Page 20 - KVIS Book

LIS02A

Prolonging the Effective Time of Ant Repellent by
Encapsulation of Citronella Oil in Hydroxypropyl Beta-

Cyclodextrin

Natnarun Prutthiarphakul, Mathina Chaoenwat
Kamnoetvidya Science Academy, Thailand
Supervisor: Suranan Anantachaisilp
Email: mathina_c@kvis.ac.th

Ants are common nuisance insects around the world. People often use synthetic
chemicals to repel them. These chemicals not only harm ants but also harm to human
bodies and poison the environment. Existing research, however, has found that some
essential oils, like citronella oil, can be used as an ant repellent. However, its volatility
limits its use. This research aims to use the concept of encapsulation to increase the
stability of citronella oil as an ant repellent spray. Hydroxypropyl beta-cyclodextrin(HP-
β-CD) was chosen as a nanocarrier to encapsulate citronella oil through magnetic
stirring. The first step was to make a calibration curve of light absorbance and various
concentrations of essential oil to find the maximum wavelength of the inclusion
complex. Then, citronella oil was encapsulated into hydroxypropyl beta-cyclodextrin at
various time intervals to find an optimal condition. Fourier transform infrared
spectroscopy (FTIR) and UV-visible spectroscopy were used for physicochemical
characterization and to test stability. Our results showed that citronella oil successfully
encapsulated in hydroxypropyl beta-cyclodextrin and made into an inclusion complex
property is less volatile than normal citronella oil and has a longer effective time (at
least 3 months).

Keywords: citronella oil, hydroxypropyl beta-cyclodextrin(HP-β-CD), encapsulation