TY - JOUR
T1 - Effect of PPTA pre-impregnation with phosphoric acid on the porous texture of carbons prepared by CO2 activation of PPTA chars
AU - Castro-Muñiz, Alberto
AU - Martínez-Alonso, Amelia
AU - Tascón, Juan M.D.
N1 - Funding Information:
A.C.-M. acknowledges receipt of an I3P pre-doctoral contract from CSIC. Financial support from the Spanish MEC (project CTQ2005-01905-C04-02-PPQ) is gratefully acknowledged.
PY - 2009/3/1
Y1 - 2009/3/1
N2 - Activated carbon fibers (ACFs) were prepared by CO2 gasification to different burn-offs of chars from the polyaramid fiber, poly(p-phenylene terephthalamide) (PPTA) pre-impregnated with 5 wt.% H3PO4. Thermogravimetric analysis showed that the addition of phosphoric acid produces a significant increase in the yield of solid residue. While the char yield of the pure polymer at 1000 °C amounted to 39.5 wt.%, it rose to 52.8 wt.% in the case of 5 wt.% H3PO4-impregnated PPTA. The chars and derived ACFs were characterized by physical adsorption of N2 (-196 °C) and CO2 (0 °C). No significant differences were found as concerns chars porosity. At equivalent burn-offs, the surface area of the ACFs prepared by physical activation with CO2 was up to 70% higher in the case of PPTA pre-impregnated with phosphoric acid, the pore size distribution being displaced towards somewhat wider pores within the 2-10 nm range. These results are in contrast with those obtained previously with the poly(m-phenylene isophthalamide) (PMIA) polymer, where H3PO4 pre-impregnation did not significantly affect the porosity of chars and ACFs.
AB - Activated carbon fibers (ACFs) were prepared by CO2 gasification to different burn-offs of chars from the polyaramid fiber, poly(p-phenylene terephthalamide) (PPTA) pre-impregnated with 5 wt.% H3PO4. Thermogravimetric analysis showed that the addition of phosphoric acid produces a significant increase in the yield of solid residue. While the char yield of the pure polymer at 1000 °C amounted to 39.5 wt.%, it rose to 52.8 wt.% in the case of 5 wt.% H3PO4-impregnated PPTA. The chars and derived ACFs were characterized by physical adsorption of N2 (-196 °C) and CO2 (0 °C). No significant differences were found as concerns chars porosity. At equivalent burn-offs, the surface area of the ACFs prepared by physical activation with CO2 was up to 70% higher in the case of PPTA pre-impregnated with phosphoric acid, the pore size distribution being displaced towards somewhat wider pores within the 2-10 nm range. These results are in contrast with those obtained previously with the poly(m-phenylene isophthalamide) (PMIA) polymer, where H3PO4 pre-impregnation did not significantly affect the porosity of chars and ACFs.
KW - Activated carbon fibers
KW - Adsorption
KW - Mesoporosity
KW - Microporosity
KW - PPTA
KW - Phosphoric acid
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U2 - 10.1016/j.micromeso.2008.10.025
DO - 10.1016/j.micromeso.2008.10.025
M3 - Article
AN - SCOPUS:58149386196
VL - 119
SP - 284
EP - 289
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
SN - 1387-1811
IS - 1-3
ER -