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Topic Review
Fully Implanted Hearing Systems
The ear and brain work together in the hearing process. Sound energy in the audible frequency range (20 Hz–20 kHz) propagates through air medium as an acoustical mechanical wave which enters from the outer ear towards the middle ear to vibrate the eardrum. 
  • 1.4K
  • 02 Aug 2021
Topic Review
Vitreous Substitute
The ideal vitreous substitute should mimic the native vitreous in terms of both structure and function such as transparency, biocom-patibility, elasticity, easy injectability, except for its liquefication and biodegradability with age. Current vitreous substitutes are used in order to maintain certain criterias such as optical and biomechanical properties and intraocular pressure. Therefore, extensive research with biomaterials is underway taking into consideration its composition, structure and physiological properties as well to overcome the downside of the currently used tamponades.
  • 1.4K
  • 15 Jan 2021
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.
  • 1.4K
  • 12 May 2022
Topic Review
Thermocatalytic Conversion of Plastics into Liquid Fuels
The problem of recycling polymer waste remains the main one in the context of the growth in the use of plastics. Given the non-renewability of fossil fuels, the task of processing plastic waste into liquid fuels seems to be a promising one. Thermocatalytic conversion is one of the methods that allows obtaining liquid products of the required hydrocarbon range. Clays and clay minerals can be distinguished among possible environmental-friendly, cheap and common catalysts.
  • 1.4K
  • 08 Jun 2022
Topic Review
Polyurea for Blast and Impact Protection
Polyurea has attracted extensive attention from researchers and engineers in the field of blast and impact protection due to its excellent quasi-static mechanical properties and dynamic mechanical properties. Its mechanical properties and energy absorption capacity have been tuned by means of formulation optimization, molecular dynamics (MD) simulation and the addition of reinforcing materials. Owing to the special molecular structure of polyurea, the mechanism of polyurea protection against blasts and impacts is the simultaneous effect of multiple properties. For different substrates and structures, polyurea needs to provide different performance characteristics, including adhesion, hardness, breaking elongation, etc., depending on the characteristics of the load to which it is subjected. 
  • 1.4K
  • 11 Jul 2022
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.
  • 1.3K
  • 28 Sep 2021
Topic Review
Zinc Oxide Doped with Transition Metal Ions
As an excellent semiconductor photocatalyst, zinc oxide is widely used in the field of photocatalysis and is regarded as one of the most reliable materials to solve environmental problems. However, because its band gap energy limits the absorption of visible light and reduces the efficiency of catalytic degradation, it needs to be doped with other substances or compounded with other substances and precious metal. 
  • 1.3K
  • 11 Nov 2022
Topic Review
Bigels
Bigels have been mainly applied in the pharmaceutical sector for the controlled release of drugs or therapeutics. However, these systems, with their intricate structures, hold great promise for wider application in food products. Besides their classical role as carrier and target delivery vehicles for molecules of interest, bigels may also be valuable tools for building complex food structures. In the context of reducing or even eliminating undesirable (but often highly functional) food components, current strategies often critically affect food structure and palatability. The production of solid fat systems that are trans-fat-free and have high levels of unsaturated fatty acids is one of the challenges the food industry currently faces. 
  • 1.3K
  • 13 Nov 2023
Topic Review
Plastic Mismanagement in Africa
Plastic waste pollution is one of the main items on international agendas. It leads to more and more leakages and constitutes a dangerous threat to living beings and the ecosystem (toxic substances). Globally, only 9% of plastic waste is recycled, while 22% of it is mismanaged. A large part of this waste ends up legally or illegally in Africa.
  • 1.3K
  • 22 Jan 2024
Topic Review
Polyurethanes and Green Chemistry
Polyurethanes are most often called “green” when they contain natural, renewable additives in their network or chemical structure, such as mono- and polysaccharides, vegetable oils, polyphenols, or various compounds derived from agro-waste white biotechnology. The use of these natural substrates is in line with the principles of green chemistry. However, other principles among all 12 can also be used in the production of polyurethanes.
  • 1.3K
  • 11 Nov 2021
Topic Review
Incorporation of Biochar
Biochar can be used as a reinforcing filler improving the mechanical, thermal and even electrical properties of polymer composites. The incorporation of this cost effective sustainable filler not only improves the applicability of the resulting composite but also makes the process and end product sustainable. 
  • 1.3K
  • 25 Aug 2021
Topic Review
Biopolymer-Based Dye Removal Technologies
Synthetic dyes have become an integral part of many industries such as textiles, tannin and even food and pharmaceuticals. Industrial dye effluents from various dye utilizing industries are considered harmful to the environment and human health due to their intense color, toxicity and carcinogenic nature.
  • 1.3K
  • 23 Nov 2021
Topic Review
Hypercrosslinking of Poly(vinylbenzyl chloride) PolyHIPEs
The concept of polymer chain hypercrosslinking was introduced by Davankov, Rogoshin and Tsyurupa, using linear polystyrene or swollen gel-type poly (styrene-co-divinylbenzene) in the presence of an external crosslinker, solvent and a Lewis base as a catalyst.
  • 1.3K
  • 30 Aug 2021
Topic Review Peer Reviewed
Fluorescence in Smart Textiles
Fluorescence has been identified as an advantageous feature in smart fabrics, notably for the protection of humans during outdoor athletic activities, as well as for preventing counterfeiting and determining authenticity. Fluorescence in smart fabrics is achieved using dendrimers, rare earth metal compounds, and fluorescent dye. The principal method for producing fluorescent fabrics is to immerse the sample in a solution containing fluorescent agents. However, covalent connections between fluorophores and textile substates should be established to improve the stability and intensity of the fluorescent characteristics. Fabric can be fluorescent throughout, or fluorescent fibers can be woven directly into the textile structures, made of natural (cotton, silk) or synthetic (polyamide- and polyester-based) fibers, into a precise pathway that becomes visible under ultraviolet irradiation.
  • 1.3K
  • 14 Nov 2023
Topic Review
Polymeric Carriers
RNA therapeutics have gained popularity due to their ability to affect targets that small molecules cannot. Additionally, they can be manufacture more rapidly and cost-effectively than small molecules or recombinant proteins. RNA therapeutics can be synthesised chemically and altered quickly, which can enable a more personalised approach to treatment. Even though a wide range of RNA therapeutics are being developed for various indications, none has reached the clinic to date. One of the main reasons for this is attributed to the lack of safe and effective delivery systems for this type of therapeutic. Polymeric carriers have been widely studied for the delivery of RNA therapeutics because of their versatility, potential multi-functionality and relative low cost.
  • 1.3K
  • 29 Aug 2022
Topic Review
Bio-Vitrimers for Sustainable Circular Bio-Economy
The traditional polymer circular economy (CE) continues to be challenging due to its reprocessing/recycle ability; also, at the same time, newly developed substitute materials have not expressed similar performance to conventional materials involved in contemporary applications. Hence, linear approaches such as “take-make-use-waste” have severely affected sustainability modules where non-renewable resources have been used at maximum levels. In addition, sustainability is termed along with the circular economy paradigm in recent times, although material sustainability differs from CE material. The circular economy mainly focuses on the economic, environmental and social impacts, whereas sustainability is more about an ecological importance. Globally, frameworks have been formed to enhance the sustainable environment. The United Nations (UN) has designed 17 sustainable development goals to be enforced in all countries in order to reach the goal of a sustainable society by 2030.
  • 1.3K
  • 01 Nov 2022
Topic Review
Filled Polymers and DMA
Dynamic mechanical analysis (DMA) provides reliable information about the viscoelastic behavior of neat and filled polymers. The properties of filled polymers are relevant to different industries as protective organic coatings, composites etc. Interfacial interactions in filled polymers play an important role in determining their bulk properties and performance during service life. In this entry, studies which used DMA to characterize the interfacial interactions in filled polymers have been reviewed.
  • 1.3K
  • 26 Apr 2021
Topic Review
Polymer Electrolyte Membrane Fuel Cell
Polymer electrolyte membrane fuel cells (PEMFCs) have been considered as electric power sources for cars, as well as stationary and portable power sources, due to their high energy efficiency, ease of operation, and environmental friendliness. Furthermore, as a promising power source, integrating PEMFCs into microgrids, which are a common structure in the smart grid framework, has been gaining traction around the world, encouraging the usage of hydrogen energy.
  • 1.3K
  • 09 Aug 2021
Topic Review
Carbon Dioxide Capture By Biopolymer-Derived Porous Materials
Rising atmospheric carbon dioxide (CO2) concentration in the atmosphere is responsible for global warming which in turn causes abrupt climate change and consequently poses a threat to the living organisms in the coming years. CO2 capture and separation are crucial to reduce the CO2 content in the atmosphere. Post-combustion capture is one of the most useful techniques for capturing CO2 due to its practicality and ease of use. For adsorption-driven post-combustion CO2 capture, sorbents with large surface area, high volume, and narrow pores are highly effective. Natural polymers, such as polysaccharides, are less expensive, more plentiful, and can be modified by a variety of methods to produce porous materials and thus can be effectively utilized for CO2 capture. A significant amount of research activities has already been established in this field, especially in the last ten years and are still in progress. In this review, we have introduced the latest developments to the readers about synthetic techniques, post-synthetic modifications and CO2 capture capacities of various biopolymer-based materials published in the last five years (2018–2022).
  • 1.3K
  • 21 Aug 2023
Topic Review
Self-Healing Mechanism of Hydrogel
The route to achieve self-healing of hydrogels is by noncovalent or reversible dynamic covalent bonding in polymeric materials, and enhancing the conductivity of hydrogels by the addition of conductive fillers, conductive polymers or conductive ions.
  • 1.3K
  • 29 Nov 2021
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