Formation of reactive aerogels and their reactivity in aqueous media. Wettability induces hydrophobic vs. hydrophilic selectivity
作者:Thi-Thanh-Tam Nguyen、François-Xavier Simon、Niaz Ali Khan、Marc Schmutz、Philippe J. Mésini
DOI:10.1039/c2jm30184a
日期:——
Aerogels were formed from organogels of diamides by a supercritical drying process. The used organogels are composed of self-assembled nanotubes of 29 nm in diameter. SEM studies reveal that the resulting aerogels are made of fibers with diameters comprised between 40 and 200 nm, corresponding to bundles of the starting nanotubes, while WAXS indicated that most of the crystalline structure detected in the self-assemblies of the starting gel is preserved in aerogels. Two different reactive diamides bearing respectively an alkynyl and an azido function were investigated. We have tested the reactivity of the resulting aerogels under copper-catalyzed azide–alkyne cycloaddition in aqueous solution. These aerogels react easily with hydrophobic compounds although reactants are in separate phases. In contrast, they do not react with hydrosoluble compounds, because of their superhydrophobicity.
气凝胶是由二酰胺有机凝胶通过超临界干燥工艺形成的。使用的有机凝胶由直径为 29 纳米的自组装纳米管组成。扫描电子显微镜(SEM)研究表明,气凝胶由直径介于 40 纳米和 200 纳米之间的纤维组成,与起始纳米管束相对应,而 WAXS 表明,在起始凝胶的自组装中检测到的结晶结构大部分在气凝胶中得以保留。我们研究了两种不同的活性二酰胺,它们分别具有炔基和叠氮功能。我们在水溶液中测试了铜催化叠氮-炔环化反应下生成的气凝胶的反应性。尽管反应物处于不同的相中,但这些气凝胶很容易与疏水性化合物发生反应。相反,由于它们具有超疏水性,因此不会与水溶性化合物发生反应。