Thermal stability and thermal-oxidative breakdown (TGA) of the initial specimens and of the weld have been studied with TGA Q50 device by TA Instruments (New Castle, DE, USA), in the dried air atmosphere under temperatures from 30 to 700°C with a linear heating rate of 20°C/min.
Thermomechanical behavior and deformational characteristics (TMA) of the initial specimens and of the weld have been investigated with TMA Q400 EM device by TA Instruments (New Castle, DE, USA), in the dried air atmosphere, with a linear heating rate of 10°C/min under temperatures from 30 to 250°C.
Thermogravimetry analysis (TGA) was performed using Netzsch STA-409PC (Germany) from 313 to 873 K under a dried nitrogen atmosphere, and the heating rate was 10 K/min.
The repeated combustion and contraction processes of the dried powders under N2 atmosphere produce the desired Mn Sn O C composite powders with yolk-shell structure.
All manipulations involving air- and moisture-sensitive compounds were carried out under an atmosphere of dried and purified nitrogen using standard Schlenk and vacuoline techniques.
Briefly, the appropriate amounts of dried glycerol, dried 6-caprolactone, glycolide, and stannous octoate (0.1 wt-%) were mixed in a 100-ml flask and heated under an argon atmosphere with mechanical stirring to 135°C.
Reactions were performed in pre-dried apparatus under an atmosphere of argon unless otherwise stated.
After adding acylating reagent (3 equiv., 0.15 mmol), the solution was transferred to a 1.5-mL sealed-cap vial containing BCL (immobilized on diatomaceous earth, Amano Enzyme Inc., transesterification activity >500 u/g, 150 mg), ZnI2 (0.5 equiv., 0.025 mmol) and ground 4 Å molecular sieves under an argon atmosphere, pre-dried for 2 days before use.
Samples were cut into 3-mm long sections and were fixed in 2.5% glutaraldehyde solution in 100 mM sodium phosphate buffer (pH 7.2) for more than 24 h, dehydrated in a graded ascending series of ethanol, and critical-dried in a CO2 atmosphere.
