SDP poster

This project aims to develop graphene oxide (GO) based membranes for water filtration applications. This was accomplished by selecting a suitable substrate for deposition of GO on it. GO was synthesized using two recipes based on Hummer’s method. The home-made GO flakes were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman microscopy. GO was deposited on the selected substrate and the developed membrane was tested with diffusion test for salt rejection.

Design and synthesis of graphene oxide (GO) based membranes for water filtration applications

Student Names: 1. Ahmad Khalil 201192010 ME 412 Advisor: Dr. Tahar Laoui 2. Ghaith Nadhreen 201142310 Section: 4 Co-Advisor: Dr. Zafarullah Khan

10min PT PES substrate was chosen because of its least contact angle and higher surface contact area.

From XRD results, both methods yielded strong peak at~ 10o 2θ angle which is comparable to the literature, however second method gave more amorphous GO which is preferred.

FTIR results showed that Recipe 2 yielded GO similar to commercial GO if compared to the Recipe1. C-O peak in commercial is stronger than that obtained in 2nd method.

From Raman spectra, the D and G bands are shown indicating the presence of GO. The ratio of the intensity between the two peaks should almost be equal to 1 as shown in the commercial GO result. This is observed in the second method which indicates better quality GO in contrast with the first method.

From figure 4, the slope increases with increasing salt concentration. Higher slope means lower salt rejection. The salt rejection for home made GO membrane is 75.6%, and 94.2% for commercial GO. Homemade GO membrane shows a good rejection of KCl compared to bare substrate

• Based on water contact angle and SEM, 10min PT PES was chosen as a substrate.

• Based on fig 3, the 2nd recipe yielded higher quality GO that is more oxidized (amorphous).

• Substrate was functionalized by PAM.• GO was deposited on the chosen substrate via dead-end cell. The fluid

used was nitrogen at 900psi.• Two membranes were prepared, one from homemade GO and the other

from commercial GO.• Diffusion test was done on both substrate.• The salt rejection for home made GO membrane is 75.6%, and 94.2%

for commercial GO• Making our GO flakes is more economical compared to commercial GO.

Clean water is very essential for human beings. Many countries are suffering from water shortage due to limited water resources, and as a result, some governments face difficulties in supporting people with drinkable water. Also, there are many processes in which water is cleaned (water treatment) or desalted (water desalination) to be suitable for drinking is not easy and is costly. There is continuous effort to develop new ways for treating water efficiently and affordably. Nowadays, lot of research is conducted about an interesting material called “Graphene Oxide”.

Graphene oxide (GO) is a compound of carbon, oxygen, and hydrogen in variable ratios, obtained by treating graphite with strong oxidizers using modified Hummer’s method2.

Our challenge was to design and synthesize GO based membranes for water filtration applications. This was performed by first synthesizing GO flakes, followed by substrate selection, then depositing GO on the chosen polymeric substrate.

INTRODUCTION

Work Plan - Methodology

1. Tran, Diana N.H. "A Green Approach for the Reduction of Graphene Oxide Nanosheets Using Non-aromatic Amino Acids." Sciencedirect. Sept. 2014. Web. 2 May 2016.

2. Chen, Ji. "An Improved Hummers Method for Eco-friendly Synthesis of Graphene Oxide." Sciencedirect. Nov. 2013. Web. 2 May 2016.

3. Marcano, Daniela C. "Improved Synthesis of Graphene Oxide." ACS Publications. 22 July 2010. Web. 2 May 2016.

CONCLUSIONS

SUMMARY & DISCUSSION

CHARACTERIZATION RESULTS

REFERENCES

ABSTRACT

Figure 6. diffusion test chart: Concentration vs. Time

Literature review

• GO synthesis• Characterization techniques for GO• GO adherence on support• Functionalization

Substrate selection

• Selection criteria: hydrophilicity, high permeability and good adhesion with GO

• Three substrates considered: PS, PES and PVDF• Plasma treatment (PT)

GO synthesis

• Conventionally by Hummer’s method• Performed 2 methods of synthesis• Characterization by SEM, XRD, FTIR, and Raman.

Membrane Synthesis

• 10min PT PES functionalized by Polyacrylamide (PAM)• Deposition of GO by dead-end cell

Membrane testing

• Diffusion test for salt rejection• Tested for commercial & homemade GO

DIFFUSION TEST RESULTS

5 10 15 20 25

200

300

400

500

600

700

800

Recipe-01Recipe-02

2theta (degree) 

Inte

nsity

XRD spectra 

1000 1200 1400 1600 1800 2000 2200

0.1

0.12

0.14

0.16

0.18

0.2

0.22

X: 1221Y: 0.1572

X: 1400Y: 0.1386

X: 1717Y: 0.1165

X: 1042Y: 0.1995

CommercialRecipe-01Recipe-02G-Substrate

OH

C-O  

C-O  

C=OC=

C  

Wavelength (cm-1) 

Abso

rban

ce

Commercial 

1st method 

2nd method 

Glass slide 

FTIR spectra 

1000 1200 1400 1600 1800 2000 2200 2400 2600 2800

100

200

300

400

500

600

Recipe-01Recipe-02

Raman shift (cm-1) 

Inte

nsity

Raman spectra 

Commercial-GO 

D  G

 1st

2nd

Figure 3. characterization results

0:00:00 0:02:52 0:05:45 0:08:38 0:11:31 0:14:2400.00020.00040.00060.0008

0.0010.00120.00140.00160.0018

f(x) = 0.176512351648352 x + 0.000105689285714286

f(x) = 0.0421868571428571 x + 0.000144171428571429

f(x) = NaN x + NaN

Bare Substrate Linear (Bare Substrate)Comm. GO Linear (Comm. GO)homemade Linear (homemade)

2 mm

PES

GO Film

Figure 4. membrane after Diffusion test

Figure 1. GO membrane schematic1

Figure 2. GO Diffusion test apparatus

Figure 5. Dead-end Cell used for GO deposition