SAXS, real-time

It has been shown above that during the induction period no change occurs in DSC, macroscopic density, and WAXD. Does nothing change in this period In order to answer this question, we made real-time SAXS measurements. 

Calo JM, Hall PJ, Houtmann S, Lozano-Castello D, Winans RE, and Seifert S. Real time determination of porosity development in carbons A combined SAXS/TGA approach. In Rodriguez-Reinoso F, et al., eds. Studies in Surface Science and Catalysis, Characterisation of Porous Solids IV, vol. 144, the Netherlands Elsevier Science. 2002 pp. 59-66. 

Real time determination of porosity development in carbons a combined SAXS/TGA approach... 

Particle size distributions are important information for evaluating the synthesis, growth and kinetics of formation of nanoparticles and nanoparticle aggregates. The main contrasting techniques are imaging via TEM, and SAXS analysis. TEM analysis is independent of the type of aggregation, shape and size of nanoparticles, whereas SAXS interpretation requires assumptions about the nature of the sample. On the other hand, SAXS can be done on in situ systems, and often in real time during particle formation. 

Caputo, F.E. Burghardt, W.R. Real-time 1-2 plane SAXS measurements of molecular orienta-... 

In an attempt to identify the sequence of deformation events, tensile testing was performed simultaneously with real-time SAXS (17, 18). Using SAXS,... 

Small-angle X-ray scattering (SAXS) experiments using synchrotron radiation (SR) are performed at present mainly in the areas of real time scattering and anomalous dispersion.1 Typical applications are the study of melting or recrystallisation of semicrystalline polymers [4, 5], phase separation of alloys [6], muscle diffraction and stopped flow experiments on dissolved biopolymers [7, 8]. Anomalous dispersion has been exploited in order to determine partial structure factors in alloys [9] or polymers containing heavy atoms [10],... 

At present only a pinhole geometry without focusing elements has been studied. The SAXS resolution would in this case be more limited as for the real-time camera with Lmax x 4500 A. Focuring in the horizontal plane would, however, be possible by sagittal focusing via the second crystal [47],... 

Time resolved SAXS/SANS allow a structural observation of kinetic processes on the nanoscale (1-100 nm) on a time scale ranging from milliseconds to hours. This allows micellar kinetics to be followed in real time, giving direct structural information of the process and its evolution. Synchrotron SAXS can reach smaller time scales and exhibits better resolution compared to neutron-based methods. However, SANS offers the possibility for contrast variation via simple H/D exchange chemistry, which opens up a world of possibilities for the investigation of kinetics in soft matter systems, in particular transport and exchange processes that otherwise would be invisible in scattering experiments. As most of these techniques have become available over recent years with advancements in both instrumentation and sample environments, there is a need for an overview of the development and the possibilities that are now available in the field of soft matter in general and micellar systems in particular. 

Although the investigation in this paper mainly concentrated on the time evolution of the 001 reflection and the 4-point pattern in the SAXS region, the measurements of the time dependence of overall diffraction patterns in the WAXS region will be required in order to elucidate the microscopic mechanism of the structure formation in oriented PET. In particular, real-time measurement of the intensity distribution of the meridional reflections of higher order will reveal the detailed mechanism of the structure formation. Real-time relaxation measurements such as dielectric relaxation spectroscopy are also desired for this purpose. 

Addressing the Thermal Behavior of Semirigid Chain Poiymers with a Combination of Real-Time SAXS/WAXS and AFM... 

Figure 21.4 shows the real-time SAXS patterns acquired during tensile testing of several polymethylmethacrylate/epoxy blends. The perpendicular streaks indicating the formation of crazes can be seen in most of the data related to higher strains, on the right side of Figure 21.4. 

Several other authors reported data acquired in real-time SAXS experiments, by which they were able to elucidate particular aspects of the mechanism of deformation during tensile testing, such as the appearance of cavitation, crazing and debonding. ... 

Real-Time Crystallization and Melting Study of Ethylene-Based Copolymers by SAXS, WAXD, and DSC Techniques... 

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