Abstract:
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 m2 g-1 and 60.28 mg g-1, 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.
摘要:
为了获得具有刚性孔结构和所需柔韧性的气凝胶,硬羧基官能化纤维素纳米纤维(CNFs)被引入到柔性聚乙烯醇-聚乙烯亚胺(PVA-PEI)交联网络中,4-甲酰基苯基硼酸(4FPBA)桥接在PVA-PEI网络中,以形成动态的环硼氧烷和亚胺键。CNF和交联网络之间的强共价键和氢连接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和柔性聚合物链之间的协调不仅促进了气凝胶的柔韧性,而且通过改善孔结构增强了其增加的比表面积。此外,CNF的加入提高了气凝胶的吸附能力,使其有效去除重金属离子。添加3wt%的CNF悬浮液,气凝胶的比表面积和对铜离子的吸附能力显着增加。分别达到19.74m2g-1和60.28mgg-1。这些值代表了590.21%和213.96%的显着增长,分别,与空白气凝胶相比。这项研究中的CNF增强气凝胶,以其明确的孔隙结构为特征,和所需的灵活性,展示了跨多个领域的通用适用性,包括环境保护,隔热,电极制造,和超越。