Handbook of Solvents - George Wypych - ChemTech - Ventech!

398 Seung Su Kim, Jae Chun Hyun
Figure 7.3.11. Drying rate curve of low volatile solution: N-methylpyrrolidone (NMP) - LiCoO 2 - PVDF solution.
Figure 7.3.12. Comparison of drying rate between coating solution and pure solvent : N-methylpyrrolidone (NMP)
- LiCoO 2 - PVDF solution and pure NMP.
The example of measurement is shown in Figure 7.3.7. The remained solvent means
the percent of remained solvent to the total solvent load, and the drying rate of coating is
readily calculated using Equation 7.3.9. The drying rate at the specific time equals the slope
of the drying curve of Figure 7.3.7, and it is depicted in Figure 7.3.8. The drying rate of coating
shows constant and falling rate period with solvent content decreases. The temperature
of coating is nearly constant at the beginning of drying where the slope of weight loss remains
constant. As shown in Figure 7.3.7, most of the solvent is evaporated during the constant
rate period.
Figure 7.3.11 is the drying rate profile according to the solvent content at the various
drying temperatures. The coating solution is consisted of LiCoO 2 and poly(vinylidene fluoride)
(PVDF) solution. Polymer is dissolved in N-methylpyrrolidone (NMP), and this solu-