Journal of Materials Chemistry Blog

Scientists in China have made zinc oxide replicas of single scales from butterfly wings to understand and exploit their optical properties for sensor and solar cell applications. 

The Morpho menelaus butterfly with a magnified image of a wing scale (left) and zinc oxide scale replicas with a magnified image (right)

Butterfly wings are made up of chitin scales and their iridescent blue and green colours are generated by light and air travelling through the chitin. The way the scales are arranged dictates which colour is seen. Studying the wings’ properties to replicate the process could lead to the design of new photonic crystal structures for optical devices. 

Until now, researchers have focused on making devices based on whole butterfly wings, but Jiajun Gu and Di Zhang from Shanghai Jiao Tong University and their team, believe that this misses important mechanisms and phenomena. This is because whole wings are covered by redundant parts, such as wing membranes, which could alter the optical properties of the wings’ scales. 

To view the full Chemistry World article, please click here: A single scale tells more than a whole wing

Link to journal article

ZnO single butterfly wing scales: synthesis and spatial optical anisotropy
Yu Chen, Xining Zang, Jiajun Gu, Shenmin Zhu, Huilan Su, Di Zhang, Xiaobin Hu, Qinglei Liu, Wang Zhang and Dingxin Liu, J. Mater. Chem., 2011
DOI: 10.1039/c1jm10678c

Cross-linked enzyme aggregates have great potential in marine antifouling paints claim Danish scientists.

Paints with antifouling activity are used in the marine industry to prevent undesirable accumulation of microorganisms, plants and animals on ship surfaces below the waterline. Previously tributyltin self-polishing copolymer (TBT-SPC) paints have been used however they were banned in January 2008 due to environmental regulations.

The main alternatives are copper-based paints but these also cause concern for the environment. Consequently it non-toxic alternatives are desirable which is where enzymes can have a niche explains Stepan Shipovskov at Aarhus University, Denmark.

Environmentally friendly paints for boats use enzymes instead of metals

Enzymes can interact directly with microorganisms on the ships surface but organic solvents, such as xylene, are the main base of paints and can inactivate the enzymes. Shipovskov and co-workers tested cross-linked enzyme aggregates (CLEAs) of proteases in artificial sea water and found that they are tolerant to xylene and have great stability in dried paint. Shipovskov explains that ‘a stabilisation effect occurs due to the covalent linking between enzyme molecules which prevents enzyme inactivation in organic solvents’.

To view the full Highlights in Chemical Science article, please click here: Enzymes – a new ingredient for marine paint?

Link to journal article

Implementation of cross-linked enzyme aggregates of proteases for marine paint applications
Jonas Skovgaard, Charlotte A. Bak, Torben Snabe, Duncan S. Sutherland, Brian S. Laursen, Karsten M. Kragh, Flemming Besenbacher, Charlotte H. Poulsen and Stepan Shipovskov, J. Mater. Chem., 2010, 20, 7626
DOI: 10.1039/c0jm01249a