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Technology for Long Last Senses
Assoc. Prof. Ubonthip Nimmannit, Ph.D.April 2nd, 2010
National Nanotechnology CenterNSTDA Pathumthani, Thailand
Topnote
• First impression
• High volatility, coefficients ranging 1-14
• No residual scent after 2 h
– Citrus, fruity, green note– Ginger, galanga, cardamom
Middle note
• Establishing the whole fragrance
• Medium volatility, coefficients ranging 15-60
• Last for 2-6 h
– Jasmine, rose, aldehyde, spicy note– Tuberose, coriander
Lasting note (Basic note or Fixer)
• Low volatile fixatives, coefficients ranging 61-100
• Last for more than 6 h– Oakmoss, woody note, animal note, civet
absolute, myrrh, velvety balsamic scent
Basic note/ Fixation– Musk ambrette– Ambergris extract– Ethyl vanillin/ vanillin– Methyl nonyl acetaldehyde– Fixateur 404
Persistence of Perfumes• Coefficient: ↑ nature of evaporation
↓ value of the threshold concentration
Volatility
• Odor intensity• Threshold value• Odor tonality
Microcapsules
• Small particles (1-100 μm)
• Active agent surrounded by polymeric membrane
• Protect from oxidation (by heat, light, humidity, exposure to other substances)
• Prevent evaporation
• Control release rate
Techniques of encapsulation (Micro/ Nano)
• Phase separation techniques
• Interfacial polymerization techniques
• Mechanical techniques
Phase separation techniques
• Aqueous phase separation– Simple coacervation– Complex coacervation
• Nonaqueous phase separation– Non solvent addition– Temperature reduction
Complex coacervation
Positive charge polymer-negative charge polymer
Colloidal rich phase + equilibrium liquid
Microcapsules
Nanocapsules
dry
stirred
Phase separation
Interfacial Polymerization Technique
Monomer A + Monomer B
(Hydrophobic liquid) (Hydrophilic liquid)
Emulsifying
Polymer AB
Microcapsules + by product
Stirring
Selection of the technique and shell material
– Application of products– Physical and chemical stability– Concentration– Desire particle size– Release mechanism– Manufacturing cost
Microencapsulation process of limonene by interfacial polymerization.
Rodrigues, et al., Ind. Eng. Chem. Res. 2008, 47, 4142–4147
Oil phase (HMDI) + Aqueous phase 1 (PVA)
Formation of oil/water emulsion
Urethane formation
Aqueous phase 2 (PEG 400, DBTDL)
Urea formation
Aqueous phase 3 (EDA)
Urea formation
Aqueous phase 4 (HYD)
Separation/Washing
Polymerization and shell formation
Optical microscopy of microcapsules solution. Magnification: (a) 20x (b) 100x.
Textile Impregnated with Microcapsules Characterization. SEM Analysis
Rodrigues, et al., Ind. Eng. Chem. Res. 2008, 47, 4142–4147
Macrocapsules
• Diameter over 1000 mm
show a different porosity distribution,
T. Gum ํ et al. / Desalination 245 (2009) 769–775
Polysulfone capsules containing different vanillin concentrations.
Polymeric microspheres
• Fragrance incorporated in the polymer– Controlled by
• Initial loading of fragrance• Ability of fragrance to diffuse through polymeric
barrier
– Driving force• Interaction between fragrance molecule and
polymer matrix• Vapor pressure of fragrance
SEMandTEMimages of spheres obtained with the starting polymer concentrations of (a) 2000–16,000 ppm, (b) 18,000ppmand (c) 24,000–28,000 ppm.
(a) SEM, (b) TEM and (c) AFM images of menthol-encapsulated polymeric nanoparticle suspension (polymer blend : EC, HPMC, PV(OH)
A. Sansukcharearnpon et al. / Int J Pharm xxx (2010) xxx–xxx
Multiarm star-block copolymer• Multiarm star-block copolymer compared to
dendrimer– Less complex synthesis– Less time consuming– Lower cost
Limitation– Lower loading capacity than dendrimer
Multiarm star-block copolymer
Amphiphilic multiarm star-block copolymers with a hydrophilic inner and hydrophobic outer shell (top) and with a hydrophobic inner and hydrophilic outer shell (bottom).
Ternat et al., Macromolecules, Vol. 41, No. 19, 2008
Hydrophilic arms
Hydrophobic armsHyperbranched core structure
Multiarm star-block copolymer
Average structures of the Boltorn H40 core and amphiphilic multiarm star-block copolymers H40-(PnBuMA)p-b-(PPEGMA)q and H40-(PCL)p-b-(PAA)q.
Ternat et al., Macromolecules, Vol. 41, No. 19, 2008
Comparison of the evaporation rates of benzyl acetate from an aqueous solution (containing 5% of ethanol) in the presence and absence of amphiphilic multiarm star-block copolymer H40-(PCL)24-b-(PAA)82.
Multiarm star-block copolymer
Benzyl acetate
Benzyl acetate/ H40-(PCL)24-b-(PAA)82
Alginate complex capsules containing eucalyptus oil
• Interfacial insolubilization reaction
• Release by crashing the capsule between fingers
• Closed capsule wall
• Optimum condition– Concentration of alginate– Concentration of calcium salt– Cross-linking time
Microphotographs of alginate complex capsules before (a) and after (b) the hardening process (/80).
The capsuleswerepr eparedatconcentrati
onsof1 .5 %sodium alginate and1 .0 %c
alciumchloride, and t - he cross linking time
m mmm20
C.P. Chang, T. Dobashi / Colloids and Surfaces B: Biointerfaces 32 (2003) 257/262
Time courses of oil release from capsules at incubation process for the samples prepared at various conditions: At different concentrations of sodium alginate at constant calcium chloride concentration of 1 w/v% at cross-linking time of 20min. The symbols (circle), (triangle), (square) and (diamond) denote concentrations of sodium alginate of 0.25, 0.50, 1.0 and 2.0%, respectively.
Light induced controlled release of fragrances
Alkyl phenyl ketones serve as delivery systems for fragrance molecules upon exposure to natural sunlight
Preparation of alginate nanocapsules containing turmeric oil
Sodium alginate crosslink with calcium chloride
alginate nanocapsule
Lertsutthiwong P., Noomun K., Jongaroonngamsang N., Rojsitthisak P., Nimmannit U. 2008. Preparation of alginate nanocapsules containing turmeric oil. Carbohydrate Polymers. 74. 209–214.
Morphology and size of turmeric oil-loaded alginate nanocapsules
TEM characterization of nanocapsules, indicating an average size of about 95 nm.