Wood-Inspired Ultrafast High-Performance Adsorbents for CO2 Capture

Construction of low-energy regenerative bagasse-based carbon capture material for high efficiency CO2 capture

Using biomass for the production of low-energy regenerative carbon capture materials represents an effective strategy to advance carbon dioxide capture and storage technologies. In this study, a low-energy regenerative bagasse-based CO2 capture material is synthesized through a one-step, rapid crosslinking strategy. In this method, epichlorohydrin is used to crosslink bagasse with temperature sensitive Pluronic® F-127 and polyethyleneimine, thereby addressing the challenge of simultaneously incorporating multiple functional groups into the biomass matrix. The resulting material with abundant amino adsorption sites demonstrates a high adsorption capacity of 4.52 mmol/g. Interestingly, the temperature-sensitive response of the material facilitates the grafted amine chain segments on bagasse to stretch and shrink reversibly within a narrow temperature range of 25 °C for adsorption and 55 °C for desorption. The shrinkage state is conducive to the CO2 desorption process, resulting in an ultralow regeneration temperature of 55 °C. Additionally, the water contained in the material enhances its cyclic stability in extreme environments, such as pure CO2 atmosphere at high temperature. Overall, this research not only provides new ideas for enhancing the long-term stability and economic viability of CO2 capture materials but also offers feasible solutions for combating climate change and promoting sustainable development.

Phenolic Modified SiO2 Aerogel as a Hybrid Thermal Insulation Systems

SiO2 aerogel is a good thermal insulation material, but its porous nanostructure makes it brittle and has a poor mechanical property. SiO2 aerogel with a good elastic property was prepared by combining methyltrimethoxysilane (MTMS) and hexadecyltrimethoxysilane to form a composite organic silane precursor. However, its mechanical properties were not significantly improved. SiO2/phenolic-modified aerogel was prepared by modifying SiO2 aerogel with thermosetting phenolic resin, which effectively improved the mechanical properties of SiO2 aerogel. The results show that when the molar ratio of hexadecyltrimethoxysilane to MTMS is in the range of 0-0.05, the elastic properties of the aerogel continue to improve with the increase of the introduction of hexadecyltrimethoxysilane. The maximum compressive strength can reach 0.03 MPa, and the strain tolerance range is 10-18%. When the mass ratio of MTMS to phenolic resin is within the range of 0-5.5, the modified aerogel presents a nanoscale gel network structure. The maximum compressive strength can reach 0.048 MPa, which is nearly 60% higher than the maximum compressive strength of the aerogel before modification. The allowable strain range is 14.7-17.5%. After 20 stress-strain tests, the maximum compressive strength only decreases by 4%, indicating good stability. It simultaneously possessing low density (0.176 g/cm3), volume shrinkage rate, and low thermal conductivity. The thermal conductivity in an air atmosphere at 28 °C is 0.057 W/(m·K). The modified aerogel prepared by the sol-gel reaction and atmospheric drying process has broad application prospects.

High-Efficiency Silane Utilization in Amine-Modified Adsorbents for Direct Air Capture through Interconnected Three-Dimensional Pores

Economic synthesis of amine-modified solid adsorbents is pivotal for the global-scale direct air capture (DAC) technologies required to realize net-zero emissions. To address the problems of the traditional reflux method using excessively costly amino silane, we propose introducing silane by impregnation into mesoporous silica with interconnected three-dimensional pores. X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption-desorption, transmission electron and scanning electron microscopies, magic-angle spinning nuclear magnetic resonance, and elemental analysis identified the spatial distribution of amino silane in the materials with different loading levels. The results of structure characterization and a comparison with a reference experiment (using a porous support with one-dimensional pores and/or the conventional reflux method) revealed that the proposed strategy provided a uniform amine distribution, together with a high utilization efficiency of the amino silane. We also demonstrate that the obtained material has a high adsorption capacity and good recycling stability comparable to those of the previously reported amino silane modified adsorbents under simulated DAC conditions.

Application-Driven High-Thermal-Conductivity Polymer Nanocomposites

Polymer nanocomposites combine the merits of polymer matrices and the unusual effects of nanoscale reinforcements and have been recognized as important members of the material family. Being a fundamental material property, thermal conductivity directly affects the molding and processing of materials as well as the design and performance of devices and systems. Polymer nanocomposites have been used in numerous industrial fields; thus, high demands are placed on the thermal conductivity feature of polymer nanocomposites. In this Perspective, we first provide roadmaps for the development of polymer nanocomposites with isotropic, in-plane, and through-plane high thermal conductivities, demonstrating the great effect of nanoscale reinforcements on thermal conductivity enhancement of polymer nanocomposites. Then the significance of the thermal conductivity of polymer nanocomposites in different application fields, including wearable electronics, thermal interface materials, battery thermal management, dielectric capacitors, electrical equipment, solar thermal energy storage, biomedical applications, carbon dioxide capture, and radiative cooling, are highlighted. In future research, we should continue to focus on methods that can further improve the thermal conductivity of polymer nanocomposites. On the other hand, we should pay more attention to the synergistic improvement of the thermal conductivity and other properties of polymer nanocomposites. Emerging polymer nanocomposites with high thermal conductivity should be based on application-oriented research.