tl, dr February

news · 5 years ago
by Krisztián Niesz
Hi Folks! As the biggest American award ceremony closes I think it is safe to create my own Oscar list. Enjoy this TL; DR featuring news mainly from nanotechnology. Bimetallic Nanocage for Energy Storage Gemstone on Your Eyes Already an Artificial Graphene Structure Self-Healing Polymers Increasing CO2 Emission and One Way to Handle It #1 So, without further ado “my” Oscar goes to the researchers from Lawrence Berkeley and Argonne National Laboratories for developing a novel catalyst system that could be the base of the next-generation fuel cells.1 Preliminary results showed that the activity of this electro-catalyst in question not only has reached the target set by DOE for 2017, but exceeded that significantly. What we are talking about here is a Pt/Ni bimetallic catalyst system, but it’s not the composition that is so special about it. It is the hollow nanoframe structure that the platinum and nickel intermediates are built into that makes it so unique and relevant. Because of the 3D open structure the system provides extremely high surface area for catalysis to happen, not to mention the reduced cost associated with its preparation compared to the currently used all platinum catalysts.
#2 A new drug delivery system was developed by researchers. Nothing special so far, right? But researchers from UCLA actually used 5 nm nanodiamond particles for this, and embedded them into contact lenses to treat glaucoma, a disorder of the eye that affects tens of millions.2 Now we’re talking. Who would not be interested in wearing diamond contact lenses? It may sound as a surprising fact to many, but the research around nanodiamond-based drug delivery systems is a quite hot area these days, even in cancer treatment. In this case the nanodiamond component has quite a lot of roles: it precisely controls the drug release that is triggered when in contact with the patient’s tears; it improves the durability of the lenses; and at last, some says it even increases the comfort of wearing contact lenses.
#3 It is only 10 years that have passed since the discovery of graphene (one atom thick honeycomb lattice, made up of sp2 carbon atoms), and the research community is already developing artificial graphene-like materials mimicking its properties. What makes graphene the next disruptive technology, said by many, or a super-material, holding promises in many applications, is its absolutely stunning electrical, optical characteristics as well as its extremely high surface area and low weight. Recently an international research group, lead by a scientist from the University of Luxembourg, has successfully designed and produced a graphene-like honeycomb structure, but in this case instead of C atoms they have used traditional semiconductor nanocrystals (e.g. Zinc-blende and Cd-chalcogenides).3 The importance of this artificial graphene is that via simply changing the size, shape and composition of the nanoparticle building blocks one can change the overall physical properties of the macrostructure. Pretty cool!
#4 Researchers from the University of Illinois have created a self-healing polyureas and poly(urethane-urea)s from commercial ingredients via slightly altering their structures before polymerization.4 With making the bonds that hold together the molecules in the polymer a little bit longer they could achieve that the ruptured molecules can re-bond more easily and at lower temperature without the need of adding extra catalysts into the pot. These sorts of dynamic materials and the chemistry behind have a lot of grounds in self-healing materials applied consumer products.
#5 We’re all aware of the enormous and continuous threat that the greenhouse gas emission is causing to us, however, it is another thing how seriously is taken and how far we are able to / want to go in solving it. According to the latest report from the Global Carbon Project despite of the warning signs we, humans, further increased the global emission of CO2 into a record high level (9.7 Gt carbon in 2012), that is 58%!!! Higher than the emission was in 1990.5 And this is only for CO2, not taking into account other green-house gases (GHGs), such as methane and nitrous oxides. You may wonder about the connection to nanotechnology here. Well, the connection is really the high quality science that comes out of research laboratories lead by a very distinguished group of people called scientists. Among these people let me mention briefly the team of researchers from the University of Delaware that developed a novel highly porous silver electro-catalyst to turn carbon dioxide into carbon monoxide, which is an actually useful energy source (via the Fischer-Tropsch process), while reducing industrial CO2 emission.6 What makes this silver catalyst special is its large and highly curved internal surface caused by its porous nature, it reduces the activation barrier of the CO2 reduction reaction, hence much smaller voltage is needed to drive the reaction. It is demonstrated that the catalyst is able to convert CO2 to CO with an astonishing 92% efficiency and with high stability.
References 1) http://www.sciencemag.org/content/early/2014/02/26/science.1249061 2) http://www.sciencedaily.com/releases/2014/02/140218143324.htm 3) http://journals.aps.org/prx/abstract/10.1103/PhysRevX.4.011010 4) http://www.nature.com/ncomms/2014/140204/ncomms4218/full/ncomms4218.html 5) http://vitalsigns.worldwatch.org/vs-trend/record-high-global-greenhouse-gas-emissions 6) http://www.nature.com/ncomms/2014/140130/ncomms4242/full/ncomms4242.html