Abstract:The evaporation kinetics of pure Romascone 1 (methyl 2,2-dimethyl-6-methylene-1-cyclohexanecarboxylate) and Romascone 1 when mixed with vinyl acetate (VAc) nanoparticles have been determined by using thermogravimetric analysis. For pure Romascone 1 , the evaporation rate follows an Arrhenius dependence with temperature. When Romascone 1 is mixed with VAc nanoparticles, two evaporation mechanisms are identified depending on the presence of comonomer and crosslinking degree. (a) Evaporation limited by the presen… Show more
“…Markus et al [26] provided a process for the preparation of essential oil microcapsules with a polyurea and/or polyurethane film through interfacial polymerization. Ouali [27] proposed a method for producing microcapsules of 40-1000 nm containing fragrances, in which the shell was made by reactions between isocyanates, diols and diamines. Unilever PLC [28] provided a process for the manufacture of core-shell perfume particles by emulsion polymerization, in which the core of the particles comprised a perfume and the shell comprised a non-ionic deposition aid that was substantive for textiles.…”
Methyl methacrylate (MMA)-styrene (St) copolymer nanocapsules containing cologne essential oil for fragrant fabrics treatment were prepared by miniemulsion polymerization. The morphology, chemical composition and thermal properties were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA). The nanocapsules had relatively small size (ca. 136 nm of mean particle diameter), regular sphericity and uniform particle size distribution. The encapsulation efficiency and loading capacity of the nanocapsules were 85.4% and 42.7%, respectively. The nanocapsules had good thermostability. The release experiments showed that 6.8% cologne essential oil still existed after being washed 15 times in the fabrics treated with nanocapsules, indicating that the fabrics treated with nanocapsules had good washing durability.
“…Markus et al [26] provided a process for the preparation of essential oil microcapsules with a polyurea and/or polyurethane film through interfacial polymerization. Ouali [27] proposed a method for producing microcapsules of 40-1000 nm containing fragrances, in which the shell was made by reactions between isocyanates, diols and diamines. Unilever PLC [28] provided a process for the manufacture of core-shell perfume particles by emulsion polymerization, in which the core of the particles comprised a perfume and the shell comprised a non-ionic deposition aid that was substantive for textiles.…”
Methyl methacrylate (MMA)-styrene (St) copolymer nanocapsules containing cologne essential oil for fragrant fabrics treatment were prepared by miniemulsion polymerization. The morphology, chemical composition and thermal properties were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA). The nanocapsules had relatively small size (ca. 136 nm of mean particle diameter), regular sphericity and uniform particle size distribution. The encapsulation efficiency and loading capacity of the nanocapsules were 85.4% and 42.7%, respectively. The nanocapsules had good thermostability. The release experiments showed that 6.8% cologne essential oil still existed after being washed 15 times in the fabrics treated with nanocapsules, indicating that the fabrics treated with nanocapsules had good washing durability.
“…The geraniol release kinetics for particles formed using ξ = 3 was measured by isothermal thermogravimetric analysis (TGA) on a Perkin Elmer 4000 instrument according to the method adapted from [21]. Samples weighing 30 mg were placed in 50 μL alumina pans.…”
Geraniol was successfully micro-encapsulated with zein in a one-step phase separation process in which the zein and geraniol were both initially dissolved in a water-ethanol mixture. Microcapsules were only formed at geraniol-to-zein mass ratios above unity. This is ascribed to the relative solubility of the oil and protein in the solvent at the point of incipient phase separation: The geraniol must phase separate first before zein precipitation commences. The resultant oil droplets subsequently provide the interfacial surfaces that act as nucleation sites for the precipitation of the amphoteric zein molecules on continued dilution with water. The near spherical microcapsules formed under these conditions, comprised a foamed closed-cell wall that enclose large internal cavities in which the geraniol was trapped. The highest particle yield, 85.3%, and oil encapsulation efficiency, 83.5%, were obtained at a geraniol to zein mass ratio of 3:1. The particle size distribution for this system was log-normal with d 10 , d 50 and d 90 values of 10, 32 and 88 μm respectively. The temperature dependent geraniol release rate from these capsules followed power law kinetics with a release exponent of 0.80.
“…Long used in the pharmaceutical industry to improve drug bioavailability, stabilize drugs against various degradation pathways, minimize side effects or modify drug release kinetics, encapsulation techniques have gained increased attention in other fields, particularly food and fragrances . Lipids, though useful both as ingredients in food products and as solvents for hydrophobic substances, are generally difficult to disperse in aqueous media and can be susceptible to auto‐oxidation .…”
Section: Introductionmentioning
confidence: 99%
“…Carotenoids in food products also suffer from susceptibility to degradation, which lowers the final nutritional properties of products . Though sustained presence of volatile fragrances in consumer products is desirable because it is associated with a feeling of pleasantness or cleanliness, the volatility of fragrances prevents persistence over long time frames . Flavors can be the most valuable ingredients in food products, but these precious compounds are usually highly volatile and chemically unstable, degrading in the presence of air, light, moisture, and high temperatures .…”
Section: Introductionmentioning
confidence: 99%
“…Controlled release may be defined as a method by which one or more active agents or ingredients are made available at a desired site and time and at a specific rate. This precise timing and targeting of release could be used to maximize a given compound's effectiveness and optimize dosage …”
Microencapsulation is becoming increasingly important in the food, cosmetics, and medicinal industries due to its potential for stabilization and delivery of volatile and delicate compounds. Novel food-safe techniques for encapsulating oil in silk biomaterials using emulsion-based processes that exploit silk's unique properties (including amphiphilicity, biocompatibility, aqueous and ambient processing, and tunable physical crosslinking behavior) are described. The sonication-induced self-assembly of silk previously applied to hydrogel fabrication replaced the use of the thermal or chemical suspension crosslinking traditionally used to stabilize the aqueous protein phase in emulsions. Stable, physically crosslinked silk micro-and macro-particles loaded with oil or water-soluble dye were produced by aliquoting sonicated silk solutions into an oil bath. Oil micro-droplets emulsified in aqueous silk solutions did not impede the self-assembly of silk into films or hydrogel networks. In O/W/O emulsions, particle morphology and silk permeability to a model lipophilic dye in the interior phase were controllable via processing.
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