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Topic Review
Aggregation-Induced Emission Properties in Polymers
Aggregation-Induced Emission (AIE) is a phenomenon that consists of the appearance of fluorescence in solid state or aggregation greater than that of molecules in solution and has recently attracted the attention of the scientific community because of their potential applications in different fields. Compared to small molecules, little attention has been paid to polymers and oligomers that exhibit AIE, despite having excellent properties such as high emission efficiency in aggregate and solid states, signal amplification effect, good processability and the availability of multiple functionalization sites. In addition to these features, if the molecular structure is fully conjugated, intramolecular electronic interactions between the composing chromophores may appear, thus giving rise to a wealth of new photophysical properties. In this review, we focus on selected fully conjugated oligomers, dendrimers and polymers, and briefly summarize their synthetic routes, fluorescence properties and potential applications. An exhaustive comparison between spectroscopic results in solution and aggregates or in solid state has been collected in almost all examples, and an opinion on the future direction of the field is briefly stated.
  • 855
  • 02 Feb 2021
Topic Review
Polymeric Emissive Materials Based on Dynamic Covalent Bonds
Dynamic covalent polymers, composed of dynamic covalent bonds (DCBs), have received increasing attention due to their adaptive and reversible nature compared with common covalent linked polymers. Incorporating the DCBs into the polymeric material endows it with advanced performance including self-healing, shape memory property, and so forth.
  • 855
  • 25 Nov 2022
Topic Review
Poly(Ionic Liquid) Materials-Based Advanced Formulations for Additive Manufacturing
Innovation in materials specially formulated for additive manufacturing is of great interest and can generate new opportunities for designing cost-effective smart materials for next-generation devices and engineering applications. Nevertheless, advanced molecular and nanostructured systems are frequently not possible to integrate into 3D printable materials, thus limiting their technological transferability. In some cases, this challenge can be overcome using polymeric macromolecules of ionic nature, such as polymeric ionic liquids (PILs). Due to their tuneability, wide variety in molecular composition, and macromolecular architecture, they show a remarkable ability to stabilize molecular and nanostructured materials. The technology resulting from 3D-printable PIL-based formulations represents an untapped array of potential applications, including optoelectronic, antimicrobial, catalysis, photoactive, conductive, and redox applications.
  • 849
  • 08 Dec 2022
Topic Review
High-Voltage Film Capacitors
High-voltage capacitors are key components for circuit breakers and monitoring and protection devices, and are important elements used to improve the efficiency and reliability of the grid. Different technologies are used in high-voltage capacitor manufacturing process, and at all stages of this process polymeric films must be used, along with an encapsulating material, which can be either liquid, solid or gaseous.
  • 843
  • 24 Mar 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. 
  • 842
  • 11 Nov 2022
Topic Review
3D Printed Silicone Meniscus Implants
Osteoarthritis of the knee with meniscal pathologies is a severe meniscal pathology suffered by the aging population worldwide. However, conventional meniscal substitutes are not 3D-printable and lack the customizability of 3D printed implants and are not mechanically robust enough for human implantation. Similarly, 3D printed hydrogel scaffolds suffer from drawbacks of being mechanically weak and as a result patients are unable to execute immediate post-surgical weight-bearing ambulation and rehabilitation. To solve this problem, we have developed a 3D silicone meniscus implant which is (1) cytocompatible, (2) resistant to cyclic loading and mechanically similar to native meniscus, and (3) directly 3D printable. The main focus of this study is to determine whether the purity, composition, structure, dimensions and mechanical properties of silicone implants are affected by the use of a custom-made in-house 3D-printer. We have used the phosphate buffer saline (PBS) absorption test, Fourier transform infrared (FTIR) spectroscopy, surface profilometry, thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) to effectively assess and compare material properties between molded and 3D printed silicone samples.
  • 841
  • 17 Apr 2021
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.
  • 841
  • 26 Apr 2021
Topic Review
MIPs Preparation by Computational Simulation–Aided
Molecularly imprinted polymers (MIP) are obtained by initiating the polymerization of functional monomers surrounding the template molecule in the presence of crosslinkers and porogens. Usually the best adsorption performance can be obtained by optimizing the polymerization conditions, but the process is time-consuming and labor-intensive. At the same time, the use of a large number of organic reagents in the process of experimental optimization also limits the development and promotion of molecular imprinting technology. Theoretical calculation based on calculation simulation and intermolecular force is an effective method to solve this problem because it is convenient, versatile, environmentally friendly and low in price. It is not affected by the space environment, and the calculation efficiency is high.
  • 841
  • 27 Aug 2021
Topic Review
Hydrogen Permeation Test Methods of Polymer Liner Material
Type IV hydrogen storage cylinders comprise a polymer liner and offer advantages such as lightweight construction, high hydrogen storage density, and good fatigue performance. However, they are also characterized by higher hydrogen permeability. Consequently, it is crucial for the polymer liner material to exhibit excellent resistance to hydrogen permeation. International organizations have established relevant standards mandating hydrogen permeation tests for the liner material of type IV on-board hydrogen storage cylinders. 
  • 840
  • 14 Aug 2023
Topic Review
Supramolecular Polymer Nanocomposites
Polymer nanocomposites, a class of innovative materials formed by polymer matrixes and nanoscaled fillers (e.g., carbon-based nanomaterials, inorganic/semiconductor nanoparticles, metal/metal-oxide nanoparticles, polymeric nanostructures, etc.), display enhanced mechanical, optoelectrical, magnetic, catalytic, and bio-related characteristics, thereby finding a wide range of applications in the biomedical field. In particular, the concept of supramolecular chemistry has been introduced into polymer nanocomposites, which creates myriad “smart” biomedical materials with unique physicochemical properties and dynamic tunable structures in response to diverse external stimuli. 
  • 835
  • 25 Feb 2021
Topic Review
Interaction-Induced Structural Transformations in Polysaccharide and Protein-Polysaccharide Gels
Polysaccharides are biocompatible nontoxic natural polymer compounds. They are widely used as functional soft-matter for exploration in the food industry, drug delivery, regenerative medicine, and other biomedical research and applications. The tunable macroscopic properties of gels should meet case-dependent requirements. The admixture of proteins to polysaccharides and their coupling in more sophisticated structures opens an avenue for gel property tuning via physical cross-linking of components and the modification of gel network structure.
  • 829
  • 24 May 2022
Topic Review
3D Printing of ECHs
Electrically conductive hydrogels (ECHs), an emerging class of biomaterials, have garnered tremendous attention due to their potential for a wide variety of biomedical applications, from tissue-engineered scaffolds to smart bioelectronics. Along with the development of new hydrogel systems, 3D printing of such ECHs is one of the most advanced approaches towards rapid fabrication of future biomedical implants and devices with versatile designs and tuneable functionalities.
  • 826
  • 06 May 2021
Topic Review
Perfluoropyridine
The fluorine atom exhibits many unique properties, including a small atomic radius, large electronegativity, and minimal polarizability. Thus, when coupled with carbon in the form of a C-F bond, organofluorine compounds with highly sought after properties can be obtained. Perfluoropyridine (PFPy) is an organofluorine compound that has been employed for a variety of applications, from straightforward chemical synthesis to more advanced functions, such as fluorinated networks and polymers. This can be directly attributed to the highly reactive nature of PFPy, especially towards nucleophilic aromatic substitution (SNAr).
  • 826
  • 10 Mar 2022
Topic Review
Modification of Glucomannan as an Excipient
Glucomannan (GM) is a polysaccharide generally extracted from the tuber of Amorphophallus konjac. It consists of mannose and glucose residues linked by β-(1-4) and exhibits hydrocolloid characteristics which can be applied as thickening and gelling agents. However, it has poor water resistance and low mechanical strength when used as an excipient in solid form. Several physical and chemical modifications have been carried out to improve these drawbacks. Chemical modification involves the substitution of functional groups in GM’s structure including esterification and etherification. It causes a decrease in its high hydrophilic film behavior and produce water-resistant films. Physical modification involves mixing native GM with other excipients through processes involving milling, moisture, temperature, pressure, radiation, etc. It causes variations to particle size, shape, surface properties, porosity, density, and to functional properties such as swelling capacity and gelation ability
  • 823
  • 26 Jul 2022
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.
  • 822
  • 30 Aug 2021
Topic Review
Rechargeable Lithium Battery
Electrochemical behaviors, advantages, and disadvantages of existing electrospun nanofiber anode materials were thoroughly reviewed by classifying into four groups according to the lithium storage principles.
  • 821
  • 17 Sep 2020
Topic Review
Topical Insulin Delivery
Insulin is one of the cheapest growth factors in the market able to accelerate the re-epithelialization and stimulate angiogenesis and cell migration. However, the effectiveness of topical insulin in wound healing is hampered by the proteases in the wound bed. The encapsulation into nanoparticles improves its stability in the wound, providing adhesion to the mucosal surface and allowing its sustained release. 
  • 821
  • 13 Sep 2021
Topic Review
Self-Healing Elastomers
It is impossible to describe the recent progress of our society without considering the role of polymers; however, for a broad audience, “polymer” is usually related to environmental pollution. The poor disposal and management of polymeric waste has led to an important environmental crisis, and, within polymers, plastics have attracted bad press despite being easily reprocessable. Nonetheless, there is a group of polymeric materials that is particularly more complex to reprocess, rubbers. These macromolecules are formed by irreversible crosslinked networks that give them their characteristic elastic behavior, but at the same time avoid their reprocessing. Conferring them a self-healing capacity stands out as a decisive approach for overcoming this limitation. By this mean, rubbers would be able to repair or restore their damage automatically, autonomously, or by applying an external stimulus, increasing their lifetime, and making them compatible with the circular economy model.
  • 821
  • 26 May 2022
Topic Review
Collagen Type I Biomaterials
Collagen type I is the main organic constituent of the bone extracellular matrix and has been used for decades as scaffolding material in bone tissue engineering approaches when autografts are not feasible. Polymeric collagen can be easily isolated from various animal sources and can be processed in a great number of ways to manufacture biomaterials in the form of sponges, particles, or hydrogels, among others, for different applications. Despite its great biocompatibility and osteoconductivity, collagen type I also has some drawbacks, such as its high biodegradability, low mechanical strength, and lack of osteoinductive activity. Therefore, many attempts have been made to improve the collagen type I-based implants for bone tissue engineering. 
  • 817
  • 20 Apr 2021
Topic Review
PIL-Based SPEs
Poly(ionic liquide)s (PILs) can be used as solid polymer electrolytes because they have high thermal and electrochemical stabilities. This review is focused on the influence of macromolecular architecture on the ionic conductivity and electrochemical stability of PILs based electrolytes. Imidazolium based PILs are discussed as an example in the review. It is found that the electrolytes with a network structure exhibit better ionic conductivity and mechanical strength.
  • 817
  • 27 Oct 2020
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