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[Display omitted] • Macro PPBESK beads with hierarchical pores are fabricated via NIPS approach. • PPBESK beads have a good thermal insulation property in a wide temperature window. • The compression modulus of PPBESK beads is more than 50 times higher than PS foam. • The performance can be controlled by the composition of the coagulation bath. Preparation of porous materials from high-performance polymers holds great promise for various advanced engineering applications like thermal insulation. However, it is still a great challenge to fabricate them due to the difficulties in manufacturing them. Herein, a high performance polymer material poly(aryl ether sulfone ketone)s containing phthalazinone and biphenyl moieties (PPBESK) was utilized to fabricate porous materials via a frequently used and simple method named non-solvent induced phase separation (NIPS). Macro porous PPBESK beads have been fabricated in different non-solvent coagulation baths. The kinetics of the phase inversion processes are visualized by the optical microscope. The multi-scale porous structures formed inside the beads endow them an excellent thermal insulation performance in a wide temperature window and a high mechanical performance that the compression modulus is more than 50 times higher than Polystyrene (PS) foam. Therefore, these PPBESK beads provide an optimized combination of functionalities including high mechanical strength and good thermal insulation, which could turn out to be useful in harsh environmental applications. [ABSTRACT FROM AUTHOR]

A hierarchical host-guest structural composite was developed via introducing shear stiffening polyborosiloxane gel into robust porous polyimide matrix. The synergistic effect of host and guest phases contributed to favorable balance between mechanical and thermal properties, which endowed the composite with exceptional impact resistance, acoustic and thermal insulation capacity. The composite performed well as a protective wrapping in resisting multiple interferences to ensure the electrical superstability of conductive elements. [Display omitted] • A host-guest composite was developed by introducing PBS into polyimide foam. • The composite showed ideal impact resistance and acoustic insulation property. • The composite had low thermal conductivity and good thermal insulation capacity. • The composite could act as protective wrappings to guarantee electro-stability. The ubiquitous existence of mechanical impact, sound pollution and thermal damage conferred severe risks to both individuals and devices, which catalyzed increasing demand for advanced protective materials. Though biomimetic structures have motivated the development of high-performance protective composites against a simple threat, the realization of multi-mode interference protection remained a challenging issue. This work proposed a host-guest structural composite, consisting of viscoelastic polyborosiloxane (PBS) dispersively distributed in porous polyimide (PI) matrix. The resulting PI-PBS composite presented effective impact force attenuation (85.8%-92.3%), arising from the multi scale energy dissipation mechanism of strain-rate enhancement, structural densification and synergistic stress transfer, which was intuitively demonstrated by an innovative mechano-discoloration approach. The viscous dissipation effect endowed PI-PBS with extraordinary acoustic insulation effectiveness in a wide frequency region (1–6.3 kHz). Due to the low thermal conductivity (0.051 W/(m·K)), PI-PBS presented good thermal insulation performance over a wide temperature range (∼ −80 – 300 °C). The structure dependence of thermal conduction behavior was revealed via FE simulation, while demonstrating various applications in dynamic infrared thermal camouflage. PI-PBS, as a functional wrapping, provided reliable guarantee for electrical stability of conductive elements against impact, ultrasonic and thermal interferences, which indicated significant value in electromagnetic shielding, sensing and electrothermal fields. Therefore, PI-PBS could assist in efforts to lighten, integrate and intelligentize protective materials in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous coral-like Co/CoO/RGO hybrid aerogels are successfully developed. • The special structure brings multiple loss modes and good impedance matching. • Achieving high EM wave loss, hydrophobicity and thermal insulation properties. • DFT simulations are adopted to verify the interface polarization of interfaces. Addressing the growing issue of electromagnetic radiation calls for urgent exploration of effective electromagnetic wave absorbers. Herein, a series of coral-like Co/CoO nanoparticles/reduced graphene oxide (Co/CoO/RGO) hybrid aerogels were synthesized via a freeze drying-thermal reduction strategy. Their advantages involving porous interconnected framework, abundant heterogeneous interfaces, and integration of dielectric/magnetic units could bring multiple loss modes. By manipulating the Co(CO 3) 0.5 (OH)·0.11H 2 O (CCOH) addition and reduction temperature, the electromagnetic parameters could be tuned, ultimately resulting in optimal absorption capability with maximal reflection loss of –32.4 dB and effective bandwidth of 4.2 GHz. More importantly, excepting the high electromagnetic wave loss, Co/CoO/RGO hybrid aerogels also exhibit good hydrophobicity and thermal insulation properties, making them suitable for application in harsh environment. Besides, the special structure and multiple components lead to multiple heterointerfaces in aerogels, the resultant interface polarization is deemed to contribute to electromagnetic wave loss. Here, Density Functional Theory (DFT) simulation based on first-principles is adopted to verify the contribution of interface polarization from the theoretical level. According to the simulation results, the electron-occupied states near the Fermi level are significantly different among the different phases comprising the heterointerfaces, and there is a noticeable accumulation of charge at these interfaces, successfully affirming the interface polarization behavior at different interfaces. [ABSTRACT FROM AUTHOR]

• Gibbs free energy mainly dominates the formation of bixbyite-structured five-principal rare-earth element HEOs. • Cooling rate is the second factor on the phase structure formation of HEOs. • HEO4 exhibits higher fracture toughness and lower thermal conductivity than Y 2 O 3. • HEO4 shows a superior oxygen barrier property than 8YSZ. Cubic bixbyite-structured high-entropy oxides (HEOs) are regarded as potential candidates in high temperature thermal insulation field in recent years. However, their relevant properties are still needed to be explored for possible applications. In this work, twelve new high-entropy oxides (HEO1-12) of (5Re 0.2) 2 O 3 (Re represents five elements selected from Ce, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb) are prepared by solution combustion synthesis method combined with conventional sintering. Except HEO10 with a single monoclinic phase, other samples have a single bixbyite phase. The average grain size of bixbyite-structured samples is within 0.76 ∼ 4.96 μm. Then, the samples of HEO4, 5, 7–9 are chosen to study their mechanical and thermal properties. Their nano-modulus, nano-hardness, fracture toughness K IC , brittleness M and surface fracture energy are in the range of 152.42 ∼ 237.33 GPa, 9.22 ∼ 12.65 GPa, 1.77 ∼ 2.51 MPa·m1/2, 2.35 ∼ 3.09 μm−1/2 and 9.00 ∼ 22.49 J m−2, respectively. HEO4, i.e., (Ce 0.2 Nd 0.2 Sm 0.2 Dy 0.2 Gd 0.2) 2 O 3 , exhibits higher K IC (1.92 MPa·m1/2) and lower M (2.71 μm−1/2) than another reported cubic bixbyite-structured HEO of (Eu 0.2 Er 0.2 Lu 0.2 Y 0.2 Yb 0.2) 2 O 3. Among the five samples, HEO4 has the lowest thermal conductivity κ (1.88 ∼ 2.55 W·m−1·K−1 in 25 ∼ 500 °C), which is much lower than bixbyite-structured Y 2 O 3. In addition, HEO4 possesses a lower oxygen diffusion compared with 8YSZ in 600 ∼ 700 °C, which endows it the better oxygen barrier property. To sum up, HEO4 could be a promising candidate for high temperature thermal insulation applications due to its excellent comprehensive properties. [ABSTRACT FROM AUTHOR]

• Laminated CMPFA membranes were fabricated via electrospinning, vacuum filtration, and magnetron sputtering. • Waster polyester clothes were used to fabricate substrate membranes. • The asymmetrically wettable improve sweat transportation properties of CMPFA membranes. • Laminated CMPFA membranes can reflect thermal radiation and absorb solar energy to achieve dual thermal insulation. • The obtained CMPFA membranes have potential application in human thermal management. Wearable polyester fiber materials with excellent sweat transportation and enhanced thermal management properties have received increasing attention in functional materials and energy saving fields because of not only for wearing comfort but also for developing advanced energy-saving materials. Herein, this work presents an effective and sustainable strategy for fabrication of laminated CNTs-MnO 2 nanowires/PET fibers@Ag (CMPFA) membranes using waste polyethylene terephthalate (PET) fabric, manganese dioxide (MnO 2) nanowires, carbon nanotubes (CNTs) and silver nanoparticles as building blocks through electrospinning, vacuum filtration and subsequent magnetron sputtering processes, as well as its application in personal thermal management. The results indicated that simulated sweat on the PET fibers@Ag side can penetrate quickly into the CNTs-MnO 2 nanowires side within 2.4 s, implying the excellent sweat transport properties of laminated CMPFA membranes. More importantly, the synergistic thermal management properties can be obtained via infrared radiation and absorb sunlight. Compared with bare PET fibers membranes, the laminated CMPFA membranes exhibited excellent thermal insulation properties. The surface temperature of laminated CMPFA membranes is 11.9 °C higher than that of bare PET fibers membranes after 50 s of simulate sunlight exposure. In addition, the laminated CMPFA membranes show antibacterial properties, breathability, and water vapor permeability, which is beneficial to improving the comfort of wearer. This study shows that the fabrication of flexible wearable laminated membranes for personal thermal management application can be extended for the fabricated of other waste plastic based-materials with controlled structures and desired functions for various applications. [ABSTRACT FROM AUTHOR]

• Unidirectional anisotropic PIAs have been prepared by freeze-drying. • The PIA shows excellent thermal stability and stable mechanical behavior. • The u -PIA-6 exhibits great strength, which is over twice as high as that of the TEEK-HH at 177 °C with a similar density. • The u -PIA shows great thermal insulation properties in anisotropic. Polyimide aerogels (PIAs) are the new type of high-performance lightweight material that combines the excellent thermal and mechanical behavior of polyimides with the highly porous and lightweight properties of aerogels. PIAs can meet the increasing material requirements of high-tech fields such as the aerospace and transportation industries. This study reports a series of all-aromatic anisotropic polyimide aerogels (p-phenylenediamine (PDA) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA)) with unprecedented behavior. These PIAs were synthesized using a random or unidirectional freeze-drying method followed by thermal imidization of the precursor solution. Their mechanical and thermal conductivity performance were anisotropic (u -PIA-8 strength: 1.86 and 0.14 MPa, thermal conductivity: 62.9 and 50.1 mW·m−1·K−1 along the axial and radial direction, respectively). Furthermore, the PIAs possessed excellent compression behavior in a wide temperature range from 25 °C to 316 °C, with a compressive strength over twice that of the commercial polyimide foam TEEK-HH (u -PIA-6 strength: 0.83 and 0.32 MPa at 177 and 316 °C, TEEK-HH strength: 0.31 MPa at 177 °C). These aerogels also demonstrated good thermal insulation performance after being held at 300 °C for 20 min (u -PIA-8: 76.3 °C at 25 mm). These highly anisotropic aerogels exhibit flexible thermal protection properties that extend the potential use of PIAs to applications such as high-temperature-resistant rocket fairings, sandwich structures, and arc-shaped structures for aerobats or the automobile industry. [ABSTRACT FROM AUTHOR]