The XRD patterns of the cycled samples confirmed that the there is no particle growth with cycling.
The thermo cycled samples were analyzed by SEM.
The compression strength of the non-cycled samples averaged ∼35 MPa (5076 psi) before failing whereas the cycled samples fractured at about 7 MPa (1015 psi).
The absence of any oxide phase in all the cycled samples of SAC confirms the formation of self protected metal nanoparticles.
Microscopic examination of the fracture surfaces from the cycled samples showed clear de-bonding of the sulfur from the aggregate whereas it was seen adhering in those non-cycled.
A concise series of five cycled samples, as well as a soaked and pristine sample, were measured at different states of sodiation after the initial sodiation and after the following full cycle of sodiation and desodiation.
The evaluation of the microstructures and RA values show that the thermally cycled samples contain cavities of varying amount along the gauge and exhibit higher homogeneous plastic deformation than those isothermally tensile tested at 430 °C.
The EXAFS data of the cycled samples reveal the morphology of the PtCo inner core under in situ conditions and thereby provide unique insight into the concentration gradient within the PtCo core when combined with the EXFAS data of the BOL samples.
The melting of this thermally-cycled sample is a sharp single peak (melting temperature 427 K) as shown in Figure S1 (see Additional File 5), and which indicates a high level of purity of the sample.
Based on a simple analysis it was concluded that the large strength discrepancy between cycled and non-cycled samples is due to differences between the coefficients of thermal expansion of the materials constituting the concrete.
