{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T22:34:03Z","timestamp":1775082843213,"version":"3.50.1"},"reference-count":50,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2023,4,7]],"date-time":"2023-04-07T00:00:00Z","timestamp":1680825600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Vestu\u00e1rio de prote\u00e7\u00e3o ativa contra agentes qu\u00edmicos e biol\u00f3gicos com base em nanotecnologia","award":["POCI-01-0247-FEDER-045240"],"award-info":[{"award-number":["POCI-01-0247-FEDER-045240"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Chemical protective clothing (CPC) has become mandatory when performing various tasks to ensure user protection and prevent chemicals from contacting the skin and causing severe injuries. In addition to protection, there is a need to develop a simple mechanism that can be attached to CPC and be capable of detecting and alerting the user to the presence of harmful chemical agents. In this study, a double-sensor strategy was investigated, using six different pH indicators stamped on cotton and polyester knits to detect acidic and alkaline substances, both liquid and gaseous. Functionalized knits underwent microscopic characterization, air permeability and contact angle evaluation. All samples exhibited hydrophobic behavior (contact angle &gt; 90\u00b0) and air permeability values above 2400 L\/min\/cm2\/bar, with the best condition demonstrating a contact angle of 123\u00b0 and an air permeability of 2412.5 L\/min\/cm2\/bar when the sensor methyl orange and bromocresol purple (MO:BP) was stamped on polyester. The performed tests proved the functionality of the sensors and showed a visible response of all knits when contacting with different chemicals (acids and bases). Polyester functionalized with MO:BP showed the greatest potential, due to its preeminent color change. Herein, the fiber coating process was optimized, enabling the industrial application of the sensors via a stamping method, an alternative to other time- and resource-consuming techniques.<\/jats:p>","DOI":"10.3390\/ma16082938","type":"journal-article","created":{"date-parts":[[2023,4,7]],"date-time":"2023-04-07T04:04:16Z","timestamp":1680840256000},"page":"2938","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Halochromic Textiles for Real-Time Sensing of Hazardous Chemicals and Personal Protection"],"prefix":"10.3390","volume":"16","author":[{"given":"Liliana","family":"Leite","sequence":"first","affiliation":[{"name":"Fibrenamics\u2014Institute of Innovation on Fiber-Based Materials and Composites, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"Centre for Textile Science and Technology (2C2T), University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2584-9900","authenticated-orcid":false,"given":"V\u00e2nia","family":"Pais","sequence":"additional","affiliation":[{"name":"Fibrenamics\u2014Institute of Innovation on Fiber-Based Materials and Composites, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"Centre for Textile Science and Technology (2C2T), University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2636-0034","authenticated-orcid":false,"given":"Cristina","family":"Silva","sequence":"additional","affiliation":[{"name":"Fibrenamics\u2014Institute of Innovation on Fiber-Based Materials and Composites, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"Centre for Textile Science and Technology (2C2T), University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"given":"In\u00eas","family":"Boticas","sequence":"additional","affiliation":[{"name":"Fibrenamics\u2014Institute of Innovation on Fiber-Based Materials and Composites, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"Centre for Textile Science and Technology (2C2T), University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0950-4961","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Bessa","sequence":"additional","affiliation":[{"name":"Fibrenamics\u2014Institute of Innovation on Fiber-Based Materials and Composites, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"Centre for Textile Science and Technology (2C2T), University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"given":"Fernando","family":"Cunha","sequence":"additional","affiliation":[{"name":"Fibrenamics\u2014Institute of Innovation on Fiber-Based Materials and Composites, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"Centre for Textile Science and Technology (2C2T), University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"given":"C\u00e1tia","family":"Relvas","sequence":"additional","affiliation":[{"name":"A. Ferreira & Filhos, Rua Amaro de Sousa 408, 4815-901 Caldas de Vizela, Portugal"}]},{"given":"Noel","family":"Ferreira","sequence":"additional","affiliation":[{"name":"A. Ferreira & Filhos, Rua Amaro de Sousa 408, 4815-901 Caldas de Vizela, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3303-6563","authenticated-orcid":false,"given":"Raul","family":"Fangueiro","sequence":"additional","affiliation":[{"name":"Fibrenamics\u2014Institute of Innovation on Fiber-Based Materials and Composites, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"Centre for Textile Science and Technology (2C2T), University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"Department of Textile Engineering, University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,4,7]]},"reference":[{"key":"ref_1","unstructured":"Dhanapala, S. (2017). Materials and Technology for Sportswear and Performance Apparel, CRC Press."},{"key":"ref_2","unstructured":"Zhou, W., Reddy, N., and Yang, Y. (2005). Textiles for Protection, Woodhead Publishing."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Mao, N. (2014). High Performance Textiles and Their Applications, Woodhead Publishing.","DOI":"10.1533\/9780857099075.91"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1016\/B978-1-78242-465-9.00010-0","article-title":"Technical textiles for survival","volume":"Volume 2","author":"Holmes","year":"2016","journal-title":"Handbook of Technical Textiles"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1177\/1528083718779426","article-title":"Advances and applications of chemical protective clothing system","volume":"49","author":"Bhuiyan","year":"2018","journal-title":"J. Ind. Text."},{"key":"ref_6","unstructured":"Institute of Medicine (US) Committee on R&D Needs for Improving Civilian Medical Response to Chemical and Biological Terrorism Incidents (1999). Chemical and Biological Terrorism: Research and Development to Improve Civilian Medical Response, National Academies Press (US)."},{"key":"ref_7","first-page":"516","article-title":"Chemical warfare agent detection: A review of current trends and future perspective","volume":"5","author":"Aguilar","year":"2013","journal-title":"Front. Biosci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"125619","DOI":"10.1016\/j.jhazmat.2021.125619","article-title":"Ultrafast-response, highly-sensitive and recyclable colorimetric\/fluorometric dual-channel chemical warfare agent probes","volume":"415","author":"Zheng","year":"2021","journal-title":"J. Hazard. Mater."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Sousa, R.P.C.L., Figueira, R.B., Gomes, B.R., Sousa, S., Ferreira, R.C.M., Costa, S.P.G., and Raposo, M.M.M. (2021). Hybrid Sol\u2013Gel Matrices Doped with Colorimetric\/Fluorimetric Imidazole Derivatives. Nanomaterials, 11.","DOI":"10.3390\/nano11123401"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1950","DOI":"10.1002\/app.26724","article-title":"Optical sensor for aliphatic amines based on the simultaneous colorimetric and fluorescence responses of smart textile","volume":"106","author":"Staneva","year":"2007","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1039\/C6DT03969C","article-title":"Halochromic coordination polymers based on a triarylmethane dye for reversible detection of acids","volume":"46","author":"Zavakhina","year":"2017","journal-title":"Dalton Trans."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.talanta.2017.04.002","article-title":"Novel cellulose-based halochromic test strips for naked-eye detection of alkaline vapors and analytes","volume":"170","author":"Khattab","year":"2017","journal-title":"Talanta"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"131310","DOI":"10.1016\/j.snb.2021.131310","article-title":"Stable, reusable, and rapid response smart pH-responsive cotton fabric based on covalently immobilized with naphthalimide-rhodamine probe","volume":"355","author":"Zhou","year":"2022","journal-title":"Sens. Actuators B Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1016\/j.snb.2011.11.077","article-title":"Novel cellulose and polyamide halochromic textile sensors based on the encapsulation of Methyl Red into a sol\u2013gel matrix","volume":"162","author":"Brancatelli","year":"2012","journal-title":"Sens. Actuators B Chem."},{"key":"ref_15","first-page":"420","article-title":"Halochromic Composite Materials","volume":"2","author":"Bilgin","year":"2021","journal-title":"Encycl. Mater. Compos."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2234","DOI":"10.1016\/j.tsf.2009.07.158","article-title":"Organically modified silicate thin films doped with colourimetric pH indicators methyl red and bromocresol green as pH responsive sol\u2013gel hybrid materials","volume":"518","author":"Steinberg","year":"2010","journal-title":"Thin Solid Films"},{"key":"ref_17","first-page":"47","article-title":"Halochromic Textile Materials as Innovative pH-Sensors","volume":"80","year":"2013","journal-title":"Adv. Sci. Technol."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Stojkoski, V., and Kert, M. (2020). Design of pH Responsive Textile as a Sensor Material for Acid Rain. Polymers, 12.","DOI":"10.3390\/polym12102251"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"590","DOI":"10.1177\/0040517509346443","article-title":"The Use of pH-indicator Dyes for pH-sensitive Textile Materials","volume":"80","year":"2010","journal-title":"Text. Res. J."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Park, Y.K., Oh, H.J., Bae, J.H., Lim, J.Y., Lee, H.D., Hong, S.I., Son, H.S., Kim, J.H., Lim, S.J., and Lee, W. (2020). Colorimetric Textile Sensor for the Simultaneous Detection of NH3 and HCl Gases. Polymers, 12.","DOI":"10.3390\/polym12112595"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"\u0160aravanja, A., Pu\u0161i\u0107, T., and Dekani\u0107, T. (2022). Microplastics in Wastewater by Washing Polyester Fabrics. Materials, 15.","DOI":"10.3390\/ma15072683"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"19313","DOI":"10.1007\/s11356-017-9621-1","article-title":"Release of polyester and cotton fibers from textiles in machine washings","volume":"24","author":"Sainio","year":"2017","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3921","DOI":"10.1080\/10643389.2021.1966254","article-title":"An overview of cotton and polyester, and their blended waste textile valorisation to value-added products: A circular economy approach\u2013research trends, opportunities and challenges","volume":"52","author":"Subramanian","year":"2022","journal-title":"Crit. Rev. Environ. Sci. Technol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"8771","DOI":"10.1007\/s10570-021-04071-7","article-title":"Halochromic cellulose textile obtained via dyeing with biocolorant isolated from Streptomyces sp. strain NP4","volume":"28","author":"Kramar","year":"2021","journal-title":"Cellulose"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"9125","DOI":"10.1080\/15440478.2021.1982442","article-title":"Investigation of the Dyeability of Cotton Fabrics with a Halochromic Dye According to Exhaust and Padding Methods","volume":"19","author":"Atav","year":"2021","journal-title":"J. Nat. Fibers"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1111\/cote.12511","article-title":"Fabric dyeing with colorimetric pH-responsive colours","volume":"137","author":"Peila","year":"2021","journal-title":"Color. Technol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/j.foodcont.2017.06.028","article-title":"On-package dual sensors label based on pH indicators for real-time monitoring of beef freshness","volume":"82","author":"Kuswandi","year":"2017","journal-title":"Food Control"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/j.foodchem.2018.02.110","article-title":"Non-destructive monitoring of apple ripeness using an aldehyde sensitive colorimetric sensor","volume":"267","author":"Kim","year":"2017","journal-title":"Food Chem."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Pais, V., Mota, C., Bessa, J., Dias, J.G., Cunha, F., and Fangueiro, R. (2021). Study of the Filtration Performance of Multilayer and Multiscale Fibrous Structures. Materials, 14.","DOI":"10.3390\/ma14237147"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Leite, L., Pais, V., Cunha, F., Relvas, C., Ferreira, N., and Fangueiro, R. (2023). Prussian Blue Sensor for Bacteria Detection in Personal Protection Clothing. Polymers, 15.","DOI":"10.3390\/polym15040872"},{"key":"ref_31","unstructured":"Mishra, R., Militky, J., and Venkataraman, M. (2019). Nanotechnology in Textiles: Theory and Application, Woodhead Publishing."},{"key":"ref_32","unstructured":"Hu, J.Y., Li, Y.I., and Yeung, K.W. (2006). Clothing Biosensory Engineering, Woodhead Publishing."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1080\/00140139.2011.558638","article-title":"Heat stress in chemical protective clothing: Porosity and vapour resistance","volume":"54","author":"Havenith","year":"2011","journal-title":"Ergonomics"},{"key":"ref_34","unstructured":"Montemor, M.F. (2016). Smart Composite Coatings and Membranes, Woodhead Publishing."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1221","DOI":"10.1080\/00405000.2018.1553346","article-title":"Hydrophobic properties of textile materials: Robustness of hydrophobicity","volume":"110","author":"Melki","year":"2019","journal-title":"J. Text. Inst."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2719","DOI":"10.1177\/00405175211010669","article-title":"Hydrophobic performance of electrospun fibers functionalized with TiO2 nanoparticles","volume":"92","author":"Pais","year":"2022","journal-title":"Text. Res. J."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"012012","DOI":"10.1088\/1742-6596\/1893\/1\/012012","article-title":"Hydrophobic Coating on Woven Material for Personal Protective Equipment","volume":"1893","author":"Hildayani","year":"2021","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Irzma\u0144ska, E., Korzeniewska, E., Pawlak, R., Tomczyk, M., Smejda-Krzewicka, A., and Adamus-W\u0142odarczyk, A. (2022). Enhanced Hydrofobicity of Polymers for Personal Protective Equipment Achieved by Chemical and Physical Modification. Materials, 15.","DOI":"10.3390\/ma15010106"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Antunes, J., Matos, K., Carvalho, I., Carvalho, S., Ferreira, F., and Cruz, S.M.A. (2022). Physical Vapor Deposition Technology in Personal Protective Equipment Production: Improved Antibacterial and Hydrophobic Character of Textiles. Coatings, 12.","DOI":"10.3390\/coatings12101399"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Irzma\u0144ska, E., Sici\u0144ski, M., Smejda-Krzewicka, A., Adamus-W\u0142odarczyk, A., Makowicz, M., and Gozdek, T. (2022). Enhanced Hydrophobicity of Polymers for Protective Gloves Achieved by Geometric, Chemical and Plasma-Surface Modification. Int. J. Environ. Res. Public Health, 19.","DOI":"10.3390\/ijerph19095239"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Thomas, O., and Brogat, M. (2017). UV-Visible Spectrophotometry of Water and Wastewater, Elsevier.","DOI":"10.1016\/B978-0-444-63897-7.00009-3"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1016\/j.saa.2017.05.040","article-title":"Determination of equilibrium structures of bromothymol blue revealed by using quantum chemistry with an aid of multivariate analysis of electronic absorption spectra","volume":"185","author":"Shimada","year":"2017","journal-title":"Spectrochim. Acta Part A Mol. Biomol. Spectrosc."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/0143-7208(91)85014-Y","article-title":"A spectrophotometric study of the tautomeric and acid- base equilibria of methyl orange and methyl yellow in aqueous acidic solutions","volume":"16","author":"Tawarah","year":"1991","journal-title":"Dye. Pigment."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"118550","DOI":"10.1016\/j.carbpol.2021.118550","article-title":"Covalent immobilization of bromocresol purple on cellulose nanocrystals for use in pH-responsive indicator films","volume":"273","author":"Khanjanzadeh","year":"2021","journal-title":"Carbohydr. Polym."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Leite, L., Boticas, I., Navarro, M., Nobre, L., Bessa, J., Cunha, F., Neves, P., and Fangueiro, R. (2022). Halochromic Inks Applied on Cardboard for Food Spoilage Monitorization. Materials, 15.","DOI":"10.3390\/ma15186431"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1080\/00405000.2020.1785071","article-title":"Smart textiles: An overview of recent progress on chromic textiles","volume":"112","author":"Ramlow","year":"2021","journal-title":"J. Text. Inst."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Seto, Y. (2015). Handbook of Toxicology of Chemical Warfare Agents, Elsevier. [2nd ed.].","DOI":"10.1016\/B978-0-12-800159-2.00060-9"},{"key":"ref_48","unstructured":"Kuza, C., and McIsaac, J.H. (2018). Basics of Anesthesia, Elsevier."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"864","DOI":"10.1016\/j.saa.2014.02.171","article-title":"A novel pH optical sensor using methyl orange based on triacetylcellulose membranes as support","volume":"128","author":"Hosseini","year":"2014","journal-title":"Spectrochim. Acta Part A Mol. Biomol. Spectrosc."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"2001058","DOI":"10.1002\/admt.202001058","article-title":"Elastic Halochromic Fiber as a Reversible pH Sensor","volume":"6","author":"Hong","year":"2021","journal-title":"Adv. Mater. Technol."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/16\/8\/2938\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:11:41Z","timestamp":1760123501000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/16\/8\/2938"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,4,7]]},"references-count":50,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2023,4]]}},"alternative-id":["ma16082938"],"URL":"https:\/\/doi.org\/10.3390\/ma16082938","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,4,7]]}}}