Impregnation of in-house synthesized carbon nanotubes in bacterial cellulose

Bacterial cellulose (BC) synthesized by Acetobacter xylinum has been discovered as a potential matrix for impregnating carbon nanotubes (CNT). The main objective of this study is to produce bacterial cellulose/carbon nanotube (BC/CNT) with improved hydrophobic surface. CNT addition is by mean to imp...

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Main Author:	Adnan, Sharmeen
Format:	Thesis
Language:	English
Published:	2011
Subjects:	Hydrophobic surfaces Bacterial cell surfaces
Online Access:	http://psasir.upm.edu.my/id/eprint/41651/1/FK%202011%20123R.pdf
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spelling	my-upm-ir.416512015-12-23T01:12:25Z Impregnation of in-house synthesized carbon nanotubes in bacterial cellulose 2011-08 Adnan, Sharmeen Bacterial cellulose (BC) synthesized by Acetobacter xylinum has been discovered as a potential matrix for impregnating carbon nanotubes (CNT). The main objective of this study is to produce bacterial cellulose/carbon nanotube (BC/CNT) with improved hydrophobic surface. CNT addition is by mean to improve the electrical property of BC to be a conductive membrane. Hydrophobic membrane is more practical in device development since it can adhere with other hydrophobic material, which is achieved in this study by acetylation process. In this work, the membranes were produced using date extract (DE) culture medium. Three CNT impregnation techniques were tested, i.e. immersion, dispersion and spraying, whilst the acetylation conducted were homogeneous and heterogeneous processes. In this study, morphological characteristic is an important property for sample selection to be characterized further. BC/CNT nanocomposite produced via spraying technique has uniform CNT dispersion and has the most dielectric conductivity value i.e. ~4.66 x 10-1 S/cm than the other techniques. Therefore, spraying was used to prepare BC/CNT acetate nanocomposite. Since the morphology of BC/CNT acetate obtained from heterogeneous process proves that the acetylation only occurred on the surface and the inner core structures of the BC are still intact, this process was used further. The most significant characteristic of BC/CNT acetate is the existence of C=O, CH3 and C-O functional groups of acetyl and higher water contact angle (~77°) than that of BC/CNT (~45°). When tested, decomposition and glass transition temperatures of BC/CNT acetate have reduced by 203°C and 35°C respectively, compared to that BC/CNT. The reduction is occurred mainly because the swollen BC structure of BC/CNT acetate is easily degraded by heat treatment. The acetylated BC/CNT on the other hand, has higher crystal BC fraction, i.e. 51% compared to that of BC/CNT (49%). These findings indicate that the CNT hinders the degradation of nanocomposite and protects the BC crystals. Thus when acetylated, both elasticity and crystallite size of BC/CNT has only reduced by 9%, i.e., from 34 to 31 GPa and from 27.3 to 24.9 nm, respectively. The bigger pore size of the acetate nanocomposite (~22 Å) than that of BC/CNT (~-103 Å) might allows further functionalization process introduced to the membrane. As a conclusion, the CNT impregnation by spraying technique during the growing fermentation of BC coupled with heterogeneous acetylation treatment resulted in a more water resistant,increased dielectric conductivity and increased crystal BC fraction. While, the sheet elasticity,crystallite size, surface area, decomposition and glass transition temperatures became lower.These characteristics makes acetylated BC/CNT sheet a potential as a biomaterial membrane in device development. Hydrophobic surfaces Bacterial cell surfaces 2011-08 Thesis http://psasir.upm.edu.my/id/eprint/41651/ http://psasir.upm.edu.my/id/eprint/41651/1/FK%202011%20123R.pdf application/pdf en public masters Universiti Putra Malaysia Hydrophobic surfaces Bacterial cell surfaces
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English
topic	Hydrophobic surfaces Bacterial cell surfaces
spellingShingle	Hydrophobic surfaces Bacterial cell surfaces Adnan, Sharmeen Impregnation of in-house synthesized carbon nanotubes in bacterial cellulose
description	Bacterial cellulose (BC) synthesized by Acetobacter xylinum has been discovered as a potential matrix for impregnating carbon nanotubes (CNT). The main objective of this study is to produce bacterial cellulose/carbon nanotube (BC/CNT) with improved hydrophobic surface. CNT addition is by mean to improve the electrical property of BC to be a conductive membrane. Hydrophobic membrane is more practical in device development since it can adhere with other hydrophobic material, which is achieved in this study by acetylation process. In this work, the membranes were produced using date extract (DE) culture medium. Three CNT impregnation techniques were tested, i.e. immersion, dispersion and spraying, whilst the acetylation conducted were homogeneous and heterogeneous processes. In this study, morphological characteristic is an important property for sample selection to be characterized further. BC/CNT nanocomposite produced via spraying technique has uniform CNT dispersion and has the most dielectric conductivity value i.e. ~4.66 x 10-1 S/cm than the other techniques. Therefore, spraying was used to prepare BC/CNT acetate nanocomposite. Since the morphology of BC/CNT acetate obtained from heterogeneous process proves that the acetylation only occurred on the surface and the inner core structures of the BC are still intact, this process was used further. The most significant characteristic of BC/CNT acetate is the existence of C=O, CH3 and C-O functional groups of acetyl and higher water contact angle (~77°) than that of BC/CNT (~45°). When tested, decomposition and glass transition temperatures of BC/CNT acetate have reduced by 203°C and 35°C respectively, compared to that BC/CNT. The reduction is occurred mainly because the swollen BC structure of BC/CNT acetate is easily degraded by heat treatment. The acetylated BC/CNT on the other hand, has higher crystal BC fraction, i.e. 51% compared to that of BC/CNT (49%). These findings indicate that the CNT hinders the degradation of nanocomposite and protects the BC crystals. Thus when acetylated, both elasticity and crystallite size of BC/CNT has only reduced by 9%, i.e., from 34 to 31 GPa and from 27.3 to 24.9 nm, respectively. The bigger pore size of the acetate nanocomposite (~22 Å) than that of BC/CNT (~-103 Å) might allows further functionalization process introduced to the membrane. As a conclusion, the CNT impregnation by spraying technique during the growing fermentation of BC coupled with heterogeneous acetylation treatment resulted in a more water resistant,increased dielectric conductivity and increased crystal BC fraction. While, the sheet elasticity,crystallite size, surface area, decomposition and glass transition temperatures became lower.These characteristics makes acetylated BC/CNT sheet a potential as a biomaterial membrane in device development.
format	Thesis
qualification_level	Master's degree
author	Adnan, Sharmeen
author_facet	Adnan, Sharmeen
author_sort	Adnan, Sharmeen
title	Impregnation of in-house synthesized carbon nanotubes in bacterial cellulose
title_short	Impregnation of in-house synthesized carbon nanotubes in bacterial cellulose
title_full	Impregnation of in-house synthesized carbon nanotubes in bacterial cellulose
title_fullStr	Impregnation of in-house synthesized carbon nanotubes in bacterial cellulose
title_full_unstemmed	Impregnation of in-house synthesized carbon nanotubes in bacterial cellulose
title_sort	impregnation of in-house synthesized carbon nanotubes in bacterial cellulose
granting_institution	Universiti Putra Malaysia
publishDate	2011
url	http://psasir.upm.edu.my/id/eprint/41651/1/FK%202011%20123R.pdf
_version_	1747811878556401664

Impregnation of in-house synthesized carbon nanotubes in bacterial cellulose

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