13th International Ceramics Congress
C:PL1 From Metamaterials to Metadevices
N.I. ZHELUDEV, Optoelectronics Research centre, University of Southampton, Southampton, UK; Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore
Metamaterials, artificial electromagnetic media achieved by structuring on the subwavelength scale, were initially suggested as negative index material for the “superlens” and for transforming electromagnetic space to control propagation of waves. The research agenda is now shifting to achieving tunable, switchable, nonlinear and sensing functionalities using metamaterials. We show how engaging the changing balance of forces, structural transformation, light confinement and quantum effects at the nanoscale brings about the emerging field of metadevices that we define as devices with unique and useful functionalities achieved by structuring of functional matter on the subwavelength scale.
C:PL2 Multifunctionality of Liquid-filled Porous Ceramic Coatings: From Encryption to Anti-fouling
J. AIZENBERG, Harvard University, Cambridge, MA, USA
Liquids entrapped within a structured solid begin to exhibit unique behaviors often providing the surrounding material with unprecedented properties. Recently we have developed two award-winning materials platforms (R&D 100 awards in 2012 and 2013), both based on the infusion of a liquid into a porous substrate. First, we introduced a new strategy to create self-healing, Slippery Lubricant-Infused Porous Surfaces (SLIPS) that outperform state-of-the-art synthetic surfaces in their ability to resist ice and microbial adhesion and repel various simple and complex liquids. Second, we pioneered a technique for patterning 3D photonic crystals, generating complex wettability patterns, and illustrated multilevel encryption, with selective decoding by specific liquids, so-called Watermark Ink, or W-INK. We developed generalized, low-cost, and scalable methods to manufacture SLIPS and W-Ink using various ceramic materials, such as silica, titania or alumina. We anticipate that such slippery surfaces can find important applications in fluid handling and transportation, optical sensing, medicine, and as antifouling surfaces against highly contaminating media operating in extreme environments, while chemically patterned photonic structures can serve as colorimetric indicators for liquids, or used in encryption or anti-tampering applications.
C:PL3 From MAX to MXene - From 3D to 2D
M.W. BARSOUM, Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, USA
The layered, hexagonal carbides and nitrides with the general formula, Mn+1AXn, (MAX) where n = 1 to 3, M is an early transition metal, A is an A-group (mostly IIIA and IVA) element and X is either C and/or N – sometimes referred to as polycrystalline nanolaminates because every basal plane is a potential deformation or delamination plane - combine some of the best attributes of metals and ceramics (1). Like metals, they are electrically and thermally conductive, most readily machinable (manual hack saw will suffice) not susceptible to thermal shock, plastic at high temperatures, and exceptionally damage tolerant. Like ceramics, they are elastically rigid, lightweight, and maintain their strengths to high temperatures. The ternaries Ti3SiC2 and Ti2AlC are also creep, fatigue and oxidation resistant. Over the past decade we have also shown that the MAX phases are but a subset of solids that we termed kinking nonlinear elastic, KNE, because one of their important deformation mode is the formation of fully reversible, dislocation-based incipient kink bands. The latter is the main reason why the MAX phases combine record combinations of stiffness and damping. In this talk, special emphasis will be given to creep, crack healing and oxidation resistance.
More recently we showed that by simply soaking MAX phase powders at room temperature in HF, it is relatively easy to etch out the A-layers of select MAX phases (2). We labeled the resulting 2D materials MXenes to emphasize the loss of the A-group element and their similarities to graphene. Unlike graphene, however, that is hydrophobic, MXenes are hydrophilic. In other words, one can think of the MXenes as “conductive clays”, a hitherto impossible combination. MXenes such as Ti2C, V2C, Nb2C and Ti3C2 can be used as electrode materials in lithium-ion batteries (LIBs) and supercapacitors (SC’s) with remarkable performances that are quite impressive, especially given their very young age (≈ 2 yrs). In all the cases, when used as anodes in LIB, MXenes showed an excellent capability to handle high cycling rates. Flexible additives-free electrodes of delaminated Ti3C2 showed reversible capacities of > 400 mAhg-1 at 1C and 110 mAhg-1 at 36 C, the latter for > 700 cycles (3). Supercapacitors with volumetric capacities of > 300 F/cm3 were also demonstrated (4). The potential of using MXenes in energy storage and other applications will be highlighted.
(1) Barsoum, M. W. MAX Phases: Properties of Machinable Carbides and Nitrides; Wiley VCH GmbH & Co.: Weinheim, 2013.
(2) Naguib, M.; Kurtoglu, M.; Presser, V.; Lu, J.; Niu, J.; Heon, M.; Hultman, L.; Gogotsi, Y.; Barsoum, M. W. Advan. Mater. 2011, 23, 4248.
(3) Mashtalir, O.; Naguib, M.; Mochalin, V. N.; Dall'Agnese, Y.; Heon, M.; Barsoum, M. W.; Gogotsi, Y. Nature Comm. 2013, 4, Article Number: 1716.
(4) Lukatskaya, M.; Mashtalir, O.; Ren, C. E.; Dall'Agnese, Y.; Rozier, P.; Taberna, P. L.; Naguib, M.; Simon, P.; Barsoum, M. W.; Gogotsi, Y. Science 2013.