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Graphical abstract Highlights • Heterogenous bio-based films were made to be used in green electronics. • Cellulose nanofibrils, chitosan, magnetite and glycerol led to heterogenous films. • Incorporation of magnetite improved magnetic and electrical properties of the films. • Magnetite and glycerol combined enhances charge storage and insulative properties. Abstract The objective of this work was to prepare bio-based thin films and evaluate the additions of magnetite and glycerol on the physico-chemical (flexibility, wettability and barrier properties) and dielectric properties of cellulose/chitosan-based films. The films were prepared by solution casting and presented a suitable dispersion of the constituents observed by SEM and FTIR. The films were thermally stable up to 150 °C and had a higher flexibility, wettability and lower barrier properties upon addition of glycerol. The calculated dielectric constant (εr) for the composite films was based on measurements of capacitance, at 100 and 1000 Hz, with the additions of magnetite and glycerol more than doubling the εr increasing the charge storage capacity. The bio-based thin films have potential to be used as insulators in capacitors on the production of green electronics thus, reducing toxic and nonrenewable e-waste generation. [ABSTRACT FROM AUTHOR]

In many revolutions of the cellulose based conductive materials, the most significant one was the developed material could be either directly used as a working electrode or used as the underlying substrate for the electrochemical deposition metal electrodes. In this work, an in situ polymerization of aniline monomer onto the porous structured cellulose scaffolds has been carried out, and then electrodeposition of Ag nanoparticles on the obtained conductive composites directly by using it as electrode. The Ag nanoparticles were deposited homogeneously on the matrix of polyaniline (PANI)/cellulose gels. The conductivity of PANI/cellulose nanocomposite gels containing Ag nanoparticles was increased to 0.94 S C m −1 , which was higher than that of pure PANI/cellulose composites (3.45 × 10 −2 S C m −1 ). Furthermore, it could be used as electrode for the supercapacitors, and the highest specific capacitance of the cellulose/PANI/Ag aerogels was 217 F g −1 . This approach offered a facile method for improving the electronic conductivity of native polymer nanohybrids, and suggested a new strategy for fabricating nanostructured polymer nanohybrids for application in energy storage. [ABSTRACT FROM AUTHOR]

The unparalleled dependency on petroleum based sources urged the research community to focus on developing renewable products, among which nanocellulose based commodities stands at the zenith due to its abundance, biodegradability and biocompatibility. Nanocellulose in form of coatings, aerogels, hydrogels, films and membranes have its own space in the research platform. The different coating technologies like spray, bar, roller, dip and foam coating are currently employed for the fabrication. The profound surface hydroxyl groups on the cellulose helps to incorporate desired properties like antimicrobial or antioxidant activities, barrier properties, superhydrophobicity or superhydrophilicity as per the applications ranging from biomedical to material engineering. Yet, the chemistry of these coatings have to be precisely tuned for its commercialization since many factors play challenging roles while the fabrication process like adhesion, brittleness and barrier properties. The manuscript discusses these aspects of the nanocellulose based coatings along with its challenges and future perspectives. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, we introduce the horizontal centrifugal casting (HCC) process that enables centrifugal force-assisted, scalable production of large-area (10 in.) polymer composite films based on nanocellulose (CNF) and nanochitin (ChNF). The HCC employs a cylinder mold with its rotation pivot being in a horizontal posture to harness centrifugal force to help flatten the film being cast, from which polymer composite films with excellent uniformity and flatness can be reliably produced in the size of the lateral surface of the cylinder mold. The combination of centrifugal force and horizontal layout of cylinder mold can allow reliable fabrication of large-area self-standing films from both polymeric solution and/or suspension in a scalable and simple fashion, which is a task not readily achieved in common film-forming techniques, such as solvent casting and vacuum filtration. We demonstrate such reliability and versatility of the HCC process by fabricating typical biocomposite films out of both a solution blend of ChNF/silk fibroin and a colloidal suspension of CNF/nanoclay as well as investigating their processing-structure-property relation as an optically transparent composite film targeting for structural component for flexible green optoelectronics and fire-retardant film, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

• BC/PEDOT composite films were developed as a high-performance conductive film. • A vapor phase polymerization was used to fabricate a BC/PEDOT composite films. • A BC/PEDOT film exhibited good electrical conductivity and excellent flexibility. Eco-friendly conductive polymer nanocomposites have garnered attention as an effective alternative for conventional conductive nanocomposites. Here, we report the fabrication and optimization of flexible, self-standing, and conductive bacterial cellulose/poly(3,4-ethylene dioxythiophene) (BC/PEDOT) nanocomposites using the vapor phase polymerization (VPP) method. Eco-friendly bacterial cellulose (BC) is used as a flexible matrix, and the highly conductive PEDOT polymer is introduced into the BC matrix to achieve electronic conductivity. We demonstrate that vapor phase polymerized BC/PEDOT composites exhibit more than 10 times lower sheet resistance (18 Ω/square) compared to solution polymerized BC/PEDOT (188 Ω/square). The resultant BC/PEDOT fabricated could be bent up to 100 times and completely rolled up without a notable decrease in electronic performance. Moreover, bent BC/PEDOT films enable operation of a green light-emitting diode (LED) light, indicating the flexibility and stability of conductive BC/PEDOT films. Overall, this study suggests a strategy for the development of eco-friendly, flexible, and conductive nanocomposite films. [ABSTRACT FROM AUTHOR]

• Polysaccharides serve as a suitable material for the development of TENGs. • Polysaccharide-based TENGs exhibit high output performance and durability. • Polysaccharide-based TENGs are biodegradable and cause minimum environmental impact. • Future research must focus on realistic and in vivo applications of bio-TENGs. Triboelectric nanogenerators (TENGs) are versatile electronic devices used for environmental energy harvesting and self-powered electronics with a wide range of potential applications. The rapid development of TENGs has caused great concern regarding the environmental impacts of conventional electronic devices. Under this context, researching alternatives to synthetic and toxic materials in electronics are of major significance. In this review, we focused on TENGs based on natural polysaccharide materials. Firstly, a general overview of the working mechanisms and materials for high-performance TENGs were summarized and discussed. Then, the recent progress of polysaccharide-based TENGs along with their potential applications reported in the literature from 2015 to 2020 was reviewed. Here, we aimed to present polysaccharide polymers as a promising and viable alternative to the development of green TENGs and tackle the challenges of recycling e-wastes. [ABSTRACT FROM AUTHOR]