A superelastic and cushioning aerogel with dual sensing for intelligent safety protection

Abstract

Safety protection equipment necessitates the use of aerogel materials with effective mechanical impact resistance. However, conventional materials often suffer from limited resilience and a lack of multi-sensing functionality, making them inadequate for safety monitoring in complex scenarios. To address this, we developed a composite aerogel (denoted as G-T@M/C) based on cellulose nanofibers and MXene, fabricated through oxidation, cross-linking, and freeze-drying. This aerogel demonstrates mechanical resilience, achieving a rebound rate of 95% even under 90% compressive strain. It showed a static cushioning coefficient of 3.32 in the stress range of 2.4-36.2 kPa, and demonstrated significantly better practical cushioning performance than expanded polyethylene and expanded polystyrene. Moreover, this aerogel exhibits piezoresistive sensitivity of 3.9 and high stability throughout 1,500 compression-release cycles at 80% strain. Simultaneously, this aerogel possesses sensitive gas sensing capabilities, exhibiting a response concentration to ammonia gas ranging from 0.001 to 10 ppm, with a response time to 1 ppm NH₃ achieved within 17 s. These characteristics enable its integration into blasters’ safety helmets, providing not only reliable impact protection but also early warning of ammonia leaks in the environment, thereby ensuring timely safety alerts.

Keywords

Highly resilient / cushioning / pressure sensing / gas sensing / intelligent safety protection

References

[1] Lakzian K.Comprehensive analysis of a major ammonium nitrate accident: causes, consequences, safety recommendations, and emergency response for ammonium nitrate incidents.Next Res2025;2:100270

[2] Liu T,He H.Bioinspired triboelectric droplet sensor for ammonia monitoring.Nat Commun2026;17:2153 PMCID:PMC12957501

[3] Zhang D,Wang X.UV illumination-enhanced ultrasensitive ammonia gas sensor based on (001)TiO₂/MXene heterostructure for food spoilage detection.J Hazard Mater2022;423:127160

[4] Kim Y,Song J.2D transition metal dichalcogenide heterostructures for p- and n-type photovoltaic self-powered gas sensor.Adv Funct Mater2020;30:2003360

[5] Du L,Sun M.Polyurethane nonwovens integrated with nanocomposite as twist-assisted healing flexible sensor for ultrasensitive room-temperature NO₂ detection.Adv Mater2026;38:e09512

[6] Jiang Y,Wang T.Wireless wearable MOF-based NH₃ gas sensor patch with a zeolite overlayer for suppressing NO₂ interference.ACS Sens2026;11:2656-67

[7] Zhou M,Wang D,Zhang L.A wearable acetone gas sensor enabled by quantum dot-sensitized flower-like Ti₃C₂T_x for metabolic monitoring.ACS Sens2026;11:157-67

[8] Yang J,Zheng Y.Versatile aerogels for sensors.Small2019;15:e1902826

[9] Zhou J,Sang M.Advanced functional Kevlar composite with excellent mechanical properties for thermal management and intelligent safeguarding.Chem Eng J2022;428:131878

[10] Wang Y,Zhao Y.Temperature-triggered fire warning PEG@wood powder/carbon nanotube/calcium alginate composite aerogel and the application for firefighting clothing.Compos Part B Eng2022;247:110348

[11] Hu Z,Wu J.Robust multi-scale bionic ANF/PMSQ aerogel featuring impact protection, thermal insulation and anti-icing functions.Compos Part B Eng2025;297:112304

[12] Du H,Xu T.Lignocellulosic films: preparation, properties, and applications.Chem Rev2025;125:11666-814 PMCID:PMC12746420

[13] Saleh AK,El-Sakhawy MA.Cellulose-based conductive materials for bioelectronics.ChemSusChem2025;18:e202401762

[14] Gao M,Li B.Sustainable preparation of cellulose nanocrystals: state of the art and perspectives.Green Chem2022;24:9346-72

[15] Isogai A.Diverse nanocelluloses prepared from TEMPO-oxidized wood cellulose fibers: nanonetworks, nanofibers, and nanocrystals.Curr Opin Solid State Mater Sci2019;23:101-6

[16] Xu K,Liu L.Silicified wood-inspired, high-strength fire-resistant chitin-based aerogels for sustainable high-temperature thermal insulation.Adv Funct Mater2026;36:e75626

[17] Zhao Y,Yang Z.Mechanically strong and flame-retardant cellulose-based aerogel prepared via phosphorylation-coupled Ca²⁺ coordination.Gels2025;11:408 PMCID:PMC12191589

[18] Pan X,Xu Z.Improving electronics stability via covalent-linked interfaces for ultra-robust pressure sensing array.Chem Eng J2024;489:151354

[19] Shi X,Zhu Y.Pushing detectability and sensitivity for subtle force to new limits with shrinkable nanochannel structured aerogel.Nat Commun2022;13:1119 PMCID:PMC8891261

[20] Cheng H,Wang B.Chemical crosslinking reinforced flexible cellulose nanofiber-supported cryogel.Cellulose2018;25:573-82

[21] Kuang, D.; Wang, L.; Guo, X., et al. Facile hydrothermal synthesis of Ti₃C₂T_x-TiO₂ nanocomposites for gaseous volatile organic compounds detection at room temperature.J Hazard Mater2021;416:126171

[22] Tai, H.; Duan, Z.; He, Z., et al. Enhanced ammonia response of Ti₃C₂T_x nanosheets supported by TiO₂ nanoparticles at room temperature.Sens Actuators B Chem2019;298:126874

[23] Xu T,Liu K.Nanocellulose-assisted construction of multifunctional MXene-based aerogels with engineering biomimetic texture for pressure sensor and compressible electrode.Nanomicro Lett2023;15:98 PMCID:PMC10086089

[24] Zhao J,Yang C.A hydrophobic surface enabled salt-blocking 2D Ti₃C₂ MXene membrane for efficient and stable solar desalination.J Mater Chem A2018;6:16196-204

[25] Kim WB,Lee JS.Quantitative analysis of Ti−O−Si and Ti−O−Ti bonds in Ti−Si binary oxides by the linear combination of XANES.J Phys Chem B2000;104:8670-8

[26] Liu R,Mao Z.Well-cushioned and highly-elastic aerogel for multifunctional intelligent transportation packaging.Chem Eng J2024;493:152660

[27] Ren J,Liu S,Xie K.Silica–titania mixed oxides: Si–O–Ti connectivity, coordination of titanium, and surface acidic properties.Catal Lett2008;124:185-94

[28] Niu M,Chen J,Wu D.Structure and energetics of SiOC and SiOC - modified carbon-bonded carbon fiber composites.J Am Ceram Soc2017;100:3693-702

[29] Lin W,You X.Hydrophobic modification of nanocellulose via a two-step silanation method.Polymers2018;10:1035 PMCID:PMC6403911

[30] Wetzelaer GAH.Comment on “Enhanced charge selectivity via anodic-C₆₀ layer reduces nonradiative losses in organic solar cells”.ACS Appl Mater Interfaces2022;14:7523-6 PMCID:PMC8855338

[31] Chen Y,Yang Y.Recent progress on nanocellulose aerogels: preparation, modification, composite fabrication, applications.Adv Mater2021;33:e2005569 PMCID:PMC11468492

[32] Lipatov A,Alhabeb M., Elastic properties of 2D Ti₃C₂T_x MXene monolayers and bilayers.Sci Adv2018;4:eaat0491 PMCID:PMC6003751

[33] Firestein KL,Kvashnin DG.Young’s modulus and tensile strength of Ti₃C₂ MXene nanosheets as revealed by in situ TEM probing, AFM nanomechanical mapping, and theoretical calculations.Nano Lett2020;20:5900-8

[34] Gavezzotti A.Comparing the strength of covalent bonds, intermolecular hydrogen bonds and other intermolecular interactions for organic molecules: X-ray diffraction data and quantum chemical calculations.New J Chem2016;40:6848-53

[35] Dereka B,Lewis NHC,Bowman JM.Crossover from hydrogen to chemical bonding.Science2021;371:160-4

[36] Yu H,Zhang Z,Weng J.Oxygen functionalization-induced crossover in the tensile properties of the thinnest 2D Ti₂C MXene.J Mater Chem C2021;9:2416-25

[37] Dai J,Wu C.Fracture of Ti₃C₂-TiO₂ atomically thin films.Extreme Mech Lett2024;71:102211

[38] McIntosh BJ,Nyáry A,Forró L.Surface chemistry-driven oxidation mechanisms in Ti₃C₂T_x MXenes.Small Sci2025;5:2500209 PMCID:PMC12362798

[39] Xie K,Xu K,Zhang M.In-situ synthesis of fluorine-free MXene/TiO₂ composite for high-performance supercapacitor.Arab J Chem2024;17:105551

[40] Zhang X,Jiang Y.A 3D crinkled MXene/TiO₂ heterostructure with interfacial coupling for ultra-fast and reversible potassium storage.J Mater Chem A2024;12:7598-604

[41] Lu X,Song W.Sustainable lignocellulose bio-based foam with good cushioning performance and thermal insulation for transportation packaging.Ind Crops Prod2024;216:118758

[42] Song W,Wang X.Load-bearing structure inspired cellulose-based aerogel with high resilience and water tolerance.Adv Funct Mater2025;35:2415937

[43] Hakozaki K,Takahashi S.Study on the drop impact acceleration of the radioactive package by new approximation method based on velocity obtained by integrating acceleration.J Nucl Sci Technol2023;60:401-14

[44] Xia Y,Tong W.Ultra-stiff yet super-elastic graphene aerogels by topological cellular hierarchy.Adv Mater2025;37:e2417462

[45] Qin B,Huang J.A petrochemical-free route to superelastic hierarchical cellulose aerogel.Angew Chem Int Ed Engl2023;62:e202214809

[46] Wang A,Wu S.Superelastic and ultra-soft MXene/CNF aerogel@PDMS-based dual-modal pressure sensor for complex stimuli monitoring.Adv Sci2025;12:e2502797 PMCID:PMC12244993

[47] Wang Y,Ou H,Xiang X.Polydopamine-bridged MXene/graphene composite aerogel for bifunctional applications in supercapacitors and piezoresistive sensors.Chem Eng J2025;522:167528

[48] Marszewski M,Mcneil PE.Elastic and plastic mechanical properties of nanoparticle-based silica aerogels and xerogels.Microporous Mesoporous Mater2022;330:111569

[49] Niu Y,Huang B.Bovine rumen inspired multiple-nested porous aerogel pressure sensor with high sensitivity and wide detection range.Sens Actuators B Chem2026;450:139291

[50] Cheng Y,Liu Z.3D porous MXene aerogel through gas foaming for multifunctional pressure sensor.Research2022;2022:9843268 PMCID:PMC11715778

[51] Chen T,Wu X,Yang S.Ethanediamine induced self-assembly of long-range ordered GO/MXene composite aerogel and its piezoresistive sensing performances.Appl Surf Sci2021;566:150719

[52] Zhou Y,Wang Y.MXene Ti₃C₂T_x-derived nitrogen-functionalized heterophase TiO₂ homojunctions for room-temperature trace ammonia gas sensing.ACS Appl Mater Interfaces2021;13:56485-97

[53] Wang Y,Wang Y.Humidity activated ionic-conduction formaldehyde sensing of reduced graphene oxide decorated nitrogen-doped MXene/titanium dioxide composite film.Sens Actuators B Chem2020;323:128695

[54] Li Y,Tian J,Cui H.Ti₃C₂ MXene-derived Ti₃C₂/TiO₂ nanoflowers for noble-metal-free photocatalytic overall water splitting.Appl Mater Today2018;13:217-27

[55] Dogra N,Sharma A,Sharma S.TiO₂ decorated MXene nanosheets for high-performance ammonia gas sensing at room-temperature.Surf Interfaces2024;48:104290

[56] Zhang D,Li P.Layer-by-layer self-assembly of Co₃O₄ nanorod-decorated MoS₂ nanosheet-based nanocomposite toward high-performance ammonia detection.ACS Appl Mater Interfaces2017;9:6462-71

[57] Kamachi T,Toyao T.Linear correlations between adsorption energies and HOMO levels for the adsorption of small molecules on TiO₂ surfaces.J Phys Chem C2019;123:20988-97

[58] Lu Z,Hua L.Porous and flexible aramid nanofiber/MXene nanosheet composite aerogel for rapid ammonia sensing at room temperature.ACS Appl Nano Mater2025;8:7407-17

[59] Xu W,Gwon J.Ice-crystal-templated “accordion-like” cellulose nanofiber/MXene composite aerogels for sensitive wearable pressure sensors.ACS Sustain Chem Eng2023;11:3208-18 PMCID:PMC9976353