abstract
Silica aerogels are amorphous materials with remarkable properties, such as very high porosity and specific surface area, and low bulk density and thermal conductivity. However, the potential applications of these materials are limited as they exhibit poor mechanical strength. Nevertheless, silica aerogels allow easy incorporation of different compounds into their structure, enabling the production of materials with distinct characteristics from those of the native silica aerogels. The addition of particles, polymers or fibers, for improving the mechanical, optical or thermal properties has been extensively investigated by several authors in the last decade. A relatively recent alternative is their modification with carbon nanomaterials, which include carbon nanotubes, carbon nanofibers, graphene and carbon aerogels. These nanostructures have well-known characteristics, such as high electrical conductivity and high mechanical strength. The combination of these carbon materials with silica aerogels can lead to new materials with unique electrochemical performance, and thermal and adsorption properties that can be useful in several fields such as electronics, insulation and wastewater treatment. This paper presents a literature review on the synthesis of composite systems containing silica aerogels and carbon nanostructures, and describes their new properties and applications. Examples are the treatment of oily water and removal of heavy metals from wastewater, as well as their application as thermal insulators or anode materials. Along with these new properties, very promising results in mechanical reinforcement were already observed with the inclusion of carbon nanostructures in silica aerogel matrices, but there is still room for further developments in this regard.
keywords
SOL-GEL PROCESS; CHEMICAL-VAPOR-DEPOSITION; THERMAL INSULATION PROPERTIES; RESORCINOL-FORMALDEHYDE GELS; ORGANIC-INORGANIC MATERIALS; LITHIUM ION BATTERIES; AMBIENT-PRESSURE; SURFACE-AREA; GRAPHENE AEROGELS; AQUEOUS-SOLUTION
subject category
Chemistry; Energy & Fuels; Materials Science
authors
Lamy-Mendes, A; Silva, RF; Duraes, L
our authors
Alyne Cristina Lamy Mendes
PhD Student
Rui Ramos Ferreira e Silva
Associate Professoracknowledgements
Alyne Lamy-Mendes acknowledges CNPq (Brazil) for the funding of the PhD fellowship project 234184/2014-0/GDE, under the programme "Ciencia sem Fronteiras". The authors also would like to thank the CIEPQPF research unit (Coimbra) funded by FEDER funds through the Operational Programme for Competitiveness Factors - COMPETE and National Funds, through FCT - Foundation for Science and Technology, under the projects POCI-01-0145-FEDER-006910 and UID/EQU/00102/2013. This work was also developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement.