been reported that about 1–2% of the global population suffers from chronic non-healing wounds during their lifetime in developed nations. Traditional wound dressings are dry, and therefore cannot provide moist environment for wound healing and do not possess antibacterial properties. Wound dressings that are currently used consist of bandages, films, foams, patches and hydrogels. Currently, hydrogels are gaining much attention as a result of their water-holding capacity, providing a moist wound-healing milieu. 
  • 726
  • 12 Dec 2022
Topic Review
Membrane-Based Environmental Remediation
During the last century, industrialization has grown very fast and as a result heavy metals have contaminated many water sources. Due to their high toxicity, these pollutants are hazardous for humans, fish, and aquatic flora. Traditional techniques for their removal are adsorption, electro-dialysis, precipitation, and ion exchange, but they all present various drawbacks. Membrane technology represents an exciting alternative to the traditional ones characterized by high efficiency, low energy consumption and waste production, mild operating conditions, and easy scale-up. In this review, the attention has been focused on applying driven-pressure membrane processes for heavy metal removal, highlighting each of the positive and negative aspects. Advantages and disadvantages, and recent progress on the production of nanocomposite membranes and electrospun nanofiber membranes for the adsorption of heavy metal ions have also been reported and critically discussed. Finally, future prospective research activities and the key steps required to make their use effective on an industrial scale have been presented
  • 723
  • 02 Jul 2021
Topic Review
Fabrication-4D-Printed Shape Memory Polymers
Additive manufacturing (AM) is the process through which components/structures are produced layer-by-layer. In this context, 4D printing combines 3D printing with time so that this combination results in additively manufactured components that respond to external stimuli and, consequently, change their shape/volume or modify their mechanical properties. Therefore, 4D printing uses shape-memory materials that react to external stimuli such as pH, humidity, and temperature. Among the possible materials with shape memory effect (SME), the most suitable for additive manufacturing are shape memory polymers (SMPs).
  • 721
  • 27 Apr 2021
Topic Review
Stimuli-Responsive Zinc (II) Coordination Polymers
The unique role of the zinc (II) cation prompted us to cut a cross-section of the large and complex topic of the stimuli-responsive coordination polymers (CPs). Due to its flexible coordination environment and geometries, easiness of coordination–decoordination equilibria, “optically innocent” ability to “clip” the ligands in emissive architectures, non-toxicity and sustainability, the zinc (II) cation is a good candidate for building supramolecular smart tools. 
  • 721
  • 08 Nov 2021
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.
  • 716
  • 06 Apr 2021
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. 
  • 714
  • 07 May 2021
Topic Review
Miscanthus-Based Polymers
Carbon neutrality is a requisite for industrial development in modern times. The most efficient source of biomass is energy crops, and Miscanthus has been globally recognized as one of the most significant among them. Miscanthus is basically utilized for the production of heat and electric power, and it is actively displacing wood in papermaking and natural cellulose isolation technologies. However, the range of potential applications of Miscanthus is much broader.
  • 709
  • 16 Oct 2023
Topic Review
Polymeric Wastewater Purification Membranes
Over the past few years, polymeric membranes are widely used for applications in separation technologies. They show better flexibility, pore formation mechanism, thermal and chemical stability, and demand less area for installation. Wastewater purification is among the most desirable application of these membranes. In comparison to conventional separation materials, membranes offer economical and efficient treatment. The polymers employed in the synthesis of each membrane are selectively chosen to enhance the optimal performance in wastewater purification.
  • 706
  • 09 Jul 2021
Topic Review
Enzyme-Catalyzed Synthesis of Polyesters
Polyester is a kind of polymer composed of ester bond-linked polybasic acids and polyol. This type of polymer has a wide range of applications in various industries, such as automotive, furniture, coatings, packaging, and biomedical. The traditional process of synthesizing polyester mainly uses metal catalyst polymerization under high-temperature. This condition may have problems with metal residue and undesired side reactions. As an alternative, enzyme-catalyzed polymerization is evolving rapidly due to the metal-free residue, satisfactory biocompatibility, and mild reaction conditions.   
  • 705
  • 20 Dec 2022
Topic Review
Classification and Application of Natural Polymers
Natural polysaccharides are some of the most extensively used biopolymers in food, pharmaceutical, and medical applications, because they are renewable and have a high level of biocompatibility and biodegradability. The fundamental understanding required to properly exploit polysaccharides potential in the biocomposite, nanoconjugate, and pharmaceutical industries depends on detailed research of these molecules. Polysaccharides are preferred over other polymers because of their biocompatibility, bioactivity, homogeneity, and bioadhesive properties. Natural polysaccharides have also been discovered to have excellent rheological and biomucoadhesive properties, which may be used to design and create a variety of useful and cost-effective drug delivery systems. Polysaccharide-based composites derived from natural sources have been widely exploited due to their multifunctional properties, particularly in drug delivery systems and biomedical applications. These materials have achieved global attention and are in great demand because to their biochemical properties, which mimic both human and animal cells. 
  • 705
  • 07 Feb 2024
Topic Review
Synthesis of Polypeptides with Activated Amino Acid Monomers
Commonly, three different synthetic pathways are used to prepare peptides in the laboratory: via the polymerization of amino acid N-carboxyanhydrides (NCAs), amino acid N-thiocarboxyanhydrides (NTAs), and N-phenoxycarbonyl amino acids (NPCs); via various stepwise coupling reactions of α-amino acids, such as during solid phase peptide synthesis (SPPS); or via recombinant DNA techniques for expressing peptides in microorganisms. Polypeptides that are synthesized through SPPS have controlled primary sequences and can fulfill certain functionalities, but it is difficult to create high molecular weight polypeptides above 100 residues, due to the inevitable side reactions. Recombinant DNA techniques can create polypeptides with specific sequences and high molecular weights. Moreover, they allow for peptide production on a very large scale. However, specialized equipment, which is not readily available in most synthetic laboratories, is needed for this method. The polymerization of activated amino acid monomers enables the formation of bioactive and high molecular weight polypeptides in a facile and expedient manner. The process begins with the conversion of amino acids into the corresponding activated monomers; afterwards, polymerization is initiated in the presence of certain initiators. Although polypeptides that are synthesized in this way lack precise sequence control, their synthetic advantages make this method attractive and economical for synthesizing polypeptides in large quantities.
  • 704
  • 12 May 2022
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