22 KB229 KB21 KB199820252001Bešter-Rogač, MarijaJamnik, AndrejStare, JernejUrbič, Tomaž10 straništevilka:3letnik:48str. 343-352ISSN:1318-0207COBISSID:23770885URN:URN:NBN:SI:doc-RC3WLVE6enSlovensko kemijsko društvoActa chimica slovenicamakroionimodelipolielektrolitipoliioniprotiioniraztopinerentgenske metodeteorijatheorySmall-angle x-ray scattering functions of rodlike polyelectrolytes in aqueous solutions| theoretical study|A theoretical study of small angle X-ray scattering on model rodlike polyelectrolytes containing a mixture of univalent ?$(LI^+)$? and divalent (Sr^{2+}) counterions is presented. Scattering functions, based on the electron density contrast relative to solvent, were computed. The distribution of the excess electron density around the polyion was determined by numerical solving of the Poisson-Boltzmann (PB) equation within the cell model. For the systems countaining only one kind of conterions analytical solutions of the PB equation were also used. Such a model can be applied to rigid polymeric entities with rodlike shape, the entities being cither individual polymers of small constituents of otherwise flexible polymers. We studied the influence of both the polyion and its ionic atmosphere on the scattering function is significant while the contribution of the ionic atmosphere increases with increasing the fraction of stronium ions with a higher contrast in electron density against the solventV članku predstavljamo teoretsko obravnavo ozkokotnega rentgenskega sipanja na modelnih paličastih elektrolitih, obdanih z mešanico enovalnetnih ?$(Li^+)$? in dvovalentnih $?(Sr^{2+})$? protiionov. Izračunali smo sipalne funkcije, osnovane na kontrastu v elektronski gostoti med topljenim topilom. Porazdelitev presežne elektronske gostote okrog poliiona smo dobili z numeričnim reševanjem Poisson-Boltzmannove (PB) enačbe za uporabo celičnega modela. Če v ionski atmosferi le ena vrsta protiionov, je PB enačba tudi analitično rešljiva. Z opisanim modelom lahko obravnavamo iztegnjene, paličaste polimerne enote, ki so bodisi samostojni poliioni ali pa del fleksibilnega poliiona. Proučevali smo vpliv poliiona in ionske atmosfere na sipalno funkcijo. Prispevek poliiona je znaten, prispevek ionske atmosfere pa narašča z vsebnostjo visokokontrastnih stroncijevih ionovTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaSlovensko kemijsko društvo