Structurally Tunable Self-Assembled 2D Cocrystals of C60 and Porphyrins on the Ag (110) Surface

Due to the donor\u2013acceptor nature of their supramolecular interactions, nanostructured porphyrin-fullerene self-assembled architectures show attractive properties that can be exploited in high efficiency solar cells. In this work, we show that six different ordered bicomponent porphyrin-fullerene (C60) networks are obtained by controlling the peripheral functionalization of meso-tetraphenylporphyrins (TPP) with amino groups and the stoichiometry of their aggregates with C60 on Ag (110). Such networks can be grouped in two general classes, depending on their structural habit: the so-called \u201cstripes\u201d phases, formed by alternating monomolecular stripes of C60 and TPP, and the so-called \u201cpores\u201d phases, where a fullerene net accommodates isolated TPP molecules in nanometer-sized pores. These phases are of general interest in the field of surface-supported electron donor\u2013acceptor systems, since they represents a rare example of fullerene-containing surface-supported bicomponent supramolecular networks where the binary nanostructures are definitely more stable thermodynamically than the two separated single-component phases, thereby resembling three-dimensional TPP/C60 cocrystals. The thermodynamic stability in an extended temperature range has profound consequences on the degree of long-range order attainable in the self-assembly process

Theoretical insight of physical adsorption for a single component adsorbent + adsorbate system: II. The Henry region

10.1021/la900217tLangmuir25137359-7367LANG

Carbon Dioxide Adsorption-Induced Deformation of Microporous Carbons

Applying the thermodynamic model of adsorption-induced deformation of microporous carbons developed recently (Kowalczyk, P.; Ciach, A.; Neimark, A. Langmuir 2008, 24, 6603), we study the deformation of carbonaceous amorphous porous materials due to adsorption of carbon dioxide at 333 K and pressures up to 27 MPa. The internal adsorption stress induced by adsorbed/compressed carbon dioxide is very high in the smallest ultramicropores (for instance, solvation pressure in 0.23 nm ultramicropore reaches 3.2 GPa at 27 MPa). Model calculations show that any sample of carbonaceous porous solid containing a fraction of the smallest ultramicropores with pore size below 0.31 nm will expand at studied operating conditions. This is because the high internal adsorption stress in ultramicropores dominates sample deformation upon adsorption of carbon dioxide at studied operation conditions. Interestingly, the nonmonotonic deformation (i.e., initial contraction and further expansion) of the above mentioned porous materials upon adsorption of carbon dioxide at 333 K is also theoretically predicted. Our calculations reproduce quantitatively the strain isotherm of carbon dioxide on carbide-derived activated carbon at 333 K and experimental pressures up to 2.9 MPa. Moreover, we extrapolate adsorption and strain isotherms measured by the gravimetric/dilatometric method up to 27 MPa to mimic geosequestration operating conditions. And so, we predict that expansion of the studied carbon sample reaches 0.75% at 27 MPa and 333 K. Presented simulation results can be useful for the interpretation of the coal deformation upon sequestration of carbon dioxide at high pressures and temperatures