A thin film structure including a reflector layer; and a hybrid layer including an organic colored material and at least one of an organic filler and an inorganic filler; wherein a concentration of the at least one of an organic filler or an inorganic filler is in a range of from about 3 wt. % to about 30 wt. %. A method of making a thin film structure is also disclosed.

[Problems] To provide a reversibly thermochromic composition having excellent contrast between a colored state and a decolored state, and excellent light resistance, and a reversibly thermochromic microcapsule pigment encapsulating the reversibly thermochromic composition.

[Solution] Disclosed is a reversibly thermochromic composition including: (a) an electron-donating color-developing organic compound; (b) a combination of a compound having a specific structure as an electron-accepting compound; and (c) a reaction medium which reversibly induces an electron transfer reaction between the component (a) and the component (b) in a specific temperature range, and a reversibly thermochromic microcapsule pigment encapsulating the reversibly thermochromic composition.

Magnetic or non-magnetic microspheres, populations of magnetic or non-magnetic microspheres, and methods for forming magnetic or non-magnetic microspheres are provided. One microsphere configured to exhibit fluorescent and magnetic properties includes a core particle and a monolayer of magnetic particles coupled to a substantial portion of a surface of a core particle. About 60% to about 90% of a surface of a core particle is covered by the monolayer of magnetic particles. The microsphere also includes an outer polymer layer surrounding or encapsulating both the monolayer of magnetic particles and the core particle. One population of magnetic or non-magnetic microspheres is configured to exhibit fluorescent and magnetic properties includes two or more subsets of magnetic fluorescent microspheres. The two or more subsets of microspheres are configured to exhibit different fluorescent and/or magnetic properties. Individual microspheres in the two or more subsets are configured as described herein.

Novel reaction media for electron donating and electron accepting components in colour-change compositions are described. The compound is of formula (I):

##STR00001## wherein R.sub.1, and R.sub.2 are selected from a linear or branched alkyl group, alkenyl group, alkoxy group, aryl group and an alkylene aryl group having from 6 to 22 carbon atoms; X.sub.1 and X.sub.2 are selected from —OC(O)-, —CO.sub.2- and O; R.sub.3, R.sub.4 and R.sub.5 are selected from hydrogen and an linear or branched alkyl group, cycloalkyl group, alkenyl group, alkoxy group, aryl and alkylene aryl group; R.sub.6 is selected from hydrogen, R.sub.3, —X.sub.1R.sub.1 and aryl and halogen; Y.sub.1 Y.sub.2 Y.sub.3 and Y.sub.4 are selected from hydrogen, R.sub.3, —OR.sub.3 and halogen; a is 0 to 4; b is 0 or 1; x and y are independently is 0 or 1 provided that where x and y are 0, a is 0 and b is 1 and R.sub.6 is —CO.sub.2R.sub.1; and wherein when a is 0 and b is 1 and R.sub.5 or R.sub.6 is phenyl, R.sub.6 and R.sub.5 respectively are not hydrogen or C.sub.1-7 alkyl. The compounds are useful in ink compositions, writing implements containing the compound and medical and industrial applications in which temperature sensitive colour change may be required.

Nanoparticles and compositions thereof are provided for detecting and/or preventing food spoilage. Methods of making the nanoparticles and compositions, and methods of using the nanoparticles and compositions, e.g. in food packaging, are also provided. The nanoparticles can have a hydrophobic core containing a hydrophobic active agent, e.g. a hydrophobic dye and/or an antimicrobial agent, for detecting and/or preventing food spoilage. The nanoparticles can also have a copolymer of a hydrophobic polymer repeat unit, e.g. styrene or lactic acid, and a pH responsive dendrimer repeat unit. The pH responsive dendrimer repeat unit can have a pH responsive amine core having a plurality of branched acrylate arms extending therefrom. The nanoparticles can be chemically stable at neutral pH, and then release the hydrophobic active agent at a pH range indicative of food spoilage. By releasing the hydrophobic dye and/or antimicrobial agent, the nanoparticles can detect and/or inhibit food spoilage.

The invention relates to a method for preparing high-stability liquid blueberry anthocyanins, belonging to the field of food processing. A method for preparing high-stability liquid blueberry anthocyanins comprises the following process steps: adding graphene oxide and chitosan to an MES buffer solution at room temperature, mixing homogeneously and adding EDC and NHS sequentially, reacting to obtain a first solution; adding dry blueberry anthocyanin powder in the first solution, adjusting pH to 4.5 to 5.0 and mixing homogeneously to obtain a second solution, and treating the second solution at 350 to 420 MPa and 2 to 4° C. to obtain the product. The method for increasing the stability of blueberry anthocyanins provided by the present invention uses dry blueberry anthocyanin powder as a raw material and adds graphene oxide combined with chitosan compound as an anthocyanin stabilizer, thereby increasing the stability of blueberry anthocyanins during processing and production.

Described herein are polymer-encapsulated materials and a method for encapsulating materials with polymer via emulsion polymerization. The encapsulated materials include colorants (e.g., pigments and dyes, and in particular fluorescent dyes), optical brighteners, downconverters and upconverters. The encapsulated materials are produced by the emulsion polymerization of ethylenically unsaturated monomers. The polymer-encapsulation method described herein does not require the preparation of a miniemulsion homogenized with special equipment, such as an ultrasonification device, and the resulting polymer-encapsulated materials exhibit optical properties superior to polymer-encapsulated materials prepared by processes that include the preparation of a miniemulsion prepared with such special equipment, such as an ultrasonification device.

Use of an encapsulated natural color for coloring a household, industrial or institutional (HI&I) product wherein the encapsulated natural color is stable in water to simulated solar irradiation at 765 Watt in accordance with International Commission on Illumination 85 (1989, Table 4, 3 mm window glass) reference sun for a period of between 8 hours and 16 hours.

The invention provides a colour change composition containing an electron donating organic colouring compound, an electron accepting compound and a compound of formula (I): wherein E is an ester linkage O—CO or —CO2, R is independently selected from an optionally substituted linear or branched alkyl group, alkenyl cycloalkyl group, alkenyl group, alkoxy group, aryl and alkylene aryl group having from 6 to 22 carbon atoms; Y.sub.1 Y.sub.2 X.sub.1 and X2 are independently selected from hydrogen, R′, —OR′ and halogen; wherein R′ is independently selected from an optionally substituted linear or branched alkyl group, alkenyl group, alkoxy group, aryl group and an alkylene aryl group; having from 5 to 22 carbon atoms; r and p each represent and integer from 0 to 3. The compound of formula (I) and compositions of the invention are useful in providing a colour change effect, in memory compositions and visual indicators, particularly in security and healthcare applications.

##STR00001##

The invention provides a droplet encapsulate comprising: a drop of a hydrophobic medium; a peripheral layer of non-polymeric amphipathic molecules around the surface of the drop; and an aqueous droplet within the peripheral layer, the aqueous droplet comprising: (a) an aqueous medium and (b) an outer layer of non-polymeric amphipathic molecules around the surface of the aqueous medium. The invention also provides processes for preparing the droplet encapsulates. Various uses of the droplet encapsulates are also described, including their use as drug delivery vehicles, in synthetic biology, and in the study of membrane proteins.