2010/02/08 > eTech France 237 > Smart Capsules Release an Active Principle

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		Innovation News Smart Capsules Release an Active Principle http://www.bulletins-electroniques.com/actualites/62207.htm So-called 'smart' capsules recently designed by researchers at the Integrative Chemistry, Multiscale Materials and Emulsions (CIMMEs), Paul Pascal Research Center (CRPP) in Bordeaux can release their contents on demand, merely by raising the temperature. The novel, easy-to-make, recently patented system is described in article published in the February issue of Langmuir, an interdisciplinary journal. To make the capsules, the scientists began by dispersing the oil (which may contain a special agent) in water. When silica particles stabilize the emulsion as droplets, its distinctive characteristic is that it is made of liquid oil at production temperature (65°C), but solid at ambient temperature. A silica shell is then polymerized around the cooled droplets producing stable capsules that can be stored. Then, the release of capsule contents can be triggered by warming the capsules to a temperature exceeding the melting temperature of the selected oil. The transition from the solid to the liquid state leads to the expansion of the confined oil, which is enough to break the silica shell. Any release temperature from 35°C to 56°C can easily be selected by choosing the appropriate oil or a mix of oils. Another adjustable parameter is the way in which the contents are released, either as strings or droplets, or all at one go, thus enabling the control of the release rate of the contents. The principle is very simple, cheap and applicable to numerous systems. For instance, the method could be used to indicate food freshness, release perfume into the air, onto fabric or the skin. Another possibility could be the release of a therapeutic agent onto the skin, which could triggered locally by rubbing on the application, thus causing warming. The capsule could also release a bactericide when the temperature reached the proliferation temperature of bacteria in air ducts. The researchers are already designing double emulsion systems that could be used to extend the technique to multi-therapy.	>> Suivant << Précédent Version imprimable >> Transmettre cette info par email >> Recommander ce site à un collègue / ami >> S'abonner au eTech France >> FAQ / foire aux questions >> Conditions d'utilisation >>


	Pour en savoir plus, contacts :	CNRS - Paul Pascal Research Center (Centre de Recherche Paul Pascal, CRPP) - Integrative Chemistry, Multiscale Materials and Emulsions Unit (Unité "Chimie Intégrative, Matériaux Multiéchelles et Emulsions, CIMMEs) - Véronique Schmitt - Phone: +33 (0)5 56 84 56 67 - Email: schmitt@crpp-bordeaux.cnrs.fr	Code brève ADIT : 62207

	Rédacteur :	ADIT - Jean-François Desessard - email: jfd@adit.fr


	Origine :	eTech France numéro 237 (8/02/2010) - ADIT / ADIT - http://www.bulletins-electroniques.com/actualites/62207.htm

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