Nanopore walls

Adsorption using different probe molecules is available for determination of the pore entrance structure. N2 molecules adsorbed near the pore entrance at 77 K often block further adsorption, indicating the presence of ultramicropores and pore-neck structures. The preadsorption technique is also effective for elucidation of the pore entrance structure. Fractal analysis using adsorption is helpful to understand the fine structure of nanopore walls. [10,11] However, the probe molecules must be carefully chosen and the monolayer capacity must be evaluated precisely, because the BET monolayer should not be used. 

The synthesis of the CMK-n carbons is controlled to various pore shapes, connectivity, diameters (typically, 1-10 nm in diameter) and pore wall thickness. These carbons exhibit high specific surface areas (typically, the BET specific surface areas up to 2000 mV )> uniform pore diameters, large adsorption capacities, and high thermal, acid-base and mechanical stabilities. The CMK-type carbons are also suitable for the formation of well-defined nanocomposite with organic polymers, so that the nanopore walls can be modified with various functional groups. These carbons show new possibilities for various applications in adsorption, catalysis and electrochemistry. 

The peaks of the profiles in Fig. 6 indicate that below 500 K, the tubular structure of the confined ionic liquid is weakly affected by temperature. However, as the temperature increases, the shell ions near the nanopore wall become less ordered. These changes suggest that the ions are mobile at these temperatures and that the ordered packing may suffer significant damage at higher temperatures. 

FIGURE 9.14 SEM micrographs of (a) PES and (b) PEI foams showing the sub-microcellular structures with nanoporous walls produced at 240°C. (Reported from Sorrentino, L M. Aurilia, and S. lannace, 2011, Advances in Polymer Technology 30,3, September 8,234-243, doi 10.1002/adv.20219, http //onlinelibrary.wiley.eom/doi/10.1002/adv.20219/full.)... 

I. Vlassiouk and S. Z. Siwy, Nanofluidic diode. Nano Letters, 2007, 552 556. Y. He, M. Tsutsui and C. Fan, Controlling DNA Translocation through Gate Modulation of Nanopore Wall Surface Charges, ACS Nano, 2011, 5509 5518. 

He, Y. H. Tsutsui, M. Fan, C. Taniguchi, M. Kawai, T. Controlling DNA translocation through gate modulation of nanopore wall surface charges. ACS Nano 2011, 5, 5509-5518. 

Interestingly, Ti02 hollow fibers with controllable multichannel and nanoporous wall structures have been fabricated, which results in an effective increasement of photocatalytic activity toward the degradation of gaseous acetaldehyde because this novel structure exhibited a cooperative effect of trapping more gaseous acetaldehyde molecules and reflection of light inside the channels [27]. 

Fig. 1.23 Cartoon representing the NH3 adducts formed within an aU-sdica zeolite nanopore, a NH3 H— bonded at polar sites (Si—OH nests), b NH3 interacting with the nanopore walls through dispersion forces. Courtesy of Prof. Piero Ughengo, University of Torino...

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