Search

For many years, the performance of Li-ion batteries (LIBs) and supercapacitors (SCs) has relied mainly on two factors, (1) the optimization of electrodes composition and/or structure and (2) the selection of salts or ionic liquids (ILs) matching well with the compositional and/or structural features of electrodes. Solvents included in electrolyte composition have been typically seen as a mere medium where the electrochemically active salts or ILs are dissolved or mixed. More recently, attention has also been paid to specific issues, such as flammability, toxicity, electrical conductivity and/or electrochemical stability window (ESW). Recent reports describing water-in-salt (WIS), solvent-in-salt (SIS) and bi-solvent-in-salt (BSIS) electrolytes demonstrated that solvent molecules may indeed play a more active role in the achievement of high-performance LIBs and SCs. This work accomplished the design of a tri-solvent-in-salt (TSIS) electrolyte where every solvent contributed (with an IL such as EMIMBF4) to the formation of an electrochemically active hydrogen bond (HB) complex structure. Raman and NMR spectroscopies, as well as molecular dynamic (MD) simulations helped elucidate the ratio among all compounds (e.g., solvents and IL) in the HB complex structure that best works as an electrolyte. For instance, one could start from the eutectic mixture of H2O and dimethylsulfoxide (DMSO) in a 2 to 1 molar ratio and then add acetonitrile (CH3CN) in different molar ratios. Thus, the 2H2O:DMSO mixture offers low melting point and low flammability, and CH3CN provides an improvement of the rate capability to the resulting electrolyte. As compared to other electrolytes, the TSIS electrolyte composed of 1.5EMIMBF4:2H2O:DMSO:3.5CH3CN (5.8 m, TSIS-5.8) was cost efficient and exhibited self-extinction rates as low as 40 s g-1. Moreover, SCs operating with TSIS-5.8, at -70 °C and up to 2.7 V provided energy densities of ca. 49 and 18 Wh kg-1 at, respectively, power densities of 10,000 and 17,000 W kg-1, a capacitance retention of ca. 82% after 15,000 cycles at 4 A g-1 and a self-discharge as low as 22%.

[EN] Knitted iron phthalocyanine-based porous polymer networks (K-FePcs) were prepared in a single step using solvent-knitting strategies with commercial iron phthalocyanine as a building monomer. The incorporation of different aryl comonomers (biphenyl and 1,2,4,5-tetraphenylbenzene) to FePc allowed quantitative yields, high porosities, and excellent ORR activity. The reversible Fe(III)/Fe(II) redox potential of FeN4 centers of the knitted polymer networks in N2-saturated electrolyte solution (i.e., ∼0.8 V vs RHE) were shown as good descriptors of their ORR activity. K-FePc2Ph presented the highest amount of FeN4 active sites and an adequate degree of steric hindrance to maintain the isolation between catalytically active sites. Moreover, it displayed comparable current density limits and superior mass activity and half-wave potential (i.e., 0.88 V vs RHE) than those of 20% Pt/C benchmark catalyst, while keeping higher stability toward methanol oxidation. K-FePc2Ph can be an interesting alternative to Pt-based ORR electrocatalysts., The authors acknowledge MINECO of Spain MAT2017-82288-C2-2-P and RTI2018-097728-B-I00 projects for financial support. A.V.-G. thanks Ministerio de Educación y Formación Profesional for FPU17/03463. L.Z.G. also acknowledges the Chinese Scholarship Council for a PhD research fellowship (CSC no. 201608330266).

Water-in-salt (WIS) electrolytes are gaining increased interest as an alternative to conventional aqueous or organic ones. WIS electrolytes offer an interesting combination of safety, thanks to their aqueous character, and extended electrochemical stability window, thanks to the strong coordination between water molecules and ion salt. Nonetheless, cost, the tendency of salt precipitation, and sluggish ionic transfer leading to poor rate performance of devices are some intrinsic drawbacks of WIS electrolytes that yet need to be addressed for their technological implementation. It is worth noting that the absence of "free'' water molecules could also be achieved via the addition of a certain cosolvent capable of coordinating with water. This is the case of the eutectic mixture formed between DMSO and H2O with a molar ratio of 1:2 and a melting point as low as -140 °C. Interestingly, addition of salts at near-saturation conditions also resulted in an increase of the boiling point of the resulting solution. Herein, we used a eutectic mixture of DMSO and H2O for dissolution of LiTFSI in the 1.1-8.8 molality range. The resulting electrolyte (e.g., the so-called aqueous-eutectic-in-salt) exhibited excellent energy and power densities when operating in a supercapacitor cell over a wide range of extreme ambient temperatures, from as low as -35 °C to as high as +65 °C.

Deep eutectic solvents (DESs) resulting from the right combination between a hydrogen-bond donor (HBD) and a hydrogen-bond acceptor (HBA) are becoming quite popular in number of applications. More recently, natural DESs (NADESs) containing sugars, natural organic acids, and amino acids as HBDs and ChCl as HBA have received great attention because of their further environmental sustainability as compared to regular DESs. Within this context, mixing water in controlled amounts has been widely accepted as a simple and practical way of altering DES chemical and thermodynamic properties, with viscosity and conductivity experiencing the most significant changes. However, the number of papers describing eutectic mixtures with water as the only HBD is scarce and basically none has been done in fundamental terms. Herein, we investigated mixtures composed of water as the only HBD and ChCl as the HBA using differential scanning calorimetry (DSC) as well as

Neural tissue engineering approaches show increasing promise for the treatment of neural diseases including spinal cord injury, for which an efficient therapy is still missing. Encouraged by both positive findings on the interaction of carbon nanomaterials such as graphene with neural components and the necessity of more efficient guidance structures for neural repair, we herein study the potential of reduced graphene oxide (rGO) microfibers as substrates for neural growth in the injured central neural tissue. Compact, bendable, and conductive fibers are obtained. When coated with neural adhesive molecules (poly-L-lysine and N-cadherin), these microfibers behave as supportive substrates of highly interconnected cultures composed of neurons and glial cells for up to 21 days. Synaptic contacts close to rGO are identified. Interestingly, the colonization by meningeal fibroblasts is dramatically hindered by N-cadherin coating. Finally, in vivo studies reveal the feasible implantation of these rGO microfibers as a guidance platform in the injured rat spinal cord, without evident signs of subacute local toxicity. These positive findings boost further investigation at longer implantation times to prove the utility of these substrates as components of advanced therapies for enhancing repair in the damaged central neural tissue including the injured spinal cord., This work was supported by the Instituto de Salud Carlos III-MINECO-FEDER (CP13/00060), the Ministerio de Economía y Competitividad, and the Fondo Europeo de Desarrollo Regional (MAT2016-78857-R and MAT2015-68639-R, MINECO/FEDER, UE). It was also partially funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 737116.

The elimination of small amounts of water from alcohols is by no means a trivial issue in many practical applications like, for instance, the dehumidification of biocombustibles. The use of carbonaceous materials as sorbents has been far less explored than that of other materials because their hydrophobic character has typically limited their water uptake. Herein, we designed a synthetic process based on the use of eutectic mixtures that allowed the homogeneous dispersion of graphene oxide (GO) in the liquid containing the carbon precursor, e.g., furfuryl alcohol. Thus, after polymerization and a subsequent carbonization process, we were able to obtain porous carbon–GO composites where the combination of pore diameter and surface hydrophilicity provided a remarkable capacity for water uptake but extremely low methanol and ethanol uptake along the entire range of relative pressures evaluated in this work. Both the neat water uptake and the uptake difference between water and either methanol or ethanol of our carbon–GO composites were similar or eventually better than the uptake previously reported for other materials, also exhibiting preferential water-to-alcohol adsorption, e.g., porous coordination polymers, metal–organic frameworks, polyoxometalates, and covalent two-dimensional nanosheets embedded in a polymer matrix. Moreover, water versus alcohol uptake was particularly remarkable at low partial pressures in our carbon–GO composites. This work was supported by MINECO/FEDER (Project Numbers MAT2015-68639-R, MAT2016-80285-P, and RTI2018-097728-B-I00). L.Z.G. acknowledges the Chinese Scholarship Council for a PhD research fellowship (CSC No. 201608330266). C.C.-C. acknowledges UA for a research contract.

Vortex ring (VR) processes have proved highly effective in tailoring the morphology/shape of particles prepared from nanoclays, silica nanocolloids, magnetic nanoparticles and different polysaccharides. Herein, we have prepared toroidal-, teardrop-, jellyfish-, and cap-shaped vortex ring particles by drip- ping an aqueous suspension of graphene oxide (GO) into a cetyl trimethylammonium bromide (CTAB) aqueous solution that played the role of coagulating agent. Interestingly, the GO suspension exhibited liquid crystalline features. We demonstrated how controlling the drop impact force against the liquid surface was critical to produce VR particles with such intriguing shapes. With the purpose of controlling the drop impact force, we studied the drop density/viscosity, the speed at which the drop impacts the surface of the liquid pool and the surface tension of the CTAB solution. Finally, we also demonstrated the antibacterial activity of the resulting GO-based VR particles against Escherichia coli and Bacillus subtilis, and discussed about the origin of such a behaviour. In particular, we investigated the occurrence of (1) membrane damage by physical contact between GO and bacteria, (2) GO-induced oxidative stress, or (3) CTAB released into the bacteria culture, the antiseptic and disinfectant action of which may ultimately kill bacteria., This work was supported by MINECO/FEDER (Project Numbers MAT2015-68639-R and BIO2015-66203-P). L. Z. Guan also acknowledges Chinese Scholarship Council for a PhD research fellowship.

Ionic liquids (ILs) are being widely used in many diverse areas of social interest, including catalysis, electrochemistry, etc. However, issues related to hygroscopicity of many ILs and the toxic and/or nonbiodegradable features of some of them limit their practical use. Developing materials capable of IL recovery from aqueous media and dehydration, thus allowing their recycling and subsequent reutilization, in a single and efficient process still poses a major challenge. Herein, electrically conductive aerogels composed of carbon nanofibers (CNFs) with remarkable superhydrophobic features are prepared. CNF-based 3D aerogels are prepared through a cryogenic process, so called ice-segregation-induced self-assembly (ISISA) consisting of the unidirectional immersion of an aqueous chitosan (CHI) solution also containing CNFs in suspension into a liquid nitrogen bath, and subsequent freeze-drying. The CNF-based 3D aerogels prove effective for absorption of ILs from aqueous biphasic systems and recovery with quite low water contents just through a single process of filtration. Moreover, the electrical conductivity of CNF-based 3D aerogels is particularly interesting to treat highly viscous ILs because the Joule effect allows not only shortening of the absorption process but also enhancement of the flux rate when operating in flow-through conditions.

Deep eutectic solvents are a new class of ionic liquids obtained via the complexion of quaternary ammonium salts with hydrogen-bond donors (such as acids, amines, and alcohols, among others). The charge delocalization that occurs through hydrogen bonding between the halide anion with the hydrogen-donor moiety is responsible for the decrease in the freezing point of the mixture, relative to the melting points of the individual components. We have recently reported on the use of deep eutectic solvents as suitable solvents, to carry out the polycondensation of resorcinol−formaldehyde. [Chem. Mater. 2010, 22, 2711−2719.] Herein, we describe the synthesis of deep eutectic solvents (DESs) based on resorcinol, the use of which as both carbonaceous precursors and structure-directing agents allowed the preparation of hierarchical porous (bimodal, with micropores and mesopores) carbon monoliths via formaldehyde polycondensation and subsequent carbonization. The performance of resorcinol-based DESs as carbonaceous p...

Deep eutectic solvents (DESs) composed of resorcinol, either 2-cyanophenol or 4-cyanophenol, and choline chloride were used for the synthesis of hierarchical nitrogen-doped carbon molecular sieves. Carbons were obtained with high conversions by polycondensation of resorcinol and either 2-cyanophenol or 4-cyanophenol with formaldehyde, and subsequent carbonization at 800 °C in nitrogen atmosphere. The nitrogen content was ca. 2.4 wt%, revealing an excellent nitrogen-doping efficiency for cyanophenol derivatives when used in the form of DES. The use of either 2-cyanophenol or 4-cyanophenol modified the contribution of quaternary-Nvalley groups in the resulting carbons, being larger in carbons coming from 4-cyanophenol than in those coming from 2-cyanophenol. The hierarchical porous structure was composed of micro-, meso- and macropores, and the diameter distribution of mesopores was also related to the use of either 2-cyanophenol or 4-cyanophenol. These structural and compositional differences were critical for the use of the resulting hierarchical nitrogen-doped carbons as efficient metal-free electrocatalysts. In particular, the carbons coming 4-cyanophenol proved particularly effective in the direct reduction of oxygen to OH− (H2O in acidic solution) through a four-electron (4e−) process with high catalytic activity and selectivity, and longer stability and stronger tolerance to crossover effects than platinum-based electrocatalysts.

Eutectic mixtures of the monohydrated form of p-toluenesulfonic acid (pTsOH·HO) and triethyl phosphate (TEP) in a 1: 1 molar ratio were used as the medium to disperse previously functionalized multiwalled carbon nanotubes (MWCNTs), and to catalyse the polycondensation of furfuryl alcohol. Hierarchically structured P-doped carbon-CNT composites were obtained after carbonization. The high surface area, the phosphate functionalization, the hierarchical structure and the good electrical conductivity exhibited by these composites provided remarkable metrics when they were used as electrodes in a supercapacitor cell, with energy densities of around 22.6 W h kg and power densities of up to 10 kW kg for operational voltages of up to 1.5 V. This performance surpasses any performance previously reported for electrodes weighing (at least) 10 mg per cm of current collector and using an aqueous electrolyte. Actually, the supercapacitor cell built up with these electrodes provided enough neat energy to turn an IR LED of 30 mW on and emit light over a certain period., This study was supported by MINECO (MAT2012-34811). J. P. and N. L.-S. acknowledge MINECO for their respective FPI contracts.

Correction for ‘Nitrogen-doped carbons prepared from eutectic mixtures as metal-free oxygen reduction catalysts’ by Nieves López-Salas et al., J. Mater. Chem. A, 2016, 4, 478–488.

Poly(octanediol-co-citrate) elastomers containing high loading of lidocaine were synthesized at temperatures below 100 °C by means of using deep eutectic mixtures of 1,8-octanediol and lidocaine. The preservation of lidocaine integrity resulted in high-capacity drug-eluting elastomers.

This chapter discusses the use of deep eutectic solvent-assisted syntheses which allow the preparation of both chemically and structurally modified carbon monoliths suitable as electrodes in supercapacitor cells. Either carbons or carbon–carbon nanocomposites exhibiting a hierarchical structure and a tailored composition (either nitrogen or phosphorus doped) could be attained by the use of different mixtures of deep eutectic solvents (DESs). Carbons prepared from DESs are also suitable for CO2 adsorption and CO2–N2 and/or CO2–CH4 separation processes. These features, besides the low-cost character of our carbons, open interesting perspectives for their application as sorbents in separation technologies for CO2 low-pressure post-combustion processes and natural gas upgrading.

The use of deep eutectic solvents (DESs) that act as all-in-one solvent-template-reactant systems offers an interesting green alternative to conventional syntheses in materials science. This Review aims to provide a comprehensive overview to emphasize the similarities and discrepancies between DES-assisted and conventional syntheses and rationalize certain green features that are common for the three DES-assisted syntheses described herein: one case of radical polymerization and two cases of polycondensations. For instance, DESs contain the precursor itself and some additional components that either provide certain functionality (e.g., drug delivery and controlled release, or electrical conductivity) to the resulting materials or direct their formation with a particular structure (e.g., hierarchical-type). Moreover, DESs provide a reaction medium, so polymerizations are ultimately carried out in a solventless fashion. This means that DES-assisted syntheses match green chemistry principles 2 and 5 because of the economy of reagents and solvents, whereas the functionality incorporated by the second component allows the need for any post-synthesis derivatization to be minimized or even fully avoided (principle 8). DESs also provide new precursors that favor more efficient polymerization (principle 6) by decreasing the energy input required for reaction progress. Finally, the use of mild reaction conditions in combination with the compositional versatility of DESs, which allows low-toxic components to be selected, is also of interest from the viewpoint of green chemistry because it opens up the way to design biocompatible and/or eco-friendly synthetic methods (principle 3). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim., MINECO. Grant Numbers: MAT2009-10214, MAT2011-25329, MAT2012-34811.

Hierarchically structured graphitic carbons synthesized from deep eutectic solvents exhibit a bicontinuous structure where the continuity of the graphitic domains throughout the entire 3D carbon network provides electrical conductivities of up to 31 S/cm to the depicted monoliths. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim., Funded by: MINECO. Grant Numbers: MAT2009–10214, MAT2011–25329, MAT2012–34811.

Deep Eutectic Solvents (DESs) formed between Acrylic Acid (AA) and Choline Chloride (CCl) exhibit certain properties of ionic liquids (e.g. high viscosity) that make them suitable for frontal polymerization (FP). The use of DESs not only as a monomer but also as the solvent prevents the use of additional solvents (i.e. typically of organic nature) and offers a green tool for the synthesis of functional composites. We have recently explored this approach for the preparation of poly(acrylic acid) (PAA) and poly(methacrylic acid). In this work, we have taken advantage of the outstanding capability of DESs to solubilize and/or disperse a number of substances to incorporate-in a homogeneous fashion-carbon nanotubes (in this particular case, N-doped MWCNT-CNxMWCNTs) in the polymerizable DES. Interestingly, CNxMWCNTs also played the role of an inert filler in FP. The resulting PAA-CNxMWCNT composites exhibited some distinct features as compared to previous PAA also obtained via DES-assisted FP. For instance, PAA-CNxMWCNT composites can undergo swelling depending on the pH, as bare PAA. However, the presence of CNxMWCNTs allows the formation of a macroporous structure after submission to a freeze-drying process, the achievement of which was not possible in bare PAA. The combination of structural (e.g. macroporosity) and functional (e.g. stimuli responsive) properties exhibited by these materials besides an eventually high biocompatibility-coming from the green character of the DES-assisted synthesis-should make the resulting macroporous PAA-CNxMWCNT composites excellent candidates for their future application as biomaterials. © 2013 The Royal Society of Chemistry., F. dM. acknowledges support from Grant reference numbers MAT2009-10214, MAT2011-25329,MAT2012-34811. P. Santiago acknowledges financial support from DGAPA-UNAM, through grant IN113411.

Carbon nanotubes and graphene are some of the most intensively explored carbon allotropes in materials science. This interest mainly resides in their unique properties with electrical conductivities as high as 104 S cm-1, thermal conductivities as high as 5000 W m-1 K and superior mechanical properties with elastic moduli on the order of 1 TPa for both of them. The possibility to translate the individual properties of these monodimensional (e.g. carbon nanotubes) and bidimensional (e.g. graphene) building units into two-dimensional free-standing thick and thin films has paved the way for using these allotropes in a number of applications (including photocatalysis, electrochemistry, electronics and optoelectronics, among others) as well as for the preparation of biological and chemical sensors. More recently and while recognizing the tremendous interest of these two-dimensional structures, researchers are noticing that the performance of certain devices can experience a significant enhancement by the use of three-dimensional architectures and/or aerogels because of the increase of active material per projected area. This is obviously the case as long as the nanometre-sized building units remain accessible so that the concept of hierarchical three-dimensional organization is critical to guarantee the mass transport and, as consequence, performance enhancement. Thus, this review aims to describe the different synthetic processes used for preparation of these three-dimensional architectures and/or aerogels containing either any or both allotropes, and the different fields of application in which the particular structure of these materials provided a significant enhancement in the efficacy as compared to their two-dimensional analogues or even opened the path to novel applications. The unprecedented compilation of information from both CNT- and graphene-based three-dimensional architectures and/or aerogels in a single revision is also of interest because it allows a straightforward comparison between the particular features provided by each allotrope. © The Royal Society of Chemistry 2013., This work was supported by MINECO (projects MAT2012-34811, MAT2011-25329 and MAT2009-10214).

Microwave irradiation combined with mild heating was demonstrated as a suitable synthetic method for the preparation of NiCo2O4 nanowires and NiCo2O4-graphene oxide nanocomposites. In both cases, the synthesis was carried out in just a few minutes, at relatively low temperatures and with a certain economy of reagents. In the particular case of the nanocomposites, NiCo2O4 was deposited in form of not only nanowires, but also ultrafine nanoparticles on the surface of graphene oxide sheets due to the preferred activation of these sheets under microwave irradiation. The nanocomposites exhibited a superior performance to NiCo 2O4 nanowires as electrodes in pseudocapacitors with capacitance retentions of nearly 735 F g-1 at current densities of up to 33 A g-1. © 2013 The Royal Society of Chemistry.

Ionic liquids and deep eutectic solvents (a new class of ionic liquids obtained by complexation of quaternary ammonium salts with hydrogen bond donors such as acids, amines, and alcohols among others) have been recently used as solvents and even as precursors in the synthesis of carbonaceous materials. The use of long-alkyl-chain derivatives of ionic liquids that, playing the role of structure directing agents, were capable of designing the mesoporous structure of the resulting carbons is of particular interest. Meanwhile, deep eutectic solvents proved efficient in tailoring the structure comprised between large mesopores and small macropores, but the control over the smaller ones (e.g. small mesopores and micropores) is still a challenge as compared to ILs. Herein, we have used deep eutectic solvents composed of resorcinol, 4-hexylresorcinol and tetraethylammonium bromide for the synthesis of carbon monoliths with a tailor-made narrow microporosity. Behaving as molecular sieves, these carbons exhibited not only good capacities for CO2 adsorption (up to 3 mmol g−1) but also an outstanding – especially at low pressures – CO2–CH4 selectivity., This work was supported by MINECO (MAT2009‐10214 and MAT2011‐25329). DC acknowledges MINECO for a JdelaC research contract. JP acknowledges MINECO for a FPI fellowship. COA and JBP thank the financial support of FICYT (EQUIP08‐36, file num. 04010208000281).

Deep eutectic solvents promoted the stabilization of the collapsed state of elastin-like recombinamers - and the subsequent formation of aggregates - upon the loss of the structural water molecules involved in hydrophobic hydration. Cryo-etch scanning electron microscopy allowed the observation of these aggregates in neat deep eutectic solvents. The suppression of the lower critical solution temperature transition, observed by differential scanning calorimetry and dynamic light scattering, confirmed the presence of the elastin-like recombinamers in their collapsed state. Actually, the transition from the collapsed to the expanded state was suppressed even after moderate aqueous dilution - for water contents ranging from nil to ca. 45 wt % - and it was only recovered upon further addition of water - above 50 wt %. These features revealed the preferred stabilization of the collapsed state in not only neat deep eutectic solvents but also partially hydrated deep eutectic solvents. We consider that the capability to trigger the lower critical solution temperature transition by partial hydration of deep eutectic solvent may open interesting perspectives for nano(bio)technological applications of elastin-like recombinamers.

The treatment of bone lesions, including fractures, tumor resection and osteoporosis, is a common clinical practice where bone healing and repair are pursued. It is widely accepted that calcium phosphate-based materials improve integration of biomaterials with surrounding bone tissue and further serve as a template for proper function of bone-forming cells. Within this context, mineralization on preformed substrates appears as an interesting and successful alternative for mineral surface functionalization. However, mineralization of >true> 3D scaffolds -in which the magnitude of the third dimension is within the same scale as the other two- is by no means a trivial issue because of the difficulty to obtain a homogeneous mineral layer deposited on the entire internal surface of the scaffold. Herein, a >flow-through> electrodeposition process is applied for mineralization of 3D scaffolds composed of multiwall carbon nanotubes and chitosan. It is demonstrated that, irrespective of the experimental conditions used for electrodeposition (e.g., time, temperature and voltages), the continuous feed of salts provided by the use of a flow-through configuration is the main issue if one desires to coat the entire internal structure of 3D scaffolds with a homogeneous mineral layer. Finally, mineralized scaffolds not only showed a remarkable biocompatibility when tested with human osteoblast cells, but also enhanced osteoblast terminal differentiation (as early as 7 days in calcifying media). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim., This work was supported by grants from MINECO (Project Numbers MAT2009-10214 and MAT2011-25329) and from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number 263289 (Green Nano Mesh). S.N. acknowledges CSIC for a JAE-Pre fellowship. M. C. S. is greatly in debt with MINECO for a Juan de la Cierva fellowship. Fernando Pinto (from the Instituto de Ciencias Agrarias-CSIC) and Sylvia Gutierrez (from the Centro Nacional de Biotecnologia-CSIC) are acknowledged for their assistance with SEM and confocal microscopy studies, respectively.

Significant progress is described in the development of cellular solids, specifically functional and multifunctional foams, prepared by bioinspired approaches and consisting of green components. This article covers recent examples mainly developed at the Materials Science Institute of Madrid, ICMM-CSIC, on bionanocomposites and bioinspired materials conformed as foams. These novel hierarchical porous systems bring out a broad range of advanced applications from biomedical purposes to energy generation and storage. Recent progress in the development of advanced bionanocomposite and bioinspired foams with controlled porosity and low relative density is paving the way towards applications in a wide range of fields, from energy storage and insulating materials with reduced flammability for application in building and transport productivity sectors to novel scaffolds for tissue engineering and other biomedical purposes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim., E. R.-H., P. A., and M. D. are grateful for funding from CICYT (Spain), projects MAT2009-09960 and NAN2007-31173-E, and from CSIC-Academie Hassan II, project 2010MA0003. F.d.M., M. L. F., and M. C. G. acknowledge support from MICINN grant nos. MAT2009-10214 and PET2008-0168-01.

Three-dimensional microchannelled nanocomposite electrodes fabricated by ice-segregation induced self-assembly of chitosan-dispersed multiwall carbon nanotubes are shown to provide a scaffold for growth of electroactive bacteria for use as acetate-oxidizing bioanodes in bioelectrochemical systems. The hierarchical structure provides a conductive surface area available for G. sulfurreducens colonization, with a flow through configuration along the electrode providing a substrate for bacterial colonization and bio-electrochemical processes. This configuration, whilst resulting in sub-monolayer biofilm coverage over the three-dimensional surface, is capable of providing acetate oxidation current densities of up to 24.5 A m−2, equating to a volumetric current density of 19 kA m−3, in the flow-through configuration. Such bioanodes, when operated in non-optimized flow-through microbial fuel cell configuration, provide a maximum power density of 2.87 W m−2, which is equivalent to 2.0 kW m−3 volumetric power density.