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. 2018 Oct 20;8(10):859.
doi: 10.3390/nano8100859.

Ultrasonic Irradiation Coupled with Microwave Treatment for Eco-friendly Process of Isolating Bacterial Cellulose Nanocrystals

Endarto Yudo Wardhono  1 , Hadi Wahyudi  2 , Sri Agustina  3 , François Oudet  4 , Mekro Permana Pinem  5 , Danièle Clausse  6 , Khashayar Saleh  7 , Erwann Guénin  8
Affiliations

Ultrasonic Irradiation Coupled with Microwave Treatment for Eco-friendly Process of Isolating Bacterial Cellulose Nanocrystals

Endarto Yudo Wardhono et al. Nanomaterials (Basel). .

Abstract

The isolation of crystalline regions from fibers cellulose via the hydrolysis route generally requires corrosive chemicals, high-energy demands, and long reaction times, resulting in high economic costs and environmental impact. From this basis, this work seeks to develop environment-friendly processes for the production of Bacterial Cellulose Nanocrystals (BC-NC). To overcome the aforementioned issues, this study proposes a fast, highly-efficient and eco-friendly method for the isolation of cellulose nanocrystals from Bacterial Cellulose, BC. A two-step processes is considered: (1) partial depolymerization of Bacterial Cellulose (DP-BC) under ultrasonic conditions; (2) extraction of crystalline regions (BC-NC) by treatment with diluted HCl catalyzed by metal chlorides (MnCl₂ and FeCl₃.6H₂O) under microwave irradiation. The effect of ultrasonic time and reactant and catalyst concentrations on the index crystallinity (CrI), chemical structure, thermal properties, and surface morphology of DP-BC and BC-NC were evaluated. The results indicated that the ultrasonic treatment induced depolymerization of BC characterized by an increase of the CrI. The microwave assisted by MnCl₂-catalyzed mild acid hydrolysis enhanced the removal of the amorphous regions, yielding BC-NC. A chemical structure analysis demonstrated that the chemical structures of DP-BC and BC-NC remained unchanged after the ultrasonic treatment and MnCl₂-catalyzed acid hydrolysis process.

Keywords: bacterial cellulose nanocrystals; catalyzed hydrolysis; crystallinity index; microwave treatment; ultrasonic irradiation.

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Conflict of interest statement

The authors declare no conflict of interest. Moreover, the funding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results. The design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Figures

Figure 1
Figure 1
Fourier Transform Infrared (FT-IR) spectra of: 1. native Bacterial Cellulos (BC); 2. depolymerized cellulose, depolymerization of Bacterial Cellulose (DP-BC), (optimum conditions of ultrasonic irradiation step); 3. extracted crystalline regions, bacterial cellulose nanocrystals (BC-NC) (the best results of the catalyzed hydrolysis treatment).
Figure 2
Figure 2
X-ray diffractogram of: (a) BC that was fitted by Gauss function; (b) XRD pattern of: 1. native BC; 2. depolymerized cellulose, DP-BC, (the optimum result of ultrasonic irradiation step); 3. extracted crystalline regions, BC-NC (the best results of the catalyzed hydrolysis treatment).
Figure 3
Figure 3
Differential Scanning Calorimetry (DSC)-Thermograms of: 1. BC; 2. depolymerized cellulose, DP-BC; 3. extracted nanocrystalline cellulose, BC-NC.
Figure 4
Figure 4
Transmission Electron Microscopy (TEM) and Scanning Transmission Electron Microscopy (STEM) micrograph of BC-NC (A,C) produced with 0.1M HCl and 5% w/w of MnCl2 compare to commercial NCC (B,D).
Figure 5
Figure 5
The evolutions of crystalline regions formations for treatment of bacterial cellulose after 30 min irradiation time in pure water (blue curve) or a mixture of ethanol / water 50% (w/w) (red line) observed by XRD (A) and by DSC (B in insert) (untreated BC, dark line).
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References

    1. Guilbert S., Gontard N., Gorris L.G. Prolongation of the shelf-life of perishable food products using biodegradable films and coatings. LWT-Food Sci. Technol. 1996;29:10–17. doi: 10.1006/fstl.1996.0002. - DOI
    1. Makaremi M., Pasbakhsh P., Cavallaro G., Lazzara G., Aw Y.K., Lee S.M., Milioto S. Effect of morphology and size of halloysite nanotubes on functional pectin bionanocomposites for food packaging applications. ACS Appl. Mater. Interfaces. 2017;9:17476–17488. doi: 10.1021/acsami.7b04297. - DOI - PubMed
    1. Khan A., Khan R.A., Salmieri S., Tien C.L., Riedl B., Bouchard J., Chauve G., Tan V., Kamal M.R., Lacroix M. Mechanical and barrier properties of nanocrystalline cellulose reinforced chitosan based nanocomposite films. Carbohydr. Polym. 2012;90:1601–1608. doi: 10.1016/j.carbpol.2012.07.037. - DOI - PubMed
    1. Bertolino V., Cavallaro G., Lazzara G., Merli M., Milioto S., Parisi F., Sciascia L. Effect of the biopolymer charge and the nanoclay morphology on nanocomposite materials. Ind. Eng. Chem. Res. 2016;55:7373–7380. doi: 10.1021/acs.iecr.6b01816. - DOI
    1. Khan A., Huq T., Saha M., Khan R.A., Khan M.A., Gafur M.A. Effect of silane treatment on the mechanical and interfacial properties of calcium alginate fiber reinforced polypropylene composite. J. Compos. Mater. 2010;44:2875–2886. doi: 10.1177/0021998310371536. - DOI

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