SYNTHESIS OF NANOCELLULOSE VIA [email protected] 10 SYNTHESIS OF NANOCELLULOSE VIA...

SYNTHESIS OF NANOCELLULOSE VIA ACID HYDROLYSIS AND TEMPO OXIDATION AND APPLICATION IN THE ADSORPTION OF Co2+

Braz, W. F. , Teixeira, L. T., Navarro, R. C. S., Pandoli, O.G.

1. INTRODUCTION

• CNF (cellulose nanofibril) and CNC (cellulose

nanocrystals) - morphology and properties;

• CNF - 2,2,6,6-tetramethylpiperidine-1-oxyl

(TEMPO);

• CNC - acid hydrolysis.

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Figure 1: Nanocellulose samples a) Wet CNF b) Dried CNC.

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• Adsorption of organic and inorganic substances in aqueous solution;

• Further applications:

• Wastewater treatment;

• Enhance nanocellulose chemical and mechanical properties;

• Use as a template for nano compound synthesis.

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1. INTRODUCTION



• Adsorption

• For CNF, it is reported cobalt removal from aqueous solutions of almost 87% at room

temperature, after 6h 40min (Narwade et al., 2018);

• Anirudhan et al. (2019) studied cobalt adsorption from Co(NO3)2 solutions with CNC-magnetite

composite as adsorvent. The cobalt recoveries were near 97.8% at 30º C after 4h.

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1. INTRODUCTION



CNC Synthesis

H2SO4 40% Dilution Centrifugation

6000 rpm

8 min

Sonication Characterization

8 min AFM

FTIR SEM-EDS 60oC 30 min

20:1

4oC Water

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2. METHODS

STEP 1

STEP 2 STEP 3

FTIR SEM-EDS

100 mL water 1 g cellulose

0.016 g TEMPO 0.1 g NaBr

2.5 mL NaClO pH 10

Solution #1

Solution #2

Constant stirring

Drops of NaOH 0.5 M

Keep pH 10

Centrifugation

6000 rpm

5 min

Sonication Characterization

7 min AFM

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CNF Synthesis

2. METHODS

STEP 1

STEP 2 STEP 3

• Adsorption time for CNF (0.5h; 1h; 1.5h; 3 h) and for CNC (0.75h; 1.5h; 2.25h and 3 h).

Characterization Constant stirring

(150 rpm)

SEM-EDS ICP-OES

1 g Nanocellulose

pH 6

1g/L Cobalt Nitrate

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Adsorption tests

2. METHODS

Centrifugation

6000 rpm

8 min

STEP 1

STEP 2 STEP 3

Atomic Force Microscopy

• The sample was deposited by drop coating, and vacuum dried at room temperature for 3 hours;

• Bruker AFM multi mode 8, which operates with Nanoscope V controller (version 7.3) and Nanoscope

(version 8.1);

• Gwyddion 2.55, open source software.

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Characterization

2. METHODS

Scanning Electron Microscopy/Energy Dispersive X-ray Spectrometry (SEM/EDS)

• Preliminary morphological study, and assess the nanofibers chemical composition (sulfur, sodium, chlorine

and cobalt);

• SEM TM3000 HITACHI electron microscope with EDS SWIFT ED 3000.

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Characterization

2. METHODS

Infrared spectroscopy (IR) analysis

• PERKIN ELMER Frontier FT-IR spectrometer;

• Vacuum dried at room temperature;

• Then, 0.002g of each sample were mixed with 0.198g of KBr (Pellet).

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Characterization

2. METHODS

Inductively coupled plasma optical emission spectrometry (ICP-OES)

• The solutions were analyzed to determine the cobalt concentrations after the adsorption process for

different contact time with both CNC and CNF;

• PerkinElmer 7300DV.




Characterization

2. METHODS

3. RESULTS AND DISCUSSION

• CNF - Randomly assembled nanofibrils (Isogai et al, 2011; Saito et al, 2007);

• Nanofibers with 5.61 ± 0.48 nm thickness.

CNF - AFM




Figure 2: AFM image of CNF, using drop coating as preparation method to AFM analysis.

• CNC – needle-like particles (Morán et al. 2008; Kvien et al. 2005);

• Average length 63.89 ± 41.51 nm and thickness of 9.99 ± 2.58 nm.




Figure 3: AFM image of CNC using drop coating as preparation method to AFM analysis.


CNC - AFM

• The fibrils tend to agglomerate, resulting in

micro-metric scale particles with a rough surface;

• Based on EDS maps, besides C and O,

measurable amounts of Na and Cl have been

detected in CNF.




Figure 4: Images of dried CNF surface a) SEM 500x magnification b) EDS distribution

map of Na c) EDS map of Cl.


CNF - SEM/EDS

• The fibrils tend to agglomerate;

• Sulfur was detected in CNC;

• Homogeneously dispersed over the agglomerates

surface.




Figure 5: Images of dried CNC surface a) SEM 2500x magnification b) EDS

distribution map of S.


CNC - SEM/EDS




Figure 6: Comparison of FTIR spectrum of cellulose, CNF and CNC.


FTIR






FTIR

• Absorbed water (MOHAMED et al., 2015);

• Sodium carboxylate groups (-COONa).






FTIR

• Presence of sulfate groups (-OSO3H);

• Overlapping bands due to the

abundance of C-O-C and C-O-H bonds.






FTIR

• β-1,4 glycosidic bonds (C-O-C).




Figure 7: Cobalt recovery as a function of time for both CNC and CNF samples.

• Up to 90 ± 2.7% percent cobalt

removal for CNF;

• Around 86 ± 2.6% for CNC.


Cobalt Adsorption




Cobalt Adsorption - SEM/EDS

• 3 hours adsorption time.

• Physisorption and Chemisorption

Figure 8: SEM/EDS results a) CNF-Co SEM image b) CNF-Co cobalt EDS distribution map c) CNC-Co d) CNC-Co cobalt EDS distribution

map.





4. CONCLUSION

• The characterization results displayed different characteristics, which is in agreement with earlier work

related to these chemical processing routes.

• For CNC, particles exhibited a needle-like shape with average length and thickness of 63,89 ± 41,51 nm

and 9,99 ± 2,58 nm respectively.

• For the CNF sample, nanofibrils have a branched structure with thickness of 5.61 ± 0,48 nm. Both

results are consistent with early works.




4. CONCLUSION

• The SEM/EDS element chemical analysis after synthesis indicated the presence of sulfur in CNC and

sodium in CNF, serving as indicative of -OH substitution for -OSO3H and -COONa units, respectively,

which is supported by FTIR data.

• Cobalt removal for CNC was of 86% after nearly 40 min contact, and for CNF was of 90% after 30 min.

• The SEM/EDS analysis supports the ICP-OES removal results, showing a homogeneous distribution of

cobalt over the samples Surface in the EDS map.




5. REFERENCES

• NARWADE, VIJAYKIRAN N. AND KHAIRNAR, RAJENDRA S. AND KOKOL, VANJA. In Situ Synthesized Hydroxyapatite—Cellulose Nanofibrils as Biosorbents for

Heavy Metal Ions Removal. Journal of Polymers and the Environment, 26:2130–2141, 2018.

• ANIRUDHAN, T. S.; SHAINY, F. ; DEEPA, J. R.. Effective removal of Cobalt(II) ions from aqueous solutions and nuclear industry wastewater using sulfhydryl

and carboxyl functionalised magnetite nanocellulose composite: batch adsorption studies. Chemistry and Ecology, 35(3):235–255, 2019.

• ISOGAI, AKIRA AND SAITO, TSUGUYUKI AND FUKUZUMI, HAYAKA. TEMPO-oxidized cellulose nanofibers, 2011.

• SAITO, TSUGUYUKI AND KIMURA, SATOSHI AND NISHIYAMA, YOSHIHARU AND ISOGAI, AKIRA. Cellulose nanofibers prepared by TEMPO-mediated oxidation

of native cellulose. Biomacromolecules, 8:2485–2491, 2007

• MORÁN, J. I.; ALVAREZ, V. A.; CYRAS, V. P. ; VÁZQUEZ, A.. Extraction of cellulose and preparation of nanocellulose from sisal fibers. Cellulose, 15(1):149–

159, 2008.

• KVIEN, I.; TANEM, B. S. ; OKSMAN, K.. Characterization of cellulose whiskers and their nanocomposites by atomic force and electron microscopy.

Biomacromolecules, 6(6):3160–3165, 2005.

• MOHAMED, M. A.; SALLEH, W. N.; JAAFAR, J.; ASRI, S. E. ; ISMAIL, A. F.. Physicochemical properties of "green"nanocrystalline cellulose isolated from

recycled newspaper. RSC Advances, 5(38):29842–29849, 2015.

ACKNOWLEDGEMENTS

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Coordenação de Aperfeiçoamento

de Pessoal de Nível Superior

Conselho Nacional de Desenvolvimento

Científico e Tecnológico Pontifícia Universidade

Católica do Rio de Janeiro

Associação Brasileira Técnica de

Celulose e Papel

Departamento de química e

Laboratório de Espectrometria

Atômica (LABSPECTRO)

Chemical Processes Research Group - DEQM

Wanderson Braz Lucas Tonette

Prof. Omar Pandoli Prof. Rogério Navarro

PhD Student DEQM

PUC-Rio

PhD Student DEQM

PUC-Rio

DEQM PUC-Rio DQ PUC-Rio

• Adsorption applications;

• Synthesis of nanocellulose;

• Chemical modification of nanocellulose

• Template for Nano compound synthesis;

• Cosmetic applications (Startup)

Recent Researches

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SYNTHESIS OF NANOCELLULOSE VIA [email protected] 10 SYNTHESIS OF NANOCELLULOSE VIA...

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