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Printed electronic paper identifies its interest in flexible organic electronics and sustainable and clean energy applications because of its straightforward production method, cost-effectiveness, and positive environmental impact. However, current limitations include restricted material thickness and the use of supporting substrate for printing. Here, 2D and 3D electronic patterned paper are fabricated from direct ink writing (DIW) nanocellulose and PEDOT:PSS-based materials using syringe deposition and 3D printing. The conductor patterns are integrated in the bulk of the paper, while non-conductive sections are used as support to form free-standing paper. The strong interface between the patterns of electronic patterned paper gives mechanical stability for practical handling. The conductive paper-based electrode has 202 S cm(-1) and is capable of handling electric current up to 0.7 A, which can be used for high-power devices. Printed supercapacitor papers show high specific energy of 4.05 Wh kg(-1), specific power of 4615 W kg(-1) at 0.06 A g(-1), and capacitance retention above 95% after 2000 cycles. The new design structure of electronic patterned papers presents a solution for additive manufacturing of paper-based composites for supercapacitors, wearable electronics, or sensors for smart packaging.

The need for achieving sustainable technologies has encouraged research on renewable and biodegradable materials for novel products that are clean, green, and environmentally friendly. Nanocellulose (NC) has many attractive properties such as high mechanical strength and flexibility, large specific surface area, in addition to possessing good wet stability and resistance to tough chemical environments. NC has also been shown to easily integrate with other materials to form composites. By combining it with conductive and electroactive materials, many of the advantageous properties of NC can be transferred to the resulting composites. Conductive polymers, in particular poly(3,4-ethylenedioxythiophene:poly(styrene sulfonate) (PEDOT:PSS), have been successfully combined with cellulose derivatives where suspensions of NC particles and colloids of PEDOT:PSS are made to interact at a molecular level. Alternatively, different polymerization techniques have been used to coat the cellulose fibrils. When processed in liquid form, the resulting mixture can be used as a conductive ink. This review outlines the preparation of NC/PEDOT:PSS composites and their fabrication in the form of electronic nanopapers, filaments, and conductive aerogels. We also discuss the molecular interaction between NC and PEDOT:PSS and the factors that affect the bonding properties. Finally, we address their potential applications in energy storage and harvesting, sensors, actuators, and bioelectronics., Funding Agencies|Vinnova for the Digital Cellulose Competence Center (DCC) [2016-05193]; Swedish Foundation for Strategic Research [GMT14-0058]; Wallenberg Wood Science Centre

The interphase properties in nanocomposites indicate the interaction between filler and matrix, which is dependent on the preparation method, shape, and size of filler and the chemical interaction between two phases. Local chemical environment in polymer matrix give rise to the different dielectric properties compared to that of bulk material. These properties allow the understanding of their effects on the dielectric properties and glass transition (T-g) of the nanocomposites. In this study, interphase power law model was used to predict the interphase properties based on the experimental dielectric constant of polyimide (PI) with BaTiO3, TiO2, and ZrO2 nanocomposites. They were prepared via in situ polymerization of PI whose dielectric constant were increased at interphase filler volume fraction of BaTiO3, TiO2, and ZrO2 at 3.8, 2.05, and 1.7, respectively. These results indicate that PI/ceramics nanocomposites had poor dispersion and weak interphase interaction between the filler and the matrix, as an evidence of scanning electron microscopy and Fourier transform infrared spectroscopy results. However, PI incorporated with high aspect ratio of BaTiO3 nanofiber shows better dispersion than nanocomposites of TiO2 and ZrO2 filled PI; therefore provide higher dielectric constant and T-g., Funding Agencies|AUN/SEED-Net [6050315]; RU (I) [814242]

The need for achieving sustainable technologies has encouraged research on renewable and biodegradable materials for novel products that are clean, green, and environmentally friendly. Nanocellulose (NC) has many attractive properties such as high mechanical strength and flexibility, large specific surface area, in addition to possessing good wet stability and resistance to tough chemical environments. NC has also been shown to easily integrate with other materials to form composites. By combining it with conductive and electroactive materials, many of the advantageous properties of NC can be transferred to the resulting composites. Conductive polymers, in particular poly(3,4-ethylenedioxythiophene:poly(styrene sulfonate) (PEDOT:PSS), have been successfully combined with cellulose derivatives where suspensions of NC particles and colloids of PEDOT:PSS are made to interact at a molecular level. Alternatively, different polymerization techniques have been used to coat the cellulose fibrils. When processed in liquid form, the resulting mixture can be used as a conductive ink. This review outlines the preparation of NC/PEDOT:PSS composites and their fabrication in the form of electronic nanopapers, filaments, and conductive aerogels. We also discuss the molecular interaction between NC and PEDOT:PSS and the factors that affect the bonding properties. Finally, we address their potential applications in energy storage and harvesting, sensors, actuators, and bioelectronics., QC 20221114

In this work, the feasibility of converting dead leaf biomass into green activated carbon for use as a reinforcement filler in natural rubber composites was assessed. The dead leaf activated carbon (DLAC) was prepared by pyrolysis at 550, 700, 900, and 1000 degrees C at a heating rate of 10 degrees C min(-1) under nitrogen gas flow of 100 cm(3) min(-1) and was activated by CO2 gas at the same flow rate when the pyrolysis temperature was reached. The properties of DLACs were characterized by particle size analysis, density, scanning electron microscopy, elemental energydispersive X-ray spectroscopy and Raman spectroscopy. The results revealed that the DLAC obtained by pyrolysis at 1000 degrees C had a small particle size of 28.86 tint; a highly porous structure; high carbon purity, at 82.58%; and a low density, at 1.588 g cm(-3). The effect of different DLAC contents (5, 10, and 15 phr) on the curing properties and the physical and mechanical performance of the rubber composites was investigated and compared with rubber composites containing carbon black (CB). The results showed that the addition of DLAC increased the maximum torque and reduced the scorch and cure times. The tensile strength for rubber composites containing 15 phr of DLAC increased by 8%, the M100 and M300 improved 40%, and the elongation at break and crosslink density decreased by approximately 5% and 24%, respectively. The studied DLAC is a promising, cost-effective alternative to commercial carbon black for improving the performance of rubber composites., Funding Agencies|Universiti Sains Malaysia under Research University Incentive (RUI) [1001/PBAHAN/8014138]

The rise of internet of things (IoTs) applications has led to the development of a new generation of light-weight, flexible, and cost-effective electronics. These devices and sensors have to be simultaneously easily replaceable and disposable while being environmentally sustainable. Thus, the introduction of new functionalized materials with mechanical flexibility that can be processed using large-area and facile fabrication methods (as, for example, printing technologies) has become a matter of great interest in the scientific community. In this context, cellulose nanofibers (CNFs) are renewable, affordable, robust, and nontoxic materials that are rapidly emerging as components for eco-friendly electronics. Their combination with conductive polymers (CPs) to obtain conductive nanopapers (CNPs) allows moving their functionality from just substrates to active components of the device. In this work, a route for the inkjet-printing of organic diodes is outlined. The proposed strategy is based on the use of CNPs as both substrates and bottom electrodes onto which insulator and organic semiconducting layers are deposited to fabricate novel diode structures. Remarkable rectification ratios of up to 1.2 x 10(3) at |3 V| and a current density up to 5.1 mu A cm(-2) are achieved. As a proof-of-concept of the potentiality of the approach for versatile, low-temperature, and disposable sensing applications, an NO2 gas sensor is presented., Funding Agencies|MICIU-Spain [RTI2018-102070-B-C21]; Generalitat de CatalunyaGeneralitat de Catalunya [2017SGR-1159]; FEDER fundsEuropean Union (EU); University of Girona [BTI2018/12]

The objective of this study was to compare the physical and mechanical performance of poly(lactic acid) (PLA), acrylonitrile butadiene styrene (ABS), and nylon 6 fabricated using fused deposition modeling (FDM) and conventional injection molding. It is found that different processing methods did not affect the viscosity of the samples, and the percentage difference for the density measurement is less than 4%. Water absorption of FDM samples is approximately 108% higher compared to those fabricated using the injection molding. The results also revealed that the FDM method did not strongly affect the degree of crystallinity of ABS, but it increased the degree of crystallinity of PLA and nylon 6. The tensile strength, Youngs modulus, elongation at break, and impact strength of FDM samples were approximately 48%, 50%, 48%, and 78%, lower compared with the injection molded samples. The results presented can provide a guide to manufacturing the final products using FDM with the desired performance., Funding Agencies|Ministry of Education Malaysia, FRGS [203/PBAHAN/6071349]; Emerging Polymer Group, Polymer Engineering Department, University Sains Malaysia