Bacterial cellulose (BC) and graphene are materials that have attracted the attention of researchers due to their outstanding properties. BC is a nanostructured 3D network of pure and highly crystalline cellulose nanofibres that can act as a host matrix for the incorporation of other nano-sized materials. Graphene features high mechanical properties, thermal and electric conductivity and specific surface area. In this paper we review the most recent studies regarding the development of novel BC-graphene nanocomposites that take advantage of the exceptional properties of BC and graphene. The most important applications of these novel BC-graphene nanocomposites include the development of novel electric conductive materials and energy storage devices, the preparation of aerogels and membranes with very high specific area as sorbent materials for the removal of oil and metal ions from water ...

The eggshell membrane (ESM) is a biopolymer network that may have potential applications in biomedicine, but it also may reveal important details regarding the behaviour of biopolymer networks. In this paper, we have studied the mechanical and morphological properties of the ESM in order to reveal important structure-property relationships. Light optical microscopy and atomic force microscopy were used to assess the morphology of the ESM. The mechanical properties of membranes and individual fibres were studied by means of tensile tests and nanoindentation tests, respectively. The mechanical behaviour of ESM networks in different environmental conditions showed a non-linear and a linear regime. As for elastomers and other biopolymer systems, the non-linear regime was modelled by the Mooney-Rivlin relation. The Young's modulus in the linear regime of the network was related to the Young's...

In this study, we analyzed the contribution of NH4I and glycerol on the ionic conductivity of carboxymethyl κ/ι-hybrid carrageenan-based solid bio-electrolytes. Electrochemical impedance spectroscopy was used to assess the electrochemical properties of the developed biopolymeric films and their interfaces over a wide range of frequencies (1& Hz–7& MHz). X-ray diffractograms demonstrated the increment of the amorphous fraction in the material as the NH4I content increases, suggesting an enhancement of ion transport processes and the successful incorporation of the salt into the host matrix.

This work was supported by the Vice-Rectorate for Research of the Pontificia Universidad Católica del Perú, the National Council of Science, Technology and Technological Innovation of Peru (CONCYTEC/FONDECYT) and The National Innovation Program for Competitiveness and Productivity (INNOVATE-PERU) of the Peruvian Ministry of Production.

The effect of carboxymethylation and NH4I incorporation on the molecular dynamics of carrageenan films was studied. Broadband Dielectric Spectroscopy (BDS) assessed the presence of α and β relaxation processes. The effect of NH4I content was analyzed using the Havriliak-Negami model and parameterizing the temperature dependence of the relaxation times according to the Vogel-Fulcher-Tammann-Hesse (VFTH) equation. The glass transition temperature was found to decrease with the increase of NH4I content. These results suggest that carboxymethylation and the salt doping treatment increase the molecular mobility of NH4+ ions, making the films suitable for the development of solid electrolytes for energy storage applications. © 2018, © 2018 Taylor & Francis Group, LLC.

In this study, we analyzed the contribution of NH4I and glycerol on the ionic conductivity of carboxymethyl κ/ι-hybrid carrageenan-based solid bio-electrolytes. Electrochemical impedance spectroscopy was used to assess the electrochemical properties of the developed biopolymeric films and their interfaces over a wide range of frequencies (1& Hz–7& MHz). X-ray diffractograms demonstrated the increment of the amorphous fraction in the material as the NH4I content increases, suggesting an enhancement of ion transport processes and the successful incorporation of the salt into the host matrix. The shift of the OH peaks in the FTIR spectra confirmed the interaction between carboxymethyl carrageenan, NH4I, and glycerol. EIS results were represented in the complex plane and were fitted to an Rs(R1Q1) equivalent circuit. The ionic conductivity for carboxymethyl carrageenan doped with xNH4I (...

This research was funded by FONDECYT-CONCYTEC , grant number 063-2018-FONDECYT-BM .

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the National Council of Science, Technology and Technological Innovation [CONCYTEC-FONDECYT]; and the Vice-Rectorate for Research of the Pontificia Universidad Catolica del Peru [VRI-PUCP].

The Vice-Rectorate for Research (VRI-PUCP) of the Pontificia Universidad Catolica del Peru and the National Council of Science, Technology and Technological Innovation (CONCYTEC-FONDECYT) are greatly acknowledged for financial support. The Institute of Polymer Science and Technology of the Spanish Council for Scientific Research (ICTP-CSIC, Madrid, Spain) is acknowledged for experimental assistance.