During cyclic loading, untreated material is hardened under high strain amplitude (±0.8%, ±1.25%), but softened under low strain amplitude (±0.5%).
Further, the in vitro cytocompatibility of FeB-Fe2B layer on AISI 316 L steel and the untreated material was evaluated by the indirect contact method, in which cell lines of immortalized human fibroblast (CHON-002) and normal renal epithelium of Cercopithecus aethiops (Vero) were used.
When untreated material was used, the obtained yield was even lower compared to that with the untreated VP, reaching only 20.2 ± 13.0 mL CH4/gVS.
In order to check whether this was the case, some untreated material was ground to a fine powder, and ATR-FTIR spectra were obtained from the homogenised material.
A sample of each steam-exploded solid and untreated material was frozen in liquid nitrogen and freeze-milled into a fine powder to gain a homogenous sample for chemical analysis (3 min, SPEX 6700 freezer/mill, Spex Industries, NJ) and dried to constant mass (40 °C, overnight).
Untreated materials were studied by means of differential scanning calorimetry (d.s.c)., size exclusion chromatography (s.e.c)., Fourier-transform infrared spectroscopy (FTi.r)., attenuated total reflectance (ATR) and transmission measurements, and the effect of plasma treatment conditions was followed by X-ray photoelectron spectroscopy (X.p.s).
The treated and untreated materials were then enzymatically hydrolyzed for 96 h.
The chemical compositions of untreated materials were calculated as the average values and standard deviations (average ± SD).
Organosolv pretreatments in four different conditions were performed on the three different lignocellulosic materials, and the methane yields of the pretreated and untreated materials were then measured through batch SSAD assays.
Enzymatic hydrolysis of the untreated materials was included for comparison.
