Dexter Annette F, Malcolm Andrew S, Middelberg Anton P J
Centre for Biomolecular Engineering, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia Queensland 4072, Australia.
Nat Mater. 2006 Jun;5(6):502-6. doi: 10.1038/nmat1653. Epub 2006 May 21.
Designer peptides have recently been developed as building blocks for novel self-assembled materials with stimuli-responsive properties. To date, such materials have been based on self-assembly in bulk aqueous solution or at solid-fluid interfaces. We have designed a 21-residue peptide, AM1, as a stimuli-responsive surfactant that switches molecular architectures at a fluid-fluid interface in response to changes in bulk aqueous solution composition. In the presence of divalent zinc at neutral pH, the peptide forms a mechanically strong 'film state'. In the absence of metal ions or at acid pH, the peptide adsorbs to form a mobile 'detergent state'. The two interfacial states can be actively and reversibly switched. Switching between the two states by a change in pH or the addition of a chelating agent leads to rapid emulsion coalescence or foam collapse. This work introduces a new class of surfactants that offer an environmentally friendly approach to control the stability of interfaces in foams, emulsions and fluid-fluid interfaces more generally.
近年来，设计肽已被开发为具有刺激响应特性的新型自组装材料的构建单元。迄今为止，这类材料基于在大量水溶液中或固液界面处的自组装。我们设计了一种21个残基的肽AM1，作为一种刺激响应性表面活性剂，它能响应大量水溶液组成的变化，在液-液界面处切换分子结构。在中性pH值下存在二价锌时，该肽形成机械强度高的“膜态”。在没有金属离子或酸性pH值条件下，该肽吸附形成可移动的“洗涤剂态”。这两种界面状态可以被主动且可逆地切换。通过改变pH值或添加螯合剂在两种状态之间切换会导致快速的乳液聚结或泡沫破裂。这项工作引入了一类新型表面活性剂，它们提供了一种环境友好的方法，更广泛地控制泡沫、乳液和液-液界面中界面的稳定性。
