WO2010010321A1 - Capteur d’uv - Google Patents

Capteur d’uv Download PDF

Info

Publication number
WO2010010321A1
WO2010010321A1 PCT/GB2009/001680 GB2009001680W WO2010010321A1 WO 2010010321 A1 WO2010010321 A1 WO 2010010321A1 GB 2009001680 W GB2009001680 W GB 2009001680W WO 2010010321 A1 WO2010010321 A1 WO 2010010321A1
Authority
WO
WIPO (PCT)
Prior art keywords
composition
sensitive
light
semiconductor material
dye
Prior art date
Application number
PCT/GB2009/001680
Other languages
English (en)
Inventor
Andrew Mills
Pauline Grosshans
Michael Mcfarlane
Original Assignee
University Of Strathclyde
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University Of Strathclyde filed Critical University Of Strathclyde
Publication of WO2010010321A1 publication Critical patent/WO2010010321A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
    • G01N31/22—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using chemical indicators
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
    • G01J1/429—Photometry, e.g. photographic exposure meter using electric radiation detectors applied to measurement of ultraviolet light
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/48—Photometry, e.g. photographic exposure meter using chemical effects
    • G01J1/50—Photometry, e.g. photographic exposure meter using chemical effects using change in colour of an indicator, e.g. actinometer
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
    • G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
    • G01N21/78—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator producing a change of colour

Definitions

  • the present invention relates to the provision of UV sensitive compositions and sensors comprising the compositions.
  • the sensors can find use in a wide range of applications including as dosimeters for indicating the amount of exposure to UV light of a person or an article.
  • UVR Ultraviolet radiation
  • UVA i.e. electromagnetic radiation spanning the wavelength range 315-400 nm
  • solar UVB i.e. 280-315 nm a large portion of which is blocked by the ozone layer.
  • UVB On a typical summer' s day approximately 6% of terrestrial UV light is UVB but this contributes 80% towards the harmful effects associated with the sun, while the remaining 94% UVA contributes to the other 20%.
  • UVA and UVB radiation have been shown to increase biological melanin production and hence pigmentation of human skin, consequently both are used in tanning booths.
  • UVR UVC light ( ⁇ 280 nm) is not observed in nature at significant levels as it is absorbed by the earth' s atmosphere.
  • Applications of artificial UVC sources include the use of germicidal lamps, i.e. Hg fluorescent tubes without phosphor coating, to destroy bacteria, 3 ' 4
  • UVR ultraviolet radiation
  • erythema i.e. the reddening of the skin or sunburn
  • melanogensis the process that causes an individual to develop a suntan. While the latter still remains a largely socially-desired side effect, the former is not.
  • UVR can also damage DNA under the skin resulting in local immune suppression. 5 Cumulative DNA damage can encourage the development of skin cancers such as melanomas. 6"11 In the UK, approximately 8,000 malignant melanoma cases are diagnosed and around 1,800 die from the condition 12 each year
  • the amount of solar UV radiation absorbed by the skin at any time is known as the erythemal dose.
  • ⁇ minimum erythemal dose' is useful, where the MED is defined as the minimum amount of radiation likely to cause erythema.
  • the MED for an individual is largely dependent on their skin type of which 6 types, I - VI, have been defined 1 where a skin type of I is associated with skin with little natural melanin (red-heads) and so likely to burn quickly and type VI, is associated with skin with very high levels of natural melanin (very dark skinned individuals) and is therefore much more resistant to erythema.
  • UV-activated photochemical reactions have been identified as possible routes to generate an effective dosimeter, and some have been commercialised.
  • One such commercial product is the solar wrist band developed by Solar Safe ®17 for people with skin type II. It comprises a polymer matrix in which a structurally photochromic material is dispersed.
  • the wristbands are personal dosimeters, which change colour upon exposure to UVR and are designed to indicate when to apply sunscreen and when it is time to get out of the sun.
  • SunHealth Solutions LCC has produced a dosimeter called a SunSignal UV Sensor. 18 These respond specifically to UVB radiation and are comprised of a radiation sensitive material including an organic halogen such as hexachloroethane, which is capable of producing at least one acidic product, such as HCl, upon UV exposure, and a pH indicator, such as methyl orange, capable of producing a colour change in response to the UV generation of the acidic product. 19
  • a radiation sensitive material including an organic halogen such as hexachloroethane, which is capable of producing at least one acidic product, such as HCl, upon UV exposure, and a pH indicator, such as methyl orange, capable of producing a colour change in response to the UV generation of the acidic product. 19
  • the UV sensor can comprise a hydroxy ethyl cellulose film containing: a redox dye, for example methylene blue (MB) , a sacrificial electron donor such as triethanolamine (TEOA) and as photocatalyst, titania nano particles (TiO 2 ) .
  • a redox dye for example methylene blue (MB)
  • TEOA triethanolamine
  • TiO 2 titania nano particles
  • the film acts as a UV indicator in which the TiO 2 nanoparticles absorb the UV light enabling it -A- to photo-oxidise the TEOA and simultaneously reduce the redox dye from its highly coloured (blue) oxidised form, (MB) to its colourless form, leuco methylene blue (LMB) .
  • the degree of bleachedness exhibited by a naked MB film of this type is directly dependent upon the level of UVR, due to a dynamic equilibrium between the photoreduction process (MB ⁇ LMB) and the dark re-oxidation process (LMB + O 2 ⁇ MB) . Therefore in an atmosphere of essentially constant oxygen content (the air) the colour of the film will be dependent on the currently incident UV radiation and will not show a measure of the cumulative UV dose.
  • the re-oxidation step is not possible and the covered MB film is able to act as a UV dosimeter.
  • the oxygen barrier prevents return of the dye towards the reduced state the colour of the film shows the dose of UV absorbed.
  • the present invention provides a composition for detecting ultraviolet light comprising: at least one redox sensitive dye which displays different visible properties in the oxidised and reduced forms and is reactive to oxygen when in its reduced state,- at least one electron donor,- at least one semiconductor material specifically sensitive to light of about 200-400nm; wherein upon irradiation of said semiconductor material by light of about 200-400nm an electron is donated by the electron donor to the semiconductor material which in turn provides an electron to the redox sensitive dye causing the redox sensitive dye to be reduced; and wherein the pH of the composition is at a neutral or sufficiently acid pH so as to render the reduced form of the dye insensitive to oxidation by oxygen.
  • the redox sensitive dyes used in the invention display a high sensitivity to oxygen when in their reduced (leuco) form. They are usually rapidly oxidised back from the reduced state to the oxidised state in the presence of atmospheric oxygen, for example.
  • the redox sensitive dyes may be azine, oxazine, thiazine or indophenol dyes. Other redox sensitive dyes may be used. It will be understood that the term redox sensitive dye refers to a substance that exhibits colour in the visible light region or fluorescence .
  • compositions of the invention can show a different behaviour.
  • the normal oxidation of the reduced form of the dyestuff by oxygen in air can be significantly slowed and even stopped. This effect allows the use of readily available and inexpensive, but normally air sensitive when reduced, dyes, in sensors of the invention.
  • the semi conductor material is specifically sensitive to light of about 200-400nm (ie. UV light) and this is understood to mean that the semi conductor material is substantially insensitive to light outside • the range of about 200-400nm.
  • the semiconductor material when irradiated by UV of the appropriate wavelength (i.e. light of energy greater than or equal to its bandgap) the semiconductor material becomes electronically excited, i.e. activated under UV irradiation.
  • the electronically excited state of the semiconductor material is a better oxidising agent than its non-excited, ground-state, form. As a consequence the excited semiconductor material is able to oxidize the electron donor present in the sensor formulation.
  • the electron donor is chosen so that this process is irreversible, i.e. the electron donor is sacrificed.
  • the key products of the above photoinduced electron transfer reaction are the irreversibly oxidised form of the sacrificial electron donor and the reduced form of the semiconductor material.
  • the latter then reduces the redox- sensitive dye from (typically) its highly-coloured form, to its less-coloured, reduced form.
  • the semiconductor material is also able to store, or pool, reduction potential on its surface and/or reduce other species present so that they can act as an electron pool to reduce the redox- sensitive dye.
  • the depth of this electron pool will depend directly upon the duration of the irradiation; the longer the deeper.
  • the semiconductor material is usually referred to as a photocatalyst, or photosensitiser, i.e. a material that absorbs light and then effects a change but, is itself left unchanged at the end of the process.
  • the composition may be in the form of a tablet or pellet in which the components are, for example, pressed together, or as a plastic film in which the components are encapsulated in some medium, such as a polymer.
  • the composition may be in the form of an ink which may be printed to form a label, logo or text i.e. writing.
  • the intimate contact of the various components allows the composition to undergo a reduction reaction wherein there is a transfer of electrons from the photogenerated reduced form of the semiconductor material to the redox sensitive dye .
  • Azine, thiazine, oxazine and indophenol dyes may be used in the invention.
  • azine dyes include but are not limited to: methylene violet 3RAX or safranine O
  • examples oxazine dyes include but are not limited to: resazurin and cresyl violet acetate
  • examples of thiazine dyes include but are not limited to: methylene blue and thionin.
  • Preferred dyes include dichloroindophenol (DCIP) and methylene blue (MB) .
  • a mixture of dyes may be used. It will be understood that the selected dye or dyes may be used in the manufacture of a composition of the invention in their usual, commercially available, form. For example methylene blue may be used as the chloride salt and dichloroindophenol as the sodium salt. Other forms of a chosen dye may be used.
  • the pH of the composition is neutral (7) or lower as discussed below with reference to specific examples.
  • the pH is pH 2 or less for methylene blue and pH 6 or less for dichloroindophenol.
  • the desired pH, where the selected dye or dyes is not sensitive to oxidation is readily determined by simple experiment. Some compositions may not require pH adjustment to effect the removal of the sensitivity to oxidation.
  • the composition comprises an added acid component .
  • Preferred acids that may be employed include hydrochloric, nitric, perchloric and sulfuric acids. Organic acids may also be used.
  • the pH of the composition may be buffered to a selected pH by use of a buffering agent or agents if desired.
  • a composition for detecting ultraviolet light where the oxidation of the reduced form of the dye does not occur at a significant rate has a number of advantages over previously known compositions, especially when used in a UV sensor as discussed with respect to another aspect of the invention described hereafter.
  • the semiconductor material has the ability to form an excited electronic state that is sufficiently oxidising to oxidize the sacrificial electron donor and has a reduced form that is able to reduce the redox sensitive material.
  • semiconductor material materials which are usually solids which have an electronic structure comprising a nearly filled valence band and a nearly empty conductance band. The difference in energy between these two levels is called the bandgap of the semiconductor.
  • a semiconductor material has a bandgap that typically lies in the range of 0.1-4eV and exhibits a degree of conductivity that is usually less than that of metals which have bandgaps less than 0. IeV but greater that that of insulators which have bandgaps greater than 4eV.
  • the conductivity of the semiconductor material increases with increasing temperature.
  • the semiconductor material may be classed as a photosensitiser or a photocatalyst i.e.
  • a material that is able to promote a process through the creation of an electronically exited state generated by the absorption of a photon of light.
  • the energy of the light is usually greater than or equal to the bandgap.
  • the initial excitation of the system is followed by subsequent electron transfer and/or energy transfer, which results in overall photsensitised or photocatalysed reactions.
  • the photocatalyst or photosensitiser remains chemically unchanged at the end of the overall reaction.
  • the semiconductor material may be an oxide of titanium (such as titanium (IV) oxide; TiO 2 or strontium titanate; SrTiO 3 ), tin (such as tin(IV) oxide ,-SnO 2 ) , cerium (CeO 2 ) , niobium (Nb 2 O 5 ) , tantalum (Ta 2 O 5 ) , tungsten (such as tungsten(VI) oxide ,-WO 3 ) or zinc (such as zinc (II) oxide ;
  • a semiconductor material that is more effective at absorbing UVB light than UVA light can provide a sensor that can is a dosimeter for measuring absorbance of the damaging UVB light.
  • Titania has a band gap of only 3.2 eV and is effective at absorbing both UVA and UVB light. Accordingly a semiconductor material that selectively absorbs UVB light (280-315 nm equivalent to a band gap of 4.4 to 3.9 eV) is preferred, for example in applications where biological damage is measured.
  • a semiconductor material that absorbs UV light over another selected range may be employed.
  • a mixture of two or more semiconductor materials may be used in a composition of the invention, for example to broaden the range of sensitivity to UV light.
  • the semiconductor material has a band gap of between 3.4 and 4.4 eV. Even more preferably the semiconductor material has a band gap that lies in the range 3.6 to 4.1 eV. Most preferably the semiconductor material has a band gap of 3.6 eV.
  • the semiconductor material is tin (IV) oxide (SnO 2 ) , most preferably nanocrystalline tin (IV) oxide (SnO 2 ). SnO 2 has the highly preferred band gap of ca. 3.6 eV and can be used to prepare highly effective compositions that are selective for UVB as discussed hereafter with reference to specific embodiments.
  • the electron donor has the ability to donate electrons, preferably irreversibly.
  • the electron donor is a mild reducing agent, at the pH selected to render the dye insensitive to oxidation.
  • the electron donor may, for example, be an amine for example ethylenediaminetetraacetic acid disodiutn salt or triethanolamine (Na 2 EDTA or TEOA) , reducing saccharide (such as glucose and fructose) , readily oxidisable polymer (such as polyvinyl alcohol) , and other general anti-oxidant (such as ascorbic and citric acid) or easily oxidizable material (such as a polyol, such as glycerol) and/or mixtures thereof.
  • amine for example ethylenediaminetetraacetic acid disodiutn salt or triethanolamine (Na 2 EDTA or TEOA)
  • reducing saccharide such as glucose and fructose
  • readily oxidisable polymer such as polyvinyl alcohol
  • other general anti-oxidant such as ascorbic and citric acid
  • certain reducing agents are basic, for example TEOA, and therefore act to increase the pH environment of the dye in a composition.
  • a basic component such as TEOA is used in a composition of the invention adjustment of pH with acid may be required to achieve the required inactivation of the oxidation of the dye.
  • Glycerol is a preferred electron donor.
  • compositions of the invention may further comprise a binder which binds all the components together.
  • the binder may be a polymeric material such as gelatin, hydroxyethyl cellulose (HEC) , polyvinyl alcohol (PVA) , ethyl cellulose (EC) , cellulose acetate (CEA) , polyvinylpyrrolidone (PVP) , polyvinylbutral (PVB), polyethylene oxide, and polymethylmethacrylate (PMMA) .
  • compositions of the invention have been switched off by the choice of an appropriate pH.
  • the composition can therefore be used in a sensor, which can be a reliable dosimeter for measuring exposure to ultraviolet light.
  • the present invention provides a sensor for detecting UV light including a composition
  • a composition comprising: at least one redox sensitive dye which displays different visible properties in the oxidised and reduced forms and is reactive to oxygen when in its reduced state; at least one electron donor; at least one semiconductor material specifically sensitive to light of about 200-400nm; wherein upon irradiation of said semiconductor material by light of about 200-400nm an electron is donated by the electron donor to the semiconductor material which in turn provides an electron to the redox sensitive dye causing the redox sensitive dye to be reduced; and wherein the pH of the composition is at a neutral or sufficiently acid pH so as to render the reduced form of the dye insensitive to oxidation by oxygen.
  • compositions may be supported on at least one inert material, such as glass, paper, fabric, ceramic and metal.
  • the composition may be in the form of an ink and printed on a substrate to form a sensor.
  • the invention provides a dosimeter for measuring a quantity of UV light comprising a sensor according to the second aspect of the invention.
  • a sensor of the invention as a dosimeter is advantageous in comparison to the dosimeters of WO03021252 where the oxidation reaction is prevented by placing an oxygen (O 2 ) impermeable barrier over the redox system.
  • O 2 oxygen
  • Such a barrier may have limited effectiveness and if it does leak oxygen then the oxidation reaction will occur leading to an inaccurate indication of UV absorbed.
  • the senor is used as a disposable device formed to be worn by an individual as a UV dosimeter to show when too much exposure to sunlight occurs.
  • the device may take the form of a plastic wristband that includes an area coated with or impregnated with the UV sensitive composition.
  • the sensor may be used in label form with the composition printed on the label as an ink, for example.
  • the sensor may be in the form of a transfer applied to the skin or a composition in the form of an ink may be used to mark directly on to skin.
  • prior art sensors with O 2 sensitive dye can be coated with sunscreen to provide a measure of the UV dose absorbed through the sunscreen if desired.
  • a composition of the present invention the sensor will provide correct results.
  • the operation of the dosimeter will not be compromised by oxygen ingress through a damaged barrier layer .
  • a sensor can be constructed where the end point of reaction (i.e. the point where all of the dye in the composition has been converted to the reduced form) indicates that a selected quantity of ultraviolet light has been absorbed.
  • end point of reaction i.e. the point where all of the dye in the composition has been converted to the reduced form
  • LMB reduced form leuco methylene blue
  • a sensor can be prepared where the change to colourless indicates absorption of a chosen quantity of ultraviolet light.
  • a sensor may comprise an array of two or more compositions each with different end points of reaction, for example of decreasing sensitivity, allowing indication of the absorption of increasing amounts of UV.
  • a sensor using methylene blue may include a row of adjacent bands or areas having compositions of decreasing sensitivity. As each band becomes colourless in succession the increasing dose of UV absorbed over time is particularly easily seen.
  • a sensor may have two or more compositions with sensitivity to different wavelengths of UV light.
  • a sensor may be made with an area having a composition sensitive to UVA and another area a composition sensitive to UVB. For example, by selection of the semiconductor material as discussed above.
  • Such a sensor can find application in tanning salons where UV light is used to tan an individual' s skin.
  • the sensor can show the dose of UVA administered. At the same time the sensor indicates if a level of the, more damaging, UVB that is considered unsafe has been administered.
  • UVB sensitive composition Alternatively using a composition sensitive to both UVA and UVB (200-400nm) and another only sensitive to UVB can also be useful.
  • the UVB sensitive composition will warn of overexposure to the more damaging UVB light whilst the UVA and UVB sensitive composition gives a measure of overall exposure to UV (dose of tanning radiation) .
  • Sensors may include permanently coloured areas, whose colour corresponds to that of the UV sensitive composition when a particular amount of UV has been absorbed. Visual comparison between the composition and a coloured area or coloured areas allows estimation of the UV light absorbed.
  • UV (or fluorescence) of the UV sensitive composition may be measured using a spectrophotometer. This approach can be useful when an automated measurement of UV dose is desired.
  • Sensors of the invention may be used in tags attached to large numbers of items being subject to a UV sterilisation procedure.
  • the sensors provide a measure of the UV exposure that can be rapidly confirmed by the results from the spectrophotometer and collated automatically for analysis in a computer.
  • compositions are formed in a suitably thin layer then the layer will be relatively transparent when a coloured dye is reduced by UV absorption.
  • a light sensitive layer (for example a visible light sensitive photovoltaic layer) may be provided under the composition. The light sensitive layer detects light passing through the composition when the colour of the dye is reduced and leads to an alarm signal being generated.
  • compositions of the invention are stable with the dye in its oxidised state for many months provided they are protected from UV light.
  • Sensors of the invention may therefore be provided with a removable UV impermeable barrier.
  • a sheet of UV impermeable plastics material such as polymer containing a polyoxyalkylene, provided with a layer of a peelable pressure sensitive adhesive that is attached to the sensor to cover and protect the UV sensitive composition from UV light until it is removed at the point of use .
  • Fig.l shows Absorption spectra of a sensor of the invention which includes a composition of the invention,- Fig.2 a and b show photographs of a sensor before and after UV irradiation;
  • Fig.3 is a schematic illustrating reaction processes for a typical UV dosimeter;
  • Fig.4 shows response to UV light over time of a preferred embodiment of the sensor of the invention
  • Fig.5 shows absorption change with time of sensors of the invention following irradiation with different strengths of
  • Fig.6 shows absorption change with time of sensors of the invention containing different dye concentrations
  • Fig.7 shows absorption change with time of sensors of the invention containing different amounts of photocatalyst ;
  • Fig.8 shows absorption change with time of sensors of the invention containing different amounts of electron transfer agent
  • UV visible spectra for sample films were recorded using a Lambda 35 UV Visible spectrophotometer (Perkin Elmer, UK) .
  • the DCIP (dichloroindophenol) UV dosimeter films were irradiated for 300 seconds with spectra recorded at varying intervals .
  • UV irradiation of samples was carried out using UVA or UVB light provided by two 8 W fluorescence tubes (Vilber Lourmat) , with the appropriate emission spectra maximum peak in these regions i.e. at 365 and 315 nm respectively) .
  • the irradiance (i.e. radiant power per unit area) for each lamp was measured as 3 mW cm "2 using a Multi-sense 100 UV light meter fitted with the appropriate UVA and UVB sensors .
  • the UV solar simulator used in this work comprised a 180 W xenon arc lamp, with UG5 and the WG20 filters placed inline as described previously by Diffey 2 .
  • the former allows transmission at UV wavelengths and absorbs in the visible region, while the latter absorbs in the short wavelength UVC region.
  • the UVI of the UV solar simulated light was measure using a SafeSunTM solar meter 17
  • UV sensitive ink compositions and preparation of dosimeters A typical UV dosimeter casting ink, was prepared in the absence of significant levels of UV light (i.e. ambient room light) by dissolving 5 g of HEC in 95 ml water at room temperature, followed by stirring for 24 hours. 5 mg of DCIP, 100 mg SnO 2 and 100 mg glycerol were then added to 2 g of the HEC polymer solution. The suspension was well stirred to ensure dissolution of the dye and dispersion of the SnO 2 . The blue-coloured casting solution contained 5 phr of DCIP i.e. 5 parts per hundred resin (or 5 g of DCIP for 100 g polymer) . The pH of the composition was 6.
  • the pH of ink compositions using the same components and prepared as above, is typically around pH 5.7.
  • Films were cast on quartz discs, 25 mm in diameter and 1 mm, thick using a spin coater. Thus, a few drops of casting solution were deposited on the surface of the disc, which was then spun at 2400 rpm for 15 seconds. The final product was then dried for 2-3 minutes at 70 0 C and cooled to room temperature (5 minutes) before use.
  • the final UV dosimeter film product was a blue coloured, ca. 3.9 ⁇ m thick (as measured using a scanning electron microscope) on a quartz disc, referred to forthwith as a standard DCIP film. This product constitutes a sensor of the invention with the film being a composition of the invention.
  • a series of casting solutions were prepared comprising the standard DCIP UV sensitive ink formulation with various components omitted, with the exception of the encapsulating polymer HEC and solvent, water. These solutions were used to cast the following films on quartz discs: HEC, Glycerol/HEC, DCIP/HEC and the typical dosimeter itself DCIP/Sn0 2 /Glycerol/HEC.
  • the UV/Visible absorption spectra of these films were recorded and the results are illustrated in Figure 1.
  • Line A shows the absorption spectrum of an HEC film and also of a HEC/glycerol film.
  • Line B shows absorption spectrum of an HEC/DCIP film
  • line C shows the absorption spectrum of the DCIP/Sn0 2 /Glycerol/HEC composition prior to radiation.
  • the DCIP/HEC spectrum has a maximum absorption at 636 nm which gives the film its blue colour.
  • UVB light of 3mWcm "2 was employed. Spectra were recorded every 10 seconds for the first 90 seconds and then every 30 seconds thereafter for a total of 300 seconds. The reduction in absorbance with time is clearly shown. Using this data, and those from the same experiment conducted using UVA light instead (also 3mWcm "2 ) , it was possible to plot the variation in change in absorbance at ⁇ max i.e. ⁇ Abs 636/ as a function of irradiation time illustrated in the inset diagram in Figure 4.
  • the sensitivity of the standard DCIP UV composition towards UVB light can be readily varied by changing the amount of UV absorbing semiconductor (SnO 2 ) present.
  • SnO 2 UV absorbing semiconductor
  • a series of Sn0 2 /DCIP/glycerol/HEC casting inks were prepared containing 10 to 200 phr SnO 2 and used to spin films on quartz discs.
  • ⁇ Abs 6 ⁇ 2 versus irradiation time profiles were generated with 3 mW cm "2 UVB source and the results are illustrated in Figure 7.
  • the films contained 5 phr DCIP, 100 phr glycerol and the amount of SnO 2 was 0,10,30,50,100 and 200 phr for lines A to F respectively.
  • the ri of decolouration for each film was determined and found to be directly proportional to the level of SnO 2 present over the range studied. As it is the UVB activation of the semiconductor which initiates the reduction reaction, it was expected that an increase in
  • the effect of the level of glycerol present was also investigated.
  • Glycerol acts as a sacrificial electron donor, trapping the photogenerated holes and thus promoting the reduction of the DCIP molecules by the photogenerated electrons.
  • a series of casting inks were prepared, containing 0 to 300 phr glycerol, and were used to produce films which were then irradiated with 3 mW cm "2 UVB light.
  • a series of ⁇ Abs 6 i2 versus irradiation time profiles were generated as shown in Figure 8 and used to determine r ⁇ of decolouration, which were then plotted against [glycerol] as seen in insert of Figure 8.
  • the films contained 5 phr DCIP, 100 phr SnO 2 and the amount of glycerol was 0,30,50,100,200 and 300 phr for lines A to E respectively.
  • UV solar simulated light (UVI 5) was used to irradiate a standard DCIP film. The observed variation of the absorbance of this film at
  • Line A shows the results for a standard HEC film of 5 phr DCIP, 100 phr glycerol and 100 phr SnO 2 .
  • Line B shows the results for A

Landscapes

  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Molecular Biology (AREA)
  • Biophysics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)

Abstract

La présente invention concerne la fourniture de compositions sensibles aux UV et de capteurs qui comprennent les compositions. Les capteurs sont utiles dans une vaste gamme d’applications y compris en tant que dosimètres pour indiquer la quantité d’exposition d’un individu ou d’un article à la lumière UV.
PCT/GB2009/001680 2008-07-22 2009-07-06 Capteur d’uv WO2010010321A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0813356.3 2008-07-22
GB0813356A GB0813356D0 (en) 2008-07-22 2008-07-22 UV Sensor

Publications (1)

Publication Number Publication Date
WO2010010321A1 true WO2010010321A1 (fr) 2010-01-28

Family

ID=39737409

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2009/001680 WO2010010321A1 (fr) 2008-07-22 2009-07-06 Capteur d’uv

Country Status (2)

Country Link
GB (1) GB0813356D0 (fr)
WO (1) WO2010010321A1 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009048403A1 (de) * 2009-10-06 2011-05-05 Heraeus Noblelight Gmbh Messeinrichtung und Messmethode zur spektral selektiven Bestimmung der Strahlungsexposition im VUV-Bereich
CN102980882A (zh) * 2012-11-16 2013-03-20 内蒙古包钢钢联股份有限公司 Fe-Ce中间合金中铈含量的测定方法
WO2017019455A3 (fr) * 2015-07-24 2017-03-16 Skylit Corporation Systèmes et procédés permettant de maîtriser une luminothérapie
WO2017147655A1 (fr) * 2016-03-01 2017-09-08 Newsouth Innovations Pty Limited Composition d'impression photosensible
CN108872211A (zh) * 2018-04-17 2018-11-23 广西大学 一种生物质纤维素基Ag+检测材料及其制备方法和应用
CN108982489A (zh) * 2018-07-05 2018-12-11 广西大学 一种生物质纤维素基Cu2+检测材料的制备方法及应用
US11231506B2 (en) 2018-09-14 2022-01-25 Billion Bottle Project Ultraviolet (UV) dosimetry
US11549883B2 (en) 2017-08-17 2023-01-10 Logicink Corporation Sensing of markers for airborne particulate pollution by wearable colorimetry
US11583695B2 (en) 2014-02-03 2023-02-21 Zerigo Health, Inc. Systems and methods for phototherapy
US11786748B2 (en) 2015-04-10 2023-10-17 Zerigo Health, Inc. Phototherapy light engine

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003021252A1 (fr) * 2001-09-05 2003-03-13 University Of Strathclyde Capteur pour agents oxydants
WO2004080595A1 (fr) * 2003-03-12 2004-09-23 University Of Strathclyde Indicateur pour detecter un photo-catalyseur

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003021252A1 (fr) * 2001-09-05 2003-03-13 University Of Strathclyde Capteur pour agents oxydants
WO2004080595A1 (fr) * 2003-03-12 2004-09-23 University Of Strathclyde Indicateur pour detecter un photo-catalyseur

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
KOUSHITA K; KAWAHARA T: "EVALUATION OF PHOTOCATALYTIC ACTIVITY BY DYE DECOMPOSITION", JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, SPRINGER, NEW YORK, NY, US, vol. 22, no. 1/02, 1 September 2001 (2001-09-01), pages 91 - 98, XP001100710, ISSN: 0928-0707 *
SUMITA T; ET AL: "A NEW CHARACTERIZATION METHOD OF PHOTOCATALYTIC ACTIVITY IN SEMICONDUCTOR PHOTOCATALYSTS", JAPANESE JOURNAL OF APPLIED PHYSICS, JAPAN SOCIETY OF APPLIED PHYSICS, TOKYO,JP, vol. 40, no. 6A, PART 01, 1 June 2001 (2001-06-01), XP001078644, ISSN: 0021-4922 *

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009048403A1 (de) * 2009-10-06 2011-05-05 Heraeus Noblelight Gmbh Messeinrichtung und Messmethode zur spektral selektiven Bestimmung der Strahlungsexposition im VUV-Bereich
CN102980882A (zh) * 2012-11-16 2013-03-20 内蒙古包钢钢联股份有限公司 Fe-Ce中间合金中铈含量的测定方法
US11583695B2 (en) 2014-02-03 2023-02-21 Zerigo Health, Inc. Systems and methods for phototherapy
US11786748B2 (en) 2015-04-10 2023-10-17 Zerigo Health, Inc. Phototherapy light engine
WO2017019455A3 (fr) * 2015-07-24 2017-03-16 Skylit Corporation Systèmes et procédés permettant de maîtriser une luminothérapie
US11638834B2 (en) 2015-07-24 2023-05-02 Zerigo Health, Inc. Systems and methods for phototherapy control
AU2017225908B2 (en) * 2016-03-01 2022-09-08 Qingdao Xin Shi Gang Technology Industry Co Ltd Photosensitive printing composition
WO2017147655A1 (fr) * 2016-03-01 2017-09-08 Newsouth Innovations Pty Limited Composition d'impression photosensible
EP3423798A4 (fr) * 2016-03-01 2019-03-20 NewSouth Innovations Pty Limited Composition d'impression photosensible
US11174407B2 (en) 2016-03-01 2021-11-16 Qingdao Xin Shi Gang Technology Industry Co Ltd Photosensitive printing composition
US11549883B2 (en) 2017-08-17 2023-01-10 Logicink Corporation Sensing of markers for airborne particulate pollution by wearable colorimetry
CN108872211A (zh) * 2018-04-17 2018-11-23 广西大学 一种生物质纤维素基Ag+检测材料及其制备方法和应用
CN108872211B (zh) * 2018-04-17 2020-12-08 广西大学 一种生物质纤维素基Ag+检测材料及其制备方法和应用
CN108982489B (zh) * 2018-07-05 2020-12-29 广西大学 一种生物质纤维素基Cu2+检测材料的制备方法及应用
CN108982489A (zh) * 2018-07-05 2018-12-11 广西大学 一种生物质纤维素基Cu2+检测材料的制备方法及应用
US11231506B2 (en) 2018-09-14 2022-01-25 Billion Bottle Project Ultraviolet (UV) dosimetry

Also Published As

Publication number Publication date
GB0813356D0 (en) 2008-08-27

Similar Documents

Publication Publication Date Title
WO2010010321A1 (fr) Capteur d’uv
EP1601462B1 (fr) Produit pour detecter un photo-catalyseur
EP1423692B1 (fr) Procede pour detecter des agents oxydants
Mills et al. Nanocrystalline SnO2-based, UVB-activated, colourimetric oxygen indicator
CA2782492C (fr) Indicateur d'ultraviolet sensible a une dose
US5028792A (en) System for the visualization of exposure to ultraviolet radiation
Khiabani et al. Based sensor for monitoring sun exposure
JP2016028238A (ja) ナノ構造の変形、破壊、および変換に基づくモニタリング装置およびモニタリング方法
US8961897B2 (en) Disposable measuring device for UV radiation
EP0325863A2 (fr) Dispositif de mesure du rayonnement ultraviolet à plusieurs couleurs
Barakat et al. Radiation effects on some dyes in non-aqueous solvents and in some polymeric films
Dransfield et al. Photoactivity tests of TiO2-based inorganic sunscreens: Part 1: Non-aqueous dispersions
Miyoshi et al. Reversible radiochromic plate based on polyvinyl alcohol-iodide complex containing silica nanoparticles
Mills et al. Development of a novel UV indicator and dosimeter film
Mills et al. UV dosimeters based on neotetrazolium chloride
Mills et al. A viologen-based UV indicator and dosimeter
Mills et al. UV dosimeter based on dichloroindophenol and tin (IV) oxide
Mills et al. UV-activated luminescence/colourimetric O2 indicator
Ebraheem et al. Polymer-based triphenyl tetrazolium chloride films for ultraviolet radiation monitoring
Rao et al. Photocatalytic degradation of crystal violet over semiconductor zinc oxide powder suspended in aqueous solution
Miyaji et al. Development of a radiation dosimeter consisting of leuco crystal violet and a small amount of halocarbons
Vesely et al. Disposable indicator card for personal monitoring of solar exposure
WO2023081207A1 (fr) Détecteur de rayonnement colorimétrique
McFarlane Development of novel indicators
JP2001303033A (ja) 遷移金属酸化物フォトクロミック材料およびそれを用いたフォトクロミック方法および装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09784645

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09784645

Country of ref document: EP

Kind code of ref document: A1