title: Towards a feasible and scalable production of bio-xerogels.
abstract: OBJECTIVE
  The synthesis process of carbon xerogels is limited, mainly due to two drawbacks that prevent their introduction onto the market: (i) the long time required for producing the material and (ii) the reagents used for the synthesis, which are costly and harmful to the environment. Microwave radiation is expected to produce a reduction in time of more than 90%, while the use of tannin instead of resorcinol will probably result in a cost-effective carbonaceous material.
  
  
  METHODS
  Resorcinol-tannin-formaldehyde xerogels containing different amounts of tannin, either with or without a surfactant (sodium dodecyl sulphate), were synthesized by means of two different heating methods: conventional and microwave heating. The effects of the surfactant, the heating method and the addition of tannin upon the porous structure and the chemical composition of the final materials were evaluated.
  
  
  RESULTS
  It was found that the addition of surfactant is essential for obtaining highly porous xerogels when using tannins. The heating method also plays an important role, as conventionally synthesized samples display a greater volume of large pores. However, tannins are less sensitive to microwave radiation and their use results in tannin-formaldehyde xerogels that have a porous structure and chemical composition similar to those of resorcinol-formaldehyde xerogels.
authors.affiliation: Instituto Nacional del Carbón, CSIC, Apartado 73, 33080 Oviedo, Spain.
authors.forename: Natalia
authors.initials: N
authors.lastname: Rey-Raap
authors.affiliation: Institut Jean Lamour, UMR CNRS - Université de Lorraine, n°7198, ENSTIB, 27 rue Philippe Séguin, CS 60036, 88026 Épinal Cedex, France.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Szczurek
authors.affiliation: Institut Jean Lamour, UMR CNRS - Université de Lorraine, n°7198, ENSTIB, 27 rue Philippe Séguin, CS 60036, 88026 Épinal Cedex, France.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Fierro
authors.affiliation: Instituto Nacional del Carbón, CSIC, Apartado 73, 33080 Oviedo, Spain.
authors.forename: J Angel
authors.initials: JA
authors.lastname: Menéndez
authors.affiliation: Instituto Nacional del Carbón, CSIC, Apartado 73, 33080 Oviedo, Spain. Electronic address: aapuente@incar.csic.es.
authors.forename: Ana
authors.initials: A
authors.lastname: Arenillas
authors.affiliation: Institut Jean Lamour, UMR CNRS - Université de Lorraine, n°7198, ENSTIB, 27 rue Philippe Séguin, CS 60036, 88026 Épinal Cedex, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Celzard
mesh_terms: D000045:Acacia; D002244:Carbon / Q000737:chemistry; D005557:Formaldehyde / Q000737:chemistry; D005782:Gels / Q000737:chemistry*; D006361:Heating; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008872:Microwaves; D016062:Porosity; D012118:Resorcinols / Q000737:chemistry; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000737:chemistry; D013634:Tannins / Q000737:chemistry
chemical_list: D005782:Gels; D012118:Resorcinols; D013501:Surface-Active Agents; D013634:Tannins; D005557:Formaldehyde; D012967:Sodium Dodecyl Sulfate; D002244:Carbon; C031389:resorcinol
keywords: Microwave radiation; Porous properties; Surfactant; Tannins; Xerogels