WO2018146592A1 - Reduced grapheneoxide nanomaterial coated cotton fabric as a heating device and method therefore - Google Patents
Reduced grapheneoxide nanomaterial coated cotton fabric as a heating device and method therefore Download PDFInfo
- Publication number
- WO2018146592A1 WO2018146592A1 PCT/IB2018/050721 IB2018050721W WO2018146592A1 WO 2018146592 A1 WO2018146592 A1 WO 2018146592A1 IB 2018050721 W IB2018050721 W IB 2018050721W WO 2018146592 A1 WO2018146592 A1 WO 2018146592A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- graphene oxide
- heating device
- nanosheets
- reduced graphene
- fabric
- Prior art date
Links
- 239000004744 fabric Substances 0.000 title claims abstract description 75
- 238000010438 heat treatment Methods 0.000 title claims abstract description 55
- 229920000742 Cotton Polymers 0.000 title claims description 54
- 238000000034 method Methods 0.000 title claims description 19
- 239000002086 nanomaterial Substances 0.000 title description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 89
- 239000002135 nanosheet Substances 0.000 claims abstract description 72
- 229910021389 graphene Inorganic materials 0.000 claims abstract description 69
- 238000004519 manufacturing process Methods 0.000 claims abstract description 12
- 239000010408 film Substances 0.000 claims description 53
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims description 20
- 229920000052 poly(p-xylylene) Polymers 0.000 claims description 17
- 239000011248 coating agent Substances 0.000 claims description 15
- 238000000576 coating method Methods 0.000 claims description 15
- 239000000203 mixture Substances 0.000 claims description 15
- 229910002804 graphite Inorganic materials 0.000 claims description 13
- 239000010439 graphite Substances 0.000 claims description 13
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 12
- 239000008367 deionised water Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 8
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 claims description 8
- 239000004020 conductor Substances 0.000 claims description 8
- 229910021641 deionized water Inorganic materials 0.000 claims description 8
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 7
- 229910052709 silver Inorganic materials 0.000 claims description 7
- 239000004332 silver Substances 0.000 claims description 7
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 239000010949 copper Substances 0.000 claims description 5
- 238000003618 dip coating Methods 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 5
- 239000000758 substrate Substances 0.000 claims description 5
- NWZSZGALRFJKBT-KNIFDHDWSA-N (2s)-2,6-diaminohexanoic acid;(2s)-2-hydroxybutanedioic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O.NCCCC[C@H](N)C(O)=O NWZSZGALRFJKBT-KNIFDHDWSA-N 0.000 claims description 4
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 4
- 238000000137 annealing Methods 0.000 claims description 4
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 4
- 229910052737 gold Inorganic materials 0.000 claims description 4
- 239000010931 gold Substances 0.000 claims description 4
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 claims description 4
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 claims description 4
- FHCPAXDKURNIOZ-UHFFFAOYSA-N tetrathiafulvalene Chemical compound S1C=CSC1=C1SC=CS1 FHCPAXDKURNIOZ-UHFFFAOYSA-N 0.000 claims description 4
- 240000000491 Corchorus aestuans Species 0.000 claims description 3
- 235000011777 Corchorus aestuans Nutrition 0.000 claims description 3
- 235000010862 Corchorus capsularis Nutrition 0.000 claims description 3
- 235000004431 Linum usitatissimum Nutrition 0.000 claims description 3
- 239000004677 Nylon Substances 0.000 claims description 3
- 229920002334 Spandex Polymers 0.000 claims description 3
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 3
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 3
- 239000004411 aluminium Substances 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 229920001778 nylon Polymers 0.000 claims description 3
- 229920000728 polyester Polymers 0.000 claims description 3
- 239000000843 powder Substances 0.000 claims description 3
- 239000004759 spandex Substances 0.000 claims description 3
- 229920002994 synthetic fiber Polymers 0.000 claims description 3
- 239000010409 thin film Substances 0.000 claims description 3
- YMWLPMGFZYFLRP-UHFFFAOYSA-N 2-(4,5-dimethyl-1,3-diselenol-2-ylidene)-4,5-dimethyl-1,3-diselenole Chemical compound [Se]1C(C)=C(C)[Se]C1=C1[Se]C(C)=C(C)[Se]1 YMWLPMGFZYFLRP-UHFFFAOYSA-N 0.000 claims description 2
- HGOTVGUTJPNVDR-UHFFFAOYSA-N 2-(4,5-dimethyl-1,3-dithiol-2-ylidene)-4,5-dimethyl-1,3-dithiole Chemical compound S1C(C)=C(C)SC1=C1SC(C)=C(C)S1 HGOTVGUTJPNVDR-UHFFFAOYSA-N 0.000 claims description 2
- 238000007865 diluting Methods 0.000 claims description 2
- 238000000227 grinding Methods 0.000 claims description 2
- 239000003960 organic solvent Substances 0.000 claims description 2
- 229910052697 platinum Inorganic materials 0.000 claims description 2
- 239000012286 potassium permanganate Substances 0.000 claims description 2
- 239000001117 sulphuric acid Substances 0.000 claims description 2
- 235000011149 sulphuric acid Nutrition 0.000 claims description 2
- 240000006240 Linum usitatissimum Species 0.000 claims 1
- 239000000243 solution Substances 0.000 description 23
- 239000004753 textile Substances 0.000 description 12
- 230000006641 stabilisation Effects 0.000 description 9
- 238000011105 stabilization Methods 0.000 description 9
- 230000008569 process Effects 0.000 description 7
- 238000006722 reduction reaction Methods 0.000 description 6
- 239000010410 layer Substances 0.000 description 5
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 239000003638 chemical reducing agent Substances 0.000 description 4
- 238000003786 synthesis reaction Methods 0.000 description 4
- 238000011282 treatment Methods 0.000 description 4
- 238000000349 field-emission scanning electron micrograph Methods 0.000 description 3
- 238000000445 field-emission scanning electron microscopy Methods 0.000 description 3
- 230000020169 heat generation Effects 0.000 description 3
- 239000011229 interlayer Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- 229920000049 Carbon (fiber) Polymers 0.000 description 2
- 229910000570 Cupronickel Inorganic materials 0.000 description 2
- 241000208202 Linaceae Species 0.000 description 2
- 238000001069 Raman spectroscopy Methods 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 230000036760 body temperature Effects 0.000 description 2
- 239000004917 carbon fiber Substances 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 238000001827 electrotherapy Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000004299 exfoliation Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000013081 microcrystal Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000003828 vacuum filtration Methods 0.000 description 2
- 238000010792 warming Methods 0.000 description 2
- 240000008574 Capsicum frutescens Species 0.000 description 1
- 229910002060 Fe-Cr-Al alloy Inorganic materials 0.000 description 1
- XOJVVFBFDXDTEG-UHFFFAOYSA-N Norphytane Natural products CC(C)CCCC(C)CCCC(C)CCCC(C)C XOJVVFBFDXDTEG-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000003776 cleavage reaction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000000975 dye Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002118 epoxides Chemical class 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 229910000953 kanthal Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000003760 magnetic stirring Methods 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 239000002114 nanocomposite Substances 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 230000029058 respiratory gaseous exchange Effects 0.000 description 1
- 230000007017 scission Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000012916 structural analysis Methods 0.000 description 1
- 230000007847 structural defect Effects 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
- H05B3/34—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater flexible, e.g. heating nets or webs
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
- D06M11/73—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with carbon or compounds thereof
- D06M11/74—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with carbon or compounds thereof with carbon or graphite; with carbides; with graphitic acids or their salts
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
- D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
- D06M15/21—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D06M15/227—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of hydrocarbons, or reaction products thereof, e.g. afterhalogenated or sulfochlorinated
- D06M15/233—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of hydrocarbons, or reaction products thereof, e.g. afterhalogenated or sulfochlorinated aromatic, e.g. styrene
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M23/00—Treatment of fibres, threads, yarns, fabrics or fibrous goods made from such materials, characterised by the process
- D06M23/08—Processes in which the treating agent is applied in powder or granular form
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
- H05B3/12—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
- H05B3/14—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material the material being non-metallic
- H05B3/145—Carbon only, e.g. carbon black, graphite
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B2214/00—Aspects relating to resistive heating, induction heating and heating using microwaves, covered by groups H05B3/00, H05B6/00
- H05B2214/04—Heating means manufactured by using nanotechnology
Definitions
- the present invention relates to the field of heating devices.
- the invention relates to reduced graphene oxide nanosheets based heating devices.
- the invention relates to reduced graphene oxide nanosheets based heating device which can be used as disposable thermal body warmers, wherein film of reduced graphene oxide nanosheets are coated on fabrics to fabricate thermal body warmer for heat generating applications and a method of fabrication thereof.
- Body warmers are generally used to combat cold weather conditions in chilly areas. They also find use in biomedical fields such as in electrotherapy treatments, medical blankets for patients in order to maintain their body temperatures; also in military jackets worn by soldiers in the defence forces and the like. However, these products are bulky, expensive, with low flexibility and huge power consumptions. There is a constant lookout for devices with effective body warming functionality, compatible size as per requirement, flexible, less energy consumption along with low manufacturing costs. In the recent past, micro and nano systems are known to play a key role in the development of miniaturized electronic devices in various applications such as chemical sensing, health care, wearable electronics, biomedical applications and the like. They also find use in heating elements designed for creating flexible electronics, flexible heaters and nanomaterials for garments.
- US 13/355,212 provides information related to the electrically conductive and radio frequency (RF) transparent films that include a graphene layer (or multilayer) and a substrate associated with the graphene layer.
- RF radio frequency
- the present invention benefits over the conventional heating systems, where the invention provides for a heating device that is corrosion free, flexible in terms of bendability, that can be formed into required shapes for minimizing the device size, biocompatible, with minimum energy consumption and low manufacturing cost.
- the present invention relates to a disposable thermal body warmer comprising a fabric integrated with a film of reduced graphene oxide nanosheets, encapsulated with parylene coatingwherein the thickness of film ranging about 200 + 10 ⁇ .
- the invention is also in relation to a method of fabrication of film of reduced graphene oxide nanosheets on the fabric to obtain thermal body warmer.
- Figure 1 provides a schematic view of reduced Graphene oxide nanosheets coated cotton cloth based thermal body warmer.
- Figure 2 provides a photograph of the fabricated reduced Graphene oxide coated cotton cloth based thermal body warmer.
- Figure 3 illustrates XRD phases of Graphene oxide and reduced Graphene oxide nanosheets coated cotton cloth based films.
- Figure 4 shows FE-SEM images: (a) Bare textile cotton cloth with pore sizes of vertical and horizontal dimensions at lower magnification, (b) the same dimensions at higher magnification.
- Figure 5 shows FE-SEM images of cross sectional view of reduced Graphene oxide coated cotton cloth films:(a) the thickness of singlemulti -layered reduced Graphene oxide nanosheets, (b) surface view in the reduced Graphene oxide nanosheets coated on the textile cotton cloth, (c) the textile cotton cloth fibres diameter with pores filled with reduced Graphene oxide nanosheets, (d) the thickness of reduced Graphene oxide nanosheets coated on the textile cotton cloth based filmsfor heating element.
- Figure 6 shows FE-SEM images of cross sectional view of parylene coated complete heating element device: (a) the thickness of single multi-layered reduced Graphene oxide nanosheets decorated polymer parylene, (b) side view of thickness of reduced Graphene oxide nanosheets coated on the textile cotton cloth after parylene coating.
- Figure 7 shows Raman Spectroscopy of (a) Graphene oxide sheets, (b) reduced Graphene oxide nanosheets.
- Figure 8 discloses the complete experimental set up for testing of reduced Graphene oxide nanosheets coated on the cotton cloth based films for heating element.
- Figure 9 provides for Temperature versus applied Voltage plot, (a) One minute stabilization for five times repeatability, (b) Five minutes stabilization for five times repeatability, (c) Under Vacuum five minutes stabilization for four time repeatability.
- Figure 10 shows Resistance profiles versus the applied Voltage, (a) One minute stabilization for five times repeatability, (b) Five minutes stabilization for five times repeatability, (c) Under Vacuum five minutes stabilization for four time repeatability.
- Figure 11 shows the average normalized resistance change of reduced Graphene oxide versus temperature generation with the applied voltage, (a) One minute stabilization time, (b) Five minutes stabilization time and (c) Under Vacuum five minutes stabilization time.
- Figure 12 provides for Temperature vs time plot for the aqueous reduced Graphene oxide nanosheets coated cotton cloth based films due to different applied voltages under atmosphere condition, (a) Temperature rise due to applied voltages 30V and 40V in heating condition, (b) Temperature drop when applied voltages are switched off (30V and 40V in cooling condition).
- Figure 13 illustrates temperature verses Voltage performance of cotton cloth heating element at different ambient temperatures.
- the present invention is in relation to a heating device (A); comprising a fabric (1) integrated with a film of reduced graphene oxide nanosheets (2), encapsulated in parylene coating (3) ; wherein the thickness of film is ranging from about 190 ⁇ to about 210 ⁇ and size of nanosheets is ranging from about 250 nm to about 550 nm; wherein the films are connected to electrical leads (4) through metal electrodes (5); and a monitor (6) of heat comprising standard thin film based RTD Pt 100 attached to bottom of the fabric (1).
- the heating device is a disposable thermal body warmer.
- the fabric is selected from a range of natural and synthetic fibres such as cotton, jute flax, polyester, acrylic, nylon and spandex; preferably cotton.
- the electrical leads is of a conductor selected from a group comprising conductors of metallic conductor comprising copper, aluminium, silver and gold; organic conductor, Tetrathiafulvalene (TTF), tetramethyltetrathiafulvalene (TMTSF) and bisethylenedithio-tetrathiafulvalene (BEDT- TTF); preferably copper.
- TTF Tetrathiafulvalene
- TTF tetramethyltetrathiafulvalene
- BEDT- TTF bisethylenedithio-tetrathiafulvalene
- the metal for the electrode is selected from a group comprising silver, gold and platinum; preferably silver.
- the device provides heat to raise the temperature from about -35°C to about 20°C by input voltage of about 60V.
- the present invention is also in relation to a method of fabrication heating device (A) of present invention, said method comprising acts of i) preparing solution of reduced graphene oxide nanosheets, comprising acts of a) oxidising graphite powder using potassium permanganate, hydrogen peroxide and deionized water in presence of sulphuric acid to obtain graphite oxide;
- the reduced graphene oxide solution is prepared in an organic solvent selected from a group comprising N- Methyl-2-pyrrolidone (NMP), Dimethyl formamide (DMF), Tetrahydrofuran (THF), acetone and water , preferably N-Methyl-2-pyrrolidone.
- NMP N- Methyl-2-pyrrolidone
- DMF Dimethyl formamide
- THF Tetrahydrofuran
- acetone preferably N-Methyl-2-pyrrolidone.
- the present invention is also in relation to heating device (B) comprising one or more heating device (A) of present invention.
- the present invention relates to reduced graphene oxide nanosheets coated as film on a fabric; to be used as disposable thermal body warmers for heating applications .
- the film is encapsulated in Parylene (thickness of ⁇ 2 ⁇ ) coating as it provides complete protection from moisture, dust, protects films from peel off while handling the device. Parylene coating gives complete conformal, uniform thickness as well as makes the film pinhole free.
- the reduced grapheme oxide is obtained by modified hummer's method as described below, typically the thickness of reduced graphene oxide is ranging about 300 + 50 nm to about 500 + 50 nm (the dimensions of the reduced grapheme oxide, nano particle size/dimensions before dispersion in NMP and coating).
- heating device (A) comprising a fabric (1) integrated with a film of reduced graphene oxide nanosheets (2), encapsulated in parylene coating (3); wherein the thickness of film ranging about 200 + 10 ⁇ and the size of nanosheets ranging from about 300 + 50 nm to about 500 + 50 nm were formed.
- Nanosheets based films connected to electrical leads (4) through metal electrodes (5) is schematically represented in figure 1 and 2. The temperature generation has been monitored by using standard thin film based RTD Pt 100 mounted or attached on the bottom of the cotton cloth (6).
- the fabric is selected from a range of natural and synthetic fibres such as cotton, jute flax, polyester, acrylic, nylon and spandex; preferably cotton ( Figure 4).
- the method of preparation of the film typically involve steps of synthesis of graphene oxide sheets; reduction of graphene oxide nanosheets using hydrazine hydrate solution; preparing the reduced graphene oxide nanosheets solution by dispersing reduced graphene oxide nanosheets and N-Methyl-2-Pyrrolidone solution. Dip coating a patterned substrate integrated in a fabric using the graphene oxide nanosheets solution for use as body warmer or any other heating applications.
- Figure 1(a) & 1(b) shows the schematic representation and photograph image of fabricated reduced graphene oxide nanosheets (RGO) based film coated on a fabric of body warmers. After the fabrication of the RGO nanosheets based cotton coated fabric, its response to various parameters such as temperature, resistance change with respect to the applied voltage variations are studied and the typical responses of saturation temperature obtained are shown in figures 9 to 12.
- RGO reduced graphene oxide nanosheets
- 2g of the graphite powder is oxidized in a strong acidic environment using 54ml of H 2 SO 4 through constant magnetic stirring, at a temperature maintained about 25 ⁇ 10°C.
- About 6g of KMn0 4 is slowly added to the solution over a period of about 20 minutes.
- the concentrated solution is then rigorously stirred for 40 min.
- 100 ml of deionized water is added to the solution in a dropwise manner for a period of about 10-15 min. As fumes evolve from the solution, stirring is continued for another 90 minutes. 200ml of deionized water is then added to the solution.
- the oxidation process is completed upon adding 30ml of hydrogen peroxide (H 2 O 2 ) to the solution.
- the Graphene oxide powder is diluted with de-ionized water taken in a weight ratio of 1:1. 0.3g (1 mgmr 1 ) of Graphene oxide is dissolved in 300 ml of deionized water. The diluted suspension is ultra- sonicated (the operating frequency is about 33 K Hz + 3 %) for 90 min. The flakes of Graphene oxide are split into the individual nano sheets. The entire mixture is reduced using reducing agent, that is, O. lg (3ml) Hydrazine hydrate solution is added to the mixture under constant stirring at 95°C for 4 hours. The mixture is filtered through Whatman filter paper by using vacuum filtration method to separate the unreacted components from the mixture and the filtration cake residue is collected at the end of the process. Finally reduced graphene oxide nanosheets are annealed at 80°C for 2 hours.
- reducing agent that is, O. lg (3ml) Hydrazine hydrate solution
- the RGO nanosheets solution is prepared by dispersing RGO nanosheets and N-Methyl-2- Pyrrolidone (NMP) solution.
- NMP N-Methyl-2- Pyrrolidone
- the mixed solution is ultra-sonicatedin order to achieve a homogenous exfoliationof the RGO nanosheets. Subsequently, this composition is used for the fabrication of resistive heating elements for wearable thermal body warmers.
- X-ray diffraction (XRD) patterns are recorded on the synthesized GO nanosheets and RGOnanosheetsfor their structural analysis.
- the same peak is shifted to 11.2°, corresponding to the (001) plane after oxidation treatment, indicating that the interlayer spacing in the Graphite Oxide increases.
- the interlayer distance is increased in the GO nanosheets due to the presence of the epoxide, carboxyl groups and water molecules between the graphene oxides layers.
- the diffraction peak at 42.82° corresponding to the (100) plane represents the reformation of graphite microcrystals nature in the GO system.
- the RGO after chemical reduction, nearly all peaks disappears indicating exfoliation of multilayers during the chemical reduction process of GO.
- a wide diffraction peak appears at 23.5° which corresponds to an interlayer spacing of 0.38 nm as shown in Fig (c).
- the RGO nanosheets self-assemble due to the reduction reaction.
- the shoulder peak appearing at 42.82° which is fingerprint peak for graphite due to (100) diffraction indicates that the reformation of graphite microcrystals on reduced graphene oxide plane is because of chemical reduction of the Graphene Oxide.
- the advanced characterized tools are used for surface morphology analysis of textile cotton cloth pieces, as-synthesized GO sheets and RGO nanosheets coated on the cotton cloth based films by field emission- scanning electron microscopy (FE-SEM (Carl Zeiss), ULTRA 55).
- FE-SEM Carl Zeiss
- Fig.4 (a) & (b) shows the pores nature of bare textile cotton cloth having dimensions around 159 ⁇ &115 ⁇ for vertical and horizontal positions separated with cotton fibers are arranged in the bundle structure.
- Fig.5 (a) - (d) shows the RGO nanosheets were used to fill the porous nature of the cotton cloth films for making functional conduction structure.
- the RGO nanosheets are homogeneously / uniformly coated onto the cotton cloth and intercalated RGO nanosheets are expected for the insulating cloth becomes electrically conductive. In the textile cotton cloth system, RGO nanosheets form conductive path between adjacent bundles of cotton fibre structure and plays an important role in thermal heat generation.
- Fig.7 The spectrum of GO and RGO nanosheets are shown in Fig.7, which depicts the existence of the D, G and 2D bands.
- D- band 1347.22 cm “1 )
- G- band 1585.42 cm “1 )
- the G line is usually assigned to the first order scattering of the E 2g phonon vibration mode of sp bonded C atoms and the D line is the breathing mode of the K-point phonons of A lg Symmetry.
- the 2D band (2717.17 cm “1 ) originates from second order double resonant Raman Scattering.
- the peak position of 2D band is similar to the monolayer graphene prepared from the mechanical cleavage method.
- the intensity of 2D- band is sensitive to doping of graphene by either holes or electrons.
- G-band is located at (1585.42 cm “1 ), while forreduced graphene oxide (RGO), the G-band moves (1581.66 cm “ l ) which is closer to the value of the pristine graphite and confirms the reduction of the GO during chemical treatment.
- RGO forreduced graphene oxide
- the existence of the D band at (1347.22 cm “1 ) and (1340.28 cm “1 ) corresponding to the GO and RGO also predict the defects are presented in the sample.
- the peak position of 2D (2703.33 cm “1 ) represents graphitic nature in the RGO nanosheets system.
- An active area of the structural device of dimensions 18 mm x 6 mm is integrated on the textile cotton cloth measuring 30 mm x 6 mm x0.175 mm.
- the structural pattern is fabricated from aluminium thick sheet / block of dimensions 30 mm x 17 mm x 28 mm.
- the RGO nanocomposite solution is used to achieve the patterns of the developed micro mold structure on textile cotton cloth substrate by dip coating method.
- the RGO nanosheets coated on cotton cloth based film is kept at 80°C temperature for 60 min.
- the thickness of active area of RGO coated cotton cloth varies depending on the number of dipping times.
- the electrical leads are taken out with thin double enamelled copper wires (70 ⁇ ) using silver paste on the top side at different respective locations of the nanosheets patterned/coated on cotton cloth films.
- the fully fabricated sensing film is annealed at 90° C in 30 min for the purpose of curing of the electrical contacts and making the device robust.
- the fabricated device is finally encapsulated with Parylene coating of thickness measuring 2 ⁇ in order to protect from the environmental conditions and also peel off.
- Parylene coating onto the device it provides complete protection from the moisture, dust, to avoid the films from peel off while handling and scratches onto the device.
- the Parylene coated devices are annealed at 80°C for 1 hr in order to obtain a uniform film by rearrangement of atoms for good stability.
- the schematic view of the complete experimental set up is shown in Fig.8.
- the electrical leads of the RGO nanosheets coated cotton cloth based films for heating elements are connected to a 6 1 ⁇ 2 digitalmultimeter (Gwinstek GDM-8261), power supply (Gwinstek GPD- 23038) and resistance temperature detector (RTD) to digital multimeter.
- DC power is applied to the conductive RGO films deposited on cotton cloth for temperature / heat generation.
- the electro thermal performance investigated under ambient conditions under three different cases are demonstrated here.
- the conductive cotton cloth is subjected to electrical power supply for one minute, five minutes and under vacuum five minutes.
- the surface temperature of the cotton cloth increases over time until a steady temperature is reached.
- the increase in temperature with applied voltage is repeated cycles as shown in Fig 9.
- the surface heating performance of the cotton cloth in one minute duration shows steady temperature of 52°C with supply voltage of 40 V as shown in Fig. 9 (a).
- Fig.9 (b) shows second case for five minutes, a saturation temperature of 56° C is reached with a shift of 4°C from the first case.
- a saturation temperature of 62° C is reached at the same operating power of 40V for five minutes and there is a shift of 6° C as shown in figure 9 (c).
- the RGO nanosheets coated cotton cloth based films consumes less power around 476 mW, 498 mW, 575 mW in one minute, five minutes and five minutes in vacuum at an operating voltage of 40V. Higher temperature generation (due to the no convention losses) can be obtained in vacuum condition. It is observed that heating limit for the device is 120° C, that is, when the cloth starts burning.
- heating element device ambient goes down to the environmental conditions (around 20 °C) to lower side, say for example between, - 15 °C to -35 °C, higher voltage is required to maintain at 20 °C.
- the typical performance of the fabricated cloth heater at different ambient temperatures is shown in Figure 13. It clearly shows that when the ambient temperature is at 0 °C, in order to maintain the body/heater temperature at 25 °C, it requires 30 V as input supply. It consumes around 198 mW of power to generate the required temperature / heat. In the same way, when the heating element ambient temperature is -25 °C, it requires an input supply of 60 V (around 737 mW) to maintain sufficient required warming. By comparing the above conditions of the heating element performance, it is evident that a moderate input voltage supply will be sufficient to maintain the needed comfortable temperature of 20 °C.
- the distribution of heat may be attributed to the thermal and electrical conductivity properties of the reduced graphene oxide, dip coated on a fabric as a uniform film. It is also noted that, the size of the films fabricated using solution based dip coating process is not limited to the small areas of fabric material, but is applicable to large active surface areas as well.
- Table 2 Characteristics of a typical example of a body warmer.
- a heating device (B) can be fabricated appropriately with one or more heating devices typically explained in Table 2 to obtain heating device of higher capacity and larger area.
- the present invention is aimed at providing a heating device which can be specifically used as a disposable thermal body warmer, it is evident that the invention can be used where heating is required by customizing the flexible heating device for example as liquid, food warmer bags, electrotherapy treatment, medical blankets for patients to maintain their body temperature and also jackets for soldiers in the defence applications and the like.
- the aforesaid description is enabled to capture the nature of the invention. It is to be noted however that the aforesaid description and the appended figures illustrate only a typical embodiment of the invention and therefore not to be considered limiting of its scope for the invention may admit other equally effective embodiments.
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Thermotherapy And Cooling Therapy Devices (AREA)
Abstract
The invention relates to a heating device comprising a fabric impregnated or coated with reduced graphene oxide nanosheets films and method of fabrication thereof.
Description
TITLE: REDUCED GRAPHENEOXIDE NANOMATERIAL COATED COTTON FABRIC AS A HEATING DEVICE AND METHOD THEREFORE
Field of invention
The present invention relates to the field of heating devices. In particular the invention relates to reduced graphene oxide nanosheets based heating devices. More specifically, the invention relates to reduced graphene oxide nanosheets based heating device which can be used as disposable thermal body warmers, wherein film of reduced graphene oxide nanosheets are coated on fabrics to fabricate thermal body warmer for heat generating applications and a method of fabrication thereof.
Background of invention
Body warmers are generally used to combat cold weather conditions in chilly areas. They also find use in biomedical fields such as in electrotherapy treatments, medical blankets for patients in order to maintain their body temperatures; also in military jackets worn by soldiers in the defence forces and the like. However, these products are bulky, expensive, with low flexibility and huge power consumptions. There is a constant lookout for devices with effective body warming functionality, compatible size as per requirement, flexible, less energy consumption along with low manufacturing costs. In the recent past, micro and nano systems are known to play a key role in the development of miniaturized electronic devices in various applications such as chemical sensing, health care, wearable electronics, biomedical applications and the like. They also find use in heating elements designed for creating flexible electronics, flexible heaters and nanomaterials for garments. Currently textiles are found to be flexible platforms for the electronic devices in the area of stretchable or bendable
and wearable electronics due to their unique properties such as large surface to volume ratio and low dimensionality. These materials are aimed to overcome the drawbacks of opacity, bulkiness, rigidity, low heating efficiency and the like. US 4722860 describes a flexible, electrically conducting cloth comprising a plurality of intermingled or interwoven fibres of a refractory material and a conducting coating encapsulating a majority of the fibres; US6501056 describes carbon heating elements comprising carbon material wherein the carbon materia! is selected from the group consisting of carbon fiber, carbon fiber cloth, a wood carbon material, a carbon rod and a shaped article of carbon powder and methods of manufacturing the elements; and US 13/355,212 provides information related to the electrically conductive and radio frequency (RF) transparent films that include a graphene layer (or multilayer) and a substrate associated with the graphene layer. The products of said disclosure are not user friendly due to heavy weight and rigidity.
Lin X, Qin.Z, Dou. Z, Liu. N, Chen. Land Zhu in RSC Advances, 2014; 4(45):23869-75. M, titled "Fabricating conductive poly (ethylene terephthalate) nonwoven fabrics using an aqueous dispersion of reduced graphene oxide as a sheet dye stuff". The method is tedious and involve multiple steps and reagents rendering the invention expensive for adoption.
Commercial film heaters made from stripes of Fe-Cr-Al (Kanthal) and CuNi (Cupronickel) based alloy, ITO and Ga doped Zinc Oxide have many disadvantages, as its fabrication technology process is complicated, associated withopacity, heavy weight, rigidity, intolerance to acid or base, fragile under mechanical deformation and lower heating efficiency.
The present invention benefits over the conventional heating systems, where the invention provides for a heating device that is corrosion free, flexible in terms of bendability, that can
be formed into required shapes for minimizing the device size, biocompatible, with minimum energy consumption and low manufacturing cost.
Summary of invention
Accordingly, the present invention relates to a disposable thermal body warmer comprising a fabric integrated with a film of reduced graphene oxide nanosheets, encapsulated with parylene coatingwherein the thickness of film ranging about 200 + 10 μιη. The invention is also in relation to a method of fabrication of film of reduced graphene oxide nanosheets on the fabric to obtain thermal body warmer.
Brief description of figures
The features of the present invention can be understood in detail with the aid of appended figures. It is to be noted however, that the appended figures illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope for the invention.
Figure 1 : provides a schematic view of reduced Graphene oxide nanosheets coated cotton cloth based thermal body warmer.
Figure 2: provides a photograph of the fabricated reduced Graphene oxide coated cotton cloth based thermal body warmer.
Figure 3: illustrates XRD phases of Graphene oxide and reduced Graphene oxide nanosheets coated cotton cloth based films.
Figure 4: shows FE-SEM images: (a) Bare textile cotton cloth with pore sizes of vertical and horizontal dimensions at lower magnification, (b) the same dimensions at higher magnification.
Figure 5: shows FE-SEM images of cross sectional view of reduced Graphene oxide coated cotton cloth films:(a) the thickness of singlemulti -layered reduced Graphene oxide nanosheets, (b) surface view in the reduced Graphene oxide nanosheets coated on the textile cotton cloth, (c) the textile cotton cloth fibres diameter with pores filled with reduced Graphene oxide nanosheets, (d) the thickness of reduced Graphene oxide nanosheets coated on the textile cotton cloth based filmsfor heating element.
Figure 6 shows FE-SEM images of cross sectional view of parylene coated complete heating element device: (a) the thickness of single multi-layered reduced Graphene oxide nanosheets decorated polymer parylene, (b) side view of thickness of reduced Graphene oxide nanosheets coated on the textile cotton cloth after parylene coating.
Figure 7: shows Raman Spectroscopy of (a) Graphene oxide sheets, (b) reduced Graphene oxide nanosheets.
Figure 8: discloses the complete experimental set up for testing of reduced Graphene oxide nanosheets coated on the cotton cloth based films for heating element.
Figure 9: provides for Temperature versus applied Voltage plot, (a) One minute stabilization for five times repeatability, (b) Five minutes stabilization for five times repeatability, (c) Under Vacuum five minutes stabilization for four time repeatability.
Figure 10:shows Resistance profiles versus the applied Voltage, (a) One minute stabilization for five times repeatability, (b) Five minutes stabilization for five times repeatability, (c) Under Vacuum five minutes stabilization for four time repeatability.
Figure 11: shows the average normalized resistance change of reduced Graphene oxide versus temperature generation with the applied voltage, (a) One minute stabilization time, (b) Five minutes stabilization time and (c) Under Vacuum five minutes stabilization time.
Figure 12: provides for Temperature vs time plot for the aqueous reduced Graphene oxide nanosheets coated cotton cloth based films due to different applied voltages under atmosphere condition, (a) Temperature rise due to applied voltages 30V and 40V in heating condition, (b) Temperature drop when applied voltages are switched off (30V and 40V in cooling condition).
Figure 13: illustrates temperature verses Voltage performance of cotton cloth heating element at different ambient temperatures.
Detailed description of invention
The foregoing description of the embodiments of the invention has been presented for the purpose of illustration. It is not intended to be exhaustive or to limit the invention to the precise form disclosed as many modifications and variations are possible in light of this disclosure for a person skilled in the art in view of the figures, description and claims. It may further be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by person skilled in the art.
The present invention is in relation to a heating device (A); comprising a fabric (1) integrated with a film of reduced graphene oxide nanosheets (2), encapsulated in parylene coating (3) ; wherein the thickness of film is ranging from about 190 μιη to about 210 μιη and size of nanosheets is ranging from about 250 nm to about 550 nm; wherein the films are connected
to electrical leads (4) through metal electrodes (5); and a monitor (6) of heat comprising standard thin film based RTD Pt 100 attached to bottom of the fabric (1).
In an embodiment of the present invention the heating device is a disposable thermal body warmer.
In still another embodiment of the present invention, the fabric is selected from a range of natural and synthetic fibres such as cotton, jute flax, polyester, acrylic, nylon and spandex; preferably cotton.
In still another embodiment of the present invention, the electrical leads is of a conductor selected from a group comprising conductors of metallic conductor comprising copper, aluminium, silver and gold; organic conductor, Tetrathiafulvalene (TTF), tetramethyltetrathiafulvalene (TMTSF) and bisethylenedithio-tetrathiafulvalene (BEDT- TTF); preferably copper.
In still another embodiment of the present invention, the metal for the electrode is selected from a group comprising silver, gold and platinum; preferably silver.
In still another embodiment of the present invention, the device provides heat to raise the temperature from about -35°C to about 20°C by input voltage of about 60V.
The present invention is also in relation to a method of fabrication heating device (A) of present invention, said method comprising acts of i) preparing solution of reduced graphene oxide nanosheets, comprising acts of a) oxidising graphite powder using potassium permanganate, hydrogen peroxide and deionized water in presence of sulphuric acid to obtain graphite oxide;
purifying the graphite oxide using hydrochloric acid and deionized water; c) exfoliating the graphite oxide to obtain graphene oxide sheets;
d) grinding the graphene oxide sheets to a powder , diluting it with de -ionized water and ultra- sonicating the diluted mixture to obtain mixture containing nano sheets; and
e) reducing the mixture containing nanosheets with hydrazine hydrate solution to obtain reduced graphene oxide nanosheets;
ii) preparing and coating the reduced graphene oxide nanosheets solution on a patterned substrate integrated on fabric by dip coating method;
iii) annealing the coating of reduced graphene oxide solution at a temperature ranging from about 75°C to about 85°C, preferably 80°C to obtain a film wherein thickness of film is about 190μιη to about 210 μιη; preferably 200μιη on the fabric;
iv) encapsulating the fabric coated with reduced graphene oxide in Parylene of about thickness of ~2 μιη and annealing at about 80°C for about 1 hr.
v) providing electrical leads through an electrode to obtain the heating device.
In still another embodiment of the present invention, the reduced graphene oxide solution is prepared in an organic solvent selected from a group comprising N- Methyl-2-pyrrolidone (NMP), Dimethyl formamide (DMF), Tetrahydrofuran (THF), acetone and water , preferably N-Methyl-2-pyrrolidone.
The present invention is also in relation to heating device (B) comprising one or more heating device (A) of present invention.
The present invention relates to reduced graphene oxide nanosheets coated as film on a fabric; to be used as disposable thermal body warmers for heating applications . The film is encapsulated in Parylene (thickness of ~ 2 μιη) coating as it provides complete protection
from moisture, dust, protects films from peel off while handling the device. Parylene coating gives complete conformal, uniform thickness as well as makes the film pinhole free.
The reduced grapheme oxide is obtained by modified hummer's method as described below, typically the thickness of reduced graphene oxide is ranging about 300 + 50 nm to about 500 + 50 nm ( the dimensions of the reduced grapheme oxide, nano particle size/dimensions before dispersion in NMP and coating).
The present invention, heating device (A); comprising a fabric (1) integrated with a film of reduced graphene oxide nanosheets (2), encapsulated in parylene coating (3); wherein the thickness of film ranging about 200 + 10 μιη and the size of nanosheets ranging from about 300 + 50 nm to about 500 + 50 nm were formed. Nanosheets based films connected to electrical leads (4) through metal electrodes (5) is schematically represented in figure 1 and 2. The temperature generation has been monitored by using standard thin film based RTD Pt 100 mounted or attached on the bottom of the cotton cloth (6).
The fabric is selected from a range of natural and synthetic fibres such as cotton, jute flax, polyester, acrylic, nylon and spandex; preferably cotton (Figure 4). The method of preparation of the film typically involve steps of synthesis of graphene oxide sheets; reduction of graphene oxide nanosheets using hydrazine hydrate solution; preparing the reduced graphene oxide nanosheets solution by dispersing reduced graphene oxide nanosheets and N-Methyl-2-Pyrrolidone solution. Dip coating a patterned substrate integrated in a fabric using the graphene oxide nanosheets solution for use as body warmer or any other heating applications.
Figure 1(a) & 1(b) shows the schematic representation and photograph image of fabricated reduced graphene oxide nanosheets (RGO) based film coated on a fabric of body warmers.
After the fabrication of the RGO nanosheets based cotton coated fabric, its response to various parameters such as temperature, resistance change with respect to the applied voltage variations are studied and the typical responses of saturation temperature obtained are shown in figures 9 to 12.
Experimental
A] The process of synthesis of the film of reduced graphene oxide nanosheets asfollows- i) Synthesis of Graphene Oxide (GO):
2g of the graphite powder is oxidized in a strong acidic environment using 54ml of H2SO4 through constant magnetic stirring, at a temperature maintained about 25 ± 10°C. About 6g of KMn04 is slowly added to the solution over a period of about 20 minutes. The concentrated solution is then rigorously stirred for 40 min. 100 ml of deionized water is added to the solution in a dropwise manner for a period of about 10-15 min. As fumes evolve from the solution, stirring is continued for another 90 minutes. 200ml of deionized water is then added to the solution. The oxidation process is completed upon adding 30ml of hydrogen peroxide (H2O2) to the solution. After few minutes, it is observed that the colour of the solution mixture changes from black to reddish brown indicating the end of the reaction process. The mixture is washed two to three times with Hydrochloric acid (HC1) solution and deionized water, in order to remove metal ions and un- oxidized graphite from the reaction mixture. The mixture is filtered through Whatman filter paper by using vacuum filtration method to separate the unreacted components from the mixture and the filtration cake residue is collected at the end of the process. Finally the thus obtained Graphene oxide (GO) powder is annealed at 90°C for 8 hours.
ii) Synthesis of RGO nanosheets:
The Graphene oxide powder is diluted with de-ionized water taken in a weight ratio of 1:1. 0.3g (1 mgmr1) of Graphene oxide is dissolved in 300 ml of deionized water. The diluted suspension is ultra- sonicated (the operating frequency is about 33 K Hz + 3 %) for 90 min. The flakes of Graphene oxide are split into the individual nano sheets. The entire mixture is reduced using reducing agent, that is, O. lg (3ml) Hydrazine hydrate solution is added to the mixture under constant stirring at 95°C for 4 hours. The mixture is filtered through Whatman filter paper by using vacuum filtration method to separate the unreacted components from the mixture and the filtration cake residue is collected at the end of the process. Finally reduced graphene oxide nanosheets are annealed at 80°C for 2 hours.
Hi) Preparation of RGO nanosheets solution:
The RGO nanosheets solution is prepared by dispersing RGO nanosheets and N-Methyl-2- Pyrrolidone (NMP) solution. The mixed solution is ultra-sonicatedin order to achieve a homogenous exfoliationof the RGO nanosheets. Subsequently, this composition is used for the fabrication of resistive heating elements for wearable thermal body warmers.
B) XRD studies of GO and RGO nanosheets (Figure 3)
X-ray diffraction (XRD) patterns are recorded on the synthesized GO nanosheets and RGOnanosheetsfor their structural analysis. The existence of XRD peak at 2Θ =25.61°, corresponding to the (002) plane of crystalline nature of GO nanosheets, which arises from stack of graphene layers before exfoliation of graphite is observed. The same peak is shifted to 11.2°, corresponding to the (001) plane after oxidation treatment, indicating that the interlayer spacing in the Graphite Oxide increases. The interlayer distance is increased in the GO nanosheets due to the presence of the epoxide, carboxyl groups and water molecules between the graphene oxides layers. The diffraction peak at 42.82° corresponding to the (100)
plane, represents the reformation of graphite microcrystals nature in the GO system. In the RGO, after chemical reduction, nearly all peaks disappears indicating exfoliation of multilayers during the chemical reduction process of GO. However, towards the end of the reaction a wide diffraction peak appears at 23.5° which corresponds to an interlayer spacing of 0.38 nm as shown in Fig (c). The RGO nanosheets self-assemble due to the reduction reaction. The shoulder peak appearing at 42.82° which is fingerprint peak for graphite due to (100) diffraction indicates that the reformation of graphite microcrystals on reduced graphene oxide plane is because of chemical reduction of the Graphene Oxide.
C) FE-SEM Surface Morphology studies of bare Cotton fabric, RGO coated cotton cloth and Parylene coated RGO nanosheets-cloth system (Figure 4, Figure 5 and Figure 6)
The advanced characterized tools are used for surface morphology analysis of textile cotton cloth pieces, as-synthesized GO sheets and RGO nanosheets coated on the cotton cloth based films by field emission- scanning electron microscopy (FE-SEM (Carl Zeiss), ULTRA 55). Fig.4 (a) & (b) shows the pores nature of bare textile cotton cloth having dimensions around 159 μηι &115 μιη for vertical and horizontal positions separated with cotton fibers are arranged in the bundle structure. Fig.5 (a) - (d) shows the RGO nanosheets were used to fill the porous nature of the cotton cloth films for making functional conduction structure. The single RGO nanosheets having the thickness 300 nm to 500 nm as can be observed on the RGO coated cotton cloth as shown in fig.5 (a) - (d). From the cross sectional images , thickness of each cotton fiber in the bundle structure is around 13 to 15 μιη and the complete RGO coated on the cotton cloth based films thickness is around 202 μιη. Also, the prepared RGO nanosheets surface morphology confirms the loosely bound sheet like structure. The RGO nanosheets are homogeneously / uniformly coated onto the cotton cloth and intercalated RGO nanosheets are expected for the insulating cloth becomes electrically conductive. In the
textile cotton cloth system, RGO nanosheets form conductive path between adjacent bundles of cotton fibre structure and plays an important role in thermal heat generation.
In order to avoid the RGO nanosheets peel off from the cotton cloth, the electrical leads taken cotton cloth was completely packaged with parylene coating thickness of around 2 μιη. From fig. 6 (a) & (b) shows the cross sectional view of the parylene coated RGO nanosheets are having dimensions of around 2.6 to 2.7 μιη .The completely packaged RGO coated cotton cloth based films have thickness around 204 to 206 μιη. Therefore, the fully packaged RGO coated cotton cloth based films are used as heating elements. D] Spectroscopic studies to depict the structural characteristics and properties of graphene based materials (Figure 7)
The spectrum of GO and RGO nanosheets are shown in Fig.7, which depicts the existence of the D, G and 2D bands. In the GO, the demonstration of two sharp peaks corresponding to D- band (1347.22 cm"1) and G- band (1585.42 cm"1), whichindicate the presence of structural defects in GO as shown in Fig.7.The G line is usually assigned to the first order scattering of the E2g phonon vibration mode of sp bonded C atoms and the D line is the breathing mode of the K-point phonons of Alg Symmetry. The 2D band (2717.17 cm"1) originates from second order double resonant Raman Scattering. The peak position of 2D band is similar to the monolayer graphene prepared from the mechanical cleavage method. The intensity of 2D- band is sensitive to doping of graphene by either holes or electrons. In GO, G-band is located at (1585.42 cm"1), while forreduced graphene oxide (RGO), the G-band moves (1581.66 cm" l) which is closer to the value of the pristine graphite and confirms the reduction of the GO during chemical treatment. However, the existence of the D band at (1347.22 cm"1) and (1340.28 cm"1) corresponding to the GO and RGO also predict the defects are presented in
the sample. The peak position of 2D (2703.33 cm"1) represents graphitic nature in the RGO nanosheets system.
E] Method of fabrication of the film of reduced graphene oxide nanosheets on the fabric to obtain disposable body warmer (Figure 5 and Figure 6)
An active area of the structural device of dimensions 18 mm x 6 mm, is integrated on the textile cotton cloth measuring 30 mm x 6 mm x0.175 mm. The structural pattern is fabricated from aluminium thick sheet / block of dimensions 30 mm x 17 mm x 28 mm. The RGO nanocomposite solution is used to achieve the patterns of the developed micro mold structure on textile cotton cloth substrate by dip coating method. The RGO nanosheets coated on cotton cloth based film is kept at 80°C temperature for 60 min. The thickness of active area of RGO coated cotton cloth varies depending on the number of dipping times. The electrical leads are taken out with thin double enamelled copper wires (70 μιη) using silver paste on the top side at different respective locations of the nanosheets patterned/coated on cotton cloth films. Also, the fully fabricated sensing film is annealed at 90° C in 30 min for the purpose of curing of the electrical contacts and making the device robust.
Furthermore, the fabricated device is finally encapsulated with Parylene coating of thickness measuring 2 μιη in order to protect from the environmental conditions and also peel off. The purpose of Parylene coating onto the device; it provides complete protection from the moisture, dust, to avoid the films from peel off while handling and scratches onto the device. Moreover, the Parylene coated devices are annealed at 80°C for 1 hr in order to obtain a uniform film by rearrangement of atoms for good stability.
F] The heating performance studies of RGO nanosheets coated on cotton cloth based films or body warmer applications is explained below:
The schematic view of the complete experimental set up is shown in Fig.8. The electrical leads of the RGO nanosheets coated cotton cloth based films for heating elements are connected to a 6 ½ digitalmultimeter (Gwinstek GDM-8261), power supply (Gwinstek GPD- 23038) and resistance temperature detector (RTD) to digital multimeter. DC power is applied to the conductive RGO films deposited on cotton cloth for temperature / heat generation. The electro thermal performance investigated under ambient conditions under three different cases are demonstrated here. The conductive cotton cloth is subjected to electrical power supply for one minute, five minutes and under vacuum five minutes. The surface temperature of the cotton cloth increases over time until a steady temperature is reached. The increase in temperature with applied voltage is repeated cycles as shown in Fig 9. In the first case, the surface heating performance of the cotton cloth in one minute duration shows steady temperature of 52°C with supply voltage of 40 V as shown in Fig. 9 (a). Fig.9 (b) shows second case for five minutes, a saturation temperature of 56° C is reached with a shift of 4°C from the first case. In the final case, in vacuum, a saturation temperature of 62° C is reached at the same operating power of 40V for five minutes and there is a shift of 6° C as shown in figure 9 (c). The RGO nanosheets coated cotton cloth based films consumes less power around 476 mW, 498 mW, 575 mW in one minute, five minutes and five minutes in vacuum at an operating voltage of 40V. Higher temperature generation (due to the no convention losses) can be obtained in vacuum condition. It is observed that heating limit for the device is 120° C, that is, when the cloth starts burning.
As shown in figure 10, similar results are seen in the resistance versus applied voltage. The surface temperature of the film, when charged with the electric power, causes a monotonic decrease in the film resistance with respect to applied voltage. In the similar way, we can see
the response of the film resistance in three cases such as for one minute, five minute with five times repeatability and under vacuum conditions with a four times repeatability profiles as shown in figure 10 (a)- (c).
The relative resistance change remains same with respect to the heat generation of the surface in ambient for one minute, five minutes and under vacuum conditions as shown in figure 11 (a)- (c).
It is observed that, sufficient heat is generated to warm up the body under relatively low applied voltages. The electro thermal performance for RGO coated cotton cloth based films with a valid heating area of 18 mm x 6 mm under ambient conditions are as follows. When a voltage is applied, temperature rises exponentially over time around at maximum 3 minutes reaching a steady value. Similarly, when voltage supply is turned off, temperature drops exponentially around at maximum 3 minutes to reach a steady value. Change in temperature is recorded using a digital oscilloscope in terms of voltage reading. The temperature rise and drop are plotted with respect to time for two different voltages 30V and 40V as shown in Fig.l2 (a) and Fig. l2 (b).
When heating element device ambient goes down to the environmental conditions (around 20 °C) to lower side, say for example between, - 15 °C to -35 °C, higher voltage is required to maintain at 20 °C. The typical performance of the fabricated cloth heater at different ambient temperatures is shown in Figure 13. It clearly shows that when the ambient temperature is at 0 °C, in order to maintain the body/heater temperature at 25 °C, it requires 30 V as input supply. It consumes around 198 mW of power to generate the required temperature / heat. In the same way, when the heating element ambient temperature is -25 °C, it requires an input supply of 60 V (around 737 mW) to maintain sufficient required warming. By comparing the
above conditions of the heating element performance, it is evident that a moderate input voltage supply will be sufficient to maintain the needed comfortable temperature of 20 °C.
The detailed performance data of RGO on cotton cloth at different ambient temperatures are shown in the following table. Power consumption at different ambient temperatures to maintain the heating element temperature at 20 °C is shown in the last column of the table 1.
Table 1: Power consumption at different temperatures
It has been observed that, the distribution of heat may be attributed to the thermal and electrical conductivity properties of the reduced graphene oxide, dip coated on a fabric as a uniform film. It is also noted that, the size of the films fabricated using solution based dip coating process is not limited to the small areas of fabric material, but is applicable to large active surface areas as well.
Due to electro thermal properties, RGO coated cotton cloth based films have profound applications. The tests conducted demonstrate that reduced graphene oxide nanosheets based films coated on fabric function as electrically conductive layers which exhibit properties of adhesion, robustness, flexibility and durability for next generation's heating elements using textiles and electronic devices.
The table 2 below provides the characteristics of a typical example of a disposable body warmer of the present invention.
Table 2: Characteristics of a typical example of a body warmer.
A heating device (B) can be fabricated appropriately with one or more heating devices typically explained in Table 2 to obtain heating device of higher capacity and larger area. Although the present invention is aimed at providing a heating device which can be specifically used as a disposable thermal body warmer, it is evident that the invention can be used where heating is required by customizing the flexible heating device for example as liquid, food warmer bags, electrotherapy treatment, medical blankets for patients to maintain their body temperature and also jackets for soldiers in the defence applications and the like. The aforesaid description is enabled to capture the nature of the invention. It is to be noted however that the aforesaid description and the appended figures illustrate only a typical
embodiment of the invention and therefore not to be considered limiting of its scope for the invention may admit other equally effective embodiments.
It is an object of the appended claims to cover all such variations and modifications as can come within the true spirit and scope of the invention.
Claims
1. A heating device (A); comprising a fabric (1) integrated with a film of reduced graphene oxide nanosheets (2), encapsulated in parylene coating (3) ; wherein the thickness of film is ranging from about 190 μπι to about 210 μπι and size of nanosheets is ranging from about 250 nm to about 550 nm; wherein the films are connected to electrical leads (4) through metal electrodes (5); and a monitor(6) of heat comprising standard thin film based RTD Pt 100 attached to bottom of the fabric (1).
2. The heating device as claimed in claim 1, wherein the heating device is a disposable thermal body warmer.
3. The heating device as claimed in claim 1, wherein the fabric is selected from a range of natural and synthetic fibres such as cotton, jute flax, polyester, acrylic, nylon and spandex; preferably cotton.
4. The heating device as claimed in claim 1, wherein the electrical leads is of a conductor selected from a group comprising conductors of metallic conductor comprising copper, aluminium, silver and gold; organic conductor, Tetrathiafulvalene (TTF), tetramethyltetrathiafulvalene (TMTSF) and bisethylenedithio-tetrathiafulvalene (BEDT- TTF); preferably copper.
5. The heating device as claimed in claim 1, wherein the metal for the electrode is selected from a group comprising silver, gold and platinum; preferably silver.
6. The heating device as claimed in claim 1, wherein the device provides heat to raise the temperature from about -35°C to about 20°C by input voltage of about 60V.
7. A method of fabrication heating device (A) of claim 1, said method comprising acts of i) preparing solution of reduced graphene oxide nanosheets, comprising acts of
a) oxidising graphite powder using potassium permanganate, hydrogen peroxide and deionized water in presence of sulphuric acid to obtain graphite oxide;
b) purifying the graphite oxide using hydrochloric acid and deionized water;
c) exfoliating the graphite oxide to obtain graphene oxide sheets;
d) grinding the graphene oxide sheets to a powder , diluting it with de -ionized water and ultra-sonicating the diluted mixture to obtain mixture containing nanosheets ; and e) reducing the mixture containing nanosheets with hydrazine hydrate solution to obtain reduced graphene oxide nanosheets;
ii) preparing and coating the reduced graphene oxide nanosheets solution on a patterned substrate integrated on fabric by dip coating method;
iii) annealing the coating of reduced graphene oxide solution at a temperature ranging from about 75 °C to about 85 °C, preferably 80°C to obtain a film wherein thickness of film is about 190μπι to about 210 μπι; preferably 200μπι on the fabric;
iv) encapsulating the fabric coated with reduced graphene oxide in Parylene of about thickness of ~2 μπι and annealing at about 80°C for about 1 hr.
v) providing electrical leads through an electrode to obtain the heating device.
The method as claimed in claim 7 wherein the reduced graphene oxide solution is prepared in an organic solvent selected from a group comprising N- Methyl-2-pyrrolidone (NMP), Dimethyl formamide (DMF), Tetrahydrofuran (THF), acetone and water , preferably N-Methyl-2-pyrrolidone.
A heating device (B) comprising one or more heating device (A) of claim 1.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IN201741004725 | 2017-02-09 | ||
IN201741004725 | 2017-02-09 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2018146592A1 true WO2018146592A1 (en) | 2018-08-16 |
Family
ID=63107284
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/IB2018/050721 WO2018146592A1 (en) | 2017-02-09 | 2018-02-06 | Reduced grapheneoxide nanomaterial coated cotton fabric as a heating device and method therefore |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2018146592A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109327925A (en) * | 2018-09-19 | 2019-02-12 | 无锡德胜红外科技有限公司 | A kind of far-infrared electric health preserving blanket and preparation method thereof |
CN111455661A (en) * | 2020-04-24 | 2020-07-28 | 安徽工程大学 | Preparation method of graphene-coated cotton fabric, product and application of product |
WO2021123078A1 (en) * | 2019-12-20 | 2021-06-24 | National University Of Ireland, Galway | A graphene oxide material and method for the production thereof |
CN114252399A (en) * | 2020-09-25 | 2022-03-29 | 中国人民解放军国防科技大学 | Ultra-high temperature temperature field platform and method of using the same |
US11760056B2 (en) | 2018-12-05 | 2023-09-19 | Battelle Memorial Institute | Flexible foam resistive heaters and methods of making flexible resistive heaters |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105088749A (en) * | 2015-08-28 | 2015-11-25 | 东华大学 | Graphene/cotton cloth flexible conducting fabric and preparing method of graphene/cotton cloth flexible conducting fabric |
US20160299543A1 (en) * | 2013-02-27 | 2016-10-13 | Vorbeck Materials Corp. | Thermal management device systems |
-
2018
- 2018-02-06 WO PCT/IB2018/050721 patent/WO2018146592A1/en active Application Filing
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160299543A1 (en) * | 2013-02-27 | 2016-10-13 | Vorbeck Materials Corp. | Thermal management device systems |
CN105088749A (en) * | 2015-08-28 | 2015-11-25 | 东华大学 | Graphene/cotton cloth flexible conducting fabric and preparing method of graphene/cotton cloth flexible conducting fabric |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109327925A (en) * | 2018-09-19 | 2019-02-12 | 无锡德胜红外科技有限公司 | A kind of far-infrared electric health preserving blanket and preparation method thereof |
US11760056B2 (en) | 2018-12-05 | 2023-09-19 | Battelle Memorial Institute | Flexible foam resistive heaters and methods of making flexible resistive heaters |
WO2021123078A1 (en) * | 2019-12-20 | 2021-06-24 | National University Of Ireland, Galway | A graphene oxide material and method for the production thereof |
CN111455661A (en) * | 2020-04-24 | 2020-07-28 | 安徽工程大学 | Preparation method of graphene-coated cotton fabric, product and application of product |
CN114252399A (en) * | 2020-09-25 | 2022-03-29 | 中国人民解放军国防科技大学 | Ultra-high temperature temperature field platform and method of using the same |
CN114252399B (en) * | 2020-09-25 | 2023-10-20 | 中国人民解放军国防科技大学 | Ultra-high Wen Wenchang platform and application method thereof |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2018146592A1 (en) | Reduced grapheneoxide nanomaterial coated cotton fabric as a heating device and method therefore | |
Xu et al. | Washable and flexible screen printed graphene electrode on textiles for wearable healthcare monitoring | |
Nguyen et al. | Ti3C2Tx MXene/carbon nanotubes/waterborne polyurethane based composite ink for electromagnetic interference shielding and sheet heater applications | |
Ren et al. | Environmentally-friendly conductive cotton fabric as flexible strain sensor based on hot press reduced graphene oxide | |
Cai et al. | Multifunctional MXene/holey graphene films for electromagnetic interference shielding, Joule heating, and photothermal conversion | |
Stempien et al. | Inkjet-printing deposition of silver electro-conductive layers on textile substrates at low sintering temperature by using an aqueous silver ions-containing ink for textronic applications | |
Huang et al. | Temperature-dependent electrical property transition of graphene oxide paper | |
Jang et al. | Fibers of reduced graphene oxide nanoribbons | |
Islam et al. | Fabrication of low cost and scalable carbon-based conductive ink for E-textile applications | |
EP4102933B1 (en) | Flexible heating device and methods of manufacture and use of same | |
Guo et al. | Multi-functional and water-resistant conductive silver nanoparticle-decorated cotton textiles with excellent joule heating performances and human motion monitoring | |
Tian et al. | Conductive reduced graphene oxide/MnO2 carbonized cotton fabrics with enhanced electro-chemical,-heating, and-mechanical properties | |
CN108018021B (en) | Biologically-contactable sensing material, biologically-contactable unit for sensing physiological parameters, and methods of making the same | |
KR102116546B1 (en) | Electrical Heating Gloves using Textile with Graphene/PVDF-HFP Composite by Various Circuit Patterning Conditions | |
Pope et al. | Thermoelectric polymer composite yarns and an energy harvesting wearable textile | |
Etana et al. | Functionalization of textile cotton fabric with reduced graphene oxide/MnO2/polyaniline based electrode for supercapacitor | |
Yang et al. | CNT/cotton composite yarn for electro-thermochromic textiles | |
Lim et al. | Flexible temperature sensors based on two-dimensional materials for wearable devices | |
US20190120701A1 (en) | Reduced graphene oxide-silver nanocomposite films for temperature sensor application | |
Kim et al. | A thermoelectric generator comprising selenium-doped bismuth telluride on flexible carbon cloth with n-type thermoelectric properties | |
Parmeggiani et al. | Laser-induced graphenization of textile yarn for wearable electronics application | |
Ran et al. | Carbon nanotube/polyurethane core–sheath nanocomposite fibers for wearable strain sensors and electro-thermochromic textiles | |
Wang et al. | Graphene/SiC-coated textiles with excellent electromagnetic interference shielding, Joule heating, high-temperature resistance, and pressure-sensing performances. | |
Chen et al. | Two-step thermal treatment of electrochemical graphene oxide films for high-performance electrical heating and electromagnetic interference shielding | |
Souri et al. | Wool fabrics decorated with carbon-based conductive ink for low-voltage heaters |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
DPE2 | Request for preliminary examination filed before expiration of 19th month from priority date (pct application filed from 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 18751729 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: 18751729 Country of ref document: EP Kind code of ref document: A1 |