Mechanical Mixing Research Articles

The reaction mechanism and interfacial crystallization of Al nanoparticle-embedded Ni under shock loading

The shock-induced reaction mechanism and characteristics of Ni/Al system, considering an Al nanoparticle-embedded Ni single crystal, are investigated through molecular dynamics simulation. For the shock melting of Al nanoparticle, interfacial crystallization and dissolution are the main characteristics. The reaction degree of Al particle first increases linearly and then logarithmically with time driven by rapid mechanical mixing and following dissolution. The reaction rate increases with the decrease of particle diameter, however, the reaction is seriously hindered by interfacial crystallization when the diameter is lower than 9 nm in our simulations. Meanwhile, we found a negative exponential growth in the fraction of crystallized Al atoms, and the crystallinity of B2–NiAl (up to 20%) is positively correlated with the specific surface area of Al particle. This can be attributed to the formation mechanism of B2–NiAl by structural evolution of finite mixing layer near the collapsed interface. For shock melting of both Al particle and Ni matrix, the liquid-liquid phase inter-diffusion is the main reaction mechanism that can be enhanced by the formation of internal jet. In addition, the enhanced diffusion is manifested in the logarithmic growth law of mean square displacement, which results in an almost constant reaction rate similar to the mechanical mixing process.

Chemical looping combustion oxygen carrier production cost study

The objective of this study was to estimate the cost of commercial production of oxygen carriers (OCs) for large-scale application in a mature, chemical looping combustion (CLC) power generation industry. Estimates of cost were made for two production facility scenarios: (1) build and operate an on-site, OC production facility located at a 550 MW CLC power plant site; and (2) build and operate a central production facility to produce and distribute OCs to the U.S. CLC power generation industry. Two OC production techniques were addressed: mechanical mixing and co-precipitation. Representative OCs that have production raw materials with sufficient commercial availability to support a CLC industry are ilmenite, a natural OC, and four engineered OC types, Fe2O3-based, CuO-based, NiO-based, and CuFeAlO4-based, with candidate OC support materials Al2O3 and TiO2. The costs of the OC production raw materials represent the major portion of the OC product cost; the OC production cost, in dollars per kg, has been found to be nearly a linear function of the OC raw materials cost, in dollars per kg. The estimated OC product costs can be used to estimate the maximum OC loss rate yielding a designated CLC power plant cost-of-electricity (COE) target as a development guide, and it has been found that the maximum OC makeup rate, in kg per hour, achieving a designated COE reduction goal relative to a conventional pulverized coal (PC) power plant, will be nearly inversely proportional to the OC production raw materials cost, in dollars per kg.

On the preparation and characterization of AlSi12-graphene powder for powder bed fusion additive manufacturing applications

This study investigates the possibility of using dry mechanical mixing techniques to prepare ideal composite powders for L-PBF applications. For this purpose, two AlSi12-reinforced composite powders with 0.5 and 1 wt% graphene were prepared by ball milling and regular mixing processes. The powder attributes (size, size distribution and shape), behaviors (absorptivity, packing density, and flowability), relative humidity, and O/C/H content of the composite powders were quantitatively assessed after mixing and compared to those of monolithic AlSi12. The attachment of the graphene particles and their evolutions during each mixing technique were qualitatively investigated. The quality of the graphene powder before and after mixing was studied by Raman spectroscopy, and the nature of the carbonaceous constituent in the composite powders was identified based on the Raman peak positions, shapes and relative intensities. The results of this study prove that only through ball milling ideal composite powders for the L-PBF applications can be achieved.

Fabrication of Multiphase Liquid Metal Composites Containing Gas and Solid Fillers: From Pastes to Foams

Gallium-based liquid metals (LMs) are suitable for many potential applications due to their unique combination of metallic and liquid properties. However, due to their high surface tension and low viscosity, LMs are challenging to apply to substrates in useful shapes, such as dots, wires, and films. These issues are mitigated by mixing the LMs in air with other materials, such as mixing with solid particles to form LM solid pastes or mixing with gases to form LM foams. Underlying these deceivingly simple mixing processes are complex and highly intertwined microscale mechanisms. Air microbubbles are inevitably incorporated while making LM pastes, making them partly foams. On the other hand, for foaming of the LM to occur, a critical volume content of solid particles must be internalized first. Consequently, both LM pastes and foams are multiphase composites containing solid and fluid microcomponents. Here, we systematically study the impact of the mixing procedure, solid particle size, and volume fraction (SiO2) on the air content of the multiphase LM composites. We demonstrate that decreasing the particle size and increasing their volume fraction substantially decrease the composite density (i.e., increases air entrapment). The foaming process can also be enhanced with the use of high-speed mechanical mixing, although leading to the formation of a more disordered internal structure. In contrast, manual mixing with larger microparticles can promote the formation of more paste-like composites with minimal air content. We explain the microscopic mechanisms underlying these trends by correlating macroscopic measurements with cross-sectional electron microscopy of the internal structure.

Using Image Texture Analysis to Evaluate Soil–Compost Mechanical Mixing in Organic Farms

Soil amendments (e.g., compost) require uniform incorporation in the soil profile to benefit plants. However, machines may not mix them uniformly throughout the upper soil layer commonly explored by plant roots. The study focuses on using image texture analysis to determine the level of mixing uniformity in the soil following the passage of two kinds of harrows. A 12.3-megapixel DX-format digital camera acquired images of soil/expanded polystyrene (in the laboratory) and soil/compost mixtures (in field conditions). In the laboratory, pictures captured the soil before and during the simulated progressive mixing of expanded polystyrene particles. In field conditions, images captured the exposed superficial horizons of compost-amended soil after the passage of a combined spike-tooth–disc harrow and a disc harrow. Image texture analysis based on the gray-level co-occurrence matrix calculated the sums of dissimilarity, contrast, entropy, and uniformity metrics. In the laboratory conditions, the progressive mixing resulted in increased image dissimilarity (from 1.15 ± 0.74 × 106 to 1.65 ± 0.52 × 106) and contrast values (from 2.69 ± 2.06 × 106 to 5.67 ± × 1.93 106), almost constant entropy (3.50 ± 0.25 × 106), and decreased image uniformity (from 6.65 ± 0.31 × 105 to 4.49 ± 1.36 × 105). Using a tooth-disc harrow in the open field resulted in higher dissimilarity, contrast, entropy (+73.3%, +62.8%, +16.3%), and lower image uniformity (−50.6%) than the disc harrow, suggesting enhanced mixing in the superficial layer.

NanoCeO2/conducting polymer based composite electrodes for high performance supercapacitor

Abstract The present research paper reports the structural, morphological and electrochemical properties of cerium oxide doped polythiophene nanocomposite. Polythiophene was first polymerized using the chemical oxidation polymerization method and further, it was mixed with an equal amount of cerium oxide (CeO2) nanoparticles by mechanical mixing. The initially generated polythiophene sample exhibited an amorphous character according to X-ray diffraction investigation, however the PTh–nCeO2 polymer nanocomposite displayed good crystallinity. The vibration bands of the PTh and PTh–nCeO2 polymer nanocomposites were further examined using Fourier-transform infrared spectroscopic studies. The morphology and elemental composition of the prepared samples were investigated using scanning electron microscope and energy dispersive X-ray analysis. The electrochemical performance of PTh and PTh–nCeO2 polymer nanocomposite was studied by cyclic voltammetry, Galvanostatic charge–discharge and electrochemical impedance spectroscopy measurements. The PTh–nCeO2 polymer nanocomposites demonstrated a high specific capacitance of 161 F g−1 at a current density of 1 A g−1 among the produced samples. The Nyquist plot (low-frequency area) and Bode plot (phase angle) electrochemical impedance tests revealed excellent capacitive performance. The PTh–nCeO2 polymer nanocomposites may be a good option for high-performance super capacitors, according to the findings.

Effective direct chemical looping coal combustion using bimetallic Ti‐supported Fe2O3‐MnO2 oxygen carriers

AbstractIn this paper five bimetallic Fe2O3‐MnO2 oxygen carriers supported on TiO2 were evaluated for direct hard coal combustion via chemical looping path. The oxygen carriers were obtained via mechanical mixing and high‐temperature calcination. The samples contained varying amounts of Fe2O3 (20–50 wt.%) and MnO2 (65–30 wt.%) but an identical amount of inert material (15 wt.%). Both the impact of the oxygen carrier's composition and the process temperature on their reactivity with the selected hard coal were evaluated. The amount of manganese in the oxygen carriers correlated positively with their reactivity toward the fuel. It was concluded that after eight reaction cycles the oxygen carriers remained resilient for side reactions with the ash residue. Thus, the physicochemical stability of the presented oxygen carriers was proved. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

Cycling performance and interface stability research of tubular protonic reversible solid oxide cells with air electrodes by different manufacturing processes

The electrode microstructure and interface stability play an important role during thermal cycles and reversible cycles for protonic reversible solid oxide cells (P-rSOCs). In this work, the effects of microstructural change of air electrodes on the performance and cycling stability are investigated by using tubular cells with large active area (7.5 cm2). The BaCe0.5Zr0.4In0.1O3@ La0.6Sr0.4CoO3 (BCZI@LSC) composite air electrode is prepared through a wet chemical procedure based on infiltration of the LSC precursor solution into the BCZI electrolyte skeleton. The LSC nanoparticles attach to the electrolyte skeleton in a continuous film-forming morphology, affording abundant three-phase reaction boundaries (TPBs) and the continuous conducting phase. Compared to the BCZI + LSC composite air electrode prepared by conventional mechanical mixing, the cell with the BCZI@LSC electrode demonstrates an increased current density of 51%. The cell with the BCZI + LSC electrode shows acceptable stability during 14 reversible FC-EC cycles and 4 thermal cycles (between 650 °C and room temperature) for 360 h in 20% H2O-air atmosphere. The differences in stability for cells prepared by the two processes are compared and discussed.

Effect of Ball-Milled Feedstock Powder on Microstructure and Mechanical Properties of Cu-Ni-Al-Al2O3 Composite Coatings by Cold Spraying

Cu, Ni and Al powders mixed in a certain stoichiometric proportion were ground via ball milling and deposited as coatings using low pressure cold spraying (LPCS) technology. The effect of particle morphology on the powder structure as well as the microstructure, composition and mechanical properties of the coatings was studied. The results revealed a core–shell structure of ball-milled powders. Compared with a mechanically mixed (MM) coating, coatings after ball milling at a rotation speed of 200 rpm exhibited the most uniform composition distribution and a lower degree of porosity (by 0.29%). Moreover, ball milling at 200 rpm was conducive to a significant increase in the deposition efficiency of the sprayed powder (by 10.89%), thereby improving the microhardness distribution uniformity. The ball milling treatment improved the adhesion of the coatings, and the adhesion of the composite coating increased to 40.29 MPa with the increase in ball milling speed. The dry sliding wear tests indicated that ball milling treatment of sprayed powder significantly improved the wear properties of the coatings. The coating after ball milling at a speed of 250 rpm showed the lowest friction coefficient and wear rate, with values of 0.41 and 2.47 × 10−12 m3/m, respectively. The wear mechanism of coatings changed from abrasive wear to adhesive wear with the increase in ball milling speed.

Enhancement of Microwave Absorption Properties of Hexaferrite/Epoxy Composites on the Addition of Non-magnetic Oxides

The effect of non-magnetic oxides such as Al2O3, TiO2 and ZnO on the microwave absorption properties of magnetoplumbite barium hexaferrite (BaFe11.8Co0.2O19) is analyzed. Barium hexaferrite nanoparticles are synthesized through the sol-gel auto-combustion method. BaFe11.8Co0.2O19-Al2O3, BaFe11.8Co0.2O19-TiO2 and BaFe11.8Co0.2O19-ZnO composites are synthesized in a 1:1 ratio through mechanical mixing and heat treatment. The epoxy composites are fabricated with 50% loading of BaFe11.8Co0.2O19-Al2O3, BaFe11.8Co0.2O19-TiO2 and BaFe11.8Co0.2O19-ZnO in epoxy matrix followed by room temperature curing. The powder XRD analyses showed homogeneous distribution of BaFe11.8Co0.2O19 and Al2O3 in BaFe11.8Co0.2O19-Al2O3 composite while TiO2 and ZnO phases dominate in BaFe11.8Co0.2O19-TiO2 and BaFe11.8Co0.2O19-ZnO composites, respectively. Scanning electron microscopy shows the evenly distributed BaFe11.8Co0.2O19 and Al2O3 in BaFe11.8Co0.2O19-Al2O3 composites. The electromagnetic characterization calculated from experimental permittivity and permeability shows reflection loss RL ≤ -10 dB (≥ 90% absorption) for a very small thickness of 0.5 mm over the entire X-band (8-12 GHz) for BaFe11.8Co0.2O19-Al2O3 composites. BaFe11.8Co0.2O19-TiO2 and BaFe11.8Co0.2O19-ZnO show RL < - 8 dB with a thickness of 2.5 mm over the frequency range 8–9.7 GHz and RL < - 8 dB with a thickness of 3.6 mm over 8.7-11.1 GHz, respectively. Further, when compared with BaFe11.8Co0.2O19 alone (RL < -7 dB at 3.2 mm in 8-11 GHz), the BaFe11.8Co0.2O19-Al2O3 composite is superior both in terms of the thickness of the coating as well as the percentage absorption in the X-band.

Insight into Enhanced Microwave Heating for Ammonia Synthesis: Effects of CNT on the Cs-Ru/CeO2 Catalyst.

Ammonia is emerging as a potential decarbonized H2 energy carrier when produced from renewable energy. The on-site production of liquid ammonia from stranded renewable energy can solve the current energy transportation challenges. The employment of microwave technology can produce the desired ammonia product at milder conditions with the supply of intermittent renewable energy sources. Our previous studies have indicated that the Cs-Ru/CeO2 catalyst is a promising catalyst for microwave-driven ammonia synthesis. In this study, the Cs-Ru/CeO2 catalyst mechanically mixed with carbon nanotubes (CNT) and chemically synthesized using coprecipitation and a hydrothermal method is investigated systematically at low temperatures and atmospheric pressure for microwave-assisted ammonia synthesis. Additionally, the combination of two Ru-based catalysts (Cs-Ru/CeO2 and Cs-Ru/CNT) is studied as well. Mechanical mixing of Cs-Ru/CeO2 with CNT exhibited superior activity as compared to the chemically synthesized Cs-Ru/CeO2-CNT catalyst. Besides the enhancement in dielectric property, the probable synergistic effect leads to increased interfacial polarization at the interface of the mechanically mixed catalyst, improving the overall heating and ammonia production rate. Moreover, the combined Ru-based catalyst also exhibited higher activity as compared to their individual activity toward ammonia synthesis. Numerous characterization techniques were performed, including thermal imaging camera and dielectric measurements, to better understand microwave interaction with the composite catalysts.

Effects of graphene oxide concentration and frequency on morphology, mechanical and rheological studies of fluoroelastomer nanocomposites

Fluoroelastomer nanocomposites have been prepared using different concentrations (1-5 wt%) of graphene oxide (GO) nanoparticles through mechanical mixing and compression molding. The surface morphology of prepared fluoroelastomer/GO nanocomposites has been studied by scanning electron microscopy (SEM). The mechanical properties of fluoroelastomer nanocomposites show increase in hardness, tensile strength, modulus, toughness and decrease in elongation at break with the increasing of GO’s concentration. This can be attributed towards excellent distribution of GO nanoparticles in the fluoroelastomer matrix. The effect of GO nanoparticle concentration on rheological properties of fluoroelastomer nanocomposites like: loss factor, storage modulus, loss modulus and complex viscosity have been studied as a function of temperature (5-100°C) and at different frequency 1, 10, and 100 Hz. The non-linear relationship between storage and loss moduli have been observed through Cole-Cole plots of fluoroelastomer/GO nanocomposites. The linear relationship of loss factor and storage modulus plots was explained on the basis of fluoroelastomer/GO interactions. The visco-elastic properties show increase in loss modulus, storage modulus, complex viscosity and decrease in loss factor with GO concentration, which can be attributed towards better fluoroelastomer-nanoparticle interactions.

Fe-Doped Metal Complex (LaCo0.9Fe0.1O3) and g-C3N4 Formed a Nanoheterojunction for the Photocatalytic Decomposition of Water.

Photocatalytic water decomposition provides an environmentally friendly method of hydrogen production similar to "photosynthesis", while current research aims to develop affordable yet efficient photocatalysts. Oxygen vacancy is one of the most significant defects in metal oxide semiconductors, including perovskite, which substantially influences the semiconductor material's efficiency. To enhance the oxygen vacancy in the perovskite, we worked on doping Fe. A perovskite oxide nanostructure of LaCoxFe1-xO3 (x = 0.2, 0.4, 0.6, 0.8, and 0.9) was prepared by the sol-gel method, and a series of LaCoxFe1-xO3 (x = 0.2, 0.4, 0.6, 0.8, and 0.9)/g-C3N4 nanoheterojunction photocatalysts were synthesized using mechanical mixing and solvothermal methods for LaCoxFe1-xO3 (x = 0.2, 0.4, 0.6, 0.8, and 0.9). Fe was successfully doped into the perovskite (LaCoO3), and the formation of an oxygen vacancy was verified by various detection methods. In our photocatalytic water decomposition experiments, we observed that LaCo0.9Fe0.1O3 demonstrated a significant increase in its maximum hydrogen release rate, reaching 5249.21 μmol h-1 g-1, which was remarkably 17.60 times higher than that of LaCoO3-undoped Fe. Similarly, we also explored the photocatalytic activity of the nanoheterojunction complex LaCo0.9Fe0.1O3/g-C3N4, and it exhibited pronounced performance with an average hydrogen production of 7472.67 μmol h-1 g-1, which was 25.05 times that of LaCoO3. We confirmed that the oxygen vacancy plays a crucial role in photocatalysis.

A Perspective on Missing Aspects in Ongoing Purification Research towards Melissa officinalis.

Melissa officinalis L. is a medicinal plant used worldwide for ethno-medical purposes. Today, it is grown everywhere; while it is known to originate from Southern Europe, it is now found around the world, from North America to New Zealand. The biological properties of this medicinal plant are mainly related to its high content of phytochemical (bioactive) compounds, such as flavonoids, polyphenolic compounds, aldehydes, glycosides and terpenes, among many other groups of substances. Among the main biological activities associated with this plant are antimicrobial activity (against fungi and bacteria), and antispasmodic, antioxidant and insomnia properties. Today, this plant is still used by society (as a natural medicine) to alleviate many other illnesses and symptoms. Therefore, in this perspective, we provide an update on the phytochemical profiling analysis of this plant, as well as the relationships of specific biological and pharmacological effects of specific phytochemicals. Currently, among the organic solvents, ethanol reveals the highest effectiveness for the solvent extraction of precious components (mainly rosmarinic acid). Additionally, our attention is devoted to current developments in the extraction and fractionation of the phytochemicals of M. officinalis, highlighting the ongoing progress of the main strategies that the research community has employed. Finally, after analyzing the literature, we suggest potential perspectives in the field of sustainable extraction and purification of the phytochemical present in the plant. For instance, some research gaps concern the application of cavitation-assisted extraction processes, which can effectively enhance mass transfer while reducing the particle size of the extracted material in situ. Meanwhile, membrane-assisted processes could be useful in the fractionation and purification of obtained extracts. On the other hand, further studies should include the application of ionic liquids and deep eutectic solvents (DES), including DESs of natural origin (NADES) and hydrophobic DESs (hDES), as extraction or fractionating solvents, along with new possibilities for effective extraction related to DESs formed in situ, assisted by mechanical mixing (mechanochemistry-based approach).

Fast Charging of a Thermal Accumulator Based on Paraffin with the Addition of 0.3 wt. % rGO

The composite of paraffin with reduced graphene oxide (paraffin/rGO) was obtained at 70 °C by the mechanical mixing of the components followed by ultrasonic dispersion. The introduction of only 0.3 wt.% rGO stained the paraffin black. It has been shown that thermal batteries made from 160 grams of pure paraffin and 160 grams of the composite are equally slow at charging when placed in boiling water. However, two minutes of microwave heating increases the temperature of the pure paraffin battery to only 32 °C, while the temperature of the paraffin/rGO composite battery rises to 74 °C, which is above the paraffin solid–liquid phase transition temperature.

Identification and quality evaluation of Citrus reticulata cv. Chachiensis varieties based on SNP markers

The desiccative and mature pericarp of Citrus reticulata cv. Chachiensis (PCRC) contenting rich flavonoids and volatile oil is used as traditional Chinese medicine. However, the biological and mechanical mixing of germplasm seriously affects the quality and clinic efficacy of PCRC. In this study, an identification system based on SNP markers was established which is capable of effectively distinguishing between two main C. reticulata cv. Chachiensis (CRC) varieties of DaZhongyoushen (DZ) and XiZhongyoushen (XZ). Moreover, mechanical mixing was confirmed to exist in another major cultivar DaDong5 (DD). Although the morphological characteristics of DZ and XZ fruits were similar, differences were observed in the contents and compositions of bioactive metabolites between the pericarps of these two CRC varieties. The content of flavonoids, especially hesperidin, in the DZ pericarp was significantly higher than that in the XZ pericarp (P < 0.01). The XZ pericarp contained many specific volatile compounds, and its volatile oil content was slightly higher than that of the DZ pericarp. In conclusion, DZ is more suitable as raw material for producing medicinal PCRC, while XZ is more promising for the development of fragranced products such as Ganpu tea. This study provides the theoretical basis and technical support for the identification and evaluation of CRC germplasm resources, which is instrumental for CRC germplasm resource innovation, further promoting the production of high-quality PCRC.

Facilitating clathrate hydrates with extremely rapid and high gas uptake for chemical-free carbon capture and methane storage

Clathrate hydrates are crystalline solid compounds comprising water and gas with remarkable potential for energy storage and carbon capture because of their large gas storage capacity and ability to selectively capture certain species upon crystallization. However, their use in real life has been hindered by low gas uptake kinetics, primarily limited by mass transfer. While extensive efforts have been made to overcome this limitation using chemical additives, their kinetic effects are insufficient, and environmental problems are caused. Here, the highest CO2 and CH4 gas uptake kinetics ever reported in clathrate hydrates were achieved without any chemical additives or mechanical mixing. The CO2 gas uptake rate and amount far exceeded previous records by 55.3% and 21.6%, respectively. Such excellent kinetics were accomplished using a fixed-bed reactor filled with surface-modified silica sand, which can be easily produced by simple treatment. Raman analysis and morphological studies demonstrated that its hydrophobic surface significantly affects interfacial interactions with water, greatly enhancing mass transfer. This new method is energy-efficient and environment-friendly, not requiring mechanical mixing or chemical injection at all. Mechanistic understandings of hydrate formation with hydrophobic surfaces would be applicable to hydrate-based carbon capture, methane storage, and natural gas hydrate production systems.

Synthesis of a composite Fe–CaO-based sorbent/catalyst by mechanical mixing for CO2 capture and H2 production: An examination on CaO carbonation and tar reforming performance

A composite CaO-based sorbent/catalyst (Fe/CaO-CA, CA stands for Ca12Al14O33) with good cyclic CO2 uptake characteristics, mechanical stability and tar reforming performance for the carbon-negative biomass calcium looping gasification (CLG) technology is prepared by mechanical mixing method. Different synthesis parameters regarding cyclic CO2 capture and Fe/CaO-CA's mechanical strength have been investigated. Different reaction conditions, such as low carbonation temperature, high calcination temperature, long cycles, and large particle size, were also investigated using a thermogravimetric analyzer. Results showed Fe/CaO-CA performed better in mechanical strength and carbonation when it was prepared by calcination at 750 °C for 4 h. In the carbonation temperature range from 650 °C to 850 °C, 750 °C was more favourable to promote CO2 capture during cyclic reactions. Fe/CaO-CA still exhibited promising CO2 uptake characteristics under severe calcination conditions, including high CO2 partial pressure, high temperature and long-term response up to 40 cycles. Additionally, the effect of Fe/CaO-CA on tar removal enhancement was also studied via the reforming of 1-methyl naphthalene (1-MN) by using a self-designed fixed-bed reactor. Fe/CaO-CA presented the maximum 1-MN conversion and the highest H2 yield (0.15 mol h−1 g−1) compared to the other three candidate samples (CaO, CaO-CA and Fe/CaO). Furthermore, Fe/CaO-CA showed the largest CO2 uptake capacity and the least amount of coke deposition during tar reforming.

Expanding the "Magic Triangle" of Reinforced Rubber Using a Supramolecular Filler Strategy.

A strategy for optimizing the rolling resistance, wet skid and cut resistance of reinforced rubber simultaneously using a supramolecular filler is demonstrated. A β-alanine trimer-grafted Styrene Butadiene Rubber (A3-SBR) pristine polymer was designed and mechanically mixed with commercially available styrene butadiene rubber to help the dispersion of a β-alanine trimer (A3) supramolecular filler in the rubber matrix. To increase the miscibility of A3-SBR with other rubber components during mechanical mixing, the pristine polymer was saturated with ethanol before mixing. The mixture was vulcanized using a conventional rubber processing method. The morphology of the assembles of the A3 supramolecular filler in the rubber matrix was studied by Differential Scanning Calorimetry (DSC) and Transmission Electron Microscopy (TEM). The Differential Scanning Calorimetry study showed that the melting temperature of β-sheet crystals in the vulcanizates was around 179 °C and was broad. The melting temperature was similar to that of the pristine polymer, and the broad melting peak likely suggests that the size of the crystals is not uniform. The Transmission Electron Microscopy study revealed that after mixing the pristine polymer with SBR, some β-sheet crystals were rod-like with several tens of nanometers and some β-sheet crystals were particulate with low aspect ratios. Tensile testing with pre-cut specimens showed that the vulcanizate containing A3-SBR was more cut-resistant than the one that did not contain A3-SBR, especially at a large cut size. The rolling resistance and wet skid were predicted by dynamic mechanical analysis (DMA). DMA tests showed that the vulcanizates containing A3-SBR were significantly less hysteretic at 60 °C and more hysteretic at 0 °C based on loss factor. Overall, the "magic triangle" was expanded by optimizing the rolling resistance, wet-skid, and cut resistance simultaneously using a β-alanine trimer supramolecular filler. The Payne effect also became less severe after introducing the β-alanine trimer supramolecular filler into the system.

A microwave cavity design and optimisation for a homogeneous and faster drying process inside an industrial Agitated Nutsche Filter

Background: Nowadays the disposal or recycling of polyethylene terephthalate (PET) material is a real-world problem. The European Union’s DEM3TO project aims at recycling PET to return it to the main chemical components with which it was produced. In a specific reactor, microwave radiation is used to quickly depolymerise the initial polymer. At the end of the de-polymerization process, a filtering and drying process through an agitated Nutsche filter (ANF) is necessary. Methods: This study aims to design and develop a High Frequency (HF) cavity inside the ANF (plugin “HF-ANF”) to speed up and improve the drying process. The effects studied are the efficiency of the HF cavity as a function of the heating process, the evaporation/drying process, and the mechanical mixing (due to the blades) of the mixture. Results: During these studies it was possible to improve the efficiency of the HF plugin and allowing to absorb more than the 95% of the microwave energy into the mixture to increase the drying speed and the drying homogeneity of the ANF. In addition, the mixture was characterised to obtain the dielectric proprieties as a function of the temperature of the ANF and the concentration of the residual water. Conclusions: The study allowed us to develop some important methodology that usually cannot to be simulated in a non-multi physics simulator. The careful modelling of certain aspects that are not normally available in EM (Electro-Magnetic) simulators, like variable geometries, mixed material, heating effect and the dielectrics characterization process are difficult and critical process but are very important steps to be undertaken in order to obtain results that can be compared with real measurements.