{ "spore": "profile", "id": "graphene-oxide", "spore_version": "0.2", "family": "carbon-materials", "name": "Graphene oxide and reduced graphene oxide", "abbreviation": "GO, rGO", "role": "Oxidised graphene sheet (GO) and its reduced form (rGO), used as membranes, composites and coatings", "category": "carbon", "type": "Graphene", "summary": "Graphene oxide (GO) is a graphene sheet carrying oxygen groups (epoxy, hydroxyl, carbonyl and carboxyl), made by oxidising graphite. It sits in the same category and type as graphene, but it is not graphene: the oxygen groups make GO an electrical insulator, lower its heat conduction and let it disperse in water. Reduced graphene oxide (rGO) has had some of those groups removed and conducts electricity far better, though still much less than graphene. The values come from a 2019 review, a 2026 review, a 2012 membrane paper, a USGS report, a supplier safety data sheet, HSE guidance and an encyclopedia entry, all read in this run.\n", "best_for": "Water-permeable membranes, polymer composites and films where an insulating or water-dispersible carbon sheet is wanted", "weakest_at": "Electrical and thermal performance: GO is an insulator, and reduced GO depends on the reduction route, so no single value describes it", "identity": { "formula": "Carbon sheet with variable epoxy, hydroxyl, carbonyl and carboxyl groups; no fixed formula", "cas": "", "crystal_system": "Two-dimensional sheet, usually stacked; no fixed crystal system", "space_group": "", "designations": [], "source": "go-synthesis", "where": "Introduction, passage on GO structure with oxygen groups in variable ratios" }, "tags": { "environments": [], "stresses": [], "applications": [ "structures", "thermal-control", "electronics-and-chips", "habitats-and-suits" ] }, "properties": [ { "benchmark": "elastic_modulus", "label": "Young's modulus, bulk GO paper", "value": 6, "value_high": 42, "bound": "range", "unit": "GPa", "scope": "material", "conditions": { "basis": "GO paper (stacked sheets); range printed in the review for different oxidation degrees and thicknesses", "test": "not stated in the review" }, "method": "Range quoted in an open-access review, which cites ref 13 of that review", "status": "ground", "source": "huang2019", "where": "Introduction, paragraph on mechanical properties of GO", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, bulk GO paper (the review calls it intrinsic strength)", "value": 76, "value_high": 293, "bound": "range", "unit": "MPa", "scope": "material", "conditions": { "basis": "GO paper (stacked sheets); range printed in the review" }, "method": "Range quoted in the review, in the same paragraph as the modulus", "status": "ground", "source": "huang2019", "where": "Introduction, paragraph on mechanical properties of GO", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "elastic_modulus", "label": "Young's modulus, GO monolayer (review value)", "value": 250, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "basis": "GO monolayer; printed as 250 ± 150 GPa", "test": "not stated in the review" }, "method": "Value quoted in the review, citing ref 11 of that review", "status": "ground", "note": "The printed spread is ± 150 GPa, so this single value is a wide estimate, not a measured range.", "source": "huang2019", "where": "Introduction, paragraph on mechanical properties of GO", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "intrinsic_strength", "label": "Intrinsic strength, GO monolayer (review value)", "value": 30, "value_high": 50, "bound": "range", "unit": "GPa", "scope": "material", "conditions": { "basis": "GO monolayer; range printed in the review, paired with the monolayer modulus above" }, "method": "Range quoted in the review, citing ref 11 of that review", "status": "ground", "note": "Snake-case name, not in the property canon; see gaps.", "source": "huang2019", "where": "Introduction, paragraph on mechanical properties of GO", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "elastic_modulus", "label": "Young's modulus, GO modified with polyvinyl alcohol", "value": 8, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "basis": "GO modified with polyvinyl alcohol (ref 133 of the review); the unmodified GO in the same row is 5 GPa", "form": "modified GO film or paper; form not stated in the row" }, "method": "Value printed in Table 1 of the review", "status": "ground", "source": "huang2019", "where": "Table 1 (Young's modulus and tensile strength of GO modified by ions and molecules), row polyvinyl alcohol, ref 133", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, GO modified with polyvinyl alcohol", "value": 125, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "basis": "GO modified with polyvinyl alcohol (ref 133 of the review); the unmodified GO in the same row is 25 MPa" }, "method": "Value printed in Table 1 of the review", "status": "ground", "source": "huang2019", "where": "Table 1 (Young's modulus and tensile strength of GO modified by ions and molecules), row polyvinyl alcohol, ref 133", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "elastic_modulus", "label": "Out-of-plane Young's modulus, conventional GO at 25 percent relative humidity", "value": 35, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "basis": "conventional porous GO at relative humidity 25 percent, out-of-plane direction" }, "method": "Experimental value quoted in the review and matched by DFT with intercalated water", "status": "ground", "note": "Printed as 35 ± 10 GPa at ambient humidity. The modulus changes with humidity, so it is not a fixed value.", "source": "huang2019", "where": "Section on out-of-plane elasticity, text on conventional GO at RH 25 percent (Fig. 13)", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "electrical_conductivity", "label": "Electrical conductivity, GO (lowest value cited)", "value": 0.0486, "bound": "exact", "unit": "S/m", "scope": "material", "conditions": { "basis": "GO; the review gives this as the lowest GO conductivity it cites", "test": "sample form and method not stated" }, "method": "Value quoted in an open-access 2026 review", "status": "ground", "source": "monir2026", "where": "Section 2.1 (electrical properties of GO and rGO)", "source_detail": { "title": "Towards greener reduced graphene oxide: a critical review of environmentally driven reduction strategies", "id": "RSC Advances 16(3), 2044 to 2061; PMC12776586", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12776586/", "year": 2026, "kind": "paper", "license": "CC BY 3.0 (as printed on the page)" } }, { "benchmark": "electrical_conductivity", "label": "Electrical conductivity, rGO monolayer after chemical reduction", "value": 0.052, "bound": "exact", "unit": "S/m", "scope": "material", "conditions": { "basis": "chemically reduced rGO monolayer on a silicon substrate, room temperature (298 K)" }, "method": "Value quoted in the review, citing Gomez-Navarro et al. (ref 189 of the review)", "status": "ground", "note": "The review says this is still about three orders of magnitude below pristine graphene.", "source": "huang2019", "where": "Section on electronic transport of GO and RGO (Fig. 23a)", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "electrical_conductivity", "label": "Electrical conductivity, rGO reduced by Shewanella", "value": 55.32, "bound": "exact", "unit": "S/m", "scope": "material", "conditions": { "basis": "rGO made by microbial reduction with Shewanella oneidensis" }, "method": "Value quoted in an open-access 2026 review", "status": "ground", "source": "monir2026", "where": "Section 2.1 (electrical properties of rGO)", "source_detail": { "title": "Towards greener reduced graphene oxide: a critical review of environmentally driven reduction strategies", "id": "RSC Advances 16(3), 2044 to 2061; PMC12776586", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12776586/", "year": 2026, "kind": "paper", "license": "CC BY 3.0 (as printed on the page)" } }, { "benchmark": "electrical_conductivity", "label": "Electrical conductivity, rGO reduced by hydrazine (comparison case)", "value": 216.56, "bound": "exact", "unit": "S/m", "scope": "material", "conditions": { "basis": "rGO made by hydrazine reduction, quoted as the comparison case in the review" }, "method": "Value quoted in an open-access 2026 review", "status": "ground", "source": "monir2026", "where": "Section 2.1 (electrical properties of rGO), hydrazine comparison", "source_detail": { "title": "Towards greener reduced graphene oxide: a critical review of environmentally driven reduction strategies", "id": "RSC Advances 16(3), 2044 to 2061; PMC12776586", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12776586/", "year": 2026, "kind": "paper", "license": "CC BY 3.0 (as printed on the page)" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity, GO and rGO papers or thin films (upper bound)", "value": 10, "bound": "upper", "unit": "W/(m·K)", "scope": "material", "conditions": { "basis": "GO or rGO paper or thin film; test temperature not stated in the review" }, "method": "Statement in the review, citing two experimental papers (refs 316 and 317 of the review)", "status": "ground", "note": "The review attributes the low value to phonon scattering at the junctions between GO nanoplatelets.", "source": "huang2019", "where": "Thermal properties section, opening paragraph on GO and RGO papers", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity, epoxy-functionalised GO (simulation)", "value": 35, "bound": "exact", "unit": "W/(m·K)", "scope": "material", "conditions": { "basis": "GO with epoxy groups at O:C ratio 0.1, sample length 300 nm" }, "method": "Non-equilibrium molecular dynamics result quoted in the review; a simulation, not a measurement", "status": "calculated", "source": "huang2019", "where": "Thermal properties section, NEMD results at O:C 0.1 and L = 300 nm", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity, hydroxyl-functionalised GO (simulation)", "value": 85, "bound": "exact", "unit": "W/(m·K)", "scope": "material", "conditions": { "basis": "GO with hydroxyl groups at O:C ratio 0.1, sample length 300 nm" }, "method": "Non-equilibrium molecular dynamics result quoted in the review; a simulation, not a measurement", "status": "calculated", "source": "huang2019", "where": "Thermal properties section, NEMD results at O:C 0.1 and L = 300 nm", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity, ether-functionalised GO (simulation)", "value": 29, "bound": "exact", "unit": "W/(m·K)", "scope": "material", "conditions": { "basis": "GO with ether groups at O:C ratio 0.1, sample length 300 nm" }, "method": "Non-equilibrium molecular dynamics result quoted in the review; a simulation, not a measurement", "status": "calculated", "source": "huang2019", "where": "Thermal properties section, NEMD results at O:C 0.1 and L = 300 nm", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "interlayer_distance", "label": "Interlayer distance of a GO membrane", "value": 10, "bound": "exact", "unit": "Å", "scope": "material", "conditions": { "basis": "GO membrane as printed (about 10 Å); hydration state not stated" }, "method": "X-ray analysis, as stated in the paper", "status": "ground", "note": "Snake-case name, not in the property canon; see gaps. Printed as approximately 10 Å.", "source": "nair2012", "where": "Results, paragraph on annealed GO membranes (Fig. 2a)", "source_detail": { "title": "Unimpeded permeation of water through helium-leak-tight graphene-based membranes", "id": "Science 335, 442 to 444 (2012); arXiv:1112.3488; Nair, Wu, Jayaram, Grigorieva and Geim", "url": "https://arxiv.org/pdf/1112.3488", "year": 2012, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "interlayer_distance", "label": "Interlayer distance of GO after annealing at 300 C in hydrogen and argon", "value": 4, "bound": "exact", "unit": "Å", "scope": "material", "conditions": { "basis": "GO annealed at 300 C in a hydrogen and argon atmosphere; printed as about 4 Å for reduced GO" }, "method": "X-ray analysis, as stated in the paper", "status": "ground", "note": "The same annealing made the membranes about 100 times less permeable to water.", "source": "nair2012", "where": "Results, paragraph on annealed GO membranes (Fig. 2a)", "source_detail": { "title": "Unimpeded permeation of water through helium-leak-tight graphene-based membranes", "id": "Science 335, 442 to 444 (2012); arXiv:1112.3488; Nair, Wu, Jayaram, Grigorieva and Geim", "url": "https://arxiv.org/pdf/1112.3488", "year": 2012, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "thermal_decomposition", "label": "Temperature above which GO oxygen groups decompose", "value": 1000, "bound": "lower", "unit": "K", "scope": "material", "conditions": { "basis": "thermodynamic stability limit for the oxygen groups, as stated in the review" }, "method": "Statement in the review", "status": "ground", "note": "Snake-case name, not in the property canon. The review gives a stated limit, not a measured onset.", "source": "huang2019", "where": "Section 2.1 (thermodynamic and kinetic stabilities)", "source_detail": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" } }, { "benchmark": "c_o_ratio", "label": "C/O ratio of rGO reduced with hydrazine", "value": 9.82, "bound": "exact", "unit": "-", "scope": "material", "conditions": { "basis": "rGO made by hydrazine reduction; ratio as printed" }, "method": "Value printed in the review text on chemical reduction", "status": "ground", "note": "A higher C/O ratio means fewer oxygen groups. The review gives no numeric C/O ratio for untreated GO.", "source": "monir2026", "where": "Section 3.1.1 (chemical reduction of GO)", "source_detail": { "title": "Towards greener reduced graphene oxide: a critical review of environmentally driven reduction strategies", "id": "RSC Advances 16(3), 2044 to 2061; PMC12776586", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12776586/", "year": 2026, "kind": "paper", "license": "CC BY 3.0 (as printed on the page)" } } ], "corrosion": [ { "environment": "Water and humidity (hydration and ageing)", "headline": "Water content changes GO stiffness and layer spacing", "effect": "The review says the out-of-plane stiffness of conventional GO depends on intercalated water, peaking near RH 25 percent. It also says ageing of GO gathers oxygen groups into highly oxidised domains, so the material changes over time. No ageing rate, time or temperature was read in a source.", "rating": "unknown", "conditions": { "basis": "qualitative statements in the review; no exposure time or temperature stated" }, "source": "huang2019", "where": "Section 2.1 (ageing statement) and out-of-plane elasticity section" }, { "environment": "Water (aqueous dispersion)", "headline": "GO disperses in water; rGO tends to restack", "effect": "The review says GO forms stable colloidal dispersions in water because its oxygen groups make it highly reactive and hydrophilic. Reduced GO has a strong tendency to agglomerate and restack in aqueous solution.", "rating": "unknown", "conditions": { "basis": "qualitative statements in the review; dispersion concentration not stated" }, "source": "monir2026", "where": "Section 2.4" }, { "environment": "Heat above about 1000 K", "headline": "Oxygen groups break down at high temperature", "effect": "The review says the oxygen-containing groups decompose above about 1000 K, and that thermal exfoliation of graphite oxide needs a suggested minimum of 550 C to give RGO. The groups break down into gases during that step.", "rating": "moderate", "conditions": { "basis": "decomposition of oxygen groups; no heating time or atmosphere stated" }, "source": "huang2019", "where": "Section 2.1 and synthesis section (thermal exfoliation)" } ], "risks": { "hazards": [ { "text": "A supplier safety data sheet for a 0.5 mg/mL graphene oxide dispersion in water classifies it under OSHA HCS as eye irritation (Category 2A, H319) and respiratory system (H335), with the signal word None.", "ghs": [ "H319", "H335" ], "source": "samaterials-sds", "where": "Section 2 (hazards identification)" }, { "text": "The same sheet lists CNT and graphite CAS numbers in its composition section, so the CAS number of the product itself is not established. Check the sheet for the exact product you handle.", "ghs": [], "source": "samaterials-sds", "where": "Section 3 (composition)" }, { "text": "No UK statutory workplace exposure limit is set for nanomaterials. HSE says the ACGIH threshold for graphite (2 mg/m3 respirable dust) is not an appropriate limit for graphene, and treats nanomaterials as substances of high concern.", "ghs": [], "source": "hsg272", "where": "Workplace exposure limits section, paragraphs 25 to 27; paragraph 38" } ], "failure_risks": [ { "mode": "Oxygen groups decompose on heating", "trigger": "Heating above about 1000 K", "consequence": "The oxygen groups break down, so the material is no longer GO in its as-made form. A design that relies on the as-made oxygen content will fail.", "severity": "moderate", "source": "huang2019", "where": "Section 2.1 (thermodynamic and kinetic stabilities)" }, { "mode": "Membrane becomes fragile and much less permeable after annealing", "trigger": "Annealing GO membranes at 300 C in hydrogen and argon", "consequence": "The membranes became fragile and needed care to avoid cracks, and became about 100 times less permeable to water.", "severity": "moderate", "source": "nair2012", "where": "Results, paragraph on annealed GO membranes (Fig. 2a)" }, { "mode": "Stiffness shifts with humidity", "trigger": "Change in relative humidity or water content", "consequence": "The out-of-plane modulus of conventional GO depends on water content, with a maximum near RH 25 percent, so a film's stiffness is not fixed.", "severity": "low", "source": "huang2019", "where": "Section on out-of-plane elasticity" } ], "side_effects": [ { "text": "During thermal exfoliation the epoxy and hydroxyl groups decompose into gases, and a suggested minimum of 550 C is needed for the product to be RGO.", "affects": "Sheet size and yield of the product", "source": "huang2019", "where": "Synthesis section, thermal exfoliation paragraph" }, { "text": "Reduced GO has a strong tendency to agglomerate and restack in water, so its dispersions can lose their state.", "affects": "Processing of dispersions and films", "source": "monir2026", "where": "Section 2.4" } ], "handling": [ { "text": "Keep dust-generating work under local exhaust ventilation, and where possible keep the material wet or damp or use slurries.", "source": "hsg272", "where": "Good practice section (wet handling) and LEV section" }, { "text": "Weigh powders over a damp sheet of absorbent material, and wipe spills with a damp sheet rather than dry sweeping.", "source": "hsg272", "where": "Good practice section on weighing and spillages" }, { "text": "Avoid dust formation and provide exhaust ventilation where dust forms. Keep the container tightly closed in a dry, well-ventilated place.", "source": "samaterials-sds", "where": "Sections 7 and 6" }, { "text": "Wear safety glasses to EN166 and gloves that pass ASTM F-1671 for dry particulate or an aqueous suspension, plus impervious clothing.", "source": "samaterials-sds", "where": "Section 8 (personal protection)" } ], "mitigations": [ { "text": "Examine and test local exhaust ventilation plant at least every 14 months, and keep a record of each check.", "source": "hsg272", "where": "LEV section (examination and testing paragraph)" } ] }, "uses": [ { "application": "structures", "device": "GO and polyvinyl alcohol composite (laboratory)", "example": "In the review's Table 1, GO modified with polyvinyl alcohol (ref 133) has a Young's modulus of 8 GPa against 5 GPa for the unmodified GO in the same row, and a tensile strength of 125 MPa against 25 MPa.", "source": "huang2019", "where": "Table 1, row polyvinyl alcohol, ref 133" }, { "application": "electronics-and-chips", "device": "Reduced GO films as transparent conductors and in field-effect transistors (research)", "example": "The review lists transparent and flexible conductors and field-effect transistors among the device applications of GO and reduced GO. These are research demonstrations, not product uses.", "source": "huang2019", "where": "Abstract, list of device applications" }, { "application": "thermal-control", "device": "GO and rGO films as low-conductivity thermal layers (research)", "example": "The review cites GO and rGO papers and films below 10 W/(m·K), and names thermoelectric materials as a use that needs suppressed heat conduction.", "source": "huang2019", "where": "Thermal properties section; abstract (thermoelectrics)" }, { "application": "habitats-and-suits", "device": "GO laminate membrane for water separation (laboratory test, not a space system)", "example": "In a laboratory test, GO membranes stopped helium while letting water permeate at least 10^10 times faster than helium. The paper does not address space or life-support use.", "source": "nair2012", "where": "Abstract" } ], "supply": [ { "subject": "Natural graphite (feedstock for graphite oxide)", "abundance": "USGS gives China 100000000 t of graphite reserves in its 2025 table; world reserve total is not in the excerpt read.", "producers": [ { "country": "China", "share_percent": 82, "year": 2025 } ], "critical_lists": [], "substitutes": [], "source": "usgs-graphite-2026", "where": "Mineral Commodity Summaries 2026, Graphite (Natural): Events, Trends and Issues; World Mine Production and Reserves table; Salient Statistics" }, { "subject": "Natural graphite imports to the United States", "abundance": "US net import reliance for natural graphite is 100 percent.", "producers": [ { "country": "China", "share_percent": 46, "year": 2024 }, { "country": "Canada", "share_percent": 13, "year": 2024 }, { "country": "Mozambique", "share_percent": 13, "year": 2024 }, { "country": "Mexico", "share_percent": 12, "year": 2024 } ], "critical_lists": [], "substitutes": [], "source": "usgs-graphite-2026", "where": "Mineral Commodity Summaries 2026, Graphite (Natural): Import Sources (2021 to 2024)" } ], "media": [], "documents": [ { "title": "Physical properties and device applications of graphene oxide (arXiv:1912.07956)", "type": "paper", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019 }, { "title": "Unimpeded permeation of water through helium-leak-tight graphene-based membranes (Science 335, 442, arXiv:1112.3488)", "type": "paper", "url": "https://arxiv.org/pdf/1112.3488", "year": 2012 }, { "title": "Towards greener reduced graphene oxide: a critical review of environmentally driven reduction strategies (RSC Advances 16, 2044, PMC12776586)", "type": "paper", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12776586/", "year": 2026 }, { "title": "Structure and Synthesis of graphene oxide (arXiv:1901.02274)", "type": "paper", "url": "https://arxiv.org/pdf/1901.02274", "year": 2019 }, { "title": "USGS Mineral Commodity Summaries 2026: Graphite (Natural)", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-graphite.pdf", "year": 2026 }, { "title": "Stanford Advanced Materials safety data sheet: Graphene Oxide Dispersion (0.5 mg/mL in water)", "type": "sds", "url": "https://samaterials.com/tds/1697119733-178-graphene-oxide-05mgml-dispersion-in-water-sds.pdf", "year": 2022 }, { "title": "HSE HSG272: Using nanomaterials at work", "type": "report", "url": "https://www.hse.gov.uk/pubns/books/hsg272.pdf", "year": 2013 } ], "gaps": [ "No product datasheet for GO or rGO was read with a stated C/O ratio, sheet resistance, lateral size or layer count. Commercial values are not included.", "No numeric C/O ratio for untreated GO was read in a fetched source. The review gives O:C ratios only as simulation inputs.", "Thermal conductivity of GO papers was not given at a stated temperature in the fetched text.", "Oxidation temperature in air (thermogravimetry) for GO or rGO was not read from a fetched primary source.", "Ageing and shelf life of GO powder, paste and dispersion were not quantified in any fetched source. The review gives only qualitative ageing statements.", "Radiation, atomic-oxygen, vacuum and thermal-cycling tests of GO or rGO were not found. The space use is not established.", "No corrosion test of GO on metal or on a current collector was found.", "No PubChem compound record for graphene oxide was found. Search results gave vendor pages and the elemental carbon entry (CID 5462310), which are not used. PubChem GHS classification was not read.", "The CAS number of GO is not established. The Stanford sheet's composition section lists CNT and graphite CAS numbers, so it was not used for a CAS value.", "Supply of the Hummers oxidants (sulfuric acid, potassium permanganate, sodium nitrate) and of hydrazine was not read. No critical-mineral status for graphite was read in this run.", "Non-canonical property names used: electrical_conductivity, intrinsic_strength, interlayer_distance, thermal_decomposition and c_o_ratio. None is in spores/property-canon.yaml.", "Two reduction results from the 2026 review's search snippets (Guex 2017, NaBH4 with C/O from 2.2 to 6.9; Compton 2011, solvent-dependent reduction) were not opened, so their numbers are not used.", "Water-permeation result (Nair 2012) is a laboratory membrane test. No space or life-support test was found.", "Recipe process details rest on the review and the Hummers paper. Reaction conditions for a commercial GO product were not read." ], "story": { "why": "Graphene oxide is graphene carrying oxygen groups. The groups make the sheet an electrical insulator and cut its heat conduction, but they also let it disperse in water and bind to other materials. Reduction removes some of the groups and raises conductivity. The useful numbers depend on the oxidation level, the form (paper, film or monolayer) and humidity, so most values here are ranges.", "uses": [ { "where": "Polymer composites", "line": "A review table lists GO modified with polyvinyl alcohol at a Young's modulus of 8 GPa, against 5 GPa for the unmodified GO in the same row. The tensile strength in that row is 125 MPa against 25 MPa." }, { "where": "Membranes", "line": "In a laboratory test, GO membranes stopped helium while letting water through at least 10^10 times faster than helium. This is a research result and not a space system." }, { "where": "Films and devices", "line": "The review lists transparent and flexible conductors and field-effect transistors as device applications of GO and reduced GO. These are research demonstrations." } ], "can_do": [ { "label": "Stiffness", "line": "Bulk GO paper is cited at 6 to 42 GPa in Young's modulus. A GO monolayer is quoted at 250 GPa, with a printed spread of 150 GPa. Measured values depend on oxidation, water content and test method.", "benchmark": "elastic_modulus", "scope": "material" }, { "label": "Electrical conduction", "line": "GO is an insulator, cited as low as 0.0486 S/m. Reduction raises the value: 0.052 S/m for a reduced monolayer, 55.32 S/m for a Shewanella-reduced rGO, and 216.56 S/m for a hydrazine-reduced rGO used as the comparison.", "benchmark": "electrical_conductivity", "scope": "material" }, { "label": "Heat conduction", "line": "GO and rGO papers and films are cited below 10 W/(m·K). Simulations at an O:C ratio of 0.1 give 35, 85 and 29 W/(m·K) for epoxy, hydroxyl and ether groups, which are not measurements.", "benchmark": "thermal_conductivity", "scope": "material" }, { "label": "Water permeation", "line": "GO membranes let water through much faster than helium. Annealing at 300 C in hydrogen and argon shrinks the interlayer distance from about 10 Å to about 4 Å and makes the membrane about 100 times less permeable to water.", "benchmark": "interlayer_distance", "scope": "material" } ], "compare": "Graphene oxide and reduced graphene oxide are not graphene. Graphene is quoted in the review at 1 TPa in stiffness and with far higher thermal conduction at room temperature, both for ideal sheets. GO has oxygen on those sheets, so its electrical conductivity drops to 0.0486 S/m as the lowest value cited, and its films conduct heat below 10 W/(m·K). Reduction recovers some conductivity, to between 0.052 and 216.56 S/m across the cited cases, depending on the reductant. The comparison is with graphene's ideal values, not with a commercial graphene product.", "compare_rows": [ { "label": "Electrical conductivity", "benchmark": "electrical_conductivity", "scope": "material" }, { "label": "Young's modulus", "benchmark": "elastic_modulus", "scope": "material" }, { "label": "Thermal conductivity", "benchmark": "thermal_conductivity", "scope": "material" } ], "handling": [ "Keep dust-generating work under local exhaust ventilation, and keep powders damp or in slurry where possible.", "Wipe spills with a damp sheet, and weigh powders over a damp sheet. Do not dry sweep.", "Wear safety glasses, gloves that pass ASTM F-1671, and impervious clothing. Check the supplier sheet for the product you use." ], "good_for": [ "Water-permeable membranes and laminates at laboratory stage, where a gas-tight but water-passing layer is the goal.", "Polymer composites: the review's polyvinyl alcohol example raises Young's modulus from 5 GPa to 8 GPa.", "Low-conductivity films where heat must not spread, such as thermoelectric research." ], "watch_out": [ "Pure GO is electrically insulating. Reduction changes conductivity by orders of magnitude, and the result depends on the reductant.", "Stiffness and strength values span wide ranges. The monolayer value of 250 GPa carries a printed spread of 150 GPa.", "Humidity changes the out-of-plane stiffness and the layer spacing, so properties drift with moisture.", "Above about 1000 K the oxygen groups decompose, which changes the material." ], "verdict": "GO suits laboratory work on water-permeable membranes and polymer composites. For electrical and thermal use, the reduction route and the form decide the result. No space or flight data were found.", "recipe": { "line": "Graphene oxide is made by oxidising graphite, usually with the Hummers method (sulfuric acid and potassium permanganate), and then exfoliating the oxidised graphite in water. The sheet keeps a carbon lattice with epoxy bridges, hydroxyl groups on its faces, and carbonyl and carboxyl groups at its edges. Reduced graphene oxide has lost some of those groups, for example by thermal exfoliation at a suggested minimum of 550 C or by chemical reduction with hydrazine.", "parts": [ { "name": "Carbon", "symbol": "C", "role": "Forms the sheet. Oxidised areas hold carbon bonded to oxygen, which breaks the flat sp2 lattice locally." }, { "name": "Oxygen", "symbol": "O", "role": "Sits in epoxy bridges, hydroxyl, carbonyl and carboxyl groups. Its amount sets the C/O ratio and how far the conductivity is suppressed." }, { "name": "Hydrogen", "symbol": "H", "role": "Sits on hydroxyl and carboxyl groups. Hydrogen species in as-made GO are thought to make the film metastable, according to the review." } ] }, "risk_groups": [ { "title": "For people", "lead": "The supplier sheet for a dispersion classifies it as an eye and airway irritant, and no exposure limit is set for graphene oxide.", "points": [ { "label": "Eyes and airways", "line": "A supplier sheet for a 0.5 mg/mL dispersion gives serious eye irritation (H319) and respiratory irritation (H335), with no signal word." }, { "label": "Dust", "line": "Keep dust out of the air with local exhaust ventilation. HSE says nanomaterials are substances of high concern, and graphite's threshold is not an appropriate limit for graphene." } ], "level": 1, "verdict": "Handle as a precaution" } ] }, "updated": "2026-10-26", "review": { "status": "draft", "method": "assistant", "checked_values": 19, "unreachable": 2, "caveats": 3, "note": "Written by an assistant on 2026-10-26 from pages read in this run: arXiv 1912.07956, arXiv 1112.3488, PMC12776586, arXiv 1901.02274, USGS MCS 2026 graphite, the Stanford Advanced Materials SDS, HSE HSG272 and Wikipedia (composition and history only). Search snippets were not used as values. Commercial GO and rGO products were not verified." }, "sources": { "huang2019": { "title": "Physical properties and device applications of graphene oxide", "id": "arXiv:1912.07956; Huang, Liu, Zhou and Zhao", "url": "https://arxiv.org/pdf/1912.07956", "year": 2019, "kind": "paper", "license": "arXiv, as listed" }, "nair2012": { "title": "Unimpeded permeation of water through helium-leak-tight graphene-based membranes", "id": "Science 335, 442 to 444 (2012); arXiv:1112.3488; Nair, Wu, Jayaram, Grigorieva and Geim", "url": "https://arxiv.org/pdf/1112.3488", "year": 2012, "kind": "paper", "license": "arXiv, as listed" }, "monir2026": { "title": "Towards greener reduced graphene oxide: a critical review of environmentally driven reduction strategies", "id": "RSC Advances 16(3), 2044 to 2061; PMC12776586", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12776586/", "year": 2026, "kind": "paper", "license": "CC BY 3.0 (as printed on the page)" }, "go-synthesis": { "title": "Structure and Synthesis of graphene oxide", "id": "arXiv:1901.02274", "url": "https://arxiv.org/pdf/1901.02274", "year": 2019, "kind": "paper", "license": "arXiv, as listed" }, "usgs-graphite-2026": { "title": "Mineral Commodity Summaries 2026: Graphite (Natural)", "id": "USGS MCS 2026", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-graphite.pdf", "year": 2026, "kind": "report", "license": "public domain (US government)" }, "samaterials-sds": { "title": "Safety data sheet, Graphene Oxide Dispersion (0.5 mg/mL in water), Stanford Advanced Materials", "id": "Revised 03/12/2022", "url": "https://samaterials.com/tds/1697119733-178-graphene-oxide-05mgml-dispersion-in-water-sds.pdf", "year": 2022, "kind": "datasheet", "license": "supplier document, linked not reproduced" }, "hsg272": { "title": "Using nanomaterials at work, including carbon nanotubes (CNTs) and other biopersistent high aspect ratio nanomaterials (HARNs), HSG272", "id": "HSE HSG272", "url": "https://www.hse.gov.uk/pubns/books/hsg272.pdf", "year": 2013, "kind": "report", "license": "Open Government Licence" }, "wiki-graphite-oxide": { "title": "Graphite oxide (Wikipedia), used for composition and history only", "id": "Wikipedia article Graphite oxide", "url": "https://en.wikipedia.org/wiki/Graphite_oxide", "year": 2026, "kind": "web", "license": "CC BY-SA 4.0 (Wikipedia)" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/graphene-oxide/" }