Recently, micro-or nanoscaled hollow spheres of conducting polymers have attracted great attention because of their potential use in encapsulation applications, confined reaction vessels, controlled release and delivery, separation systems, and biosensors.[1] Usually, hollow spheres are prepared from spherical-particle templates, such as silica colloids, [1a,2] polystyrene beads, [1d,3] inorganic particles, [1b,1c,4] followed by the removal of the sacrificial core through calcination and solvent etching. Clearly, in this template method, the complex procedures involved in preparing and removing the templates lead to poor reproducibility and make it rather difficult to retain the ordered structure after template removal. Recently, our group reported that hollow microspheres of polyaniline (PANI) could be prepared by a self-assembled method using a dopant of either salicylic acid (SA) [5a] or b-naphthalene sulfonic acid (b-NSA) at -10°C.[5b] Moreover, hollow polypyrrole (PPy) capsules in the presence of chitosan have also been reported by using a facile one-step pathway.[6] Although various methods have been reported to prepare hollow spheres of conducting polymers, control of the morphology and properties of the prepared conducting polymers using a simple and effective method still remains scientifically challenging. In practical applications, moreover, the main problems are shown as follows: the conductivity of conducting polymers is easily influenced by humidity and dust from their surroundings, and the encapsulated materials are easily dissolved or contaminated by the immerged water. Superhydrophobic surfaces, characterized by a water contact angle (CA) higher than 150°, are arousing much interest because of their high water repellency and practical applications such as in the prevention of adhesion of snow to antennas and windows, self-cleaning traffic indicators, metal refining, stain-resistant textiles. [7,8] Therefore, the combination of micro-and nanostructured conducting polymers with a superhydrophobic function has became an interesting object in materials science. Super water-repellent poly(alkylpyrrole) films, super water-and oil-repellent polythiophene films, reversible switching of polypyrrole films from superhydrophobic to superhydrophilic, and superhydrophobic PANI films have all been recently reported. [9,10] To the best of our knowledge, however, previous results mainly focus on films of superhydrophobicity. Herein, we report on conductive and superhydrophobic rambutan-like hollow spheres of PANI prepared by a self-assembly method in the presence of perfluorooctane sulfonic acid (PFOSA), which served as dopant, soft template, and induced superhydrophobicity at the same time. The resulting hollow PANI spheres were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, and X-ray photoelectron spectroscopy (XPS). Water contact angle and conductivity measurements were also conducted. In ...

Polydopamine (PDAM), a mussel adhesive protein inspired coating that can be easily deposited onto a wide range of metallic, inorganic, and organic materials, gains interest also in the field of biomaterials. In this work, PDAM is applied as coating on 316L stainless steel (SS) stents and the response of cells of the blood vessel wall, human umbilical vein endothelial cell (HUVEC), and human umbilical artery smooth muscle cell (HUASMC) as predictors for re‐endothelialization is tested. It is found that the PDAM‐modified surface significantly enhances HUVEC adhesion, proliferation, and migration, release of nitric oxide (NO), and secretion of prostaglandin I2 (PGI2). Additionally, the PDAM‐modified surface shows a remarkable ability to decrease the adhesion and proliferation of HUASMCs. As a blood‐contacting material, the PDAM tends to improve the hemocompatibility compared with the substrate 316L SS. It is noteworthy that the PDAM coating shows good resistance to the deformation behavior of compression and expansion of a stent. These data suggest the potential of PDAM as a blood‐contacting material for the application in vascular stents or grafts.

Super-hydrophilicity and super-hydrophobicity are fundamentally opposite properties of special wettability, which are governed by surface chemical composition and surface roughness. Smart responsive surfaces switching reversibly between super-hydrophobicity and super-hydrophilicity can be effectively fabricated by modification of stimuli-responsive materials on rough surfaces. The externally applied stimuli include light irradiation, electrical potential, temperature, pH or selected solvents, and mechanical forces. Such surfaces with controllable wettability are of great importance to both fundamental research and practical applications.Ying Zhu received her M.S. degree and Ph.D. degree in chemistry from the Beijing University of Chemical Technology, with Jingchang Zhang. She is currently a postdoctoral fellow in the group of Lei Jiang at the Insitute of Chemistry, Chinese Academy of Sciences.