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• Ionic conductive bio-based composite aerogels

  S. AMENTA, L. Cruz, T. Abt, N. León, A. Lamberti, L. Marchese, M. Sanchez-Soto

  Materiales Compuestos (Online first).

  
  

  Abstract

  In the realm of energy transition, significant advancements are essential on the improvement of energy storage performance as well as in sustainability and safety. Aerogels are lightweight materials that can be endowed with mechanical strength, thermal insulation capability, and fire resistance. These characteristics make them promising for electrochemical devices such as composite polymer electrolytes (CPE). Silica-based aerogels have been used as scaffolds for solid polymer electrolytes (SPE). In these applications, the aerogel not only provides structural support but also creates additional conduction channels that improve ionic conductivity (IC). In this work, we present a bio-based aerogel composed of gelatin, montmorillonite clay, and tannic acid, synthesized using water as a solvent. By employing an ice templating strategy, we achieved a 1D pore orientation, which provides more direct conduction pathways. This aerogel exhibits an axially oriented honeycomb porous structure with high porosity (92.9 ± 0.1%) and low density (0.130 ± 0.002 g/cm³). It is also categorized as a self-extinguishing material. This aerogel was infiltrated with a SPE consisting of Polyethylene glycol (PEG) and Lithium bis (trifluoromethanesulfonyl) imide (LiTFSI). With partial pore coverage, we achieved IC at room temperature on the order of 2 × 10-7 S/cm. This led to promising results, resulting in a porous (76%) ionic conductive aerogel that opens new perspectives. It enables the creation of a low-density solid electrolyte, which can increase the specific capacity of the final device. Alternatively, it can serve as an active, fire resistant, scaffold for a liquid or gel electrolyte, enhancing and maximizing IC.

  Abstract
  In the realm of energy transition, significant advancements are essential on the improvement of energy storage performance as well as in sustainability and safety. Aerogels [...]

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• Characterization and properties of bio-aerogels composed of gelatin.

  L. Cruz, T. Abt, N. Candau, N. León, M. Sanchez-Soto

  Materiales Compuestos (2025). Vol. 08 - COMUNICACIONES MATCOMP21 (2022) Y MATCOMP23 (2023), (Núm. 7 - Caracterización - Sostenibilidad y Reciclaje), 11

  
  

  Abstract

  Aerogels are low density foam-like materials that are obtained from a sol-gel process in which the solvent used is replaced by air without collapsing the previously formed three-dimensional structure. In this work, we have studied the properties of aerogels composites that have been generated only from natural substances, using gelatin as matrix, clay and tannic acid as modifiers and water as unique solvent. The aerogels were obtained through lyophilization. While pure gelatin aerogel behaves like an elastic and low-stiffness foam, the addition of tannic acid and clay allow obtaining high resistant foams, reaching of up to a 9-fold increase in the elastic modulus, maintaining very low densities ( 0.14 g/cm3). These increases were obtained, on the one hand, due to a change in the aerogel micro-structure that evolved from a layered towards a honeycomb one. On the other hand, the alkaline conditions employed lead to the oxidation of tannic acid that was then able to establish covalent bonding with the amino groups of gelatin. The presence of well-dispersed clay in the matrix significantly reduced the rate of thermal degradation of the compounds due to its rearrangement into a stable protective layer on the surface of the material. Under conditions similar to those developed in a fire, the compound exhibited low flammability and high resistance to the spread of fire thanks to the synergistic action between clay and tannic acid. The achievement of multifunctional properties in these natural aerogels, allows broadening its applications, making that eventually, can replace traditional petroleum-derived foams, such as polyurethane, polystyrene or phenol-formaldehyde that have a notable environmental impact.

  Abstract
  Aerogels are low density foam-like materials that are obtained from a sol-gel process in which the solvent used is replaced by air without collapsing the previously formed [...]

  • 58
  •  read