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Effect of micropore and mesopore structure on CO2 adsorption by activated carbons from biomass
CARBON 93 (2015) 1081– 1084
Pd nanoparticles (Pd-NPs) were deposited on the surface of
a
1083
Department of Engineering Materials, Faculty of Manufacturing
Vulcan XC-72 carbon black (CB), multi-walled carbon nanotubes
Engineering, Universiti Teknikal Malaysia Melaka (UTeM), Hang Tuah
(MWCNTs) and carbon spheres (CSs) by the spontaneous reduction
Jaya, 76100 Durian Tunggal, Melaka, Malaysia
of PdCl2 with oxygen-functional groups on the carbon surfaces to
b
Department of Telecommunication, Faculty of Electronics and
produce catalysts for the electrochemical oxidation of ethanol.
Computer Engineering, Universiti Teknikal Malaysia Melaka (UTeM),
These carbons were also modified with a cationic surfactant (hex-
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia
adecyltrimethyl ammonium bromide, CTAB) and subsequently used as supports for the deposition of Pd nanoparticles using the
Activated carbons were prepared from rubber wood sawdust
spontaneous reduction method. SEM, TEM and XRD were used to
by chemical activation using ZnCl2 as an activation agent at
characterize their structures. Pd-NPs with a size of ca. 9 nm were
500 °C for 60 min with ZnCl2/dried rubber wood sawdust mass
obtained on the surface of the CTAB-modified MWCNTs. The
ratios from 1.0 to 2.0. Flat polyurethane (PU) composites filled
amount of Pd-NPs spontaneously deposited on the CTAB-
with the activated carbons were prepared by a chemical foaming
MWCNTs is much larger than that on the MWCNTs, CB or CSs.
method using different loading amounts of the activated carbons
The Pd/CTAB-MWCNTs exhibit a higher anodic peak current den-
to investigate their complex permittivity and the microwave
in cyclic voltammetry, indicating a better elec-
absorption properties for use in electromagnetic interference
trocatalytic activity for ethanol oxidation than the other catalysts.
(EMI) shielding. It was found that the best activated carbon is
[New Carbon Materials 2015, 30(2): 150–155]
obtained at a ratio of 1.5, which has the highest Brunauer–
sity of 44.2 mAcm
2
Emmett–Teller surface area and a micropore volume of 1301 m2/ g and 0.37 cm3/g, respectively. With increasing activated carbon
http://dx.doi.org/10.1016/j.carbon.2015.04.074
content, the dielectric constant (e0 ) and the return loss increase Effect of micropore and mesopore structure on CO2 adsorption by activated carbons from biomass
8 wt% activated carbon has a maximum dielectric constant of 3.0 and its return loss is above 10 dB at the global system mobile
Tao Songa, Jing-ming Liaoa,b, Jun Xiaoa, Lai-hong Shena a
in the frequency range of 1–3 GHz. The composite filled with
phone frequency of 1.8 GHz. Its EMI shielding efficiency is in the
Key Laboratory of Energy Thermal Conversion and Control of Ministry
useful range of approximately 3 dB over a wide frequency range
of Education, Southeast University, Nanjing 210096, China
of 1–2.5 GHz. Compared with conventional materials such as
b
polyethelene and polyester filled with metal additives, this com-
Fujian Electric Power Survey & Design Institute, Fuzhou 350003, China
posite is suitable for microwave absorption and is a potential canActivated carbons (ACs) were produced by a one step process with CO2 as the physical activation agent at 800 °C. The ACs were further activated chemically using KOH, HNO3 or CH3COOH and heat-treated at 300 or 600 °C for 1 or 2 h to modify their proper-
didate for EMI shielding applications. [New Carbon Materials 2015, 30(2): 167–175] http://dx.doi.org/10.1016/j.carbon.2015.04.076
ties. The effect of CO2 concentration, activation time, types of chemical agents and the post heat-treatment conditions on CO2
Rheological properties of mesophase pitch investigated by the
capture were investigated. Results showed that the optimum con-
Giseeler fluidity method
ditions for AC production from corn stalks was at 800 °C for
Ming-lin Jin, Jie-ling Cheng, Lian-xing Wang, Shuang-ling Jin,
30 min with a CO2 concentration of 20% during the physical acti-
Rui Zhang
vation. Chemical agents and further heat-treatment modified the pore structure of the ACs, resulting in a performance improvement for CO2 adsorption. The BET surface area of one sample
School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418, China
(HNO3 activation + 100 °C water bath 1 h + post heat-treatment at 600 °C for 2 h) was 639. 8 m2/g. The maximum CO2 adsorption
The Giseeler fluidity method was used to investigate the rheo-
capacity of the sample was 7.33 wt%, which is higher than that
logical properties of pitch with and without heat treatment from
of a commercial AC (6.55 wt%). The CO2 adsorption is dominantly
room temperature to 520 °C. Results show that the fluidity has a
dependent on the mesopore volume when the BET surface area is
good repeatability at different temperatures under different heat-
smaller than 500 m2/g while the adsorption is closely associated
ing rates. The fluidity of the raw pitch slowly increases from 253
with micropore area when the BET surface area is larger than
to 282 °C, then increases exponentially from 282 to 311 °C near
500 m2/g.
the softening temperature, and finally remains unchanged from
The
adsorption
kinetics
agreed
well
with
the
Bangham kinetic model.
311 to 498 °C. This changing pattern of fluidity with temperature
[New Carbon Materials 2015, 30(2): 156–166]
has also been found for heat-treated mesophase pitch and can be formulated by the Arrhenius equation, from which the viscous
http://dx.doi.org/10.1016/j.carbon.2015.04.075
flow activation energy can be obtained. The toluene-insoluble fraction increases from 67.3% to 88.7% with heat-treatment time
Preparation of rubber wood sawdust-based activated carbon and its use as a filler of polyurethane matrix composites for microwave absorption a
a
b
Azizah Shaaban , Sian-Meng Se , Imran Mohd Ibrahim , Qumrul Ahsana
and the flow activation energy of the treated mesophase pitch in the Newtonian fluid region at low temperature range is between 203.6 and 294 kJ/mol. [New Carbon Materials 2015, 30(2): 176–180] http://dx.doi.org/10.1016/j.carbon.2015.04.077
Pd nanoparticles (Pd-NPs) were deposited on the surface of
a
1083
Department of Engineering Materials, Faculty of Manufacturing
Vulcan XC-72 carbon black (CB), multi-walled carbon nanotubes
Engineering, Universiti Teknikal Malaysia Melaka (UTeM), Hang Tuah
(MWCNTs) and carbon spheres (CSs) by the spontaneous reduction
Jaya, 76100 Durian Tunggal, Melaka, Malaysia
of PdCl2 with oxygen-functional groups on the carbon surfaces to
b
Department of Telecommunication, Faculty of Electronics and
produce catalysts for the electrochemical oxidation of ethanol.
Computer Engineering, Universiti Teknikal Malaysia Melaka (UTeM),
These carbons were also modified with a cationic surfactant (hex-
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia
adecyltrimethyl ammonium bromide, CTAB) and subsequently used as supports for the deposition of Pd nanoparticles using the
Activated carbons were prepared from rubber wood sawdust
spontaneous reduction method. SEM, TEM and XRD were used to
by chemical activation using ZnCl2 as an activation agent at
characterize their structures. Pd-NPs with a size of ca. 9 nm were
500 °C for 60 min with ZnCl2/dried rubber wood sawdust mass
obtained on the surface of the CTAB-modified MWCNTs. The
ratios from 1.0 to 2.0. Flat polyurethane (PU) composites filled
amount of Pd-NPs spontaneously deposited on the CTAB-
with the activated carbons were prepared by a chemical foaming
MWCNTs is much larger than that on the MWCNTs, CB or CSs.
method using different loading amounts of the activated carbons
The Pd/CTAB-MWCNTs exhibit a higher anodic peak current den-
to investigate their complex permittivity and the microwave
in cyclic voltammetry, indicating a better elec-
absorption properties for use in electromagnetic interference
trocatalytic activity for ethanol oxidation than the other catalysts.
(EMI) shielding. It was found that the best activated carbon is
[New Carbon Materials 2015, 30(2): 150–155]
obtained at a ratio of 1.5, which has the highest Brunauer–
sity of 44.2 mAcm
2
Emmett–Teller surface area and a micropore volume of 1301 m2/ g and 0.37 cm3/g, respectively. With increasing activated carbon
http://dx.doi.org/10.1016/j.carbon.2015.04.074
content, the dielectric constant (e0 ) and the return loss increase Effect of micropore and mesopore structure on CO2 adsorption by activated carbons from biomass
8 wt% activated carbon has a maximum dielectric constant of 3.0 and its return loss is above 10 dB at the global system mobile
Tao Songa, Jing-ming Liaoa,b, Jun Xiaoa, Lai-hong Shena a
in the frequency range of 1–3 GHz. The composite filled with
phone frequency of 1.8 GHz. Its EMI shielding efficiency is in the
Key Laboratory of Energy Thermal Conversion and Control of Ministry
useful range of approximately 3 dB over a wide frequency range
of Education, Southeast University, Nanjing 210096, China
of 1–2.5 GHz. Compared with conventional materials such as
b
polyethelene and polyester filled with metal additives, this com-
Fujian Electric Power Survey & Design Institute, Fuzhou 350003, China
posite is suitable for microwave absorption and is a potential canActivated carbons (ACs) were produced by a one step process with CO2 as the physical activation agent at 800 °C. The ACs were further activated chemically using KOH, HNO3 or CH3COOH and heat-treated at 300 or 600 °C for 1 or 2 h to modify their proper-
didate for EMI shielding applications. [New Carbon Materials 2015, 30(2): 167–175] http://dx.doi.org/10.1016/j.carbon.2015.04.076
ties. The effect of CO2 concentration, activation time, types of chemical agents and the post heat-treatment conditions on CO2
Rheological properties of mesophase pitch investigated by the
capture were investigated. Results showed that the optimum con-
Giseeler fluidity method
ditions for AC production from corn stalks was at 800 °C for
Ming-lin Jin, Jie-ling Cheng, Lian-xing Wang, Shuang-ling Jin,
30 min with a CO2 concentration of 20% during the physical acti-
Rui Zhang
vation. Chemical agents and further heat-treatment modified the pore structure of the ACs, resulting in a performance improvement for CO2 adsorption. The BET surface area of one sample
School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418, China
(HNO3 activation + 100 °C water bath 1 h + post heat-treatment at 600 °C for 2 h) was 639. 8 m2/g. The maximum CO2 adsorption
The Giseeler fluidity method was used to investigate the rheo-
capacity of the sample was 7.33 wt%, which is higher than that
logical properties of pitch with and without heat treatment from
of a commercial AC (6.55 wt%). The CO2 adsorption is dominantly
room temperature to 520 °C. Results show that the fluidity has a
dependent on the mesopore volume when the BET surface area is
good repeatability at different temperatures under different heat-
smaller than 500 m2/g while the adsorption is closely associated
ing rates. The fluidity of the raw pitch slowly increases from 253
with micropore area when the BET surface area is larger than
to 282 °C, then increases exponentially from 282 to 311 °C near
500 m2/g.
the softening temperature, and finally remains unchanged from
The
adsorption
kinetics
agreed
well
with
the
Bangham kinetic model.
311 to 498 °C. This changing pattern of fluidity with temperature
[New Carbon Materials 2015, 30(2): 156–166]
has also been found for heat-treated mesophase pitch and can be formulated by the Arrhenius equation, from which the viscous
http://dx.doi.org/10.1016/j.carbon.2015.04.075
flow activation energy can be obtained. The toluene-insoluble fraction increases from 67.3% to 88.7% with heat-treatment time
Preparation of rubber wood sawdust-based activated carbon and its use as a filler of polyurethane matrix composites for microwave absorption a
a
b
Azizah Shaaban , Sian-Meng Se , Imran Mohd Ibrahim , Qumrul Ahsana
and the flow activation energy of the treated mesophase pitch in the Newtonian fluid region at low temperature range is between 203.6 and 294 kJ/mol. [New Carbon Materials 2015, 30(2): 176–180] http://dx.doi.org/10.1016/j.carbon.2015.04.077