A polymer sponge with dual absorption of mechanical and electromagnetic energy.

Multifunctional hydrophilic MXene/Gelatin composite aerogel with vertically aligned channels for efficient sustainable solar water evaporation and Oil/Water separation

Carbon Layer Encapsulation Strategy for Designing Multifunctional Core-Shell Nanorod Aerogels as High-Temperature Thermal Superinsulators

https://www.mdpi.com/2079-6374/12/10/876/pdf?version=1665840346

Electrospinning-Based Biosensors for Health Monitoring

Ceramic matrix composites (CMCs) are designed to overcome the main drawback of monolithic ceramics, namely their brittleness, and are constituently expressed as a continuous phase, or matrix, a distributed phase, commonly referred to as the reinforcing fibers, and also an interphase layer or coating layer between them. In this regard, there is a necessity to understand the principles for choosing the reinforcing fibers and designing the fiber–matrix interfaces. Hence, an attempt is made to review the recent progresses on ceramic micro-nano fibers and their effect on the interfaces in CMCs. The development trend for CMCs is discussed, especially the future CMCs based on ceramic micro-nano fibers, including the strengthening and interface construction concerning with these fibers. • A brief review of current progress in the field of ceramic matrix composites is presented. • Two essential issues of fiber candidates and interface design are discussed. • Evolution from microfibers to nanofibers toward next-generation ceramic matrix composites is prospected. 

Evolution from microfibers to nanofibers toward next-generation ceramic matrix composites: A review

Thermal insulation under extreme conditions requires materials that can withstand complex thermomechanical stress and retain excellent thermal insulation properties at temperatures exceeding 1,000 degrees Celsius1-3. Ceramic aerogels are attractive thermal insulating materials; however, at very high temperatures, they often show considerably increased thermal conductivity and limited thermomechanical stability that can lead to catastrophic failure4-6. Here we report a multiscale design of hypocrystalline zircon nanofibrous aerogels with a zig-zag architecture that leads to exceptional thermomechanical stability and ultralow thermal conductivity at high temperatures. The aerogels show a near-zero Poisson's ratio (3.3 × 10-4) and a near-zero thermal expansion coefficient (1.2 × 10-7 per degree Celsius), which ensures excellent structural flexibility and thermomechanical properties. They show high thermal stability with ultralow strength degradation (less than 1 per cent) after sharp thermal shocks, and a high working temperature (up to 1,300 degrees Celsius). By deliberately entrapping residue carbon species in the constituent hypocrystalline zircon fibres, we substantially reduce the thermal radiation heat transfer and achieve one of the lowest high-temperature thermal conductivities among ceramic aerogels so far-104 milliwatts per metre per kelvin at 1,000 degrees Celsius. The combined thermomechanical and thermal insulating properties offer an attractive material system for robust thermal insulation under extreme conditions. 

/pdf/hypocrystalline-ceramic-aerogels-for-thermal-insulation-at-1wuicd9b.pdf

Hypocrystalline ceramic aerogels for thermal insulation at extreme conditions

Thermal sealing is essential to prevent thermal runaway in aerospace and mechanical fields. Ceramic aerogels are attractive candidates but often show limited thermomechanical performance and thermal radiation opacification that may...

Medium-entropy ceramic aerogels for robust thermal sealing

Calcium sulfoaluminate (CSA) cements have lower carbon dioxide (CO2) emissions during production compared with conventional ordinary Portland cement (OPC). However, the high cost of production is a significant limitation of the application of CSA cements. This paper aims to improve the use efficiency of CSA clinker by adding OPC and anhydrite. The low-carbon OPC-CSA clinker-anhydrite system is expected to contain less CSA clinker while showing excellent performance. A design methodology was developed to optimize the component of the OPC-CSA clinker-anhydrite blended system. The hydration mechanism of the ternary system was investigated using isothermal conduction calorimetry, X-ray diffraction (XRD), and thermogravimetric analysis (TGA), and thermodynamic modelling was used to predict the amount of hydration products. The results showed that ettringite is the main hydration products of the OPC-CSA clinker-anhydrite system, and the addition of OPC provides portlandite for the formation of ettringite. The ternary system is characterized by rapid development of strength and low CO2 emissions. The compressive strength at 4 h and the CO2 emissions are about 10 MPa and 500 kg/t, respectively. In addition, the ternary system, composed of 27.9 wt% CSA clinker, 32.5 wt% anhydrite, and 39.6 wt% OPC has the highest compressive strength at 28 d and the lowest CO2 intensity. 

Fundamental design of low-carbon ordinary Portland cement-calcium sulfoaluminate clinker-anhydrite blended system


 Inorganic aerogels have exhibited many superior characteristics with extensive applications, but still plagued a nearly century-old tradeoff between their mechanical and thermal properties. When reducing the thermal conductivity by ultralow density, inorganic aerogels generally suffer from large fragility due to their brittle nature or weak joint crosslinking, while enhancing the mechanical robustness by material design and structural engineering, they easily sacrifice the thermal insulation and stability. Here, we report a chemically bonded multi-nanolayer design and synthesis of a graphene/amorphous boron nitride aerogel to address this typical tradeoff to further enhance the mechanical and thermal properties. Attributed to the chemically bonded interface and coupled toughening effect, our aerogels display a low density of 0.8 mg cm−3 with ultrahigh flexibility (elastic compressive strain up to 99% and bending strain up to 90%), and exceptional thermostability (strength degradation < 3% after sharp thermal shocks), as well as the lowest thermal conductivities in vacuum (only 1.57 mW m−1 K−1 at room temperature and 10.39 mW m−1 K−1 at 500°C) among solid materials to date. This unique combination of mechanical and thermal properties offers an attractive material system for thermal superinsulation at extreme conditions.

/pdf/chemically-bonded-multi-nanolayer-inorganic-aerogel-with-a-2ui6npr9.pdf

Jian Zhou

Papers

Hypocrystalline ceramic aerogels for thermal insulation at extreme conditions

Medium-entropy ceramic aerogels for robust thermal sealing

Fundamental design of low-carbon ordinary Portland cement-calcium sulfoaluminate clinker-anhydrite blended system

Chemically bonded multi-nanolayer inorganic aerogel with a record-low thermal conductivity in a vacuum