Synthesis, characterisation and application of amphiphilic chitosan derivatives for water-insoluble pesticide formulations (IR)

This study investigates the feasibility of amphiphilic chitosan derivatives, namely oleoyl carboxymethyl chitosan (OCMCs), N,N-dimethylhexadecyl carboxymethyl chitosan (DCMCs) and deoxycholic acid carboxymethyl chitosan (DACMCs) as carrier agents for rotenone in water-insoluble pesticide formulation...

Full description

Saved in:
Bibliographic Details
Main Author: Nurul Farhana Ahmad Aljafree
Format: thesis
Language:eng
Published: 2017
Subjects:
Online Access:https://ir.upsi.edu.my/detailsg.php?det=215
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This study investigates the feasibility of amphiphilic chitosan derivatives, namely oleoyl carboxymethyl chitosan (OCMCs), N,N-dimethylhexadecyl carboxymethyl chitosan (DCMCs) and deoxycholic acid carboxymethyl chitosan (DACMCs) as carrier agents for rotenone in water-insoluble pesticide formulations. This research is divided into three parts, such as characterisation studies, performance studies and pot experiments. The characterisation studies were carried out using Fourier Transform Infrared (FTIR) Spectrometer, Proton Nuclear Magnetic Resonance (1H NMR) Spectrometer, CHN-O Elemental Analyser (CHN-O), Transmission Electron Microscope (TEM), Differential Scanning Calorimeter (DSC) and Thermogravimetric Analyser (TGA). The critical micelle concentration (CMC) of amphiphilic chitosan derivatives was determined using a Fluorescence Spectrometer. The ability of OCMCs, DCMCs and DACMCs to load and release rotenone in vitro system was determined using a High Performance Liquid Chromatography (HPLC). The pot experiments were conducted for 12 weeks to evaluate the effectiveness of pesticide formulations. Chilli (Capcisum annuum) was used as an indicator to monitor the effects of aphids and thrips infestation. Based on TEM analysis, findings have shown that amphiphilic chitosan derivatives formed self-assembly and exhibited spherical shape. The critical micelle concentration (CMC) for OCMCs, DCMCs and DACMCs were determined as 0.093, 0.098 and 0.468 mg/mL, respectively. The encapsulation efficiency (EE) values were within the range of 60.3 to 98.7%, meanwhile the loading capacity (LC) values were within the range of 0.97 to 7.90%. OCMCs, DCMCs and DACMCs micelles exhibited an excellent ability to control the release of rotenone, of which 90.0% of rotenone was released within 40 to 52 h. Based on pot experiments, the application of OCMCs as a carrier agent and polyvinyl alcohol (PVA) as an emulsifier was proven to be the most effective formulation to treat aphids and trips infected plants. In conclusion, OCMCs, DCMCs and DACMCs possess several key features to act as effective carrier agents for pesticide formulations. The implication of this study is the utilisation of amphiphilic chitosan derivatives could reduce the application of organic solvents in agrochemicals production by 33.3%, creating a greener and safer environment.