Themed issue on green materials and surfaces

“Imagine there’s no countries, it isn’t hard to do”.¹ And imagine a world with a mild climate, clean air and drinking water for everyone, everywhere, supported by clever new materials and technology, with products that are easy to make and simple to recycle. From a conceptual point of view, one might say that we are not far from that. Unfortunately, in practice there are many obstacles. These include less acceptable ones, such as market domination by classical technologies, which is partly justified by an ever-growing population. Sometimes though, the research is not there or has to be refreshed to include aspects of sustainability. In recent years, sustainable research has made great progress in many aspects, such as materials design, processing, catalysis, and energy generation and storage: it has turned into an attractive field of research. Why, for instance, work on catalysts based on rare elements when it is clear from the beginning that price or toxicity will restrict them to scientific curiosities? Or why use complicated fluorocarbons at surfaces, when nature can accomplish much more complicated tasks such as directional de-wetting just by applying clever nano- and microstructured surfaces?² “Green” is a hard-to-define concept, and everyone has a slightly different understanding of it, but we can all agree on its general importance. The proclaimed principles of green chemistry³ may serve as guidance, but they are proposals, not dogmas.

This special issue on green materials and surfaces focuses on materials research which incorporates such additional conditions from the initial design of the project. Materials should of course serve a use or a purpose, but being “green” gives them an extra edge in real applications and finally market entry. This issue is understandably broad: it brings together recent scientific developments and breakthroughs in materials synthesis and processing, energy conversion and storage as well as innovative sustainable materials applications. To highlight some of the areas covered, this themed issue contains work on functional materials, ranging from polymers to carbons to inorganic materials and composites, and the fabrication of scalable and safe systems such as membranes based on biopolymers (cellulose) is reported. A fundamental aspect of the manuscripts presented in this issue is the generally facile and fast preparation approaches which, however, create rather complex synergistic effects in the final materials. This leads to outstanding performances in applications in the field of environmental protection, such as gas separation, water filtration and harvesting, energy storage and conversion, ultra-light materials and photocatalytic processes. Here, targeted structural control on all length scales and the relation of structure to the properties of the respective system are of particular interest.

Lei Jiang
Markus Antonietti
Nina Fechler

References

1. J. Lennon, Imagine, Apple Records, 1971.
2. B. Su, W. Guo and L. Jiang, Learning from nature: binary cooperative complementary nanomaterials, Small, 2015, 11, 1071.
3. P. T. Anastas and J. C. Warner, Green Chemistry: Theory and Practice, Oxford University Press, 1998, p. 30.

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