Dear Readers,
Summer break has just ended and I hope everyone is now rested and ready to dive into the 2024 September issue of EMMR journal. This issue questions in particular the potential of materials combination for final product properties enhancement. In a technological world under permanent mutation, researchers are looking more and more for materials, which properties can address very specific needs related to demanding applications. Unfortunately, selecting a material individually for a specific application is often not enough to face tricky challenges. In these cases the association of properties is required and the scope of our journal is definitely to bring knowledge about strategies which can be carried out to create emerging materials, performant enough to satisfy all particular needs. The papers presented in this issue describe composite materials, which can be used to improve specific properties of final products like shape memory, strength, photo catalytic activity, shape memory, cold storage, filtration or magnetic properties.
Paper by Uyan and Celiktas1 presents a review about Shape Memory Polymers (SMPs) with a particular focus on how to strengthen these materials. Basically, SMPs are smart materials which have low cost, facile manufacturing, light gravity but limited stress recovery compared to Shape Memory Alloys (SMA). Fiber and particle reinforcements help creating Shape Memory Polymer Composite (SMPCs) characterized by increased strength. Carbon nanotubes or particles as well as Kevlar or glass fibers are typical reinforcement materials which can be used. Fabrication methods like RTM or 4D printing as well as testing and activation methods are then further described in the paper. At last, a focus is made on the applications for SMPCs.
Composites are further studied by Duan et al.2 which presents a strategy to improve the cooling properties of Sodium sulfate decahydrate (SSD; Na2SO4·10H2) inorganic phase change materials. Compared to organic materials, inorganic materials present the advantage of being widely available, having a low cost and a high energy-storage density. In this work, by combining SSD with borax as a nucleating agent, ammonium chloride (NH4Cl) as a temperature control additive, sodium hexametaphosphate as a crystal modifier and carboxymethylcellulose as a thickening agent, authors were able to produce a crystalline composite characterized by a supercooling degree of 0.70°C.
In the field of stainless steel (SS) metal part production, paper P et al.3 studies the encapsulation conditions of SS with polylactid acid polymer (PLA) in order to influence the mechanical properties of a part obtained with Metal fused filament fabrication (MFFF). It is shown that layer thickness, infill density as well as extruder temperature can influence density, roughness and hardness of the final product. The authors bring out in particular that by optimizing the combination of infill density (ID) and layer thickness (LT) the SS density can reach up to 4.758 g/cm3.
The way how to improve the photocatalytic properties of bismuth oxide is then investigated in paper by Zhu et al.4 In this study, the photocatalyst is combined with poly(ethylene glycol) PEG. By varying the quantity of PEG (0, 4, 6, 8, 10 and 12 g) it is possible to modify the morphology of the obtained Bi2O3/PEG crystals. The observed increase in specific surface when a larger amount of PEG is used leads to improvement in light penetration. The temperature of the preparation seems also to have an significant influence on the photocatalytic activity, which is improved above 160°.
The article by Liu et al.5 deals with the reprocessing of spent fuel in the nuclear industry. One goal of reprocessing is the removal of trace plutonium from complex reprocessing samples. For that purpose quaternary ammonium salts can be used. Glass fiber filters (GF), known for their resistance to chemical corrosion, radiation and thermal stability, can be used as the base material for separation and enrichment. However, this matrix material is generally characterized by poor chemical grafting efficiency. Combining the matrix with a coating can thus be necessary. The paper presents a pretreatment method that allows improving the filtration and chemical grafting of functional groups on GFs. It consists in the deposition of polydopamine on the matrix followed by the grafting of a coupling agent (chloromethyltrimethoxysilane). Adsorption experiments demonstrate the increase in plutonium adsorption capacity with the pretreatment.
The magneto sensitive properties of elastomers are explored in paper by Kamble et al.6 The work presents a state of the art relative to these hybrid composites obtained from magnetisable particles dispersed inside a non-magnetic elastomer matrix. The review study analyses the materials, preparation processes, investigation models and application of MagnetoRheological Elastomers MREs. It brings out in particular how to tune the properties of these composites for specific applications.
Magnetism is also studied in paper by Zhang et al.7 which investigates strategies to increase the ferromagnetic properties at room temperature of diluted magnetic semiconductors (DMS). The paper focuses in particular on chromium-doped cadmium sulfide and zinc sulfide which have been poorly explored in literature. The work presents how undoped and chromium-doped cadmium sulfide and zinc sulfide nano/microstructures were synthesized using a solvothermal method. Investigation is conducted on the structure, the morphology, the composition and the ferromagnetic properties of these materials in order to predict their optical and ferromagnetic properties and mechanisms.
Based on the description of the papers I presented above, I hope you’ll enjoy the content of this issue, and you’ll find the scientific and technical information that you need to make your research go forward.
