Key Laboratory of Wood Material Science and Application (Beijing Forestry University), Ministry of Education, Beijing 100083, China; Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083, China.
Key Laboratory of Wood Material Science and Application (Beijing Forestry University), Ministry of Education, Beijing 100083, China; Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083, China.
Int J Biol Macromol. 2024 Jul;273(Pt 1):132778. doi: 10.1016/j.ijbiomac.2024.132778. Epub 2024 May 31.
In order to achieve an aerogel with both rigid pore structures and desired flexibility, stiff carboxyl-functionalized cellulose nanofiber (CNFs) were introduced into a flexible polyvinyl alcohol-polyethyleneimine (PVA-PEI) crosslinking network, with 4-formylphenylboronic acid (4FPBA) bridging within the PVA-PEI network to enable dynamic boroxine and imine bond formation. The strong covalent bonds and hydrogen connections between CNF and the crosslinking network enhanced the wet stability of the aerogel while also contributed to its thermal stability. Importantly, the harmonious coordination between the stiff CNF and the flexible polymer chains not only facilitated aerogel flexibility but also enhanced its increased specific surface area by improving pore structure. Moreover, the inclusion of CNF enhanced the adsorption capacity of the aerogel, rendering it effective for removing heavy metal ions. The specific surface area and adsorption capacity for copper ions of the aerogel increased significantly with a 3 wt% addition CNF suspension, reaching 19.74 m g and 60.28 mg g, respectively. These values represent a remarkable increase of 590.21 % and 213.96 %, respectively, compared to the blank aerogel. The CNF-enhanced aerogel in this study, characterized by its well-defined pore structures, and desired flexibility, demonstrates versatile applicability across multiple domains, including environmental protection, thermal insulation, electrode fabrication, and beyond.
为了获得具有刚性孔结构和所需柔韧性的气凝胶，刚性羧基化纤维素纳米纤维（CNF）被引入到具有动态硼氧烷和亚胺键形成能力的柔性聚乙烯醇-聚乙烯亚胺（PVA-PEI）交联网络中，其中 4-甲酰基苯硼酸（4FPBA）在 PVA-PEI 网络中桥接。CNF 与交联网络之间的强共价键和氢键增强了气凝胶的湿稳定性，同时也有助于其热稳定性。重要的是，刚性 CNF 与柔性聚合物链之间的和谐协调不仅促进了气凝胶的柔韧性，而且通过改善孔结构提高了其比表面积。此外，CNF 的加入提高了气凝胶的吸附能力，使其能够有效去除重金属离子。气凝胶对铜离子的比表面积和吸附容量随着 3wt%添加 CNF 悬浮液而显著增加，分别达到 19.74m²/g 和 60.28mg/g。与空白气凝胶相比，这些值分别显著增加了 590.21%和 213.96%。本研究中增强的 CNF 气凝胶具有明确的孔结构和所需的柔韧性，在环境保护、隔热、电极制造等多个领域具有广泛的适用性。
