Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 36
·19524-19535
·
IF 11.9
Yu Yang,Zhiying Ren,Chunhui Zhou,Youxi Lin,Linwei Shi,Linxi Hou
Graphene aerogels possess unique advantages for treating oil–water mixtures, but their fragile mechanical properties hinder further development, and their separation mechanisms remain unclear. Herein, a superhydrophobic silane-crosslinked graphene oxide/polyvinyl alcohol aerogel (Si-GPA) was prepared by directional freeze-drying of a graphene oxide/polyvinyl alcohol (GO/PVA) suspension and vapor-phase deposition of methyltriethoxysilane (MTES) for efficient on-demand oil–water separation, and its separation mechanism was revealed through computational fluid dynamics (CFD) simulations. With the binding of PVA polymer chains and the cross-linking of MTES monomers, the Si-GPA exhibits excellent anisotropy, radial superelasticity (over 50 000 cycles at 50% strain), and axial superstiffness (freezing direction) (more than 20 000 times its own weight), which are the best-known results to date. The Si-GPA utilizes its superelasticity to adsorb floating oil on the sea surface and oil droplets in oil-in-water emulsions, while employing its superstiffness to filter water-in-oil emulsions in pipelines for on-demand oil–water separation. More importantly, the Si-GPA overcomes the trade-off between flux and efficiency, enabling the separation of water-in-oil emulsions with water droplet sizes several times smaller than its pore size under gravity alone, and with ultra-high flux (4350 L m−2 h−2) and ultra-high purity (99.9%), 1–2 times higher than those of 2D superwetting separation membranes that require external pressure. Additionally, visualization analysis based on simulation modeling reveals the emulsion coalescence filtration mechanism of the Si-GPA. Therefore, mechanically robust superhydrophobic graphene aerogels have enormous potential in oil–water separation applications.
研究领域:
材料科学
·
环境科学
·
计算流体力学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2020
·Vol. 9
·期 2
·373-380
·
IF 5.344
Chenglong Dong,Hailong Fan,Feng Tang,Xiaobin Gao,Kai Feng,Jiahui Wang,Zhaoxia Jin
Applications in the harsh environment require hydrogels with ultra-stiffness, toughness, and stretchability. However, it remains a challenge to increase the elastic modulus without sacrificing the maximum elongation of hydrogels, because of the trade-off between stiffness and extensibility. Inspired by the crosslinking hierarchy of mussel byssus cuticle, here, we report a strategy to fabricate an ultra-stiff, tough and stretchable triple-crosslinked (TC) hydrogel. The polymer is crosslinked by chemical crosslinker at first, subsequently by introducing a polyphenolic compound, tannic acid (TA), and metal ions. The hydrogen-bond-based network between the polymer and TA works as an extensible and energy-dissipative network, mimicking the matrix of the cuticle, while the higher crosslinked domains formed by the coordinate bonds between TA and metal ions contribute to the stiffness. The triple-crosslinked hydrogel exhibits two orders of magnitude increase in stiffness (E = 58 MPa), but without sacrificing the maximum elongation (ε = 850%), compared with those of metal-free hydrogels (E = 0.18 MPa, and ε = 860%). The combination of ultra-stiffness, toughness, and stretchability in hydrogels is successfully achieved through leveraging the hierarchically cross-linked network based on hydrogen bonding and coordination bonding. Moreover, utilizing the wide distribution of bonding strength of coordination interaction, the mechanical properties of triple-crosslinked hydrogels can be manipulated by using different kinds of catechol-metal coordination.
研究领域:
材料科学
·
生物仿生学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Nano
·
2025
·
IF 16
Yang Yang,Yingjie Cao,Shengjie Li,Yana Wang,Xiaohua Zhang,Yitan Li,Zhaohui Yang
Natural protein-based biomaterials with complex hierarchical structures often have incredible and even counterintuitive mechanical properties. Understanding and utilizing the conformational transition mechanisms of natural proteins will further guide the design of natural-inspired biomaterials. In this study, a small static-force-induced spatiotemporal “freezing” phenomenon of silk fibroins confined in porous carbon nanotube sponges has been investigated. The “freezing” silk fibroins not only bring the shape memory effect to elastic carbon nanotube sponges but also enable them to prop up heavy objects with loads exceeding 10,000 times their own weight. Also, the protein/CNTS hybrid achieves an ultrastiffness (over 10 MPa) and superelastic shape recovery (recovery strain >90%). Both experimental and numerical results indicate that the secondary conformational transition of silk fibroin plays a key role, where more α-helices/random coils transform into β-sheets under both confinement and low pressure. Our work reports a conformational transition mechanism of silk fibroin in a confined space, which provides guidance for constructing protein-based biological smart materials with potential applications in textiles, medicine, architecture, and other research fields.
研究领域:
材料科学
·
生物工程
·
生物物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）