Development of Abrasive Grain Coating Technology Protective Polymer Casing for Water-Abrasive Cutting

The article presents the technology of covering abrasive grains with a protective polymer shell, which allows to reduce the wear of the focusing tube of the nozzle of a hydroabrasive installation. A description of the manufacturing process of a prototype abrasive with a polymer coating in a fluidized bed is presented in order to determine the critical processing modes at which a high-quality product will be obtained in a minimum operating time of the installation.

ELECTRICAL IMMUNITY CHARACTERISTICS OF MULTI-PAIR LAN CABLES

Приводятся результаты экспериментальных исследованийпомехозащищенности цепей многопарных LAN-кабелей вдиапазоне частот до 100 МГц Показано, что разработанный комплекс мероприятий по технологии скрутки кабельного сердечника, наложению на него экрана и защитной полимерной оболочки позволяет обеспечить выполнение норм на электрические характеристики помехозащищенности цепей кабеля, отвечающих требованиям категории 5е. The results of experimental studies of noise immunity of multipair LAN-cable circuits in the frequency range up to 100 MHz are presented. It is shown that the developed set of measures for the technology of twisting the cable core and applying a screen and a protective polymer sheath on it made it possible to ensure compliance with the standards for the electrical characteristics of noise immunity of cable circuits that meet the requirements of category 5e.

Layer-by-Layer-Stabilized Plasmonic Gold-Silver Nanoparticles on TiO2: Towards Stable Solar Active Photocatalysts

To broaden the activity window of TiO2, a broadband plasmonic photocatalyst has been designed and optimized. This plasmonic ‘rainbow’ photocatalyst consists of TiO2 modified with gold–silver composite nanoparticles of various sizes and compositions, thus inducing a broadband interaction with polychromatic solar light. However, these nanoparticles are inherently unstable, especially due to the use of silver. Hence, in this study the application of the layer-by-layer technique is introduced to create a protective polymer shell around the metal cores with a very high degree of control. Various TiO2 species (pure anatase, PC500, and P25) were loaded with different plasmonic metal loadings (0–2 wt %) in order to identify the most solar active composite materials. The prepared plasmonic photocatalysts were tested towards stearic acid degradation under simulated sunlight. From all materials tested, P25 + 2 wt % of plasmonic ‘rainbow’ nanoparticles proved to be the most promising (56% more efficient compared to pristine P25) and was also identified as the most cost-effective. Further, 2 wt % of layer-by-layer-stabilized ‘rainbow’ nanoparticles were loaded on P25. These layer-by-layer-stabilized metals showed superior stability under a heated oxidative atmosphere, as well as in a salt solution. Finally, the activity of the composite was almost completely retained after 1 month of aging, while the nonstabilized equivalent lost 34% of its initial activity. This work shows for the first time the synergetic application of a plasmonic ‘rainbow’ concept and the layer-by-layer stabilization technique, resulting in a promising solar active, and long-term stable photocatalyst.

Features of diffusion processes in the preparation of prepregs by the method of layered application of components

The modern production of products made of composite materials based on thermosetting binders is mainly based on the use of pre – impregnated reinforcing technical threads-prepregs. The binder used for such semi-finished products must meet two important technological requirements: have a low reactivity (high viability) when stored in the temperature range from -5 to +25 ° C and the ability to adjust the curing time at the molding temperatures of the product. To eliminate the disadvantages of the traditional method of obtaining polymer composite materials, to improve their strength characteristics and reduce the cost of the resulting reinforced composites, it is proposed to use the method of layered application of components. The essence of the method consists in layer-by-layer impregnation of the fibrous filler with a binder solution, and then a developed curing system consisting of an amine hardener that prevents the interaction of the hardener with the resin under storage conditions and protective polymer emulsions. The binder-filler system is activated only at an elevated temperature under curing conditions. It is established that the optimal parameters for processing by direct pressing of the pre-pegs components obtained by the method of layer deposition are a pressure of 15 MPa and a temperature of160-170 ?С with a pressure exposure of 15 minutes. If you get products by winding, then for such products, heat treatment for 6 hours at a temperature of 120 ?С is optimal. In the conditions of forming products, that is, at an elevated temperature and at an increased pressure, the mutual diffusion of components occurs due to the movement of oncoming flows. Oligomeric molecules from the resin volume diffuse from the inner layer to the outer one, and the components of the curing system meet them from the outer layer to the inner one. The method of layered application of components makes it possible to create a macroheterogenic system of interpenetrating polymer meshes in the contact area of sequentially applied layers. The result of the research is an increase in the shelf life, the viability of prepregs (up to 10 days) and an improvement in the complex of physical and mechanical properties of composites: the destructive stress during static bending increases to 60 %, during dynamic bending (impact) - up to 50 %. The use of carboxymethylcellulose as a protective polymer provides higher indicators of the studied properties than when using butadiene styrene latex as a protective polymer..

Effect of Micelle Encapsulation on Toxicity of CdSe/ZnS and Mn-Doped ZnSe Quantum Dots

The optical properties of quantum dots (QD) make them excellent candidates for bioimaging, biosensing, and therapeutic applications. However, conventional QDs are comprised of heavy metals (e.g., cadmium) that pose toxicity challenges in biological systems. Synthesising QDs without heavy metals or introducing thick surface coatings, e.g., by encapsulation in micelles, can reduce toxicity. Here, we examined the toxicity of micelle encapsulated tetrapod-shaped Mn-doped ZnSe QDs, comparing them to 3-mercaptopropionic acid (MPA)-capped Mn-doped ZnSe QDs prepared by ligand exchange and commercial CdSe/ZnS QD systems that were either capped with MPA or encapsulated in micelles. HepG2 cell treatment with MPA-coated CdSe/ZnS QDs resulted in a dose-dependent reduction of viability (MTT assay, treatment at 0–25 μg/mL). Surprisingly, no reactive oxygen species (ROS) or apoptotic signaling was observed, despite evidence of apoptotic behavior in flow cytometry. CdSe/ZnS QD micelles showed minimal toxicity at doses up to 25 μg/mL, suggesting that thicker protective polymer layers reduce cytotoxicity. Despite their shape, neither MPA- nor micelle-coated Mn-doped ZnSe QDs displayed a statistically significant toxicity response over the doses investigated, suggesting these materials as good candidates for bioimaging applications.

Immobilization of Nanobodies with Vapor-Deposited Polymer Encapsulation for Robust Biosensors

To produce next-generation, shelf-stable biosensors for point-of-care diagnostics, a combination of rugged biomolecular recognition elements, efficient encapsulants and innocuous deposition approaches are needed. Furthermore, to ensure that the sensitivity and specificity that is inherent to biological recognition elements is maintained in solid-state biosensing systems, site-specific immobilization chemistries must be invoked such that the function of the biomolecule remains unperturbed. In this work, we present a widely-applicable strategy to develop robust solid-state biosensors using emergent nanobody (Nb) recognition elements coupled with a vapor-deposited polymer encapsulation layer. As compared to conventional immunoglobulin G (IgG) antibodies, Nbs are smaller (12-15 kDa as opposed to ~150 kDa), have higher thermal stability and pH tolerance, boast greater ease of recombinant production, and are capable of binding antigens with high affinity and specificity. Photoinitiated chemical vapor deposition (piCVD) affords thin, protective polymer barrier layers over immobilized Nb arrays that allow for retention of Nb activity and specificity after both storage under ambient conditions and complete desiccation. Most importantly, we also demonstrate that vapor-deposited polymer encapsulation of nanobody arrays enables specific detection of target proteins in complex heterogenous samples, such as unpurified cell lysate, which is otherwise challenging to achieve with bare Nb arrays.

Immobilization of Nanobodies with Vapor-Deposited Polymer Encapsulation for Robust Biosensors

To produce next-generation, shelf-stable biosensors for point-of-care diagnostics, a combination of rugged biomolecular recognition elements, efficient encapsulants and innocuous deposition approaches are needed. Furthermore, to ensure that the sensitivity and specificity that is inherent to biological recognition elements is maintained in solid-state biosensing systems, site-specific immobilization chemistries must be invoked such that the function of the biomolecule remains unperturbed. In this work, we present a widely-applicable strategy to develop robust solid-state biosensors using emergent nanobody (Nb) recognition elements coupled with a vapor-deposited polymer encapsulation layer. As compared to conventional immunoglobulin G (IgG) antibodies, Nbs are smaller (12-15 kDa as opposed to ~150 kDa), have higher thermal stability and pH tolerance, boast greater ease of recombinant production, and are capable of binding antigens with high affinity and specificity. Photoinitiated chemical vapor deposition (piCVD) affords thin, protective polymer barrier layers over immobilized Nb arrays that allow for retention of Nb activity and specificity after both storage under ambient conditions and complete desiccation. Most importantly, we also demonstrate that vapor-deposited polymer encapsulation of nanobody arrays enables specific detection of target proteins in complex heterogenous samples, such as unpurified cell lysate, which is otherwise challenging to achieve with bare Nb arrays.

Quantification of the ion transport mechanism in protective polymer coatings on lithium metal anodes

Protective Polymer Coatings (PPCs) protect lithium metal anodes in rechargeable batteries to stabilize the Li/electrolyte interface and to extend the cycle life by reducing parasitic reactions and improving the lithium deposition morphology.