Experimenting with APAN Nanofibers

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

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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