Understanding physicochemical properties changes from multi-scale structures of starch/CNT nanocomposite films

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Hydroxypropyl starch (HPS) is a versatile biopolymer with potential applications in films.
• Carbon nanotubes (CNTs) can enhance the properties of polymer matrices.
• Understanding the structure-property relationships in HPS/CNT nanocomposites is crucial for optimizing their performance.

Purpose of the Study:

• To investigate the effect of multi-scale structures on the physicochemical properties of HPS/CNT nanocomposite films.
• To correlate structural changes with mechanical, barrier, and thermal properties.
• To guide the rational design of starch-based nanocomposite films for specific applications.

Main Methods:

• Fabrication of HPS/CNT nanocomposite films with varying CNT content.
• Analysis of molecular interactions, short-range molecular conformation, and crystalline structure.
• Evaluation of mechanical properties (tensile strength, Young's modulus), barrier properties, and thermal stability.

Main Results:

• Higher tensile strength and Young's modulus were observed with 0.5% CNT due to less HPS hydrogen bonding disruption and lower crystallinity.
• Improved barrier properties were achieved with 0.05%-0.3% CNT, linked to higher overall crystallinity and larger micro-ordered regions.
• Thermal degradation temperature was not significantly increased due to disruption of HPS hydrogen bonding, but increased with higher film crystallinity.

Conclusions:

• The physicochemical properties of HPS/CNT nanocomposite films are governed by a complex interplay of multi-scale structural factors.
• Optimizing CNT content is essential for tailoring mechanical, barrier, and thermal properties.
• This research provides insights for developing advanced starch-based nanocomposite films for packaging and coating.