Showing papers by "Bing Xu published in 1999"

Making Negative Poisson's Ratio Microstructures by Soft Lithography**

Abstract: 1186 O WILEY-VCH Verlag GmbH, D-69469 Weinheim, 1999 0935-9648/99/1410-1186 $ 17.50+.50/0 Adv. Mater. 1999, 11, No. 14 quenching to room temperature. As a result, the polarization bandwidth was found to increase by a factor of 2.4 over what was expected of a constant-pitch film. The increased bandwidth was attributed to a pitch gradient resulting from photoinduced racemization of the chiral dopant at the irradiated surface with simultaneous diffusion through the film. This is the first demonstration of a pitch gradient generated in the mesomorphic fluid state and then frozen in a glassy chiral-nematic film.

Fabrication of Ordered Two‐Dimensional Arrays of Micro‐ and Nanoparticles Using Patterned Self‐Assembled Monolayers as Templates

Abstract: lar substrate is tricky, since the spin-coating solution does not wet the substrate and flies off the rotating surface. Since the OTS pattern after the lift-off technique is the inverse of the originally stamped ODT pattern, the sample in Figure 1d features macroscopically an oxide surface with printed OTS stripes on a micrometer lateral scale. Beyond the specific advantages of our technique, structured SAMs from OTS enjoy several advantages over their ODT analogs. The surface energy difference between OTS and silicon oxide is much larger than between ODT and Au, making patterned OTS substrates more suitable for structured wetting and demixing experiments. Potential applications for chemical and biological sensors also benefit from this increase in polarity. Furthermore, the silane bond is stronger than the chemisorbed thiols allowing experiments at higher temperatures. In conclusion, we have combined the well-established mCP technique of alkane-thiols on Au with a lift-off technique to transfer the stamped pattern onto a silicon-oxide surface. The main benefit of this approach compared to a direct printing technique is the improved control over environmental parameters during the deposition of the alkane-silanes, making the lift-off technique more reliable and reproducible. In addition, the lift-off technique does not depend on specific substrate materials. Therefore, extension to a wide range of surfaces and functionalized alkane chains is possible.

Using Surface Plasmon Resonance to Study the Binding of Vancomycin and Its Dimer to Self-Assembled Monolayers Presenting d-Ala-d-Ala

Abstract: Journal of the American Chemical Society is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Communication Using Surface Plasmon Resonance to Study the Binding of Vancomycin and Its Dimer to Self-Assembled Monolayers Presenting d-Ala-d-Ala Jianghong Rao, Lin Yan, Bing Xu, and George M. Whitesides J. Am. Chem. Soc., 1999, 121 (11), 2629-2630• DOI: 10.1021/ja9838763 • Publication Date (Web): 06 March 1999 Downloaded from http://pubs.acs.org on February 23, 2009

Making Honeycomb Microcomposites by Soft Lithography

Abstract: 492 Ó WILEY-VCH Verlag GmbH, D-69469 Weinheim, 1999 0935-9648/99/0604-0492 $ 17.50+.50/0 Adv. Mater. 1999, 11, No. 6 [4] P. T. Tanev, M. Chibwe, T. J. Pinnavaia, Nature 1994, 368, 321. [5] P. Behrens, Angew. Chem., Int. Ed. Engl. 1996, 35, 515; Angew. Chem. 1996, 108, 561 [6] a) D. M. Antonelli, J. Y. Ying, Curr. Opin. Colloid Interface Sci. 1996, 1, 523. b) D. M. Antonelli, J. Y. Ying, Angew. Chem., Int. Ed. Engl. 1995, 34, 2014; Angew. Chem. 1995, 107, 2202. [7] U. Ciesla, S. Schacht, G. D. Stucky, K. Unger, F. J. Schüth, Angew. Chem., Int. Ed. Engl. 1996, 35, 541; Angew. Chem. 1996, 108, 597. [8] P. Liu, J. Liu, A. Sayari, Chem. Commun. 1997, 577. [9] a) D. M. Antonelli, J. Y. Ying, Angew. Chem., Int. Ed. Engl. 1996, 35, 426; Angew. Chem. 1996, 108, 461. c) D. M. Antonelli, A. Nakahira, J. Y. Ying, Inorg. Chem. 1996, 35, 3126. [10] D. M. Antonelli, J. Y. Ying, Chem. Mater. 1996, 8, 874. [11] J. S. Reddy, A. Sayari, Catal. Lett. 1996, 38, 219. [12] M. S. Wong, D. M. Antonelli, J. Y. Ying, Nanostruct. Mater. 1997, 9, 165. [13] Z. R. Tian, J. Y. Wang, N. G. Duan, V. V. Krishnan, S. L. Suib, Science 1997, 276, 926. [14] T. Sun, J. Y. Ying, Nature, 1997, 389, 704. [15] G. A. Somorjai, An Introduction to Surface Chemistry and Catalysis, Wiley, New York 1994. [16] C.-G. Wu, T. Bein, Chem. Mater. 1994, 6, 1109.