Dsc 1 stare system

The melting behaviour and the crystallization of the composites were studied by differential scanning calorimetry (DSC) on a differential scanning calorimeter (DSC 1 STARe System, Mettler Toledo, Columbus, OH, USA). Samples of the films at the approximate weight of 5 mg each were placed in aluminium pans. Nitrogen flow was set to 50 mL/min., and the following heating program was applied: an initial heating cycle from 25 °C to 200 °C (10 °C/min), maintaining the same for 2 min, and subsequent cooling to −50 °C (20 °C/min); this temperature was maintained for 2 min prior to conducting another heating scan to 200 °C. The melting temperature (T_m) and the exothermal response relating to cold crystallization (T_c) were obtained from the second heating cycle. The degree of crystallinity (X_C) was calculated from the value for specific enthalpy of melting (ΔH_f), as determined from the area under the melting peak in the second scan, applying the theoretical enthalpy of melting for 100% crystalline PP (209 J/g); see Equation (1) below [26 ,27 (link),28 (link)].
$X_C(\%)=\frac{\Delta H_f}{\Delta H{°}_f\times W}\times 100,$
where ΔH°_f is the theoretical enthalpy of melting for 100% crystalline PP, and W is the weight fraction of PP in the composite.

Lipid phase behavior and phase transitions were monitored by Differential Scanning Calorimetry (DSC, DSC1 Stare System, Mettler Toledo, Milano, Italy) on DPPC multilamellar vesicles prepared by the thin-film hydration method. The use of cholesterol was avoided since it is known to significantly decrease the enthalpy variation associated with the solid-to-liquid state transition of the phospholipid hydrocarbon chains and thereby jeopardizes DSC investigations [24 (link)]. To assess also the possible interaction between phospholipid head groups and protectant(s), DPPC films were hydrated with (i) pure water, in which, afterwards, the solution of protectants was added to lamellar phase samples, or (ii) directly with the solution containing the selected excipient(s).
An aliquot of about 30 µL exactly weighed was transferred to an aluminum pan, sealed and subjected to cooling until 0 °C at 1 K min⁻¹, kept at 0 °C for 5 min and then heated to 60 °C at 2 K min⁻¹. The DSC cell and refrigerated cooling systems (RCS) were purged with dry nitrogen at 80 and 120 mL/min, respectively. The system was calibrated using an indium standard. All data were treated with Star^e System software Version 10.0 (Mettler Toledo).