Category Chemistry/Nanotechnology

1. How to make ceramic foam ink 2. Close up image of one node of the triangular honeycomb. The structure, which consists of air surrounded by ceramic, can be designed with specific porosity. (Image courtesy of James Weaver/Wyss Institute)

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being compressed. The plant’s hardiness comes from a combination of its hollow, tubular macrostructure and porous, or cellular, microstructure. These architectural features work together to give grass its robust mechanical properties. Harvard SEAS, Wyss Institute and MIT have developed a new method to 3D print materials with independently tunable macro-and microscale porosity using a ceramic foam ink...

A schematic illustration of a microbial fuel cell using a paper electrode coated with carbon paste. Credit: Michael Osadciw/University of Rochester

The concept behind microbial fuel cells, which rely on bacteria to generate an electrical current, is more than a century old. But turning that concept into a usable tool has been a long process. Microbial fuel cells, or MFCs, are more promising today than ever, but before their adoption can become widespread, they need to be both cheaper and more efficient. Researchers at the University of Rochester have made significant progress toward those ends. In a fuel cell that relies on bacteria found in wastewater, Kara Bren, a professor of chemistry, and Peter Lamberg, a postdoctoral fellow, have developed an electrode using paper.

Until now, most el...

Multiple Colors Output on Voile through 3D Colloidal Crystals with Robust Mechanical Properties

“Fast fashion” might be cheap, but its high environmental cost from dyes polluting the water near factories has been well documented. To help stem the tide of dyes from entering streams and rivers, scientists report in the journal ACS Applied Materials & Interfaces a nonpolluting method to color textiles using 3D colloidal crystals.

Dyes and pigments are chemical colors that produce their visual effect by selectively absorbing and reflecting specific wavelengths of visible light. Structural or physical colors – such as those of opals, peacock feathers and butterfly wings – result from light-modifying micro- and nanostructures...

W. Mtangi et al., Control of Electrons’ Spin Eliminates Hydrogen Peroxide Formation During Water Splitting, Journal of the American Chemical Society (30 January 2017). DOI: 10.1021/jacs.6b12971

A big obstacle in the production of hydrogen through water splitting is that H2O2 is also formed, which affects the efficiency stability of the reaction and the stability of the production. Researchers have now succeeded in controlling the spin of electrons in the reaction and thereby almost fully suppress the production of hydrogen peroxide in the electrochemical cell.

Led by professors Bert Meijer (Eindhoven University of Technology) and Ron Naaman (Weizmann Institute), the researchers are the first to have specifically investigated the role of the spin – the internal magnetic moment – of electron...