The morphology of polyHIPE materials directly governs their permeability, surface area, and mechanical properties, therefore developing novel strategies to enhance emulsion uniformity and influencing the droplet size is crucial for advancing their practical applications. Methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) containing high internal phase emulsions (HIPEs) with internal phase volume fractions between 75
Polymer-dispersed liquid crystal elastomer composites (PDLCEs) combine the thermomechanical capabilities of liquid crystal elastomers (LCEs) with the softness of a silicone matrix. The high-temperature persistent glass phase in LCEs allows preservation of the instilled deformations during thermal cycling, leading to reprogrammable shape-memory in both LCEs and PDLCEs. This provides a unique opportunity to study mechanical properties within a single shape-programmed specimen by imposing different mesogen configurations or particle geometries, without the need for repeated synthesis. We specifically focus on compressive programming, which induces transverse mechanical anisotropy and a mesogen configuration with a negative order parameter. Directional stress–strain and thermomechanical tests reveal that, despite the elastic matrix, PDLCEs retain mechanical properties comparable to pure LCEs, highlighting the role of mechanical anisotropy together with inclusion alignment and geometry. The degree of mesogen ordering is evaluated in LCEs, while a modified Halpin–Tsai model captures the mechanical response of PDLCEs.
In this review, a comprehensive systematic study of the research background, developments, classification, trends, and advances over the past few years in research on new electromagnetic interference (EMI) shielding materials will be described. The following groups of new materials for EMI shielding will be discussed: biochars, scaffolds, rare earth, and ferrite-based materials. We selected two novel, organic, lightweight materials (biochars and scaffolds) and compared their shielding effectiveness to inorganic materials (ferrite and rare earth materials). This article will broadly discuss the EMI shielding performance, the basic principles of EMI shielding, the preparation methods of selected materials, and their application prospects. Biochars are promising, eco-friendly, sustainable, and renewable materials that can be potentially used as a filter in polymer composites for EMI shielding, along with scaffolds. Scaffolds are new-generation, easy-to-manufacture materials with excellent EMI shielding performance. Rare earth (RE) plays an important role in developing high-performance electromagnetic wave absorption materials due to the unique electronic shell configurations and higher ionic radii of RE elements. Ferrite-based materials are often combined with other components to achieve enhanced EMI shielding, mechanical strength, and electrical and thermal conductivity. Finally, the current challenges and future outlook of new EMI shielding materials will be highlighted in the hope of obtaining guidelines for their future development and application.
