Recent years have witnessed great developments in biobased polymer packaging films for the serious environmental problems caused by the petroleum-based nonbiodegradable packaging materials. Chitosan is one of the most abundant biopolymers after cellulose. Chitosan-based materials have been widely applied in various fields for their biological and physical properties of biocompatibility, biodegradability, antimicrobial ability, and easy film forming ability. Different chitosan-based films have been fabricated and applied in the field of food packaging. Most of the review papers related to chitosan-based films are focusing on antibacterial food packaging films. Along with the advances in the nanotechnology and polymer science, numerous strategies, for instance direct casting, coating, dipping, layer-by-layer assembly, and extrusion, have been employed to prepare chitosan-based films with multiple functionalities. The emerging food packaging applications of chitosan-based films as antibacterial films, barrier films, and sensing films have achieved great developments. This article comprehensively reviews recent advances in the preparation and application of engineered chitosan-based films in food packaging fields.

In this study, thymine and melamine were introduced as nucleating agents for poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerates) (PHBVs) and poly(3‐hydroxybutyrate) (PHB), and their effects were compared with that of boron nitride (BN). Because the overall crystallization rate of PHBVs decreases significantly with the increase in the 3‐hydroxyvalerate comonomer content, the study focused on the crystallization of PHBVs. Isothermal crystallization kinetics of the neat PHBVs and the nucleated PHBVs were studied by differential scanning calorimetry (DSC). The Avrami equation was derived and the parameters were assessed for the nucleation and crystal growth mechanism. The nucleation and crystal growth were examined using polarized optical microscopy. All nucleating agents had similar particle sizes and showed good dispersion in the polymer matrix, as revealed by scanning electron microscopy. The results indicated that BN and thymine significantly increased the overall crystallization rate for all PHBVs studied and demonstrated very similar nucleating effects. Melamine reacted with PHBVs and accelerated the thermal degradation, and hence was less effective in nucleating PHBVs. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1564–1577, 2007

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In this work, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/bamboo pulp fiber composites were meltcompounded and injection-molded. Tensile, impact and dynamic mechanical properties of the composites were studied. In contrast to many other short natural fiber reinforced biocomposites which demonstrate decreased strain-at-break, impact toughness and tensile strength, the PHBV/bamboo pulp fiber composites displayed increased tensile strength and impact toughness, and maintained/increased strain-at-break. Microscopic study of the fracture surfaces revealed extensive fiber pullout in both tensile and impact tests. The fiber pullout suggests insufficient interfacial adhesion between the fiber and the matrix. The pullout process in the impact testing dissipated a significant amount of energy and hence substantially improved the impact toughness of the composites. With the improved interfacial adhesion provided by coupling agent polymeric diphenylmethane diisocyanate (pMDI), the strength and modulus of the composites were further increased. However, the toughness was decreased due to the inhibition of the fiber pullout. An acoustic emission test revealed a significantly different process of structural change for the composites with/without pMDI during tension test.

Carbon-based conductive inks are one of the most important materials in the field of printing electronics.

Energy storage devices with high performance have been extensively studied for decades due to the increasing fuel demands. The physicochemical properties of 2D materials such as MoS 2 and graphene, due to their high surface area, versatile electronic structure, high mechanical robustness, This article is protected by copyright. All rights reserved. 2 high electrical conductivity, and desirable electrochemical characteristics, make them superior candidates for energy storage applications. MoS 2 /graphene composites specially emerge as exceptional candidates that could offer new solution for energy storage applications. Many fabrication strategies to develop and synthesize MoS 2 /graphene composites have been explored and introduced, such as hydrothermal and solvothermal treatment, chemical vapor deposition, sonication, microwave and self-assembly. For these composites to be suitable for energy storage devices applications, they are often integrated with other materials such as additional agents to improve their electrochemical and stability properties. In this review, recent progresses on the development of graphene/MoS 2 composites for energy storage and conversion applications (supercapacitors, batteries, solar cells, and hydrogen evolution) is presented and discussed. Critical review and perspectives on the future directions for MoS 2 /graphene composite based energy storage devices are also presented as concluding remarks. Recent progress on the development of graphene/MoS 2 composites for energy storage applications is also presented and discussed.