This cover was co-designed with Prof. Hong Yang at UIUC for a special issue on Nanoparticles for Catalysis in Accounts of Chemical Research (2013, vol. 46). The special issue is co-edited by Prof. Younan Xia, Prof. Hong Yang and Prof. Charles T. Campbell (University of Washington, Seattle). The last decade has witnessed an explosion in the development of new methods capable of generating metal nanoparticles with controlled compositions, sizes, shapes, and structures in an effort to control the ways in which these nanoparticles can be connected to and even surrounded by support materials like oxides. These nanostructured materials form the basis for many catalysts and electrocatalysts of great importance to future technologies including energy harvesting/conversion/storage, chemical transformation, and environmental protection.
This cover was designed by Dr. Xiaohu Xia for a feature article published in the Journal of Physical Chemistry C (2013, 116, pp. 21647-21656). It shows the formation of silver nanoscale cubes, octahedrons, concave cubes (octapods), and concave octahedrons by controlling the experimental conditions used for the growth of single-crystal cuboctahedral seeds (shown in the center). Such a capability allows one to engineer the plasmonic and catalytic properties of silver nanocrystals.
This backside cover was designed by Dr. Jie Zeng for a communication published in Angewandte Chemie International Edition (2012, 51, pp.2354-2358) on the synthesis of nanocrystals with reduced symmetry by controlling the reaction kinetics. When the injection and thus deposition rate of precursor was very slow, the atoms could only nucleate on one of the six side faces of a cubic seed. As the injection rate was increased, the nucleation and growth could start to occur on three adjacent and then all six side faces.
This inside cover was designed by Professor Hui Zhang (a former visiting scholar in the Xia group from Zhejiang University) for a review article published in Angewandte Chemie International Edition (2012, 51, pp.7656-7673 ) on the design, synthesis, properties, and unique applications of noble-metal nanocrystals with concave surfaces. Due to the presence of high-index facets on the surface, concave nanocrystals are interesting and important as a novel class of catalysts with substantially improved activity.
This cover was designed by Dr. Jie Zeng for an article published in ChemCatChem (2012, 4, pp. 1668-1674). It shows the formation of Pd-Au bimetallic nanocrystals with different shapes and structures, including Pd-Au dimeric structures, Pd-Au core-shell nanocubes, and Pd-Au concave nanocubes. The key is to control the reaction kinetics for the Au precursor, which was introduced into an suspension of seeds made of Pd nanocubes. Such bimetallic nanocrystals with well-defined facets are useful in catalysis.
This cover was designed by Shuifen Xie (a visiting Ph.D. student in the Xia from Xiamen University) for an article published in Chemistry: A European Journal (2012, 18, pp.14974-14980). It shows transmission electron micrographs of Au-Cu nanocages of 50 nm in diameter with Pd cubic cores in the center. This novel nanostructures were synthesized via galvanic replacement reaction between Pd@Cu nanocubes with an aqueous HAuCl4 solution. While the Cu was oxidized, the released electrons were used to reduce Au precursor in Au atoms to be deposited around the template.
This cover was designed by Yu Zhang (Ph.D., 2013) for an article published in Macromolecular Rapid Communications (2012, 33, pp. 296-301). It shows scanning electron microscopy (SEM) images (left panels) of inverse opal scaffolds after their pores had been modified with chitosan microstructures. As a result, cells cultured in the pores of the scaffolds would experience a truly three-dimensional environment. In comparison, cells cultured in scaffolds without the modification would experience a two-dimensional environment, as indicated by the fluorescence micrographs on the right side.
This inside cover was designed by Dr. Xiaohu Xia for a communication published in Angewandte Chemie International Edition (2011, 50, pp.12542-12546) on the synthesis of Ag nanocrystals with concave surfaces. By maneuvering the experimental conditions, the growth of Ag nanocrystal seeds could be selectively accelerated or decelerated along specific directions to generate products with concave faces. Such concave nanocrystals were also shown with greatly improved performance for SERS applications.
This inside cover was designed by Professor Unyong Jeong of Yonsei University for a joint communication published in Angewandte Chemie International Edition (2011, 50, pp.724-727) on the fabrication of elastomeric patches with small capsules (or pockets) to hold drugs. When the elastomeric patches were compressed or stretched, the drug molecules will be forced to escape from the capsules. The release profile could be engineered by controlling the forces applied and the duration of compression or stretching.
This cover was designed by Jianhua Zhou (a former visiting student in the Xia group) and Dr. Jie Zeng for an article published in Small (2011, 7, pp. 3308-3316). It shows the concept of using an array of microwells for screening the experimental conditions involved in the synthesis of metal nanostructures. As shown on the cover, nanostructures in the shape/morphology of triangular pods, cubes, and wires could be formed in different microwells depending on the experimental conditions, e.g., pH value and surfactant concentration.
This cover was designed by Dr. Jingwei Xie for an article published in Small (2011, 7, pp. 293-297). It shows a fluorescence micrograph of neurites derived from DRG on electrospun nanofibers with a hexagonal, fan-out alignment that were fabricated by collecting the nanofibers with a hexagonal array of beads made of stainless steel. Due to the electrostatic stretching force, across two adjacent beads, the nanofibers took an uniaxial alignment across two adjacent beads while the region above the bead became a well.
This cover was designed by Dr. Jingwei Xie for an article published in ACS Nano (2010, 4, pp. 5027-5036). It shows the inward migration of dural fibroblasts on a two-dimensional scaffold of electrospun nanofibers with a radial alignment. The scaffolds based on radially aligned, biodegradable nanofibers show great potential as artificial dural substitutes and may be particularly useful as biomedical patches or grafts to induce wound closure and/or tissue regeneration.