ABSTRACT
Nanocomposites combine multiple favorable properties to achieve intriguing functionalities, but the formation of nanocomposites with only one constituent with the inclusion of multiple superior properties is still not known. Herein, novel self-compounded nanocomposite membranes from one single polymer-cellulose cinnamate (CCi)-with multiple outstanding properties are reported. The self-compounded membranes contain two distinct morphologies as CCi nanoparticles (CCi-NPs) and a CCi polymer matrix, while CCi-NPs are either firmly embedded in the CCi matrix or fused with adjacent CCi-NPs. The unique self-compounded nanostructure endows the membranes with a tensile strength of 94 MPa and Young's modulus of 3.1 GPa. The water vapor permeability, oxygen permeability, and oil permeability reach as low as (0.94 ± 0.03) × 10-11 g m-1 s-1 Pa-1, (8.48 ± 2.39) ×10-13 cm3·cm/cm2·s·cmHg, and 0.008 ± 0.003 g mm m-2 day-1, respectively. Moreover, self-compounded CCi nanocomposite membranes also demonstrate UV-shielding and photothermal conversion properties. UVB and UVC light are entirely blocked, while UVA light is partly blocked. The temperature increases from room temperature to 120 °C within 1 min under UV irradiation. In addition, CCi membranes also show remarkable thermal and humidity resistance. Based on these outstanding properties, CCi membranes are applied as food packaging materials. This work offers a new avenue to construct nanocomposites with multiple superior properties from one constituent, which is promising for diverse applications.
ABSTRACT
One-dimensional nanomaterials including cellulose nanocrystals (CNCs) and gold nanorods (GNRs) are widely used in optical materials due to their respective inherent features: birefringence with accompanying light retardation and surface plasmon resonance (SPR). Herein, we successfully combine these properties of both nanorods to generate synergistic and readily tunable structural colors in hybrid composite polymer films. CNCs and GNRs are embedded either in the same or in separate films after unidirectional alignment in dynamic hydrogels. By synergistically leveraging CNCs and GNRs with diverse amounts in hybrid films or stacked separate films, wide-ranging structural colors are obtained, far beyond those from films solely with aligned CNCs or GNRs. Higher GNR contents enhance light absorption at 520 nm with promoted magenta colors, while more CNCs affect the overall phase retardation with light absorption between 400 and 700 nm between crossed polarizers. Moreover, adjusting the angles between films solely with CNCs or GNRs via a stacking/rotating technique successively manipulates colors with flexible film combinations. By rotating the films with aligned GNRs (0-180°), light absorption can traverse from â¼500 to 650 nm. Thus, tuning the adjustable synergism of birefringence of CNCs and SPR of GNRs provides great potential for structural colors, which enlightens inspirations for designing functional optical materials.
