Controlled release fragrances

Fig. 20.2 Release profile of an encapsulated fragrance compared with that of the pure fragrance. CR controlled release...

Ramsey, C.P., Young, P.A., and Abramowicz, D.A. 2013. Structures and methods for controlling fragrance release using encapsulated fragrance on container bodie s. US Patent Application No. 13/861936. 

Decrease the evaporation rate of the fragrance, control the release rate and provide sustained release Promote the ease of handling of the fragrance Prevent lumping... 

Levrand, B. and Herrmann, A. (2002) Light induced controlled release of fragrances by Norrish type II photofragmentation of alkyl phenyl ketones. Photochemical e[ Photohiological Sciences, 1, 907-919. 

Polymers are becoming increasingly important in the area of controlled release, for drugs, flavors, fragrances, fertilizers, and pesticides, to name a few. Often the drug is suspended in a biodegradable polymer that is slowly degraded and metabolized (in other words, is a renewable resource). 

Solanyl s rate of degradation is adjustable and there are also grades available for controlled release purposes of active ingredients such as fertilizers and fragrances. 

Responsive nanomaterials may be obtained by dynamic assembly of components derived from biomolecules [71]. Dynamic biomaterials are of interest for biodegradability, as well as for time-delayed, dynamic formulation and controlled release strategies, for instance of antimicrobial agents [72] or of fragrances [73],... 

Dynamic formulation for controlled release of bioactive ingredients (drugs, agrochemicals, flavors, fragrances, etc.)... 

These additives can also be placed into microcapsules with a thin polymer skin. For example, they are filled with natural aromas and applied to the textile from a water dispersion in combination with a polyurethane or silicone binder. The ratio of micro bubbles to binder determines the efficiency and permanence of the finish. Good results after 4-12 washing cycles are reported. The encapsulated materials are released during wearing as the micro bubbles burst from rubbing caused by body movement or by diffusion through the thin layer of the capsules. A market available encapsulation in micro bubbles, built from chitosan, is described by Hampe. The incorporation and controlled release of fragrance compounds is also provided by the sol-gel nano-technique described in Section 18.4. 

Insects communicate by releasing pheromones—chemical substances that other insects of the same species detect with their anteimae. There are sex, alarm, and trail pheromones, and many of these are alkenes. Interfering with an insect s ability to send or receive chemical signals is an environmentally safe way to control insect populations. For example, traps with synthetic sex attractants have been used to capture such crop-destroying insects as the gypsy moth and the boll weevil. Many of the flavors and fragrances produced by certain plants also belong to the alkene family. 

Nanocapsules can be formulated from a variety of synthetic or natural monomers or polymers by using different techniques in order to fulfil the requirements of various applications. Both, hydrophobic and hydrophilic liquids are of high interest for encapsulation. So, e.g., either sensitive or volatile substances, as drugs or fragrances have to be encapsulated and protected for applications with a sustained demand of the respective compound. DNA, proteins, peptides or other active substances can be encapsulated in order to target them to specific cells. A further benefit of the polymeric shell is the possibility to control the release from the composite particles and hence the concentration in the environment. 

Theisinger S, Schoeller K, Osborn B, et al. (2009) Encapsulation of a fragrance via miniemulsion polymerization for temperature-controlled release. Macromol Chem Phys 210 411-420... 

Chemical companies are interested in the development of innovative system solutions, that is, new functional materials in which known molecules are integrated to show new effects. Flavor and fragrance companies are interested to protect and precisely release their valued molecules (the payload ). The polymer industry demands encapsulated curing agents and encapsulated reactants. These are just three examples, out of many, that show that microencapsulation is mainly used for the purpose of protection and controlled release. Since at least a decade, therefore, traditional low-volume markets for microcapsule-based products are expanding to include fine chemicals, adhesives, inks, fragrances, toners, sealants, and detergent manufacturers. ... 

Yissum Research Development Company of the Hebrew University of Jerusalem, Controlled Release of Complex Fragrances and Aromas , Technology Opportunities, code 9-2011-2594. 

Martel, B., MorceUet, M., Ruffin, D., Vinet, F., and Weltrowski, M. (2002). Capture and controlled release of fragrances by CD finished textiles. Journal of Inclusion Phenomena and Macrocyclic Chemistry, 44, 439-442. 

---