experimenting with apan nanofibers
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Experimenting with APAN Nanofibers
Emily Jeng鄭家韻
Taiwan Tech Trek 2014
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宜蘭大學National I-Lan
University 2
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PAN SolutionPAN: 0.800
gDMAC: 15
mL
4-6 hrs
4
Electrospinning
NeedleRolling Drum
Syringe (with solution)
Generator
Tubing
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PAN Nanofibers6
Making APAN Nanofibers
15 g NaOH+85 mL water
30 min reaction
DETA+water+1 g Na2CO3
1 hour reaction
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Cu Adsorption Experiments 8
ICP9
Experimental Parameters Changed
• Percentage of DETA added for reaction:• 0% (PAN nanofibers)• 10%• 20%• 30%
• Different Cu(II) Concentrations:• 5 ppm• 10 ppm• 20 ppm• 40 ppm
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11RESULTS
Na2CO3
PANDETA
APAN
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Effect of Concentratio
n13
Effect of DETA
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Adsorption Capacities
• qe=adsorption capacity• Co=initial concentration• Cf=final concentration• V=volume• m=mass of absorbent
5 ppm 10 ppm 20 ppm 40 ppm
0% DETA
0.401 mg/g
0.475 mg/g
0.709 mg/g
1.967 mg/g
10% DETA
1.072 mg/g
2.316 mg/g
3.303 mg/g
5.793 mg/g
20% DETA
1.134 mg/g
1.861 mg/g
3.194 mg/g
4.137 mg/g
30% DETA
1.230 mg/g
2.430 mg/g
4.778 mg/g
8.048 mg/g
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Kinetics Analysis
𝐹𝑖𝑟𝑠𝑡𝑂𝑟𝑑𝑒𝑟 :𝐿𝑜𝑔 (𝑞𝑒−𝑞𝑡 )=𝐿𝑜𝑔 (𝑞𝑒 )−( 𝑘12.303 )𝑡 𝑆𝑒𝑐𝑜𝑛𝑑𝑂𝑟𝑑𝑒𝑟 : 𝑡𝑞𝑡=
1𝑘2∗𝑞𝑒2
+𝑡𝑞𝑒
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Kinetics Comparison
First Order5 ppm 10
ppm20 ppm
40 ppm
R2 0.9754 0.9317 0.9881 0.9064Qe exp (mg/g)
0.9853 1.806 2.324 2.458
Qe calc (mg/g)
1.124 1.791 2.232 2.094
k1 0.08682
0.06402
0.04813
0.06974
Second Order5 ppm
10 ppm
20 ppm
40 ppm
R2 0.998 0.9327
0.9461
0.9378
Qe exp (mg/g)
0.9853
1.806 2.324 2.458
Qe calc (mg/g)
1.120 2.428 3.531 3.263
k2 0.1376
0.0238
0.2832
0.3065
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Adsorption Isotherms
• Langmuir Isotherm: adsorption onto homogenous surface with finite number of adsorption sites.
Or
Where Ce=equilibrium concentrationqe= equilibrium adsorption capacityqm=maximum adsorption capacityb=Langmuir adsorption constant (energy of adsorption)
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Adsorption Isotherms
• Freundlich Model: adsorption on heterogenous surface of adsorbent
Or Where qe= equilibrium adsorption capacityCe=equilibrium concentrationKf=Freundlich constant: adsorption capacityn= Freundlich constant: adsorption intensity
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Looking at the R2 values, it is clear that the Langmuir model fits the best for this experiment.
Langmuir Model
R2 b qm0.9985 1.743 L/mg 2.710 mg/g
Freundlich Model
R2 Kf n0.891 1.521 mg/g 3.010
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Conclusion/Final Thoughts
• PAN nanofibers APAN nanofibers Cu(II) Adsorption Experiments ICP Analysis• As concentration increases, adsorption curves become less
steep, but adsorption capacity increases• As more DETA is added, adsorption capacity increases• Experiment fits the second order kinetic model and
Langmuir adsorption isotherm
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Thank you!! 22
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