From differential scanning calorimetric heating rate

Figure 8-9 Differential scanning calorimetric curves for l-stearoyl-2-linoleoyl-sw-glycerol. (A) Crystals of the compound grown from a hexane solution were heated from -10° to 35°C at a rate of 5°C per minute and the heat absorbed by the sample was recorded. (B) The molten lipid was cooled from 35° to -10°C at a rate of 5° per minute and the heat evolved was recorded as the lipid crystallized in the a phase and was then transformed through two sub-a phases. (C) The solid was reheated. From Di and Small.87 Courtesy of Donald M. Small.

The melting point of the copolymer was determined from the peak of the differential scanning calorimetric(DSC) spectra, measured with a Dupont apparatus. DSC measurements were made at a heating rate of 10°C/min. The samples were melted at 200 C. 

FIGURE 6.6 Differential scanning calorimetric (DSQ data for the saturated lipid sphingomyelin showing the phase transition from liquid crystal to gel phase measured with a heating rate of 207min. 

All the calorimetric experiments were performed by cooling the samples with maximal speed (320 K/min) to 210 R and subsequently heating (after equilibrium was reached). So Equation 5 was used for calculating the pore radii. A Perkin Elmer differential scanning calorimeter, model DSC II, was used. With this apparatus, pore radii from 2 to 20 nm can be determined. About 50 mg of membrane material (including water) was used for each experiment and a heating rate of 1.25 K/min gave reproducible results. 

Calorimetric measurements at a salt concentration of 0.8 M (NaCl) were carried out with a differential scanning microcalorimeter microDSC III (Setaram, Caluire, France). The melting of naphthalene was used to calibrate the apparatus. The sample cell was filled with 850 mg carrageenan solution (0.2% w/w in 0.8M NaCl) and the reference cell with exactly the same amount of NaCl solution. Heating and cooling curves were recorded in the temperature range from 10 to 120°C at a rate of 1.0°C min-1. 

Differential scanning calorimetry (DSC) is the most popular thermal analysis technique, the workhorse of thermal analysis. This is a relatively new technique its name has existed since 1963, when Perkin-Elmer marketed their DSC-1, the first DSC. The term DSC simply implies that during a linear temperature ramp, quantitative calorimetric information can be obtained on the sample. According to the ASTM standard E473, DSC is a technique in which the heat flow rate difference into a substance and a reference is measured as a function of temperature, while the sample is subjected to a controlled temperature program. As will be seen from this chapter, the expression DSC ... 

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