Chitosan Derivatives/Calcium Carbonate Composite Capsules Prepared by the Layer-by-Layer Deposition Method II Stabilization of the Shell by Crosslinking

Table 2

Relative infrared absorbance A(ν)/A(1030 cm⁻¹) due to the urea group for crosslinked chitosan shell (𝑚=1).

Crosslink reagent	𝜈=1572 or 1597 cm^−1	𝜈=1630 or 1650 cm^−1
HMDI	1.18	1.14
TDI	0.96	0.92