Aznizan, Shaari (2014) Synthesis and characterization of bionanocomposite silver nanoparticles (AgNPs)-chitosan/polylactic acid (PLA) biofilm. Masters thesis, Universiti Malaysia Pahang (Contributors, UNSPECIFIED: UNSPECIFIED).
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Abstract
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.
| Item Type: | Thesis (Masters) |
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| Additional Information: | Thesis (Master of Chemical Engineering (Bio-Process)) -- Universiti Malaysia Pahang – 2014 |
| Uncontrolled Keywords: | Biosynthesis |
| Subjects: | Q Science > QD Chemistry |
| Faculty/Division: | Faculty of Chemical & Natural Resources Engineering |
| Depositing User: | Muhamad Firdaus Janih@Jaini |
| Date Deposited: | 05 Nov 2015 03:26 |
| Last Modified: | 19 Aug 2021 04:15 |
| URI: | http://umpir.ump.edu.my/id/eprint/9466 |
| Download Statistic: | View Download Statistics |
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