Abstract

Small-angle X-ray scattering (SAXS) is a non-destructive method conveniently designed for structural characterization of materials from nano- to micron scales. This is one of only a few methods which enables material structure to be assessed in situ at different thermodynamic and processing conditions (Figure) using time-resolved measurements. Recent developments of X-ray optic components, synchrotron radiation sources and laboratory SAXS instruments, complimented by a further progress in modelling and analysis, made SAXS technique one of the most commonly-used for structural characterization of composite materials, polymers, proteins, colloids and other nanoscale objects. Basics of SAXS techniques together with analytical modelling used for structural characterization of materials will be discussed. In particular, examples of time-resolved SAXS measurements of flow-induced crystallisation of semi-crystalline polymers (Figure D), SAXS analysis of structural orientation of block-copolymers under large-amplitude oscillatory shear (Figure B), hierarchical structure of carbon black, transformation of nanodiamond into carbon onions, time-resolved measurements of polimerization-induced self-assembly of copolymers during chemical reactions and thermally-induced morphological transformations of self-assembled block-copolymers (Figure C) as well as grazing incidence X-ray scattering analysis of crystallization kinetic of organolead halide perovskites (photovoltaics used for solar cells) will be presented.

Figure. Rheo-SAXS studies of soft matter materials: A) a modified Linkam shear cell mounted on Xenocs Xeuss 2.0 Metal Jet laboratory SAXS beamline; B) SAXS pattern of polystyrene-polyisoprene block-copolymer spherical micelle dispersion aligned by oscillatory shear; C) SAXS pattern of high density polyethylene crystallised under a shear flow; D) SAXS pattern of worm-like micelles aligned by shear during thermally-induced transformation of block-copolymer self-assembled morphologies.