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

In this work, cellulose nanocrystals (CNCs) incorporated with supermagnetic iron oxide nanoparticles (Fe 3 O 4 NPs) as ( M CNC) hybrids by the co-precipitation method have developed. High-performance nanocomposite films consisting of poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) and M CNC hybrids have prepared through a simple solution casting method. The addition of CNCs in M CNC-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 M CNC 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 M CNC-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/ M CNC-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.