Structure and sorption properties of hypercrosslinked polystyrenes and magnetic nanocomposite materials based on them

Abstract

By using transition electron microscopy, X-ray diffraction and small-angle X-ray scattering technique porous structure of a series of polystyrene-type sorbents (microporous and biporous hypercrosslinked polystyrenes, mesoporous sorbent XAD-4) was investigated, as well as sizes of iron oxide nanoparticles introduced into their matrix. Nanocomposite sorbents have low density, a large inner surface area, and like the parent polymers, exhibit marked adsorption properties, e.g. take up from saturated vapors 1.4 g/g of iodine or 0.8 g/g chloropicrin. A general method for processing scattering data from polydisperse multicomponent systems, like the above nanocomposites, was suggested. A rather homogeneous distribution of scattering heterogeneities with radius around 3 nm was found to be characteristic of microporous hypercrosslinked polystyrenes. Radius of magnetic iron oxide (magnetite) nanoparticles varies in ranges of 2.1 ± 0.6 nm and 6.7 ± 3.8 nm for the above microporous and biporous hypercrosslinked polymers, while in the XAD-4 particles of all sizes from 1 to 10 nm are presented.