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    Hierarchical porous carbide-derived carbons for the removal of cytokines from blood plasma
    (Wiley-Blackwell, 2012) Presser, Volker; Yeon, Sun-Hwa; Vakıfahmetoğlu, Cekdar; Howell, Carol A.; Sandeman, Susan R.; Colombo, Paolo; Gogotsi, Yury
    Carbide-derived carbons with hierarchical porosity derived from a polymer precursor can be used for the extracorporeal removal of pro- and anti-inflammatory cytokines. The removal rates scale with the surface area of pores large enough to accommodate the protein molecules and this method has potential for efficacious treatment of sepsis, one of the major challenges in healthcare. Further information can be found in the Communication by S. Mikhalovsky, Y. Gogotsi, and co-workers on page 796.
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    Polysiloxane- derived ceramics containing nanowires with catalytically active tips
    (Wiley-Blackwell, 2014) Adam, Michael; Vakıfahmetoğlu, Cekdar; Colombo, Paolo; Wilhelm, Michaela; Grathwohl, Georg
    By direct foaming of a Pt-containing polysiloxane precursor, macroporous ceramics were generated by pyrolysis at 1400 degrees C under nitrogen or argon. The growth of nanowires was induced via a vapor-liquid-solid mechanism in which the Pt particles acted as deposition site for the decomposition gases released upon pyrolyzing the preceramic polymer. SEM, HR-SEM, TEM/EDX, and XRD investigations revealed that pyrolysis under argon atmosphere leads to short SiC nanowires of only a few micrometers length and under nitrogen atmosphere Si3N4 nanowires evolved, with length of several 10m. In both cases the tips of the nanowires mainly consisted of PtSi. In contrast to samples pyrolyzed at 600 degrees C, the components after higher temperature pyrolysis showed moderate-specific surface areas of 55-67m(2)/g. In CO oxidation experiments, a good catalytic activity was found for the Pt silicide particles, suggesting that despite their relatively large size, their location at the tips of the nanowires affords them good reactivity.
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    Porous polymer derived ceramics
    (Elsevier Science Sa, 2016) Vakıfahmetoglu, Cekdar; Zeydanli, Damla; Colombo, Paolo
    Porous ceramics, in particular cellular ceramics with open and closed porosity, are key enabling components in different demanding applications because of their favorable set of properties. The production of porous ceramics from preceramic polymers offers advantages in terms of simple processing methodology, low processing cost, and ease of control over porosity and other properties arising from the composition of the resultant ceramics. Therefore, a vast amount of research has been conducted, in the past decade, towards the fabrication and characterization of porous ceramics produced from different polymeric precursors, such as polysiloxane, polycarbosilane, polysilazane and borazine. The potential of polymer-derived-ceramics can only be fully achieved if the type of fabrication method used is tailored taking into account the specific application of interest. For brevity, this review deals specifically with the different processing strategies employed to obtain, from polymer precursors, ceramic foams, membranes, aerogels or porous ceramics for which porosity higher than 50 vol% has been deliberately introduced, including also components with high specific surface area or hierarchical porosity. The different processing strategies, such as replica, sacrificial template, direct foaming, etching, aerogel forming, fiber spinning and automated manufacturing, are explained and the published literature has been reviewed with particular concern for the critical issues that affect the pore size, the amount of porosity and strength of the ceramic components. (C) 2016 Elsevier B.V. All rights reserved.