Felületkémia és szelektivitás nagyfelületű szeneken = Chemical structure and performance of high surface area carbons

A hamumentes polimer alapu szeneken vizsgaltuk a feluletkemia es a szorpcios tulajdonsagok kozti kapcsolatot. Morfologiailag igen hasonlo, vizmentes es vizes kozegben jellemzett oxigen, nitrogen es hidrogen heteroatomot tartalmazo szeneken mind gőz-, mind higoldat adszorpcios folyamatokban igazoltuk a felulet kemiai tulajdonsagainak meghatarozo jelleget. A feluleti tulajdonsagok nem csak az egyensulyt, de a folyamatok sebesseget is befolyasoljak. Uj fuggvenyt vezettunk be a poruskitoltődes nyomonkovetesere es ennek hasznalhatosagat mind polaros, mind apolaros gőzok eseten bemutattuk. Vizsgaltuk tovabbi, elsősorban fem heteroatomok beviteli lehetősegeit polimer alapu szenmatrix kialakitasanak kulonboző stadiumaiban. Megallapitottuk, hogy lignocelluloz alapu szenek eseteben a Na es Si atomok bevitele (vizuveges modositas) gyakorlatilag nem befolyasolja a vizsgalt szorpcios tulajdonsagokat, de kedvezően hat a mechanikai tulajdonsagokra. Amennyiben a femionok hozzaadasa a prekurzor polimer szintezise soran ill. a porusos szerkezet rogzitese (szaritas) előtt tortenik, a matrix szerkezete, a fajlagos felulet es a porusszerkezet is jelentősen modosul. Utolagos kezeles eseten a porozitashoz kapcsolhato valtozasokat elsősorban a porusok eltomődese okozza. | The relationship between surface chemistry and sorption performance was studied on ash-free polymer-based carbons. In carbons that were morphologically similar and contained oxygen, nitrogen and hydrogen hetero atoms, the role of the surface chemistry was demonstrated in sorption processes from both the vapour and the liquid phase. The surface properties influence not only the adsorption equilibrium but play a role in the kinetics as well. A new function was introduced to follow the pore filling. Its applicability was shown for polar and nonpolar vapours. The possibility of introducing further, mainly metal, heteroatoms was studied at various stages of the carbon synthesis. In the case of lignocellulosic matrices we found that introducing Si and Na atoms (in the form of waterglass) results in improvement of mechanical strength rather than of the adsorption properties. When metal ions were added to the polymer precursor during the polymerization step or before the drying process, both the morphology and the porosity of the matrix can be severely influenced. Post-carbonization treatment, however, leads to obstruction of the pore entrance and thus a reduction of the accessible porosity.