Geomimetics and Extreme Biomimetics Inspired by Hydrothermal Systems-What Can We Learn from Nature for Materials Synthesis?

'Extreme biomimetics' and 'geomimetics' are relatively recent fields of materials chemistry. Both take inspiration from natural materials for generating novel synthetic materials or enhanced properties in known materials. In geomimetics, the source of inspiration is geological systems, while extreme biomimetics is motivated by organisms operating in-from an anthropocentric point of view-extreme conditions. This review article focuses on geomimetic and extreme biomimetic hydrothermal synthesis. Since hydrothermal preparative chemistry typically uses nothing but water and the required precursors, the field belongs to the research area of 'green materials chemistry'. Geomimetics, on the one hand, takes inspiration from natural materials formation. Extreme Biomimetics, on the other hand, is inspired by materials found in extremophile organisms, instead of aiming to implement their actual biosynthesis. In this contribution, both extreme biomimetics and geomimetics are first defined, and further critically discussed on the basis of recent, selected examples. Moreover, the necessity for the two closely related fields as well their prospects are commented on.

Water as Solvent in Polyimide Synthesis III: Towards the Synthesis of Polyamideimides

Four different approaches to the synthesis of polyamideimides, which employ aqueous imidization, were studied in order to assess the viability of their preparation in water. Building on previous studies of synthesizing polyimides in water both one- and two-step methods were explored. The first direct method for polyamideimide synthesis forms both the amide and imide linkages simultaneously and is limited to appropriately activated diamine monomers. The second direct method uses commercially sourced diaminobenzanilide with standard tetracarboxylic acids in an imidization step to give the polyamideimide. This method, demonstrates the viability of using amide-containing diamines in a polyimidization step to synthesize the desired polymer. The third and fourth methods are both two-step processes and use aqueous imidization to produce imide-containing monomers with either amine or carboxylic acid terminal functionality. This is followed by standard amidation to produce high-quality polyamideimides.