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Topic Review
Catalytic Synthesis of Glycerol Carbonate
Glycerol carbonate (GC) belongs to the family of organic carbonates that are regarded as very typical “green chemistry” products for their unique advantages in many fields, such as high boiling point solvents, pharmaceutical intermediates, and material intermediates.
  • 1.6K
  • 10 Feb 2022
Topic Review
Nanojoining
Nanojoining is the process of joining two or more surfaces together using nanomaterials as the primary building blocks. This includes, but is not limited to, nanosoldering, nanobrazing, nanowelding, nanoscale diffusion bonding, and additive manufacturing. Note that, like with conventional soldering and brazing, only the filler metal undergoes melting, not the base material. Nanomaterials are materials in which at least one dimension 100 nm or less and include 0-D (e.g. nanoparticles, 1-D (e.g. nanowires and nanorods), 2-D (e.g. graphene), and 3-D (e.g. nanofoam) materials. Nanomaterials exhibit several notable properties that allow joining to occur at temperatures lower than the melting temperature of their bulk counterpart. For example, the melting temperature of Ag is 961.78 °C, but Ag nanomaterials begin to melt at a much lower temperature that is dependent depending on the size and shape. These properties include high surface area to volume ratio, the Gibbs-Thompson effect, and high surface energy. The low joining temperature of nanomaterials has been exploited numerous times for flexible electronics, printable electronics, and soldering applications; only within the last two decades have they been explored for high-temperature joining applications (>450 °C).
  • 1.6K
  • 07 Jul 2022
Topic Review
Circulatory Management of Polymer Waste
In modern society, it is impossible to imagine life without polymeric materials. However, managing the waste composed of these materials is one of the most significant environmental issues confronting us in the present day. Recycling polymeric waste is the most important action currently available to reduce environmental impacts worldwide and is one of the most dynamic areas in industry today. Utilizing this waste could not only benefit the environment but also promote sustainable development and circular economy management. In its program statement, the European Union has committed to support the use of sorted polymeric waste. This study reviews recent attempts to recycle this waste and convert it by alternative technologies into fine, nano-, and microscale fibers using electrospinning, blowing, melt, or centrifugal spinning.
  • 1.6K
  • 13 Sep 2021
Topic Review
Sulfur Mustard
Sulfur mustard, commonly known as mustard gas, is the prototypical substance of the sulfur-based family of cytotoxic and vesicant chemical warfare agents known as the sulfur mustards, which can form large blisters on exposed skin and in the lungs. They have a long history of use as a blister-agent in warfare and along with organoarsenic compounds are the most well-studied such agents. Related chemical compounds with similar chemical structure and similar properties form a class of compounds known collectively as sulfur mustards or mustard agents. Pure sulfur mustards are colorless, viscous liquids at room temperature. When used in impure form, such as warfare agents, they are usually yellow-brown and have an odor resembling mustard plants, garlic, or horseradish, hence the name. The common name of "mustard gas" is considered inaccurate because the sulfur mustard is not actually vaporized, but dispersed as a fine mist of liquid droplets. Sulfur mustard was originally assigned the name LOST, after the scientists Wilhelm Lommel and Wilhelm Steinkopf, who developed a method of large-scale production for the Imperial German Army in 1916. Mustard agents are regulated under the 1993 Chemical Weapons Convention. Three classes of chemicals are monitored under this Convention, with sulfur and nitrogen mustard grouped in Schedule 1, as substances with no use other than in chemical warfare. Mustard agents could be deployed by means of artillery shells, aerial bombs, rockets, or by spraying from warplanes or other aircraft. Sulfur mustard can be readily decontaminated through reaction with chloramine-T.
  • 1.6K
  • 11 Nov 2022
Topic Review
Root Canal Filling Material
Endodontic treatment for a tooth with damaged dental pulp aims to both prevent and cure apical periodontitis. If the tooth is re-infected as a result of a poorly obturated root canal, periapical periodontitis may set-in due to invading bacteria.To both avoid any re-infection and improve the success rate of endodontic retreatment, a treated root canal should be three-dimensionally obturated with a biocompatible filling material. Recently, bioactive glass, one of bioceramics, is focused on the research area of biocompatible biomaterials for endodontics. Root canal sealers derived from bioactive glass-based have been developed and applied in clinical endodontic treatments. However, at present, there are few of evidence aboutthe patient outcomes, sealing mechanism, sealing ability, and removability of the sealers. Herein, we have developed a bioactive glass-based root canal sealer and provided evidence concerning its physicochemical properties, biocompatibility, sealing ability, and removability. We also review the classification of bioceramics and characteristics of bioactive glass. Additionally, we describe the application of bioactive glass to facilitate the development of a new root canal sealer. Furthermore, this review shows the potential application of bioactive glass-based cement as a root canal filling material in the absence of semisolid core material.
  • 1.6K
  • 31 Jul 2020
Topic Review
Graphene as Reinforcing Filler
Graphene represents an innovative material, which possesses a unique combination of properties. The remarkable features of this material allow it to be often used as a reinforcing filler in organic based coatings. The excellent conductivity and mechanical strength properties of graphene produce a significant increase in the performance of the polymer matrix. Recently, however, scholars have focused on the barrier effect properties that can be provided by graphene flakes to obtain high corrosion resistance coatings. If well distributed in the polymeric matrix, in fact, the graphene-based sheets are able to provide a high resistance to the passage of aggressive ions, fundamental for the development of corrosion processes on the metal substrate. The distribution of graphene-based fillers, however, is a critical aspect, which can be improved by means of certain oxidation and functionalization processes of graphene flakes. Recent studies have shown the possibility of combining the excellent features of cataphoretic processes with the remarkable protective properties of graphene-based fillers in the creation of high-performance multifunctional composite coatings. The functionalized graphene oxide flakes, in the correct amount, can in fact increase the protective performance of cataphoretic coatings, as well as providing additional features such as mechanical strength and high conductivity.
  • 1.6K
  • 01 Nov 2020
Topic Review
CO2 Hydroboration
The use of CO2 as C1 building block for chemical synthesis is receiving growing attention, due to the potential of this simple molecule as abundant and cheap renewable feedstock. Among the possible reductants used in the literature to bring about CO2 reduction to C1 derivatives, hydroboranes have found various applications, in the presence of suitable homogenous catalysts. The main results obtained since 2016 in the synthetic design of main group, first and second row transition metals for use as catalysts for CO2 hydroboration are summarized.
  • 1.6K
  • 04 Jun 2024
Topic Review
Betulinic Acid
Betulinic acid (BA, 3β-hydroxy-lup-20(29)-en-28-oic acid) is a pentacyclic triterpene acid present predominantly in Betula ssp. (Betulaceae) and is also widely spread in many species belonging to different plant families. BA presents a wide spectrum of remarkable pharmacological properties, such as cytotoxic, anti-HIV, anti-inflammatory, antidiabetic and antimicrobial activities, including antiprotozoal effects.
  • 1.6K
  • 24 May 2021
Topic Review
Intrinsic Self-Healing Polymers
Self-healing polymeric materials have been widely investigated because they can heal the damages spontaneously and thereby prolong their service lifetime. Many ingenious synthetic procedures have been developed for fabricating self-healing polymers with high performance.
  • 1.6K
  • 20 Sep 2022
Topic Review
Carbon Nanotube-Reinforced Polymer Composite
A novel class of carbon nanotube (CNT)-based nanomaterials has been surging since 1991 due to their noticeable mechanical and electrical properties, as well as their good electron transport properties. The development of CNT-reinforced polymer composites could contribute in expanding many areas of use, from energy-related devices to structural components. A CNT is defined as a one-atom thick sheet of graphite rolled into a tube with a diameter of one nanometer, which is classified as a single-wall carbon nanotube (SWCNT); if there are additional or multiple graphene tubes around the core of an SWCNT, this is known as a multiwalled carbon nanotube (MWCNT). Theoretical and experimental results on CNTs have showed a high modulus of elasticity: greater than 1 TPa (the elastic modulus of diamond is 1.2 TPa). In addition, CNTs also possess a strength that is 10–100 times higher than the resilient steel at a fraction of the weight. Additionally, CNTs have an excellent thermal stability of up to 2800 ◦C in vacuum and an electrical conductivity in the vicinity of 103 S/cm, with an electric-current-carrying capacity that is 1000 times higher and thermal conductivity of about 1900 W m−1 K−1 (which is about twice as high as diamond). SWCNTs in a hexagonal honeycomb structure consist of sp2 hybridized carbon in a that is rolled into a hollow tube morphology, while MWCNTs consist of multiple concentric tubes encircling one another.
  • 1.6K
  • 05 Aug 2021
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