Supermagnetic cellulose nanocrystal hybrids reinforced PHBV nanocomposites with high sensitivity to intelligently detect water vapor

Abstract In this work, cellulose nanocrystals (CNCs) incorporated with supermagnetic iron oxide nanoparticles (Fe3O4 NPs) as (MCNC) hybrids by the co-precipitation method have developed. High-performance nanocomposite films consisting of poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) and MCNC hybrids have prepared through a simple solution casting method. The addition of CNCs in MCNC-5% hybrids improved the surface hydrophilicity of PHBV, and displayed a reduction in water vapor permeability by 68.1 %, compared with pristine PHBV. The results prove that the addition of MCNC hybrids can be acted like a sensor to detect voltage change of the nanocomposites as functions of water vapor. The existence of CNCs in the MCNC-5% hybrids caused an increase in tensile strength and Young’s modulus by 74.6 % and 120.2 %, respectively. The addition of CNCs could enhance cell-matrix interactions and thus cytocompatibility of PHBV nanocomposites. The PHBV/MCNC-5% exhibited saturation magnetization (Ms) values of 1.5 emu g−1 and displayed almost a regular and operative voltage response signal with real-time monitoring of water vapor. This work provides sustainable smart packaging materials with high sensitivity for water vapor and excellent biocompatibility.