Ultrahigh stability (>1400 °C) is found for the highly ordered mesoporous polymers and carbon frameworks synthesized from polymerization of phenol and formaldehyde around triblock copolymer templates. Calcination and carbonization lead to removal of the templates and formation of hexagonal and cubic carbon mesostructures with large uniform pores and surface areas (see schematic diagram).

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Außergewöhnlich stabil (>1400 °C) sind die hochgeordneten mesoporösen Polymere und Kohlenstoffgerüste, die über die Polymerisation von Phenol und Formaldehyd um Triblockcopolymer‐Template erhalten wurden. Durch Calcinierung und Verkohlung wurden die Template entfernt, und es entstanden hexagonale und kubische Kohlenstoffmesostrukturen mit großen einheitlichen Poren und Oberflächenbereichen (siehe schematische Darstellung).

sulated between any two points on the exposed area of two adjacent grids. Therefore, the transferred PPy lines are electrically separated and so might find application in plastic electronics. [19] In summary, we have demonstrated for the first time to our knowledge that electropolymerization on semiconductor substrates patterned with self-assembled films results in patternamplified conducting polymer microstructures. It is a facile and versatile way to directly form positively patterned threedimensional conducting polymer structures, which we believe will find applications in related high-technology fields, such as nano-/microscale electromechanical systems and biosensors. ExperimentalPatterning was realized making use of the well-established lCP method, using a PDMS stamp to transfer OTS onto freshly cleaned substrate [8]. The substrates used include three types of silicon wafers (n-type (111), 0.015 X cm; n-type (100), 4 X cm; p-type (111), 15 X cm); and ITO (4±7 X cm). Electrodeposition was preformed on a Chi660a (Shanghai Chenhua Apparatus Co. Ltd) electrochemical workstation. A three-electrode system was used, with the patterned substrate as the working electrode, Pt wire as the counter electrode, and Ag/Ag + (10 mM AgNO 3 in acetonitrile) as the reference electrode. The plating solution of acetonitrile contains 0.2 M pyrrole and 0.1 M 1-hexyl-3-methylimidazolium tetrafluoroborate (a gift from Dr. Wang and Dr. Ye of our laboratory) as the supporting electrolyte. To transfer the PPy microstructure, the PPy pattern on the substrate was coated with Sylgard 184 (Dow Corning) and cured at 100 C for 2 h. Then the silicone elastomer was peeled off from the substrate.Resistance measurements were performed making use of a two-probe method. The adhesion strength of the PPy to the silicone elastomer was determined by a peel-off test using a domestic adhesive tape. AFM measurements were taken using an SPM-9500 apparatus (Shimazu). Optical microscopic images were collected on a charge-coupled device (CCD) camera (USA) equipped to a microhardness tester (USA). A variety of synthetic pathways has been proposed for the development of nanostructures because of their numerous potential applications. Received[1] The use of soft templates [2±4] (chelating agents, surfactants, DNA, etc.) and hard templates [5±11] (anionic alumina, carbon nanotubes, and mesoporous materials) has sparked wonderful contributions. Though various metal and semiconductor nanostructures have successfully been exploited, [2±4] uniform mesostructured crystallized metal oxide patterns are rarely reported, [10n,o,12] probably a result of the difficulty of choosing the proper synthesis precursor and the auxiliary reagents. In this respect, a general synthetic strategy for mesostructured metal oxides guided by ªhost± guest chemistryº is much desired. For the preparation of ordered nanostructure arrays, a hard template has some advantages when compared with a soft template, especially in its specific topological stability, veracity, predictability, and...

On the basis of the consideration of "host-guest" chemistry, the interactions between guest molecules are highlighted in the synthesis of nonsiliceous mesoporous materials by the "soft-template" and "hard-template" approaches. A generalized "acid-base pair" concept is utilized in selecting appropriate guest molecules to prepare highly ordered mesoporous metal oxides, phosphates, and borates with diversified structures. Mesoscopically ordered polymer and carbon frameworks with uniformly large pore sizes are derived from the self-assembly of an organic surfactant with an organic guest. Properly building the guest unit and decorating the host are important in replicating ordered nonsiliceous single-crystal nanoarrays. Outlooks on the potential possibilities for synthesizing ordered mesoporous nonsiliceous materials are presented as well.

Mesostructured silica SBA-15 materials with different structural parameters, such as pore size, pore volume, and wall thickness, etc., were prepared by varying the postsynthesis hydrothermal treatment temperature and adding inorganic salts. The hydrothermal stabilities of these materials in steam (100% water vapor) were systematically investigated using a variety of techniques including powder X-ray diffraction, transmission electron microscopy, nitrogen sorption, and (29)Si solid-state NMR. The effect of the pore size, microporosity or mesoporosity, and wall thickness on the stability was discussed. The results show that all of the SBA-15 materials have a good hydrothermal stability under steam of 600 degrees C for at least 24 h. N(2) sorption measurements show that the Brumauer-Emmett-Teller surface area of SBA-15 materials is decreased by about 62% after treatment under steam at 600 degrees C for 24 h. The materials with thicker walls and more micropores show relatively better hydrothermal stability in steam of 600 degrees C. Interestingly, we found that the microporosity of the mesostructured silica SBA-15 is a very important factor for the hydrothermal stability. To the materials with more micropores, the recombination of Si-O-Si bonds during the high-temperature steam treatment may not cause direct destruction to the wall structure. As a result, SBA-15 materials with more micropores show better stability in pure steam of 600 degrees C. Nevertheless, these materials are easily destroyed in steam of 800 degrees C for 6 h. Two methods to effectively improve the hydrothermal stability are introduced here: one is a high-temperature treatment, and another is a carbon-propping thermal treatment. Thermal treatment at 900 degrees C can enhance the polymerization degree of Si-O-Si bonds and effectively improve the hydrothermal stability of these SBA-15 materials in 800 degrees C steam for 12 h. But, this approach will cause very serious shrinkage of the mesopores, resulting in smaller pore diameter and low surface area. A carbon-propping thermal treating method was employed to enhance the polymerization of Si-O-Si bonds and minimize the serious shrinkage of mesopores at the same time. It was demonstrated to be an effective method that can greatly improve the hydrothermal stability of SBA-15 materials in 800 degrees C steam for 12 h. Furthermore, the SBA-15 materials obtained by using the carbon-propping method possess larger pores and higher surface area after the steam treatment at 800 degrees C compared to the materials from the direct thermal treatment method after the steam treatment.

In this paper, we bring forward an effective strategy, solvothermal postsynthesis, to prepare ordered mesoporous silica materials with highly branched channels. Structural characterizations indicate that the titled mesoporous materials basically have the cubic double gyroidal (space group Ia-3d) structure with small fraction of distortions. The mesopore sizes and surface areas can be up to 8.8 nm and 540 m2/g, respectively, when microwave digestion is employed to remove the organic templates. A phase transition model is proposed, and possible explanations for the successful phase transition are elucidated. The results show that the flexible inorganic framework, high content of organic matrix, and nonpenetration of poly(ethylene oxide) segments may facilitate the structural evolution. This new synthetic strategy can also be extended to the preparation of other double gyroidal silica-based mesoporous materials, such as metal and nonmetal ions doped silica and organo-functionalized silica materials. The prepared 3D mesoporous silica can be further utilized to fabricate various ordered crystalline gyroidal metal oxide "negatives". The mesorelief "negatives" (Co3O4 and In2O3 are detailed here) prepared by impregnation and thermolysis procedures exhibit undisplaced, displaced, and uncoupled enantiomeric gyroidal subframeworks. It has been found that the amount of metal oxide precursors (hydrated metal nitrates) greatly influence the (sub)framework structure and single crystallinity of the mesorelief metal oxide particles. The single crystalline gyroidal metal oxides are ordered both at mesoscale and atomic scale. However, these orders are not commensurate with each other.

Highly ordered mesoporous silicon carbide ceramics have been successfully synthesized with yields higher than 75 % via a one‐step nanocasting process using commercial polycarbosilane (PCS) as a precursor and mesoporous silica as hard templates. Mesoporous SiC nanowires in two‐dimensional (2D) hexagonal arrays (p6m) can be easily replicated from a mesoporous silica SBA‐15 template. Small‐angle X‐ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images show that the SiC nanowires have long‐range regularity over large areas because of the interwire pillar connections. A three‐dimensional (3D) bicontinuous cubic mesoporous SiC structure (Ia3d) can be fabricated using mesoporous silica KIT‐6 as the mother template. The structure shows higher thermal stability than the 2D hexagonal mesoporous SiC, mostly because of the 3D network connections. The major constituent of the products is SiC, with 12 % excess carbon and 14 % oxygen measured by elemental analysis. The obtained mesoporous SiC ceramics are amorphous below 1200 °C and are mainly composed of randomly oriented β‐SiC crystallites after treatment at 1400 °C. N2‐sorption isotherms reveal that these ordered mesoporous SiC ceramics have high Brunauer–Emmett–Teller (BET) specific surface areas (up to 720 m2 g–1), large pore volumes (∼ 0.8 cm3 g–1), and narrow pore‐size distributions (mean values of 2.0–3.7 nm), even upon calcination at temperatures as high as 1400 °C. The rough surface and high order of the nanowire arrays result from the strong interconnections of the SiC products and are the main reasons for such high surface areas. XRD, N2‐sorption, and TEM measurements show that the mesoporous SiC ceramics have ultrahigh stability even after re‐treatment at 1400 °C under a N2 atmosphere. Compared with 2D hexagonal SiC nanowire arrays, 3D cubic mesoporous SiC shows superior thermal stability, as well as higher surface areas (590 m2 g–1) and larger pore volumes (∼ 0.71 cm3 g–1).