Anomalous small-angle X-ray scattering from charged soft matter

Abstract

Abstract. A review of recent applications of Anomalous Small-Angle X-ray Scattering (ASAXS) to charged soft matter systems is presented. Although the potential of ASAXS was realized in the eighties [1], applications to soft matter systems became feasible in recent years thanks to the technical developments at the synchrotron sources. Examples include both stiff chain and flexible polyelectrolytes, colloidal brush-like polyelectrolytes, DNA, RNA, and polysaccharides where the counterion profile could be determined with high precision and compared with theoretical models. In addition, ASAXS has also been found useful for microstructure characterization in soft materials. Finally, the present capability for ASAXS studies is illustrated by an example involving a surfactant micellar system.

Structure of Bolaamphiphile Sophorolipid Micelles Characterized with SAXS, SANS, and MD Simulations

“…This effect is expected in the case of an anomalous effect upon varying energy through the edge, and it demonstrates that Rb + ions decorate the micellar outer surface. Nevertheless, variation in I(q,E) is very mild; at 100 mM RbCl (Figure 5c), a concentration in counterions at which the anomalous effect was reported to be very important for polyelectrolytes and ionic surfactants systems, 62 (q) and v 2 (q) components, respectively, the nonresonant intensity of the macro-ion and the pure resonant contribution of the counterion, shown in Figure 5b,d. The splitting shows no noticeable effect on the 10 mM system using both the matrix and fit methods, as well as a mild anomalous effect on the 100 mM system, but only employing the matrix method.…”

The application of scattering technology in the study of polyoxometalate solutions

“…[68] . 与此同时, 通过PDDF [64] 形成是同步进行的 [68,91] . 按照这一方案, 可以通过在反离子元素吸收 边附近改变X射线电子能量, 来分离出散射曲线中反 离 子 的 贡 献 [26] .…”

Block copolymer thin films: Characterizing nanostructure evolution with in situ X-ray and neutron scattering

“…RSoXS and GI-RSoXS offers potential solutions to this challenge by using "soft" (i.e., low-energy) X-rays, which significantly reduce film damage and increase the contrast between organic domains; however, neither RSoXS nor GI-RSoXS has been employed widely for in situ experiments [223]. Additionally, anomalous small-angle X-ray scattering (ASAXS) is an emerging technique that exploits tunable X-ray energies to increase contrast between domains and could prove beneficial for analyzing side chain effects and templated metal deposition [93,121,224,225]. In particular, studies that incorporate these "soft" or resonant X-rays in reflectivity or grazing-incidence geometries will prove beneficial for further exploration of BCP thin films.…”