Table 2 ATR-FTIR and DSC data, such as wavenumber, functional groups of components, and melting point.

PL

3400–3300

3100–3000

3000–2850

1680–1650

1600–1500

~ 1450

1260–1220

1060–1040

900–700

N–H (amide) stretching

=C–H (aromatic/alkene) stretching

C–H (aliphatic CH₂/CH₃) stretching

C = O (γ-lactam carbonyl) stretching

C = C (aromatic/conjugated alkene) stretching

CH₂ (scissoring) bending

C–O (methoxy, asymmetric) stretching

C–O (methoxy, symmetric) stretching

C–H (aromatic out-of-plane) bending

124

Tween 80

3502

2922

2859

1735

1093

O–H stretching

C–H (asymmetric) stretching

C–H (symmetric) stretching

C = O (ester) stretching

C–O (ester) stretching

Liquid at room temperature

Span 80

3401

2923

2854

1739

O–H stretching

C–H (asymmetric) stretching

C–H (symmetric) stretching

C = O (ester) stretching

Liquid at room temperature

Cholesterol

3402

3000–2800

1463–1457

1054

O–H stretching

C–H (CH₃, CH₂, CH groups; sym. & asym.) stretching

C–H bending

C–O stretching

150 °C