*3.9. Statistical Analysis*

SPSS Statistics 21 (IBM SPSS Statistics 21, SPSS Inc., New York, NY, USA) analyzed the triplicate data and presented it as mean ± standard error. Figures with Y-error bars represent the standard error. *p* < 0.05, n = 3.

#### **4. Results and Discussions**

#### *4.1. FTIR Analysis*

The FT-IT spectral profile of the hydrogel can, as shown in Figure 1, determine the structural and functional analysis of the material present in hydrogels. The vibration band from 1110 to 1000 cm−<sup>1</sup> is attributed to the asymmetric stretching of –Si–O–C and –Si–O–Si due to TEOS and confirmed the successful crosslinking of bacterial cellulose and polyvinyl alcohol. These polymers and GO were also crosslinked due to hydrogen bonding (H–bonding) that presents the absence peak at 1759 cm−<sup>1</sup> and broadband at 3600–3200 cm−1. The increased broadband valley is due to increased intra and interhydrogen bonding [21]. The characteristic peaks of BC are hydroxyl, COO−, and pyranose rings. The absorption peak of the saccharine structure and pyranose ring is confirmed at 1060 cm−<sup>1</sup> and 876 cm<sup>−</sup>1, respectively. The stretching peak at 2950 cm−<sup>1</sup> is due to alkyl –CH of BC. The stretching peaks at 1643 and 1469 cm−<sup>1</sup> are attributed to functional groups of C=O and C–C and confirm the presence of GO and it is associated with the polymeric matrix via H-bonding. Hence, the FT-IR spectral confirms successful crosslinking of the polymers and GO interaction with the polymeric matrix that has been determined via available functional groups and interaction.

**Figure 1.** FTIR spectra of composite hydrogels to determine the structural, and functional groups and their physicochemical interactions.

#### *4.2. SEM Morphology*

The surface of hydrogel is a fundamental phenomenon for drug release and interaction with the body's biological system. Therefore, SEM analysis was performed to investigate the surface properties of the hydrogel materials, as shown in Figure 2. The increasing amount of GO causes more particulate-like (GO-flakes) morphology than smooth surface morphology. These GO-flakes impart their unique role in the hydrogels' morphology by increasing surface roughness and closing the packing of the hydrogel. Such surface morphology helps burn and chronic wounds by providing them with important hydration [22,23]. However, it was also observed that an increasing GO amount also causes cracking on drying. Hence, it is essential to introduce the only optimized amount of GO to have the desired surface morphology with structural integrity.

**Figure 2.** The surface morphology of the hydrogels via SEM.
