Food is fundamental to human survival, health, culture, and well-being. In response to the increasing demand for sustainable food preservation, chitosan (CS)-based electrospun nanofibers have emerged as promising materials due to their biodegradability, biocompatibility, and inherent antimicrobial properties. When combined with other biopolymers or bioactive compounds, CS-based nanofibers offer enhanced functionality for applications in food packaging, preservation, and additives. This review summarizes recent advances in the fabrication and performance of CS-polymer and CS-inorganic composite nanofibers, with a focus on their mechanical strength, thermal stability, barrier properties, and antimicrobial efficacy. The use of these nanofibers across a range of food categories—including vegetables, fruits, fresh-cut produce, dairy products, meat, seafood, and nuts—is examined. Beyond experimental approaches, the review also explores the growing role of computational simulations in predicting the mechanical strength, barrier performance, antimicrobial activity, and biodegradability of CS-based nanofibers. Key modeling techniques and simulation tools are summarized. Finally, current challenges and future research directions are discussed, underscoring the potential of CS-based electrospun nanofibers as sustainable and multifunctional solutions for modern food packaging. By integrating experimental advancements with computational insights, this review provides a comprehensive and forward-looking perspective on CS-based electrospun nanofibers for food packaging.

Semicrystalline polymers under nanoconfinement show distinct structural and thermomechanical properties compared to their bulk counterparts. Despite extensive research on semicrystalline polymers under nanoconfinement, the nanoconfinement effect on the local crystallization process and the unique structural evolution of such polymers have not been fully understood. In this study, we unveil such effects by using coarse-grained molecular dynamics simulations to study the crystallization process of a model semicrystalline polymer—polyvinyl alcohol (PVA)—under different levels of nanoconfinement induced by nanoparticles that are represented implicitly. We quantify in detail the evolution of the degree of crystallinity ($X_C$) of PVA and examine distinct crystalline regions from simulation results. The results show that nanoconfinement can promote the crystallization process, especially at the early stage, and the interfaces between nanoparticles and polymer can function as crystallite nucleation sites. In general, the final $X_C$ of PVA increases with the levels of nanoconfinement. Further, nanoconfined cases show region-dependent $X_C$ with higher and earlier increase of $X_C$ in regions closer to the interfaces. By tracking region-dependent $X_C$ evolution, our results indicate that nanoconfinement can lead to a heterogenous crystallization process with a second-stage crystallite nucleation in regions further away from the interfaces. In addition, our results show that even under very high cooling rates, the nanoconfinement still promotes the crystallization of PVA. This study provides important insights into the underlying mechanisms for the intricate interplay between nanoconfinement and the crystallization behaviors of semicrystalline polymer, with the potential to guide the design and characterization of semicrystalline polymer-based nanocomposites.

Chitosan (CS) is a biodegradable, biocompatible, and low-cost biopolymer with broad applications; however, its intrinsic backbone rigidity severely limits its processability. While small-molecule plasticizers have been explored to enhance the flexibility of CS, polymeric blending strategies using bio-based components remain less understood at the molecular scale. In particular, the role of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a biodegradable biopolymer, as a blending modifier in PHBV/CS blends remains insufficiently understood, particularly at the molecular level. In this study, we employ atomistic molecular dynamics simulations to systematically investigate the miscibility behavior and mechanical modulation mechanisms of PHBV/CS blends. Molecular-level miscibility of CS and PHBV is quantified using the Flory-Huggins interaction parameter across a series of blend compositions at both 300 K and 500 K, revealing favorable miscibility at both temperature regimes, particularly at low and high PHBV volume ratios. Steered molecular dynamics simulations demonstrate that CS chains possess substantially higher backbone stiffness and torsional resistance compared to PHBV, underscoring the mechanical modulation potential of PHBV. Two representative compositions (10:90 and 90:10 PHBV/CS) are further examined to evaluate chain mobility, mechanical response, and conformational energetics. Results show that incorporation of PHBV enhances the mobility and ductility of CS under tensile deformation, while CS imposes modest confinement on the dynamics of PHBV. Conformational energetic analysis further confirms that PHBV facilitates conformational transitions in CS chains, lowering the energetic barriers for deformation. Notably, these softening and mobility-enhancing effects persist in initially phase-separated morphology. Overall, our findings provide molecular-level insights into how contrast in polymer stiffness and conformational flexibility governs mechanical modulation in PHBV/CS blends. The findings offer mechanistic guidance for the design of fully biodegradable, mechanically adaptable polymer materials.