Visible light triggered microcapsules
May 10-15, 2015
Microcapsules are small particles which contain an active agent or core material surrounded by a coating or shell. 1 The utility of microcapsules for efficient cargo storage and targeted release is of considerable importance in self-healing materials, nutrient preservation, agricultural applications, fragrance release, and drug delivery. 2 One of the most challenging tasks and the ultimate purpose of developing delivery systems are to modulate the release of encapsulated cargo substances. Strategies such as heat treatment, pH change, magnetic fields and light-induced morphology change have been used to alter the shell density and integrity, and then to influence capsule permeability. 3-5 As one of the most interesting parts of stimuli-responsive capsules, photo-stimuli responsive capsules are capable of affecting their micro-/nano-structures in the form of remote control triggered by external light e.g., sun light, without requirement of direct contact or interactions. Moreover, triggering the release of microcapsules by light has a number of advantages over other external stimuli: light does not contaminate the reaction systems; the excitation wavelength can be controlled through the design of the photo-responsive molecule, it is easy to control the time and/or local excitation.6-9 The development of such highly light sensitive vesicles is of great importance, especially in the fields of surface sciences and environmental applications, where sometimes light would be the only available stimulus to drive the systems. Our aim was first to synthesize and characterize visible light sensitive monomer: 4,4’-bis(chlorocarbonyl)-2,2’-dimethoxy azobenzene and then, based on it, photo-triggered microcapsules containing a perfume oil as a core material. These microcapsules were obtained by oil-in-water interfacial polymerization reaction. In this communication we present preliminary results of microcapsules preparation, characterization and controlled perfume release, by means of different techniques (OM, SEM, Light scattering, GCMS). Financial support from European Community's Seventh Framework Programme, under IOF Marie Curie grant agreement no. 328794 is gratefully acknowledged.
Bartosz Tylkowski, Marta Giamberini, Todd Underiner, Susana Fernandez Prieto, and Johan Smets, "Visible light triggered microcapsules" in "Polymer Reaction Engineering IX", E. Vivaldo-Lima, UNAM; J. Debling, BASF; F. Zaldo-Garcia, CP-COMEX; J. Tsavalas, Univ. of New Hampshire Eds, ECI Symposium Series, (2015). http://dc.engconfintl.org/polymer_rx_eng_IX/18