Posted on 04/09/2010 9:48:19 PM PDT by neverdem
Crab shells provide a cheap and convenient template to make high performance carbon electrodes for energy storage and conversion, say Chinese scientists.
Carbon materials have many potential applications, including as electrodes in supercapacitors and fuel cells. The pore structure is known to affect their physicochemical properties and is normally controlled by using a porous hard template such as zeolite or silica. But the process usually involves using hydrofluoric acid to remove the templates, which can be complex and costly.
A research group from Fudan University, led by Yong-Yao Xia, has demonstrated that crab shell has a well aligned porous structure at the microscopic level. Exploiting this unique structure, they have generated porous carbon nanofibre arrays by combining the hard crab shell template with an established soft templating method. 'Biological templates are generally abundant, renewable, inexpensive and environmentally benign compared to artificial templates,' explains Xia.
|
Porous carbon nanofibre arrays can be made using crab shells as a template
|
After burning the crab shell in air, the porous template mainly consists of calcium carbonate. Adding a soft copolymer template and resol precursor forms the carbon framework. Heating under nitrogen gas removes the soft template and the hard template can be dissolved in hydrochloric acid.
'The crab shell hard template is not only easy to remove but also hierarchically porous,' says Rui Zhang, an expert in porous carbon materials at the Shanghai Institute of Technology. The templated carbon nanofibre arrays retain this hierarchical porosity, forming pores of three sizes. The largest result from the packing of nanofibres, the medium pores from voids between the nanofibres and the carbon nanofibres themselves contain the smallest pores.
The pore structure is suitable for charge storage by ion adsorption/desorption as an electrode material for supercapacitors or platinum/palladium catalyst loading for fuel cell applications, says Xia. Aided by the large surface area and complex structure, Xia' material shows excellent results in both cases.
Xia's team is now using crab shell to template other porous materials as well as investigating alternative shellfish templates.
Highly ordered mesoporous carbon nanofiber arrays from a crab shell biological template and its application in supercapacitors and fuel cells
Hai-Jing Liu, Xiao-Ming Wang, Wang-Jun Cui, Yu-Qian Dou, Dong-Yuan Zhao and Yong-Yao Xia, J. Mater. Chem., 2010
DOI: 10.1039/b925776d
Trees take on tissue engineering
Italian scientists have turned wood into bone mimics that could be used to repair damaged limbs
Latest biomaterials offer fuel cell hope
Carbon nanotube scaffolds that can support bacterial cells could be used as electrodes in microbial fuel cells.
The Chinese also prefer to eat the crab roe and liver, among other internal organs. Crab legs are thought to be "poor man's food".
That’s the best part about living here in Shanghai - my friends eat the bodies, and they give me all the legs!
Roasted crab batteries.
Crab legs are thought to be “poor man’s food”
That’s funny, we love them, chicken feet—not so much.
We trade China chicken feet for crab legs and call it even?! hahaha
Similarly, chicken processors in the USA sell chicken feet to China.
If that's the best part about living in Shanghai .... well I will leave that alone.
I found the same thing in Beijing. I actually had my Chinese friends throw crab legs at me when I was there!
How long will you be in Shanghai?
Works for me!
Vaccine works against type 1 diabetes in mouse experiments - Researchers find self-regulating feature of immune system Comment# 5 has a 'graphical abstract'.
Study: Social influence playing role in surging autism diagnoses
FReepmail me if you want on or off my health and science ping list.
Well, it’s one of the nice things about living here...:) I’m here for another week, then back to the US for 5 weeks, then back here. I spend about 5-6 months a year here, at 4-5 weeks a shot.
They also make a drug out of it. The chemical is in your eye fluid.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.