Staff directory Shuoying Yang



  • How Reproducible are Surface Areas Calculated from the BET Equation?

    Osterrieth J.W.M., Rampersad J., Madden D., Rampal N., Skoric L., Connolly B., Allendorf M.D., Stavila V., Snider J.L., Ameloot R., Marreiros J., Ania C., Azevedo D., Vilarrasa-Garcia E., Santos B.F., Bu X.-H., Chang Z., Bunzen H., Champness N.R., Griffin S.L., Chen B., Lin R.-B., Coasne B., Cohen S., Moreton J.C., Colón Y.J., Chen L., Clowes R., Coudert F.-X., Cui Y., Hou B., D'Alessandro D.M., Doheny P.W., Dincă M., Sun C., Doonan C., Huxley M.T., Evans J.D., Falcaro P., Ricco R., Farha O., Idrees K.B., Islamoglu T., Feng P., Yang H., Forgan R.S., Bara D., Furukawa S., Sanchez E., Gascon J., Telalović S., Ghosh S.K., Mukherjee S., Hill M.R., Sadiq M.M., Horcajada P., Salcedo-Abraira P., Kaneko K., Kukobat R., Kenvin J., Keskin S., Kitagawa S., Otake K.-I., Lively R.P., DeWitt S.J.A., Llewellyn P., Lotsch B.V., Emmerling S.T., Pütz A.M., Martí-Gastaldo C., Padial N.M., García-Martínez J., Linares N., Maspoch D., Suárez del Pino J.A., Moghadam P., Oktavian R., Morris R.E., Wheatley P.S., Navarro J., Petit C., Danaci D., Rosseinsky M.J., Katsoulidis A.P., Schröder M., Han X., Yang S., Serre C., Mouchaham G., Sholl D.S., Thyagarajan R., Siderius D., Snurr R.Q., Goncalves R.B., Telfer S., Advanced Materials; 34 (27, 2201502) 2022. 10.1002/adma.202201502.

    Porosity and surface area analysis play a prominent role in modern materials science. At the heart of this sits the Brunauer–Emmett–Teller (BET) theory, which has been a remarkably successful contribution to the field of materials science. The BET method was developed in the 1930s for open surfaces but is now the most widely used metric for the estimation of surface areas of micro- and mesoporous materials. Despite its widespread use, the calculation of BET surface areas causes a spread in reported areas, resulting in reproducibility problems in both academia and industry. To prove this, for this analysis, 18 already-measured raw adsorption isotherms were provided to sixty-one labs, who were asked to calculate the corresponding BET areas. This round-robin exercise resulted in a wide range of values. Here, the reproducibility of BET area determination from identical isotherms is demonstrated to be a largely ignored issue, raising critical concerns over the reliability of reported BET areas. To solve this major issue, a new computational approach to accurately and systematically determine the BET area of nanoporous materials is developed. The software, called “BET surface identification” (BETSI), expands on the well-known Rouquerol criteria and makes an unambiguous BET area assignment possible. © 2022 The Authors. Advanced Materials published by Wiley-VCH GmbH.


  • Directional elastic wave propagation in high-aspect-ratio photoresist gratings: Liquid infiltration and aging

    Alonso-Redondo E., Gueddida A., Li J., Graczykowski B., Sotomayor Torres C.M., Pennec Y., Yang S., Djafari-Rouhani B., Fytas G. Nanoscale; 9 (8): 2739 - 2747. 2017. 10.1039/c6nr08312a. IF: 7.367

    Determination of the mechanical properties of nanostructured soft materials and their composites in a quantitative manner is of great importance to improve the fidelity in their fabrication and to enable the subsequent reliable utility. Here, we report on the characterization of the elastic and photoelastic parameters of a periodic array of nanowalls (grating) by the non-invasive Brillouin light scattering technique and finite element calculations. The resolved elastic vibrational modes in high and low aspect ratio nanowalls reveal quantitative and qualitative differences related to the two-beam interference lithography fabrication and subsequent aging under ambient conditions. The phononic properties, namely the dispersion relations, can be drastically altered by changing the surrounding material of the nanowalls. Here we demonstrate that liquid infiltration turns the phononic function from a single-direction phonon-guiding to an anisotropic propagation along the two orthogonal directions. The susceptibility of the phononic behavior to the infiltrating liquid can be of unusual benefits, such as sensing and alteration of the materials under confinement. © The Royal Society of Chemistry 2017.