Synthesis and characterization of bionanocomposite silver nanoparticles (AgNPs)-chitosan/polylactic acid (PLA) biofilm
Biobased polymers derived from renewable resources are increasingly important due to intense concerns about the environmental issues and limited petrol eum resources. Poly(lactic acid) (PLA) is such polymer that has shown good potential to produce biodegradable plastics. However, poor antimicrobi...
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| Format: | Thesis |
| Language: | English |
| Published: |
2014
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| Subjects: | |
| Online Access: | http://umpir.ump.edu.my/id/eprint/9466/ http://umpir.ump.edu.my/id/eprint/9466/ http://umpir.ump.edu.my/id/eprint/9466/1/CD8275.pdf |
| Summary: | Biobased polymers derived from renewable resources are increasingly important due to
intense concerns about the environmental issues and limited petrol eum resources.
Poly(lactic acid) (PLA) is such polymer that has shown good potential to produce
biodegradable plastics. However, poor antimicrobial and mechanical properties restrict
its broad applications. The thesis pursues to overcome these limitations by blending
PLA with chitosan and reinforcing them with inorganic nanoparticles. The
performances of antimicrobial biodegradable films with enhanced properties have
potential good for many applications. Firstly, the silver nanoparticles have been
synthesized with tea extract leaves. Characterization of silver nanoparticles by UV-vis,
TEM, XRD and FTIR indicate that silver nanoparticles were present in the tea extract
solution with the range of size 10-150 nm. Antimicrobial analysis of silver nanoparticles
against gram negative (Escherichia coli) and gram positive (Micrococcus luteus)
microorganisms had proved that silver nanoparticles is a good antimicrobial agent
although incorporated with blending of PLA/chitosan films. The best concentration of
silver nanoparticles which incorporated with PLA/chitosan films was 23.08% w/w. It
means that films have showed slight growth of microorganism at 23.08% w/w of silver
nanoparticles.The films were characterized by FESEM and EDX. The morphological
images presented the shape of silver nanoparticles incorporated into the films was
almost spherical. Tensile measurement was represented by tensile strength and
elongations at break which were used as a response for choosing of the best conditions
bionanocomposite films fabrication (BFF) in the mechanical properties films. The
interaction and main effect of two factors with the range (0-30%) concentration of
plasticizer PEG and (0-100%) percentage volume PLA/chitosan were studied using 2level
full factorial design. P-value for factor A = 0.0269, B = <0.0001 significant
influence to this response. While P-value only for factor A = 0.0034 and B = <0.000.
Both factors were given the effect to the response based on higher percentage
contribution (>5%) and lower p-values (<0.05).The best conditions BFF had been chose
using rotatable central composite design under Response Surface Methodology (RSM)
with with the range (5-25%) concentration of plasticizer PEG and (20-80%) percentage
volume PLA/chitosan. The mechanical properties have improved at this the best
condition (7.93% w/w concentration of PEG and 28.79% / 71.21% percent volume of
PLA/chitosan). While the best responses (8.32 MPa tensile strength and 32.15%
elongation at break) were obtained, also using the best condition. The validation
experiment proved the empirical model developed were considerably accurate (error
between the actual and predicted values = between 5%) with the percentage errors are
ranging from 2.08% for tensile strength and 3.89% elongation at break. These results
showed that there were in agreement with the other previous studies findings. |
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