Developing nanogenerators (NGs) is achieved by exploiting the piezoelectric, triboelectric, and pyroelectric effects of both organic and inorganic materials Many exhibit beneficial electrical properties (dielectric, conductive, or insulating) or have surfaces that are polarizable upon friction or physical contact Recently, biomass‐derived materials and recycled materials, whose electrical activity can be induced, are explored for application in the design of more sustainable, cost‐effective, biodegradable, disposable NGs, and have demonstrated a wide range of output (microenergy) power densities Among them, cellulose, the most abundant biopolymer, is found to offer excellent opportunities for designing and manufacturing NGs with multifunctional capacities Cellulose can be derived into varied forms with multifunctionalities and physical morphologies This account provides an overview of how cellulose is utilized in creating NGs based on piezoelectric, triboelectric, and pyroelectric effects Because the mechanical properties of cellulose are tunable, current research trends on NGs originate with the triboelectric effect The discussion here focuses on design, fabrication methods, achievable electrical power output, and combinations with other materials and devices Challenges in efficient fabrication and consistent power densities, and opportunities for integrating different technologies and developing more sustainable (in terms of economic, environmental, and ecological) nature–human–machine interfacial devices are also discussed

An Overview of Cellulose-Based Nanogenerators

In this review, carbon-polymer-based composite electrodes for microbial fuel cells (MFCs) are reviewed in detail together with a study of carbon materials and polymers. The merits, demerits, and performance of carbon-polymer-based composites as anode and cathode materials for microbial fuel cells are discussed besides an extensive analysis of the literature and new trends in material synthesis. The development of composites with surface- and bulk-modified electrode materials can overcome the major challenge posed by the low power density of MFCs. Nitrogen- and fluorine-containing polymers, such as polyacrylonitrile (PAN), polyaniline (PANI), polytetrafluoroethylene (PTFE), polydopamine (PDA) and polyacrylamide (PAM), have been identified as potential candidates for bulk or surface modification in the presence of redox active species to enhance the biocompatibility and the effectiveness of the reduction of the cathodes.

Application of carbon-polymer based composite electrodes for Microbial fuel cells

Objective This paper introduces a simple one-step and ultra-fast method for synthesis of highly photothermally active polypyrrole-coated gold nanoparticles. The synthesis process is so simple that the reaction is very fast without the need for any additives or complicated steps. Methodology Polypyrrole-coated gold nanoparticles (AuPpy NPs) were synthesized by reacting chloroauric acid (HAuCl4) with pyrrole (monomer) in aqueous medium at room temperature. These nanoparticles were characterized by UV-visible-NIR spectrometry, transmission electron microscopy (TEM), AC conductivity, zeta sizer and were evaluated for dark cytotoxicity and photocytotoxicity using human hepatocellular carcinoma (HepG2) cell line as a model for cancer cells. Results The synthesized AuPpy NPs showed a peak characteristic for gold nanoparticles (530-600 nm, molar ratio dependent) and a wide absorption band along the visible-NIR region with intensity about triple or even quadruple that of polypyrrole synthesized by the conventional FeCl3 method at the same concentration and under the same conditions. TEM imaging showed that the synthesized AuPpy NPs were composed of spherical or semi-spherical gold core(s) of about 4-10 nm coated with distinct layer(s) of polypyrrole seen either loosely or in clusters. Mean sizes of the synthesized nanoparticles range between ~25 and 220 nm (molar ratio dependent). Zeta potentials of the AuPpy NPs preparations indicate their good colloidal stability. AC conductivity values of AuPpy NPs highly surpass that of Ppy prepared by the conventional FeCl3 method. AuPpy NPs were non-toxic even at high concentrations (up to 1000 µM pyrrole monomer equivalent) under dark conditions. Unlikely, light activated the photothermal activity of AuPpy NPs in a dose-dependent manner. Conclusion This method simply and successfully synthesized AuPpy NPs nanoparticles that represent a safe alternative photothermally active multifunctional tool instead of highly toxic and non-biodegradable gold nanorods.

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One-Step Synthesis of Polypyrrole-Coated Gold Nanoparticles for Use as a Photothermally Active Nano-System.

Polyvinylidene fluoride (PVDF)-poly(methyl methacrylate) (PMMA)-expanded graphite (ExGr) conducting polymer blends: Analysis of electrical and thermal behavior

Recently, Electrical Distribution Systems are extensively penetrated with the Distributed Energy Resources (DERs) to cater the energy demands with general perception that it enhances the system resiliency. However, it may be adverse for the grid operation due to various factors like its intermittent availability, dynamics in weather condition, introduction of nonlinearity, complexity etc. This needs a detailed understanding of system resiliency that our method proposes here. We introduce a methodology using complex network theory to identify the resiliency of distribution system when incorporated with Solar PV generation under various undesirable configurations. Complex correlated networks for different conditions were obtained and various network parameters were computed for identifying the resiliency of those networks. The proposed methodology identifies the hosting capacity of solar panels in the system while maintaining the resiliency under different unwanted conditions hence helps to obtain an optimal allocation topology for solar panels in the system. The proposed method also identifies the critical nodes that are highly sensitive to the changes and could drive the system into non-resiliency. This framework was demonstrated on IEEE-123 Test Feeder system with time-series data generated using GridLAB-D and variety of analysis were performed using complex network and machine learning models. Electrical distribution system is becoming more complex consistently with higher penetration of distributed energy resources. The complex network theory comes out as a good tool for analysis as it can easily accommodate complexities and identify system’s resiliency when subjected to undesirable conditions like overloading, unbalancing, extreme weather conditions and temperature rise. This paper introduces a methodology for identifying the resiliency of electrical distribution system. Data of IEEE-123 Test Feeder under the considered conditions were generated using GridLAB-D simulation software where of the 123 nodes, we electrical collected data at 40 nodes. The developed positive correlation networks were analyzed between the system operating normally with the system configuration incorporating varying percentage of PV to understand changes in electrical parameters like real power of the system and then evaluated resiliency by analyzing various network parameters like percolation threshold, average degree, clustering coefficient etc. We introduced 15 combinations of PV introduction in the system to identify the optimal allocation topology of DER by maintaining the resiliency of electrical network with identification of the critical nodes responsible for hampering the system resiliency. The data driven approach combining complex network and machine learning enabled us to understand the important network features there by using them to identify the resiliency, optimal topology with various degree of DER penetration.

A methodology for identifying resiliency in renewable electrical distribution system using complex network

The importance of conducting polymer composites can be gauged from the fact that they are being intensively focused in various applications like fuel cell bipolar plates, EMI shielding devices, sensors, actuators, anticorrosion coatings, solar cells, biomaterials, etc. The light-weight, cost reduction, and ease of processing of the polymer-based products make them very attractive to replace conventional materials. Harnessing the synergism in properties between both micron and nanosized conducting filler particles and the polymer, the properties of the composite system could be enhanced in a better manner. In this regard constant search of novel conducting fillers especially graphite and graphite-derived high aspect ratio fillers along with polymers paved a path for realizing high-performance conducting composites. There is an urge in understanding latest trends in the field of conducting polymer binary and hybrid composites starting from synthesis, processing to applications. Hence this book chapter is intended to review recent research activities on structure-property correlations in conducting polymer-graphite binary and hybrid composites and their applications in diversified fields.

Conducting polymer-graphite binary and hybrid composites: structure, properties, and applications

With increasing awareness on environmental issues associated with conventional energy sources, a new class of storage and integration systems of both fossil and alternative energy sources are required to meet the energy demand for the growing population of modern technological society. Among various technologies, the secondary rechargeable battery based on the sodium ion storage phenomena offers greater advantages including high energy density, the abundance of minerals, and cost-effective production and maintenance. In the sodium-ion storage systems, carbonaceous materials, i.e., hard carbons are explored as anode materials, which can provide high energy density and long-term stability for multiple charging/discharging cycles. These hard carbons can be obtained from both fossil and the abundant, low-cost biomass sources. With the advancement in the biorefinery and nanotechnology, nanoscale biomass-derived materials can offer great potential of controlling the morphological features, lignocellulosic composition, and lowering the energy input for pyrolysis/carbonization. These parameters significantly affect the final carbon structure and its performance as anode material in the battery. Hence, this chapter provides brief introduction on sodium-ion battery systems and reviews the recent progress and advantages of using biomass-derived nanoscale materials as carbon precursors.

B. T. S Ramanujam

Papers

Conducting polymer-graphite binary and hybrid composites: structure, properties, and applications

Nanocellulose-based carbon as electrode materials for sodium-ion batteries