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Porous carbon materials from food waste have gained growing interest worldwide for multiple applications due to their natural abundance and the sustainability of the raw materials and the cost-effective synthetic processing. Herein, orange waste-derived porous carbon (OWPC) was developed through a freeze-drying method to prevent the demolition of the original biomass structure and then was pyrolyzed to create a large number of micro, meso and macro pores. The novelty of this work lies in the fact of using the macro-channels of the orange waste in order to create a macroporous network via the freeze-drying method which remains after the pyrolysis steps and creates space for the development of different types of porous in the micro and meso scale in a controlled way. The results showed the successful preparation of a porous carbon material with a high specific surface area of 644 m2 g−1 without any physical or chemical activation. The material's cytocompatibility was also investigated against a fibroblast cell line (NIH/3T3 cells). OWPC triggered a mild intracellular reactive oxygen species production without initiating apoptosis or severely affecting cell proliferation and survival. The combination of their physicochemical characteristics and high cytocompatibility renders them promising materials for further use in biomedical and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Tremendous research efforts are being devoted towards extracting sustainable electricity from the pressure-driven flow of water through artificially fabricated channels of nanometer dimensions. Here, we demonstrate that the biofluidic channels of coconut (or coir) fibers (CFs) can be an ideal platform for generating electricity from nanofluidic transport. During the flow of water, the channels of CFs generated electrical signals up to 35 mV and 42 nA. Unlike typical electrokinetic energy harvesting devices, no energy was wasted to pump the liquids through the nanochannels of CFs; the gravity-driven flow of water was sufficient to generate power up to 5.66 mW m−2. The obtained electrical power is attributed to negative surface charges of the coir fibers, which ionize the water molecules flowing through the narrow channels. The power density obtained as such was drastically improved (up to 17-fold) upon modification of the delignified pores of CFs with two-dimensional flakes of graphene oxide (GO) and p-phenylenediamine (pPDA). The modification of the coir channels also resulted in a drastic improvement in the mechanical properties of CFs. The breaking stress and Young's modulus of CFs were increased by 671% and 3325% upon modification with GO and pPDA. [ABSTRACT FROM AUTHOR]

We report a facile methodology for the synthesis of inorganic-organic hydrogels based on integrative assembly of aminopropyl magnesium phyllosilicate (aminoclay) and sodium salt of hyaluronic acid. The viscoelastic materials produced by electrostatic interactions and crosslinking of hyaluronan in the presence of exfoliated synthetic organoclay results in the formation of gel-like behavior retaining a high amount of water. This was confirmed by a rheological study revealing significant dominance of the elastic response over the entire deformation frequency range used. The mechanical strength of the aminoclay-hyaluronan hydrogels was found to be higher than that for related materials based on poly(vinylpyrrolidone)-aminoclay hydrogels., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This work demonstrates the use of amino functionalized Mg-phyllosilicate clay/Nafion nanocomposite film embedded with Pt nanoparticles (Pt/AC/N) for catalyzing oxygen reduction reaction (ORR) in sulphuric acid medium. Pt/AC/N nanocomposite films were surface characterized using transmission electron microscope. Cyclic and linear scan voltammetry studies were carried out under hydrodynamic conditions taking rotating-ring disc electrode (RRDE) as the working electrode. The effects of clay content, Pt mass loading, electrode rotation rate, and temperature on the ORR kinetics were studied. The Tafel slopes were found to vary between 118 and 126 mV dec(-1) indicating a good ORR kinetics. The exchange current density values calculated after mass transfer correction ranged from 5.8×10(-7) to 2.4×10(-6) A cm(-2). From the RRDE disc currents, Koutecky-Levich plots were constructed and the ORR mechanism was found to follow a four electron path with minimum H(2)O(2) formation of ∼1.6%. The effect of temperature on ORR kinetics was found at 25, 40, and 50°C. The energy of activation calculated to be 7.68 kJ mol(-1) and comparable to the standard Pt/C catalyzed ORR systems., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Light-harvesting hybrids have gained much importance as they are considered as potential mimics for photosynthetic systems. In this Concept article we introduce the design concepts involved in the building up of light-harvesting hybrids; these resemble the well-studied organic-based assemblies for energy transfer. We have structured this article into three parts based on the strategies adopted in the synthesis of hybrid assemblies, as covalent, semicovalent, and noncovalent procedures. Furthermore, the properties and structural features of the hybrids and analogous organic assemblies are compared. We also emphasize the challenges involved in the processability of these hybrid materials for device applications and present our views and results to address this issue through the design of soft-hybrids by a solution-state, noncovalent, self-assembly process., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)