Fabrication of acid-swollen collagen fiber-based composite films: Effect of nano-hydroxyapatite on packaging related properties

Figures & data

Figure 1. Morphology of acid swollen collagen fiber (a) and collagen fiber based film (b). Picture (a) was captured by a confocal laser scanning microscope (Nikon, D-Eclipse C1) at a magnification of 40 ×, and picture (b) was captured by a digital camera (PowerShot SD 630, Canon).

Table 1. Thickness, optical properties, and color values of collagen fiber-based films reinforced with hydroxyapatite at various concentrations (n ≥ 3).

HA	Thickness (µm)	Opacity	L*	a*	b*
0%	39.30 ± 2.48^a	2.03 ± 0.15^a	85.72 ± 0.18^a	0.287 ± 0.06^a	–3.66 ± 0.08^a
1%	40.25 ± 3.53^a	2.54 ± 0.17^b	86.16 ± 0.20^b	0.263 ± 0.03^ab	–3.92 ± 0.11^b
2%	40.50 ± 2.59^a	3.60 ± 0.16^c	86.71 ± 0.11^c	0.254 ± 0.04^ab	–4.15 ± 0.11^c
4%	41.25 ± 3.68^a	6.41 ± 0.32^d	87.18 ± 0.13^d	0.242 ± 0.01^b	–4.45 ± 0.17^d

Date are expressed as mean ± SD.

Different letters in a column indicate the significant difference (p < 0.05).

Figure 2. Tensile strength (a), Elongation at break (b) and load-displacement curves (c) of collagen fiber-HA composite films. Error bars indicate the standard deviation of three replications. Different letters (a to d) indicate the significant difference.

Figure 3. Water vapor permeability (a) and water solubility (b) of collagen fiber-HA composite films. Error bars indicate the standard deviation of three replications. Different letters (a to d) indicate the significant difference.

Figure 4. POV of oil stored for 7 and 14 days. Error bars indicate the standard deviation of three replications. Different letters (a to e) indicate the significant difference.

Figure 5. DSC scans of collagen fiber films treated with various concentrations of HA.

Figure 6. SEM images (a-d) of surfaces of collagen fiber-HA films with 0, 1, 2, 4 wt% content of HA.

Figure 7. SEM images (a-d) of cross sections of collagen fiber-HA films with 0, 1, 2, 4 wt% content of HA.