The incorporation of insect repellents in textiles seemed
an alternative way to provide longer lasting protection,
although their direct application to fabrics has proven to
be inefficient in prolonging the repellence for long enough.
Microencapsulation technology has enabled an increase
in the durability of the desired effect in versatile textile
finishing. A microcapsule provides both space for storing
a certain amount of a functional agent and a protective
shield from the effects of sunlight, moisture and oxygen.
The release of the functional agent occurs by diffusion
through the capsule wall and/or rupture of the microcapsules.
Therefore, the use of microcapsules could provide a
durable repellent finish that could be applied to amultitude
of fibres.8
Fabrics with repellent activity have been previously
achieved by polymer coating methods,9 by encapsulation
of DEET in chitosan microcapsules,10 and by inclusion of
DEET and permethrin in cyclodextrins grafted to textile
substrates.11 However, to the best of our knowledge, the
repellent efficacy of cotton fabrics with microencapsulated
citronella oil finishes has not been investigated.
The aim of this work is to study the repellency to
female A. aegypti of fabrics treated with gelatin-arabic gum
microcapsules containing citronella oil. These microsystems
have been selected due to the low cost and the
biocompatible nature of the ingredients involved, which
is most desirable in fabrics intended for human use. Microcapsules
containing citronella oil were characterized and
applied to cotton textiles. The residual mosquito repellency
of treated fabrics was determined by means of an in
vivo assay and was compared to the repellency of fabrics
sprayed with non-encapsulated citronella