Characterization of Nm-PHB nanocomposite film

The surface morphology of the thin films was assessed using scanning electron microscopy (FEI Quanta FEG 200-High Resolution SEM). Briefly, the developed film was deposited on aluminum stubs and coated with a gold layer using a sputtering coater with an accelerating voltage of 10–15 kV. All the prepared films of different combinations were scanned and the film morphology, and characteristics were determined.

The degree of crystallinity of the film prepared using the three different combinations was estimated using XRD (X - ray diffraction) patterns obtained using a Rigaku (30 kv/25 mA) Geigerflex D/Mac, C series diffractometer (Tokyo, Japan) with Cu-kα radiation (λ = 1.5406 A°) at room temperature in glancing inclined angle mode. XRD analysis of the film was carried out as described in ref. ²⁵ with necessary modifications. Briefly, the film was placed on a glass slide and baseline corrections were carried out, then hot pressed at 100° for 2 min to erase the residual thermal history, and subsequently quenched to room temperature, followed by maintenance for 24 h to allow complete crystallization. The scanning range was 10–0° at a rate of 0.02°/second. Based on SEM and XRD analysis effective film prepared using 1% each of Nm, PHB, and glycerol blend was determined and the AFM ((Atomic Force Microscopy) analysis was carried out to determine the film roughness and surface morphology. The route mean squared (RMS) roughness values were estimated with the help of the NanoScope analysis software. AFM (diCaliber AFM, Bruker), was operated in the tapping mode with a spring constant of 40 N/m²⁵.