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1 Introduction to PVA-Based Bionanocomposite Films
Fig. 1.13 Schematic diagram illustrating different clay structures of polymer/layered silicate
nanocomposites [163]
most common techniques used to sophisticatedly characterise final morphological
structures of nanocomposites [142, 161]. XRD analysis allows for the determination of the distance between silicate layers in nanocomposite structures according
to Bragg’s law. For example, in an immiscible polymer/organomodified layered silicate (OMLS) composite system, the characteristics of OMLS basal reflection remain
unchanged (Fig. 1.14). However, in a miscible system, the formation of an intercalated structure leads to an increase in interlayer spacing, as evidenced by the shift
of XRD peak to lower diffraction angles. On the other hand, the relatively large
interlayer spacing for exfoliated structures generally results in a featureless diffraction pattern and disappearance of diffraction peaks in view of XRD spectra. This
phenomenon takes place because the large interlayer spacing between silicate layers
in such a nanocomposite system tends to result in well-dispersed OMLS with the
random orientation [142, 164]. Only XRD analysis would be insufficient for determining final nanocomposite structures. As a result, other techniques such as TEM
should be employed in order to offer a visual evidence of morphological structures
in nanocomposites. Layered silicates contain heavier elements such as Al, Si and O
1 Introduction to PVA-Based Bionanocomposite Films
Fig. 1.13 Schematic diagram illustrating different clay structures of polymer/layered silicate
nanocomposites [163]
most common techniques used to sophisticatedly characterise final morphological
structures of nanocomposites [142, 161]. XRD analysis allows for the determination of the distance between silicate layers in nanocomposite structures according
to Bragg’s law. For example, in an immiscible polymer/organomodified layered silicate (OMLS) composite system, the characteristics of OMLS basal reflection remain
unchanged (Fig. 1.14). However, in a miscible system, the formation of an intercalated structure leads to an increase in interlayer spacing, as evidenced by the shift
of XRD peak to lower diffraction angles. On the other hand, the relatively large
interlayer spacing for exfoliated structures generally results in a featureless diffraction pattern and disappearance of diffraction peaks in view of XRD spectra. This
phenomenon takes place because the large interlayer spacing between silicate layers
in such a nanocomposite system tends to result in well-dispersed OMLS with the
random orientation [142, 164]. Only XRD analysis would be insufficient for determining final nanocomposite structures. As a result, other techniques such as TEM
should be employed in order to offer a visual evidence of morphological structures
in nanocomposites. Layered silicates contain heavier elements such as Al, Si and O