Self-formation of 3D interconnected macroporous carbon xerogels derived from polybenzoxazine by selective solvent during the sol–gel process
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Polybenzoxazine (PBZ)-based carbon xerogel has been synthesized by a sol–gel process and carbonization. By different solvents, the microstructure of the porous carbon can be tailored for a wide range of desired properties. In addition, a new aspect to produce 3D interconnected macroporous carbon xerogels by selective solvent via self-formation is introduced. Dimethylformamide (DMF), dioxane, and isopropanol are separately used as a solvent during a sol–gel process. The SEM micrographs reveal different structures of carbon xerogel depending on the type of solvent used. Using DMF as a solvent during a sol–gel process and ambient pressure drying, the carbon xerogel shows a similar porous structure to that of a PBZ-based carbon aerogel obtained through supercritical CO2 drying. In the DMF system, a short gelation time is observed (1.15–3 h) due to the fast ring-opening polymerization accelerated by DMF resulting in the formation of 3D interconnected macroporous structure without using any template. Comparing the rates of cluster growth between DMF and dioxane systems, the rate of cluster growth in dioxane system is slower than that of DMF system, implying good miscibility between PBZ and dioxane. Moreover, microporous spherical particles are obtained from the isopropanol system due to the self-micelle-like formation.
KeywordsSolubility Parameter Gelation Time Carbon Aerogel Benzoxazine Phase Separation Process
This work has been financially supported by the Petroleum and Petrochemical College and the Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University. The authors would like to thank Prof. Suwabun Chirachanchai for his kind support on the DLS apparatus. In addition, special thanks also go to the Office of Higher Education Commission for her support of the National Research University Program (WCU-048-CC-57).
- 28.Rubenstein DA, Lu HB, Mahadik SS (2012) Characterization of the physical properties and biocompatibility of polybenzoxazine-based aerogels for use as a novel hard-tissue scaffold. J Biomater Sci Polym Ed 23:1171–1184Google Scholar
- 34.Ishida H (1996) Process for preparation of benzoxazine compounds in solventless systems. US Pat 5543516Google Scholar
- 36.Thubsuang U, Ishida H, Wongkasemjit S, Chaisuwan T (2014) Improvement in the pore structure of polybenzoxazine-based carbon xerogels through a silica templating method. J Porous Mater. doi: 10.1007/s10934-014-9786-7
- 46.Hildebrand JH, Scott RL (1949) The solubility of non-electrolytes, 3rd edn. Dover, New YorkGoogle Scholar
- 50.Kim SI, Yamamoto T, Endo A, Ohmori T, Nakaiwa M (2006) Influence of nonionic surfactant concentration on physical characteristics of resorcinol-formaldehyde carbon cryogel microspheres. J Ind Eng Chem 12:484–488Google Scholar
- 52.Gregg SJ, Sing KSW (1982) Adsorption, surface area and porosity, 2nd edn. Academic Press, LondonGoogle Scholar
- 53.Rouquerol F, Rouquerol J, Sing KSW (1999) Adsorption by powders and porous solids, principles, methodology and applications. Academic Press, LondonGoogle Scholar
- 55.Guzel F, Uzun I (2002) Determination of the micropore structures of activated carbons by adsorption of various dyestuffs from aqueous solution. Turk J Chem 26:369–377Google Scholar