DEAGGLOMERATION OF ZINC OXIDE NANOPARTICLES PRODUCED BY BIOSYNTHESIS USING BELIMBING KERIS FRUIT EXTRACT

• Main Author: Khairunnisa, Shafira
• Format: Theses
• Language: Indonesia
• Subjects: Teknik kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/54955
• Institution: Institut Teknologi Bandung

Agglomeration frequently occurs when nanoparticles are dispersed in solvent. Biologically synthesized nanoparticles are said to be able to avoid particle agglomeration because biomolecules can act as capping agents. However, some research results report that agglomeration still occurs on green synthesized nanoparticles; in fact, the prescence of biomolecules is eventhought to be one of the trigger for agglomeration. The aim of this study was to evaluate methods that can be applied to biosintesis to suppress nanoparticle agglomeration. This research is the development of latest research related to biosintesis of ZnO nanoparticles using belimbing keris (Averrhoa bilimbi) fruit extract. The ZnO nanoparticles produced by this study have both antimicrobial and antibiofilm capabilities. With the application of the right deagglomeration method, the ability of antimicrobial and antibiofilm can be increased. This research includes preliminary research, biosintesis and deagglomeration of ZnO, characterization of ZnO nanoparticles, and test of the antimicrobial activity of ZnO nanoparticles. Synthesis was carried out with Zn(NO3)2.6H2O as a precursor and belimbing keris fruit extract as a reducing agent. The experimental factors consisted of precursor-extract volume ratio, synthesis temperature, and deagglomeration method. There were two deagglomeration methods that have been tested, namely the chemical method using the polyvinyl alcohol (PVA) dispersing agent and the physical method using the ultrasonic bath. Further observations, which were antimicrobial and antibiofilm tests were carried out using the broth method in well-plate. Deagglomeration during synthesis produces ZnO with a particle size of 18.16-30.74 nm and a hydrodynamic diameter of 1168.5-3533.6 nm. The precursor-extract volume ratio factor and the deagglomeration method had a significant effect on the particle size and agglomerates, while the synthesis temperature had a significant effect when combined with the deagglomeration method. The precursor-extract volume ratio of 1: 2 not only obtained a higher product yield, but also produced ZnO with a more regular particle shape. The effectiveness of chemical deagglomeration was higher when the synthesis was carried out at room temperature, whereas physical deagglomeration was more effective when the synthesis was at high temperature (60oC). ZnO nanoparticles were able to reduce the population of Escherichia coli in planktonic form to 66-87% and in biofilms by 5-62%. The inhibition ability of both antimicrobial and antibiofilm was higher in the treatment which resulted in smaller particle size and ZnO agglomerates.