Longjian Xue

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Effect of aging on the morphology of bitumen was investigated. Two bitumens were aged according to the thin film oven test (TFOT), pressure aging vessel (PAV) test and ultraviolet (UV) radiation, respectively. The morphology of the binders before and after aging was characterized by atomic force microscopy. The physical properties and chemical compositions(More)
We promoted order-disorder transformation of poly(3-hexylthiophene) (P3HT) in solution by ultrasonic oscillation which substantially improved crystallinity in its pure film. P3HT with low molecular weight (M(w)) dispersed very well in p-xylene solvent and few aggregates generated in the solution. For P3HT with high M(w), the results suggested the(More)
Many insect species reversibly adhere to surfaces by combining contact splitting (contact formation via fibrillar contact elements) and wet adhesion (supply of liquid secretion via pores in the insects' feet). Here, we fabricate insect-inspired fibrillar pads for wet adhesion containing continuous pore systems through which liquid is supplied to the contact(More)
Two-dimensionally ordered honeycomb structures have been prepared on dodecanethiol-capped gold nanoparticle films by blowing moist air across the surface of the nanoparticle solution. The pore morphology can be altered from circle to ellipse with tunable aspect ratios by carefully controlling the direction and velocity of airflow. The formation mechanisms(More)
The tip shape of contact elements in hairy adhesion systems is crucial for proper contact formation and adhesion enhancement. While submicrometer terminal contact elements show much better adhesion performance than their larger counterparts, shaping their tips so as to maximize normal adhesion has remained challenging. We prepared durable nanorod arrays(More)
We report reversible adhesion switching on porous fibrillar polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) adhesive pads by humidity changes. Adhesion at a relative humidity of 90% was more than nine times higher than at a relative humidity of 2%. On nonporous fibrillar adhesive pads of the same material, adhesion increased only by a factor of ~3.3.(More)
This study is an attempt to deeply understand the mechanisms ensuring self-tolerance of T cells via clonal deletion of thymocytes and exploring T lymophocyte homeostasis by observing the apoptosis of single mouse thymocyte induced by S-nitrosoglutathione (GSNO, a nitric oxide donor) using fluorescence near-field scanning optical microscopy (NSOM) in(More)
The wettability of thin poly(methyl methacrylate) (PMMA) films on a silicon wafer with a native oxide layer exposed to solvent vapors is dependent on the solvent properties. In the nonsolvent vapor, the film spread on the substrate with some protrusions generated on the film surface. In the good solvent vapor, dewetting happened. A new interface formed(More)
Surface-tethered oppositely charged weak polyelectrolyte block copolymer brushes composed of poly(2-vinyl pyridine) (P2VP) and poly(acrylic acid) (PAA) were grown from the Si wafer by atom-transfer radical polymerization. The P2VP-b-PAA brushes were prepared through hydrolysis of the second PtBA block to the corresponding acrylic acid. The P2VP-b-PAA(More)
A rather simple yet effective way to fabricate gradient surfaces by changing polystyrene (PS) microsphere topography in a temperature gradient field is proposed. The wettability of the film has an obvious gradient change from 88.7 to 148.1 degrees . The changes of the PS microsphere topography are believed to be responsible for the changing of the(More)