Morphological and Structural Changes of Ultrasound treated

Bacterial Cellulose

D. Tsalagkas (1), R. Lagana (2), L. Csoka (1)

(1)Institute of Wood Based Products and Technologies, University of West Hungary, Sopron Hungary

(2) Department of Wood Science, Technical University of Zvolen, Zvolen Slovakia

BACTERIAL CELLULOSE

Parameters which affect the: i) productivity factor and ii) final performance of biomaterial (molar mass, supramolecular structure)• bacterial strain (e.g NQ5, E25)• culture techniques (static or agitated, carbon sources and concentrations)• conditions employed (temperature, time of fermentation, additives)• post fermentation operations

Changes in film properties- Morphology-Molar mass- Crystal structure: CI, Iα /Iβ ratio

Gatenholm and Klemm. 2010. MRS Bulletin. 35 (3):208-213http://www.azonano.com/news.aspx?newsID=8590/

Keshk. 2014. J. Bioproces Biotechniq. 4 (2)

BACTERIAL CELLULOSE PROPERTIES

Morphology, DP

Torres et al. 2012. J. Funct. Biomater. 3 (4):864-878

Crystallinity, purity

Porosity, surface area

Halib et al. 2012. Sains Malaysiana, 41 (2): 205-211Terinte et al. 2011. Lenzinger Berichte, 89:118-131Nishiyama et al. 2003. J. Amer. Chem. Soc., 125: 14300-14306Gatenholm and Klemm. 2010. MRS Bulletin. 35 (3):208-213

Thermal properties

Saharman et al. 2011. Bioresource Technology, 102: 9105-9110

Mechanical properties

Scionti. 2010. Mechanical properties of BC implants. MSc thesis

Chiral, viscoelasticproperties

Hirai et al. 2009. Langmuir, 25 (1): 497-502

Zhang et al. 2011. Cellulose Chem. Tech. 45, (5-6): 313-320 Piezoelectric propertiesCsoka et al. 2012. ACS Macro Lett. 1, (7): 867-870

Biocompatibility, natural, renewable, 3D shape

BACTERIAL CELLULOSE APPLICATIONS

Food industry

Biofilters forgas seperation

Hosakun et al. 2014In: Proceedings, ICCEE 2014, Barcelona Spain

Loud speakers

Kim et al. 2009. J. Bionic Engin. 6 (1):18-21

Smart materials

(Ummartyotin et al. 2012. Industrial crops and products, 35: 92-97

Biomedicalapplications

Czaja et al. 2012. Biomacromolecules, 8 (1): 1-12

Gatenholm and Klemm. 2010. MRS Bulletin. 35 (3):208-213

Energy harvesting

OBJECTIVES OF STUDY

• To analyze the effect of ultrasonictreatment on bacterial cellulose

•To obtain homogenous thin films suitable for nanotechnology

applications

NATA DE COCO

coconut juice

Acetobacter xylinum

fermentation

Nata de cocomanufacturing

Nata de coco gel

Preparation for ultrasound treatment

Washing and soaking with DW

Purification treatments

0.5 % (w/v) soaking in 0.1 M NaOH at 70 oC

One step purification2.5 wt % NaOH

Two step purification2.5 wt % NaOH2.5 wt % NaOCl

Unpurified/untreatedbacterial cellulose

Preparation for ultrasound treatment

Blending Drying

Blending

Ultrasound treatment

Concentration:0.1 wt%, 80 mL DW

Drying

Ultrasound factors

Time: 30 min

Distance of ultrasonic probe

Temperature

Maximum power

Characterizations

Bacterial cellulose films

FTIR

AFM

FTIR results

3340 OH Cellulose I

1426 cm-1 cellulose I

Treatments TCI A1372/A2900 LOI A1430/A898 HBI A3308/A1330

BC untreated 0.67 1.25 4.11

BC untreated 1 cm cold

water0.69 1.16 3.04

0.1 M NaOH untreated 0.71 1.39 3.84

0.1 M NaOH 1 cm cold

water0.72 1.27 3.68

One step pur. Untreated 0.69 1.51 3.75

One step pur. 4 cm cold

water0.88 1.28 3.31

Two step pur. Untreated 0.67 1.50 3.72

Two step pur. 1 cm ice water 0.74 1.30 3.63

AFM results

Conclusions

• Ultrasonication: homegenization, disaggregation,redispersibility

• Mild conditions: Avoid cellulose degradation due to its highpurity in relation to plant cellulose• Nice, homogeneous bacterial cellulose air dried thin films• Purification treatments: Cellulose I• Further characterizations, such as XRD, TGA, DSC are needed to

verify the results

AcknowledgementBalassi Institute, Hungarian Scholarship Board

Thank you for your attention