Thermo-optical analysis system and method of detection

Abstract

A thermoluminescence sensor includes a thermo-responsive polymer composition, and a scaled transparent container that holds the thermo-responsive polymer composition. The thermo-responsive polymer composition contains a curcumin oil, and a cyano derivative of poly(phenylenevinylene) of formula (I). ##STR00001##

Claims

1. A thermo-optical analysis system, comprising: a thermoluminescence sensor comprising: a thermo-responsive polymer composition, and a sealed transparent container for the thermo-responsive polymer composition, wherein the thermo-responsive polymer composition takes up more than 90 vol % of an inner space of the sealed transparent container; a photomultiplier tube (PMT) operatively configured to the thermoluminescence sensor; a heat transfer plate in thermal communication with the thermoluminescence sensor; wherein the heat transfer plate is configured to transfer thermal energy between a thermal source and the thermoluminescence sensor; wherein the thermo-responsive polymer composition comprises: a curcumin oil; a cyano derivative of poly(phenylenevinylene) of formula (I) ##STR00014## wherein at least a portion of the cyano derivative of poly(phenylenevinylene) is in the form of an exciplex with the curcumin oil, wherein the exciplex has formula (II) ##STR00015## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are each independently selected from the group consisting of C.sub.1-C.sub.9 alkyl, C.sub.1-C.sub.9 alkenyl, C.sub.2-C.sub.9 alkynyl, C.sub.1-C.sub.6 alkyloxy-C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6 alkylthio-C.sub.1-C.sub.6 alkyl, and C.sub.1-C.sub.6 alkylamino-C.sub.1-C.sub.6 alkyl, wherein each of the carbon-containing radicals is optionally substituted with one or more halogen atoms, and wherein n is a positive integer.

2. The thermo-optical analysis system of claim 1, wherein the cyano derivative of poly(phenylenevinylene) is poly(2,5-di(hexyloxy)cyanoterephthalylidene (PDH-CN), and wherein the exciplex formation has a formula (III) ##STR00016##

3. The thermo-optical analysis system of claim 1, wherein the thermoluminescence sensor exhibits a temperature-dependent emission intensity in a range of from 450 nanometers (nm) to 800 nm at a temperature of 0 degree Celsius ( C.) to 100 C., as determined by optical spectrum.

4. The thermo-optical analysis system of claim 3, wherein the thermoluminescence sensor exhibits a temperature-dependent emission intensity in a range of from 535 nm to 600 nm at a temperature of 0 C. to 100 C.

5. The thermo-optical analysis system of claim 3, wherein there is a linear correlation between the operation temperature of the thermoluminescence sensor and the emission characteristic during thermal cycling.

6. The thermo-optical analysis system of claim 1, wherein the thermo-responsive polymer composition has having a color change transition at a temperature of 0 C. to 100 C., and wherein the color change transition has an emission intensity of from 450 nm to 800 nm as an increase of the temperature.

7. The thermo-optical analysis system of claim 6, wherein the color change is in a reversible temperature cycle of from 0 C. to 100 C.

8. The thermo-optical analysis system of claim 1, wherein the curcumin oil comprises curcumin, bisdemethoxycurcumin, bisdeshydroxybisdemethoxycurcumin, and desmethoxycurcumin.

9. The thermo-optical analysis system of claim 8, wherein the curcumin is present in the curcumin oil in an amount of 70 weight percentage (wt. %) to 99.9 wt. % based on a total weight of the curcumin oil.

10. The thermo-optical analysis system of claim 8, wherein the cyano derivative of poly(phenylenevinylene) is PDH-CN, and wherein the thermo-responsive polymer composition further comprises a compound of formula (IV) ##STR00017##

11. The thermo-optical analysis system of claim 8, wherein the cyano derivative of poly(phenylenevinylene) is PDH-CN, and wherein the thermo-responsive polymer composition further comprises a compound of formula (V) ##STR00018##

12. The thermo-optical analysis system of claim 8, wherein the cyano derivative of poly(phenylenevinylene) is PDH-CN, and wherein the thermo-responsive polymer composition further comprises a compound of formula (VI) ##STR00019##

13. The thermo-optical analysis system of claim 1, wherein a ratio of the cyano derivative of poly(phenylenevinylene) to the exciplex formation present in the thermo-responsive polymer composition is in a range of 100:1 to 1:100.

14. The thermo-optical analysis system of claim 1, wherein the sealed transparent container is made of glass material, and/or glass-ceramic material.

15. The thermo-optical analysis system of claim 1, wherein the PMT further comprises: a lens; a photocathode configured to receive photons from the thermoluminescence sensor and to emit photoelectrons; a plurality of dynodes; wherein each of the plurality of dynodes is configured to receive photoelectrons from the previous dynode and to emit more photoelectrons than received; an anode configured to receive photoelectrons emitted from a last dynode and to output an electrical detection signal; and an electrical output configured to receive the electrical detection signal from the anode and to convert it to an output signal of the thermoluminescence sensor.

16. A method for measuring temperature, comprising: receiving a temperature of an object to be measured by the thermo-optical analysis system of claim 15; wherein the thermo-optical analysis system is in thermal communication with the object via the heat transfer plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A more complete appreciation of this disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

(2) FIG. 1A is a schematic illustration depicting a molecular structure of poly(2,5-di(hexyloxy) cyanoterephthalylidene (PDH-CN), according to certain embodiments;

(3) FIG. 1B is a schematic illustration depicting the chemical structure of curcumin oil according to certain embodiments;

(4) FIG. 2 is a schematic illustration depicting an exciplex formation of PDH-CN in curcumin oil, according to certain embodiments;

(5) FIG. 3 depicts a sensor displaying thermal-influenced fluorescence at various temperatures, according to certain embodiments;

(6) FIG. 4A depicts optical spectra and corresponding digital images of the sensor at a plurality of temperatures, according to certain embodiments;

(7) FIG. 4B depicts a linear correlation between a measured wavelength as a function of supplied temperature, according to certain embodiments;

(8) FIG. 5 is a schematic diagram illustrating a prototype of solidified PDH-CN in curcumin oil as a photon source in a photomultiplier tube (PMT), according to certain embodiments; and

(9) FIG. 6 is a schematic illustration depicting a solidification process of a scintillation material, according to certain embodiments.

DETAILED DESCRIPTION

(10) When describing the present disclosure, the terms used are to be construed in accordance with the following definitions, unless a context dictates otherwise.

(11) Embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings wherever applicable, in that some, but not all embodiments of the disclosure are shown.

(12) In the drawings, like reference numerals designate identical or corresponding parts throughout the several views. Further, as used herein, the words a, an and the like generally carry a meaning of one or more, unless stated otherwise.

(13) As used herein, the words about, approximately, or substantially similar may be used when describing magnitude and/or position to indicate that the value and/or position described is within a reasonable expected range of values and/or positions. For example, a numeric value may have a value that is +/0.1% of the stated value (or range of values), +/1% of the stated value (or range of values), +/2% of the stated value (or range of values), +/5% of the stated value (or range of values), +/10% of the stated value (or range of values), +/15% of the stated value (or range of values), or +/20% of the stated value (or range of values). Within the description of this disclosure, where a numerical limit or range is stated, the endpoints are included unless stated otherwise. Also, all values and subranges within a numerical limit or range are specifically included as if explicitly written out.

(14) A weight percent of a component, unless specifically stated to the contrary, is based on the total weight of the formulation or composition in which the component is included. For example, if a particular element or component in a composition or article is said to have 5 wt. %, it is understood that this percentage is in relation to a total compositional percentage of 100%.

(15) The use of the terms include, includes, including, have, has, or having should be generally understood as open-ended and non-limiting unless specifically stated otherwise.

(16) As used herein, the term compound generally refers to a chemical entity, whether as a solid, liquid, or gas, and whether in a crude mixture or isolated and purified.

(17) As used herein, the term room temperature or ambient temperature generally refers to a temperature in a range of 25 degrees Celsius ( C.)+3 C. in the present disclosure.

(18) As used herein, the term thermoluminescence generally refers to a form of luminescence exhibited by certain crystalline materials. It occurs when previously absorbed energy from radiation is re-emitted as light upon heating the material.

(19) As used herein, the term thermoresponsive polymers generally refers to the type of polymers that undergo significant and abrupt changes in their physical properties when subjected to changes in temperature.

(20) As used herein, the term light generally refers to radiation emitted at optical wavelengths. The term optical wavelengths is defined as wavelengths that include the part of the spectrum extending from the near-infrared, through the visible, to the ultraviolet. It is further defined to also include radiation emitted at the parts of the spectrum, which extends from the near-infrared through the long wavelength, far infrared, and from the ultraviolet to X-rays and -rays at the shortest wavelengths.

(21) As used herein, the term visible generally refers to radiation that stimulates the optical receptors of the eye and has a wavelength between about 380 nanometres (nm) to 750 nm.

(22) As used herein, the term sensor generally refers to a device that detects and responds to a certain type of input from the physical environment.

(23) As used herein, the term polymer generally includes homopolymers, co-polymers, oligomers, telomers, macromers, and pre-polymers.

(24) As used herein, the term co-polymer generally refers to a polymer derived from more than one species of monomer, including co-polymers that are obtained by co-polymerization of two monomer species, those obtained from three monomers species (terpolymers), those obtained from four monomers species (quaterpolymers), etc.

(25) As used herein, the term substituted generally refers to at least one hydrogen atom replaced with a non-hydrogen group, provided that normal valences are maintained and the substitution results in a stable compound. When a substituent is noted as optionally substituted, the substituents are selected from the exemplary group including, but not limited to, halo, hydroxyl, alkoxy, oxo, alkanoyl, aryloxy, alkanoyloxy, amino, alkylamino, arylamino, arylalkylamino, disubstituted amines (e.g. in which the two amino substituents are selected from the exemplary group including, but not limited to, alkyl, aryl or arylalkyl), alkanylamino, aroylamino, aralkanoylamino, substituted alkanoylamino, substituted arylamino, aubstituted aralkanoylamino, thiol, alkylthio, arylthio, arylalkylthio, alkylthiono, arylthiono, aryalkylthiono, alkylsulfonyl, arylsulfonyl, arylalkylsulfonyl, sulfonamide (e.g. SO.sub.2NH.sub.2), substituted sulfonamide, nitro, cyano, carboxy, carbamyl (e.g. CONH.sub.2), substituted carbamyl (e.g. CONHalkyl, CONHaryl, CONHarylalkyl or cases where there are two substituents on one nitrogen from alkyl, aryl, or alkylalkyl), alkoxycarbonyl, aryl, substituted aryl, guanidine, heterocyclyl (e.g. indolyl, imidazoyl, furyl, thienyl, thiazolyl, pyrrolidyl, pyridyl, pyrimidiyl, pyrrolidinyl, piperidinyl, morpholinyl, piperazinyl, homopiperazinyl and the like), substituted heterocyclyl and mixtures thereof and the like. The substituents may be optionally substituted and may be either unprotected or protected as necessary, as known to those skilled in the art, for example, as taught.

(26) As used herein, the term alkyl unless otherwise specified refers to both branched and straight chain saturated aliphatic primary, secondary, and/or tertiary hydrocarbons of typically C.sub.1 to C.sub.20, preferably C.sub.6-C.sub.18, more preferably C.sub.10-C.sub.16, for example C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, C.sub.8, C.sub.9, C.sub.10, C.sub.11, C.sub.12, and specifically includes, but is not limited to, methyl, trifluoromethyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl, t-butyl, pentyl, cyclopentyl, isopentyl, neopentyl, hexyl, isohexyl, cyclohexyl, cyclohexylmethyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 2-ethylhexyl, heptyl, octyl, nonyl, 3,7-dimethyloctyl, decyl, undecyl, dodecyl, tridecyl, 2-propylheptyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl. As used herein, the term optionally includes substituted alkyl groups. Exemplary moieties with which the alkyl group can be substituted may be selected from the group including, but not limited to, hydroxyl, amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate, halo, or phosphonate or mixtures thereof. The substituted moiety may be either protected or unprotected as necessary, as known to those skilled in the art.

(27) The present disclosure is intended to include all hydration states of a given compound or formula, unless otherwise noted or when heating a material.

(28) As used herein, the term optionally generally refers to includes substituted alkyl groups. The examples include, but are not limited to, hydroxy, amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate, halo, or phosphonate or mixtures thereof. The substituted moiety may be either protected or unprotected as necessary, as known to those skilled in the art.

(29) As used herein, the term cycloalkyl generally refers to cyclized alkyl groups. Suitable examples of cycloalkyl groups include but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, and adamantly, 1-methylcyclopropyl and 2-methylcyclopropyl.

(30) As used herein, the term alkoxy generally refers to a straight or branched chain alkoxy including, but not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, secondary butoxy, tertiary butoxy, pentoxy, isopentoxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, and decyloxy.

(31) As used herein, the term aryl unless otherwise specified generally refers to functional groups or substituents derived from an aromatic ring including, but not limited to, phenyl, biphenyl, napthyl, thienyl, and indolyl.

(32) As used herein, the term halogen generally refers to fluorine, chlorine, bromine and iodine.

(33) Aspects of the present disclosure are directed to a thermoluminescence sensor produced from a conjugated polymer poly(2,5-di(hexyloxy)cyanoterephthalylidene) (PDH-CN) in curcumin oil. The thermoluminescence sensor of the present disclosure can be used in a liquid-state or in a solid-state without any significant alterations in the optical characteristics.

(34) In some embodiments, the thermoluminescence sensor includes a thermo-responsive polymer composition and a sealed transparent container (herein referred to as a container) that holds the thermo-responsive polymer composition (also referred to as the composition). In some embodiments, the container may be made of a glass material and/or a glass-ceramic material in proper shape including, but not limited to, a sphere, a hemisphere, a cylinder, a cone (including frustoconical shapes), a box or a cube, a circle, a square or rectangle, and a triangle. Other shapes are also possible. In some further embodiments, the container may be a transparent plastic container in proper shape. The transparent plastic container may be made of a transparent plastic including, but not limited to polymerized methyl methacrylate. In some embodiments, the container seals the inside of the container from the outside of the container.

(35) In some embodiments, the thermo-responsive polymer composition takes up more than 50% of inner space of the sealed transparent container based on a total volume of the sealed transparent container, preferably more than 70%, preferably more than 90%, or even more preferably more than 99% of the inner space of the sealed transparent container based on the total volume of the sealed transparent container. Other ranges are also possible.

(36) In some embodiments, the composition includes a curcumin oil and a cyano derivative of poly(phenylenevinylene). Curcumin oil is a green solvent with an ultraviolet-visible (UV-Vis) absorbance in the 400-500 nm range, preferably 420-480 nm, preferably 440-460 nm, or even more preferably about 450 nm, giving it a characteristic yellow color. It has strong fluorescence properties, can emit green fluorescence under UV light, and can act as a sensitizing agent. The curcumin oil includes curcumin, bisdemethoxycurcumin, bisdeshydroxybisdemethoxycurcumin, and desmethoxy curcumin. In some embodiments, the weight percentage (wt. %) of curcumin in the curcumin oil is in an amount of 70-99.9 wt. %, preferably 71-99 wt. %, preferably 72-98 wt. %, preferably 73-97 wt. %, preferably 74-96 wt. %, preferably 75-95 wt. %, preferably 76-94 wt. %, preferably 77-93 wt. %, preferably 78-92 wt. %, preferably 79-91 wt. %, preferably 80-90 wt. %, preferably 81-89 wt. %, preferably 82-88 wt. %, preferably 83-87 wt. %, and preferably 84-86 wt. %, based on the total weight of the curcumin oil. Other ranges are also possible.

(37) The cyano derivative of poly(phenylenevinylene) is a compound of formula (I).

(38) ##STR00008##

(39) In some embodiments, at least a portion of the cyano derivative of poly(phenylenevinylene) is in the form of an exciplex with the curcumin oil. The alkyl side chains of the cyano derivative of poly(phenylenevinylene) form a hydrogen bond with the oxygen atom of the -diketone of the carbonyl group in the curcumin oil, forming an exciplex. In some embodiments, the exciplex has formula (II)

(40) ##STR00009##

(41) In both the compounds of Formula I and Formula II, R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are each independently selected from C.sub.1-C.sub.9 alkyl, C.sub.1-C.sub.9 alkenyl, C.sub.2-C.sub.9 alkynyl, C.sub.1-C.sub.6 alkyloxy-C.sub.1-C.sub.6 alkyl, C.sub.1-C.sub.6 alkylthio-C.sub.1-C.sub.6 alkyl, and C.sub.1-C.sub.6 alkylamino-C.sub.1-C.sub.6 alkyl. Each of the carbon-containing radicals may be optionally substituted with one or more halogen atoms, and n is a positive integer, preferably 2-500, preferably 10-490, preferably 20-480, preferably 30-470, preferably 40-460, preferably 50-450, preferably 60-440, preferably 70-430, preferably 80-420, preferably 90-410, preferably 100-400, preferably 110-390, preferably 120-380, preferably 130-370, preferably 140-360, preferably 150-350, preferably 160-340, preferably 170-330, preferably 180-320, preferably 190-310, preferably 200-300, preferably 210-290, preferably 220-280, preferably 230-270, and preferably 240-260. Other ranges are also possible.

(42) The ratio of the cyano derivative of poly(phenylenevinylene) to the exciplex formation in the thermo-responsive polymer composition is in a range of 100:1-1:100, preferably 90:1-1:90, preferably 80:1-1:80, preferably 70:1-1:70, preferably 60:1-1:60, preferably 50:1-1:50, preferably 40:1-1:40, preferably 30:1-1:30, preferably 20:1-1:20, and preferably 10:1-1:10. Other ranges are also possible.

(43) In an embodiment, the cyano derivative of poly(phenylenevinylene) is poly(2,5-di(hexyloxy)cyanoterephthalylidene (PDH-CN). The exciplex formation has a formula (III)

(44) ##STR00010##

(45) In an embodiment, the cyano derivative of poly(phenylenevinylene) is PDH-CN, and the thermo-responsive polymer composition further includes a compound of formula (IV)

(46) ##STR00011##

(47) In an embodiment, the cyano derivative of poly(phenylenevinylene) is PDH-CN, and the thermo-responsive polymer composition further includes a compound of formula (V)

(48) ##STR00012##

(49) In an embodiment, the cyano derivative of poly(phenylenevinylene) is PDH-CN, and the thermo-responsive polymer composition further includes a compound of formula (VI)

(50) ##STR00013##

(51) In the compounds of formula (III), (IV), (VI), and (VI), n is a positive integer, preferably 2-500, preferably 10-490, preferably 20-480, preferably 30-470, preferably 40-460, preferably 50-450, preferably 60-440, preferably 70-430, preferably 80-420, preferably 90-410, preferably 100-400, preferably 110-390, preferably 120-380, preferably 130-370, preferably 140-360, preferably 150-350, preferably 160-340, preferably 170-330, preferably 180-320, preferably 190-310, preferably 200-300, preferably 210-290, preferably 220-280, preferably 230-270, and preferably 240-260. Other ranges are also possible.

(52) In some embodiments, a molar ratio of the exciplex of formula (II) to the compound of formula (III) present in the thermo-responsive polymer composition is about 10:1 to 500:1, preferably 50:1 to 400:1, preferably 100:1 to 300:1, or even more preferably about 200:1. In some preferred embodiments, a molar ratio of the exciplex of formula (II) to the compound of formula (IV) is about 10:1 to 500:1, preferably 50:1 to 400:1, preferably 100:1 to 300:1, or even more preferably about 200:1. In some further preferred embodiments, a molar ratio of the exciplex of formula (II) to the compound of formula (V) is about 10:1 to 500:1, preferably 50:1 to 400:1, preferably 100:1 to 300:1, or even more preferably about 200:1. In some most preferred embodiments, a molar ratio of the exciplex of formula (II) to the compound of formula (VI) is about 10:1 to 500:1, preferably 50:1 to 400:1, preferably 100:1 to 300:1, or even more preferably about 200:1. Other ranges are also possible.

(53) In some embodiments, the thermo-responsive polymer composition is in a solid form. In some embodiments, the solid form thermo-responsive polymer composition further include a thermoplastic polymer. Suitable examples of thermoresponsive polymers include polymethyl methacrylate (PMMA), poly (N-isopropylacrylamide) (PNIPAAm), poly(N,N-diethylacrylamide) (PDEAAm), poly(N-vinlycaprolactam) (PVCL), derivatives of poly(phenylenevinylene), poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA), poly(DEAM-co-DMAM), poly(ethylene oxide) (PEO), poly(diethylacrylamide-co-dimethylacrylamide), or poly(methoxyethoxy)ethyl methacrylate-co-oligo(ethylene glycol) methacrylate, poly(MEO2MA-co-OEGMA), and combinations thereof. In some preferred embodiments, the thermoresponsive polymer is polymethyl methacrylate (PMMA).

(54) In some embodiments, the thermoplastic polymer is present in the thermo-responsive polymer composition at a concentration of 5 to 60 wt. %, preferably 8 to 55 wt. %, preferably 11 to 50 wt. %, preferably 14 to 45 wt. %, preferably 17 to 40 wt. %, preferably 20 to 35 wt. %, or even more preferably 25 to 30 wt. %, based on the total weight of the thermoplastic polymer. Other ranges are also possible. In this case, the thermo-responsive polymer composition in a solid form may be used in the absence of the sealed transparent container. In some preferred embodiments, the thermo-responsive polymer composition in a solid form may be in any shape including, but not limited to, a sphere, a hemisphere, a cylinder, a cone (including frustoconical shapes), a box or a cube, a circle, a square or rectangle, and a triangle. Other shapes are also possible.

(55) A method of preparing the thermo-responsive polymer composition is also provided. The method includes mixing and heating the curcumin oil and the cyano derivative of poly(phenylenevinylene) until it becomes homogenous. The mixing may be carried out manually or with the help of a stirrer. The heating can be done by using heating appliances such as hot plates, heating mantles, ovens, microwaves, autoclaves, tapes, oil baths, salt baths, sand baths, air baths, hot-tube furnaces, and hot-air guns. In some embodiments, the heating is performed at a temperature of 40-70 C., preferably 41-69 C., preferably 42-68 C., preferably 43-67 C., preferably 44-66 C., preferably 45-65 C., preferably 46-64 C., preferably 47-63 C., preferably 48-62 C., preferably 49-61 C., preferably 50-60 C., preferably 51-59 C., preferably 52-58 C., preferably 53-57 C., and preferably 54-56 C. In a preferred embodiment, the heating is performed at a temperature of 50 C.

(56) In some further embodiments, the method of preparing the thermo-responsive polymer composition in a solid form may include mixing and heating the curcumin oil, the cyano derivative of poly(phenylenevinylene), and a polymethyl methacrylate (PMMA) polymer to form a mixture. The method further includes introducing the mixture into a mold to form a sample, and curing the sample by cooling to form a solid state thermo-responsive polymer composition in the mold.

(57) In another aspect of the present disclosure, a thermo-responsive sensing system is described. The thermo-responsive sensing system includes the aforementioned thermoluminescence sensor as a photon source, a photomultiplier tube (PMT) operatively configured to the thermoluminescence sensor, and a heat transfer plate in thermal communication with the thermoluminescence sensor. The PMT further includes a lens, a photocathode configured to receive photons from the thermoluminescence sensor and for emitting photoelectrons, and a plurality of dynodes. Each of the plurality of dynodes is configured to receive photoelectrons from the previous dynode and to emit more photoelectrons than received. Further, an anode is configured to receive photoelectrons emitted from a last dynode and to output an electrical detection signal. Furthermore, the PMT includes an electrical output configured to receive the electrical detection signal from the anode and convert it to an output signal of the thermoluminescence sensor. The heat transfer plate is configured to transfer thermal energy between a thermal source and the thermoluminescence sensor.

(58) In another aspect of the present disclosure, a method for measuring temperature is described. The method includes receiving the temperature of an object to be measured by the aforementioned thermo-responsive sensing system. The thermo-responsive sensing system is in thermal communication with the object via the heat transfer plate.

(59) In some embodiments, the sensor exhibits a temperature-dependent emission intensity in a range of from 450-800 nm, preferably 500-750 nm, preferably 550-700 nm, and preferably 600-650 nm at a temperature of 0-100 C., preferably 5-95 C., preferably 10-90 C., preferably 15-85 C., preferably 20-80 C., preferably 25-75 C., preferably 30-70 C., preferably 35-65 C., preferably 40-60 C., and preferably 45-55 C. as determined by optical spectrum. In some embodiments, the sensor exhibits a temperature-dependent emission intensity in a range of from 535-600 nm, preferably 540-595 nm, preferably 545-590 nm, preferably 550-585 nm, preferably 555-580 nm, preferably 560-575 nm, and preferably 565-570 nm at a temperature of 0-100 C., preferably 5-95 C., preferably 10-90 C., preferably 15-85 C., preferably 20-80 C., preferably 25-75 C., preferably 30-70 C., preferably 35-65 C., preferably 40-60 C., and preferably 45-55 C. Other ranges are also possible.

(60) In some embodiments, there is a linear correlation between the operation temperature of the sensor and the emission characteristic during thermal cycling. In some embodiments, a color change transition occurs at a temperature of 0-100 C., preferably 5-95 C., preferably 10-90 C., preferably 15-85 C., preferably 20-80 C., preferably 25-75 C., preferably 30-70 C., preferably 35-65 C., preferably 40-60 C., and preferably 45-55 C. The color change transition has an emission intensity from 450-800 nm, 500-750 nm, 550-700 nm, and 600-650 nm as temperature increases. In some embodiments, the color change is in a reversible temperature cycle from 0-100 C., preferably 5-95 C., preferably 10-90 C., preferably 15-85 C., preferably 20-80 C., preferably 25-75 C., preferably 30-70 C., preferably 35-65 C., preferably 40-60 C., and preferably 45-55 C. Other ranges are also possible.

EXAMPLES

(61) The following examples demonstrate a thermoluminescence sensor including conjugated polymer (PDH-CN) in curcumin oil. The examples are provided solely for illustration and are not to be construed as limitations of the present disclosure, as many variations thereof are possible without departing from the spirit and scope of the present disclosure.

Example 1: Polymer Structures

(62) Poly(2,5-di(hexyloxy)cyanoterephthalylidene (PDH-CN), is a cyano-derivative of poly(phenylenevinylene). Poly(phenylenevinylene) is a highly conjugated polymer, indicating that it has many delocalized electrons that may move freely along its backbone. In addition, this polymer has two alkyl side groups attached to oxygen atoms, which are stretched directly in space. FIG. 1A depicts the molecular structure of the aforementioned polymer. Further, the molecular structure of curcumin oil is shown in FIG. 1B. The curcumin oil includes two aromatic rings linked by o-methoxy phenolic groups and a -diketone moiety as a central linker. The latter is involved in the color and stability of curcumin and plays a crucial role in dipole-dipole interactions. Furthermore, in an excited state, the alkyl side chains of PDH-CN may form a hydrogen bond with the oxygen atom of the -diketone of the carbonyl group in the curcumin oil, resulting in the formation of an exciplex as depicted in FIG. 2.

Example 2: Synthesis of Thermoluminescence Sensor

(63) In one embodiment, about 15 milligrams (mg) of the polymer PDH-CN was dissolved in 5 milliliters (mL) of curcumin oil while being continuously stirred at 50 C. until a homogeneous solution was obtained (3 mg/mL). The resulting mixture may exhibit a golden color. Further, the mixture was allowed to cool to room temperature (around 20 C.) while its optical changes were monitored (a), as depicted in FIG. 3. When the temperature equilibrated with the ambient temperature, the color gradually transitioned from a light yellow to a darker orange (b), as depicted in FIG. 3. Furthermore, thermo-optical analysis was performed by reducing the temperature to 0 C., resulting in the mixture acquiring a dark red color (c), as depicted in FIG. 3. The mixture was then cooled again before the temperature was raised to 100 C. Moreover, the mixture followed the nearly identical optical trend during the thermal process, eventually displaying a light green color at 100 C. (d), as depicted in FIG. 3. From the aforementioned observations, it may be shown that upon reversible temperature alterations (heating-cooling cycles, 0 C. to 100 C.), PDH-CN/curcumin oil aqueous solution exhibits temperature-dependent emission characteristics from (about 535 nm to 600 nm). This may lead to a sharp change in the photophysical properties of the complex that provide an output signal for a thermo-optical sensor, as shown in FIG. 4A and FIG. 4B. A model of a solid-state thermoluminescence sensor developed from conjugated polymer (PDH-CN) in curcumin oil, as shown in FIG. 5.

(64) A solid-state form of the liquid-state thermoluminescence sensor was created by solidifying the mixture into cubes or bullets with predetermined dimensions. To achieve this, a polymer matrix material such as, but not limited to, Perspex liquid or PMMA was combined with the liquid-state thermoluminescence sensor to create the solid-state phase. The liquid-state thermoluminescence sensor was mixed with different ratios of a commercial transparent polymer and formed into three-dimensional (3D) solid cylinders. The solidification process is depicted in FIG. 6. Furthermore, after the liquid-to-solid transition, any significant alterations in the optical characteristics of the thermo-optical sensor were not noticed.

(65) Aspects of the present disclosure are directed towards a conjugated polymer of PDH-CN, dissolved in curcumin oil and subjected to the solution to a temperature range of 0 C. to 100 C. The optical and spectroscopic changes in the solution were monitored as the temperature varied. The results indicate that the temperature change induces a significant fluorescence color shift in the conjugated polymer. This discovery shows this sensor may be used as a reversible thermo-optical probe, suitable for heating and cooling cycles. The liquid phase of the mixture, including PDH-CN in curcumin oil, demonstrates improved optical behavior, showing a real-time response to temperature changes.

(66) Numerous modifications and variations of the present disclosure are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.