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Topic Review
Processing Methods of Titanium Matrix Composites
Discontinuously Reinforced Particulate Titanium Matrix Composites (DRPTMCs) have been the most popular and challenging in consideration with development and heat treatment due to their significant weight-saving capacity, high specific strength, stiffness and oxidising nature compared with other metals and alloys. Owing to their excellent capabilities, DRPTMCs are widely used in aerospace, automobiles, biomedical and other industries. However, regardless of the reinforcements, such as continuous fibres or discontinuous particulates, the unique properties of DRPTMCs have dealt with these composites for widespread research and progress around the domain. 
  • 642
  • 28 Dec 2022
Topic Review
Processing Methods of Low-Clinker Multi-Component Cementitious Materials
The wide use of multi-component cement of highly reduced Portland clinker factor is largely impeded by detrimental changes in the rheological properties of concrete mixes, a substantial reduction in the early rate of cement hardening, and sometimes the insufficient strength of mature concrete. Therefore, major changes are needed in traditional concrete-production technologies if low-clinker cement is to gain wider acceptance. 
  • 281
  • 25 Jan 2024
Topic Review
Processes for Obtaining Syngas and Hydrogen
The growing demand for high-quality chemical products has already stimulated an increased interest in the conversion of hydrocarbon gases (natural gas, methane, biogas) into motor fuels and high value-added chemical products, as well as into hydrogen, which is increasingly in demand on the market. The conversion of natural gas into hydrogen and syngas is still the most complex and costly stage of modern gas chemical processes, the low efficiency of which hinders the development of modern gas chemistry. 
  • 1.1K
  • 14 Apr 2023
Topic Review
Printing Methods to Fabricate Receptor Layers of Gas Sensors
Printing technologies are nowadays an integral element of contemporary materials science applied to development of low-cost gas sensors and multisensor arrays for many applications including a development of lab-on- chips. These protocols ensure automating of technological processes, a reproducibility of microstructural and functional characteristics with a reduced time necessary for the receptor material deposition over substrates. At the same time, using an accurate positioning system improves significantly the targeting of the substance, while the dosing setups allow to ensure a high control over the volume of discretely or continuously applied inks. The printing technologies enable forming planar receptor structures, even under a complex geometry, at various thicknesses and porosity with the required spatial resolution to be in nanometer micrometer ranges. Some methods, as dip-pen nanolithography, nano-imprinting lithography, and microcontact printing, are more suitable for discrete miniature devices with unique characteristics owing to the labor-intensive and multi-step procedures, while other ones, as ink-jet printing, aerosol jet printing or microextrusion printing, can be used quite easily in scaling the procedures to design gas sensors, including a rapid tuning of their geometric parameters without a necessity to prepare appropriate stencils and masks in advance. While designing the gas-sensor receptor materials, a great variety of printing technologies are used these days which vary both in the principle of operation and in such parameters as printing speed, spatial resolution, thickness of the formed coatings, and their microstructure, etc.
  • 638
  • 23 May 2022
Topic Review
Printed Electronics
Printed electronics are manufactured in a process of registering thin functional material (ink) layer combinations on a low-cost substrate that may be recycled and/or naturally degraded in nature. Correspondingly, the manufacturing process is composed of three complementary stages: material selection, printing and post-printing. The materials for the printed electronics are principally inks of conducting, semiconducting or dielectric characteristics and substrates, which are derived from synthetic or natural polymers.  The inks are transferred with a master through direct contact to the substrate in case of contact printing, while they are deposited onto the substrate typically through nozzles in case of non-contact printing. Posterior to the printing process, it is often necessary to conduct sintering/curing in order to reach the desired functional ink and substrate characteristics. The inks, substrate and the printing technology along with the post printing requirements must be carefully evaluated for quality, repeatability and life-time aspects of the yield.
  • 1.1K
  • 23 Aug 2021
Topic Review
Printable Hydrogels
The hydrogel is a hydrophilic scaffold composed of covalent and non-covalent polymeric chains bonds, providing a 3D shape environment similar to the native extra-cellular matrix (ECM).
  • 538
  • 18 Mar 2021
Topic Review
Print-Light-Synthesis of Electrodes
Print-Light-Synthesis combines ink-based digital printing of thin liquid metal precursor films with high intensity light irradiation for the synthesis of metal nanoparticles and metal films. The method is generally applied to produce two-dimensional patterns of metal nanoparticles by printing a thin liquid film containing one or more metal precursors onto a target substrate and immediately reducing the metal precursors to metal nanoparticles by light exposure of the as-deposited thin liquid film. The process must be adjusted in a way that (i) the precursor reduction is at least as fast as printing and (ii) the light intensity is sufficient for highly efficient photo-induced processes. Otherwise, incomplete metal precursor reduction will occur. The metal precursor inks do not contain any stabilizing agents that are generally added in alternative wet chemical methods for nanoparticle synthesis. Print-Light-Synthesis is designed in such a way that pure nanomaterials remain on the substrate, while all other ink components, such as the solvents and other dissolved species, generate gases or evaporate at moderate temperatures. The use of mask-less digital printing techniques provides a large flexibility in terms of pattern design, pattern modification, and process optimization. Inkjet printing provides a high control of the desired metal loading on the substrate, simply by adjusting the ink composition and printing parameters, such as number of droplets per substrate area. Films of separate nanoparticles, inter-connected nanoparticles and complex nanostructures can be prepared. Print-Light-Synthesis can be used to reduce or oxidise metal precursors, depending on the target oxidation state of the metal.
  • 295
  • 20 Jul 2023
Topic Review
Principles of the Suzuki Coupling Reaction
The Suzuki coupling is a transition metal-catalyzed, cross-coupling carbon–carbon (C–C) bond forming reaction between organic boron compounds and organic halides. As an operationally simple and versatilely applicable procedure, the Suzuki coupling reaction has found immense applications in drug discovery and development in the pharmaceutical industry. 
  • 2.1K
  • 06 Jan 2023
Topic Review
Principles of Prototropic Equilibria
Prototropic tautomers always differ by the positions of labile proton(s) and π-electrons. The number of possible tautomeric forms is an internal property of the tautomeric molecule. It is a consequence of the number of labile protons and the number of conjugated tautomeric sites.
  • 720
  • 01 Nov 2023
Topic Review
Principles of pH-Responsive Drug Delivery
The paradigm of drug carriers’ usage to overcome the non-specific distribution of therapeutic agents in the body, including chemotherapeutic substances that exert severe toxic stress on healthy tissues, has been actively developed. One of the main pillars of this paradigm is the increased or even selective accumulation of drug delivery systems (DDSs) carrying therapeutic agents in tumor interstitium harnessing the differences between normal and cancer tissues properties. Thus, structural features of tumors, such as hypervascularization, vascular pathologies, and impaired functionality of lymphatic drainage, can be utilized to differentiate tumors from healthy tissues and selectively accumulate drug carriers. In particular, tumor-surrounding vessels are characterized by defects in the endothelial layer lining the blood vessel wall, represented by wide fenestrations (up to several microns) and other features that lead to an increase in the permeability of this barrier for small objects, making the effective extravasation of nanosized carriers from the bloodstream to tumor interstitium possible. Methods of selective therapy via the systemic administration of therapeutic agents based on increased permeability of the tumor vessels’ wall, known under the general name of the EPR effect, have become widespread and have inspired the creation of a large number of vehicles proposed for the delivery of chemotherapeutic agents. In summary, the EPR effect implies the extravasation of nanosized drug carriers through endothelial fenestra and their retention in the interstitial volume of the tumor due to dysfunctional lymphatic drainage.
  • 473
  • 01 Jun 2023
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