Comparative Study of Graphene Oxide-Gelatin Aerogel Synthesis: Chemical Characterization, Morphologies and Functional Pr
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Comparative Study of Graphene Oxide‑Gelatin Aerogel Synthesis: Chemical Characterization, Morphologies and Functional Properties Sebastián Guajardo1 · Toribio Figueroa1 · Jessica Borges1 · Manuel Meléndrez2 · Katherina Fernández1 Received: 21 August 2020 / Accepted: 25 September 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract Graphene oxide (GO)–gelatin (G) aerogels were synthesized by covalent and noncovalent methods, changing on the synthesis the GO:G ratio and the pH of the GO suspension, evaluating the physical, chemical, and functional properties of these materials. Comparatively, low GO:G ratios with alkali GO suspension promoted GO–G interactions for covalent aerogels. In contrast, high GO:G ratios under acidic conditions promoted noncovalent interactions. Scanning electron microscopy showed heterogeneous structures with pore sizes of 53.26 ± 25.53 µm and 25.31 ± 10.38 µm for covalent and noncovalent aerogels, respectively. The synthesis method did not influence the surface charge; however, differences were depending on the GO content and their chemical activation, shifting from 15.63 ± 0.55 mV to − 20.53 ± 1.07 mV. Noncovalent aerogels presented higher absorption ratios in phosphate-buffered saline (PBS) solution (35.5 ± 2.4 g PBS/gaerogel–49.6 ± 3.8 gPBS/gaerogel) than covalent aerogels. Therefore, due to these properties, noncovalent aerogels could be more useful than covalent aerogels for absorption potential applications, as biomedicine or water-treatment, where the promotion of surface interactions and high absorption capability is desired. Keywords Graphene oxide · Gelatin · Aerogels · Composite
1 Introduction Aerogels are porous structures obtained by removing the liquid from a polymeric network and replacing it with a gas; the above is completed without decisively altering the overall configuration. These materials are synthesized using inorganic (e.g., silica, alumina), organic (e.g., resorcinolformaldehyde, melamine-formaldehyde), carbon derivatives (e.g., using nanotubes, graphene oxide) and natural-based sources (e.g., cellulose, polysaccharides) [1, 2]. Aerogels have low density (0.0003–0.5 g/cm3), high surface area (50–1200 m2/g) and high porosity (70.0–99.8%), and their interesting properties make them useful for applications in diverse fields such as packaging production, food development, and biomedical uses [3]. * Katherina Fernández [email protected] 1
Laboratorio de Biomateriales, Departamento de Ingeniería Química, Facultad de Ingeniería, Universidad de Concepción, Concepción, Chile
Departamento de Ingeniería de Materiales, Facultad de Ingeniería, Universidad de Concepción, Concepción, Chile
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In particular, gelatin (G) aerogels are highlighted due to their nontoxicity, lack of immunogenicity, low price, and high sensitivity [4, 5]. G produces random polydispersed frameworks, which tend to stabilize a triple helix through intermolecular H-bonding, producing tridimensional structures [6, 7]. These matrices are not stable for a long pe
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