{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T01:08:48Z","timestamp":1760058528187,"version":"build-2065373602"},"reference-count":60,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2025,4,8]],"date-time":"2025-04-08T00:00:00Z","timestamp":1744070400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"FCT\/MCTES","doi-asserted-by":"publisher","award":["LA\/P\/0037\/2020","UIDP\/50025\/2020","UIDB\/50025\/2020","PTDC\/04191\/2022","2022.01619.PTDC","2023.06206.CEECIND"],"award-info":[{"award-number":["LA\/P\/0037\/2020","UIDP\/50025\/2020","UIDB\/50025\/2020","PTDC\/04191\/2022","2022.01619.PTDC","2023.06206.CEECIND"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT","doi-asserted-by":"publisher","award":["LA\/P\/0037\/2020","UIDP\/50025\/2020","UIDB\/50025\/2020","PTDC\/04191\/2022","2022.01619.PTDC","2023.06206.CEECIND"],"award-info":[{"award-number":["LA\/P\/0037\/2020","UIDP\/50025\/2020","UIDB\/50025\/2020","PTDC\/04191\/2022","2022.01619.PTDC","2023.06206.CEECIND"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Macromol"],"abstract":"<jats:p>Many modern technologies rely on materials that harm the environment. Glass manufacturing, for instance, is both expensive and environmentally damaging. In response, scientists have developed a technique to replace glass with transparent wood, an innovative, versatile, and sustainable alternative. Wood naturally retains heat, is durable, and remains cost-effective, making it promising substitute for glass and plastic in window production. This innovation highlights the urgent need for eco-friendly technologies to replace or improve existing materials. This work explores cork as a sustainable alternative for producing transparent materials, potentially replacing transparent wood. Unlike wood, cork can be harvested from the same tree for up to 300 years. The process followed a method like transparent wood production, involving delignification, bleaching, and forced polymer impregnation. The choice of bleaching agent significantly impacted results\u2014samples treated with sodium hypochlorite solution appeared whiter but became extremely fragile, whereas hydrogen peroxide preserved mechanical properties better. The resin-to-hardener ratio was crucial, with higher resin content improving polymer infiltration and transparency. While fully transparent cork was not achieved, the resulting translucent material lays the groundwork for future research in this field.<\/jats:p>","DOI":"10.3390\/macromol5020017","type":"journal-article","created":{"date-parts":[[2025,4,8]],"date-time":"2025-04-08T11:05:02Z","timestamp":1744110302000},"page":"17","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The Clear Choice: Developing Transparent Cork for Next-Generation Sustainable Materials"],"prefix":"10.3390","volume":"5","author":[{"given":"Pedro","family":"Gil","sequence":"first","affiliation":[{"name":"CENIMAT\u2014Centro de Investiga\u00e7\u00e3o em Materiais, i3N\u2014Institute for Nanomodelling, Nanostructures and Nanofabrication, Department of Materials Science, NOVA School of Sciences and Technology, Campus da Caparica, Caparica, 2829-516 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7356-8455","authenticated-orcid":false,"given":"Pedro L.","family":"Almeida","sequence":"additional","affiliation":[{"name":"CENIMAT\u2014Centro de Investiga\u00e7\u00e3o em Materiais, i3N\u2014Institute for Nanomodelling, Nanostructures and Nanofabrication, Department of Materials Science, NOVA School of Sciences and Technology, Campus da Caparica, Caparica, 2829-516 Lisbon, Portugal"},{"name":"Unit for Innovation and Research in Engineering\u2014UnIRE, Mechanical Engineering Department, Instituto Superior de Engenharia de Lisboa\u2014ISEL, Lisbon Superior Institute of Engineering, Rua Conselheiro Em\u00eddio Navarro, 1, 1959-007 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9760-5983","authenticated-orcid":false,"given":"Maria H.","family":"Godinho","sequence":"additional","affiliation":[{"name":"CENIMAT\u2014Centro de Investiga\u00e7\u00e3o em Materiais, i3N\u2014Institute for Nanomodelling, Nanostructures and Nanofabrication, Department of Materials Science, NOVA School of Sciences and Technology, Campus da Caparica, Caparica, 2829-516 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4984-0759","authenticated-orcid":false,"given":"Ana P. C.","family":"Almeida","sequence":"additional","affiliation":[{"name":"CENIMAT\u2014Centro de Investiga\u00e7\u00e3o em Materiais, i3N\u2014Institute for Nanomodelling, Nanostructures and Nanofabrication, Department of Materials Science, NOVA School of Sciences and Technology, Campus da Caparica, Caparica, 2829-516 Lisbon, Portugal"},{"name":"LAQV\/Requimte\u2014Laborat\u00f3rio Associado para a Qu\u00edmica Verde, Department of Chemistry, NOVA School of Science and Technology, Campus da Caparica, Caparica, 2829-516 Lisbon, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"23","DOI":"10.5962\/p.259872","article-title":"Cork: Structure, properties, applications","volume":"74","author":"Gibson","year":"2016","journal-title":"Arnoldia"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.mattod.2016.12.004","article-title":"Ecoceramics","volume":"20","author":"Pullar","year":"2017","journal-title":"Mater. Today"},{"key":"ref_3","unstructured":"AmorimCorkComposites (2023, June 09). Cork Oak Forest. Available online: https:\/\/amorimcorkcomposites.com\/en-us\/why-cork\/facts-and-curiosities\/about-oak-forest\/."},{"key":"ref_4","unstructured":"Corti\u00e7a, A.P.d. (2023, June 09). Boletim Estat\u00edstico 2020. Available online: https:\/\/apcor.pt\/pt\/anuario."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"625","DOI":"10.3390\/ma8020625","article-title":"New Cork-Based Materials and Applications","volume":"8","author":"Gil","year":"2015","journal-title":"Materials"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"843","DOI":"10.1016\/j.indcrop.2017.09.044","article-title":"All natural cork composites with suberin-based polyester and lignocellulosic residue","volume":"109","author":"Yoon","year":"2017","journal-title":"Ind. Crops Prod."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"275","DOI":"10.1515\/hf-2015-0014","article-title":"Ferulates and lignin structural composition in cork","volume":"70","author":"Marques","year":"2016","journal-title":"Holzforschung"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1007\/BF00386015","article-title":"Chemical composition and variability of cork from Quercus suber L.","volume":"22","author":"Pereira","year":"1988","journal-title":"Wood Sci. Technol."},{"key":"ref_9","unstructured":"Gil, L., and Moiteiro, C. (2000). Cork. Ullmann\u2019s Encyclopedia of Industrial Chemistry, Wiley."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1163\/22941932-90001048","article-title":"The cellular structure of cork from Quercus suber L.","volume":"8","author":"Pereira","year":"1987","journal-title":"IAWA J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1179\/174328005X41168","article-title":"Cork: Properties, capabilities and applications","volume":"50","author":"Silva","year":"2005","journal-title":"Int. Mater. Rev."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"508","DOI":"10.1016\/j.indcrop.2011.07.028","article-title":"Temperature-induced structural and chemical changes in cork from Quercus cerris","volume":"37","author":"Miranda","year":"2012","journal-title":"Ind. Crops Prod."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"685829","DOI":"10.1155\/2014\/685829","article-title":"Functionalization of natural cork composite with microcapsules after plasma treatment","volume":"2014","author":"Oliveira","year":"2014","journal-title":"Adv. Mater. Sci. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1007\/s10457-018-0231-9","article-title":"Is research supporting sustainable management in a changing world? Insights from a mediterranean silvopastoral system","volume":"93","author":"Leal","year":"2018","journal-title":"Agrofor. Syst."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1007\/s40725-022-00172-z","article-title":"The emerging development of transparent wood: Materials, characteristics, and applications","volume":"8","author":"Zhang","year":"2022","journal-title":"Curr. For. Rep."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1800059","DOI":"10.1002\/adom.201800059","article-title":"Optically transparent wood: Recent progress, opportunities, and challenges","volume":"6","author":"Li","year":"2018","journal-title":"Adv. Opt. Mater."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"228","DOI":"10.1016\/j.eurpolymj.2019.01.007","article-title":"Wood-lignin: Supply, extraction processes and use as bio-based material","volume":"112","author":"Tribot","year":"2019","journal-title":"Eur. Polym. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/S1011-1344(02)00412-8","article-title":"Yellowing and IR-changes of spruce wood as result of UV-irradiation","volume":"69","author":"Schwanninger","year":"2003","journal-title":"J. Photochem. Photobiol. B Biol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"5181","DOI":"10.1002\/adma.201600427","article-title":"Highly anisotropic, highly transparent wood composites","volume":"28","author":"Zhu","year":"2016","journal-title":"Adv. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1358","DOI":"10.1021\/acs.biomac.6b00145","article-title":"Optically transparent wood from a nanoporous cellulosic template: Combining functional and structural performance","volume":"17","author":"Li","year":"2016","journal-title":"Biomacromolecules"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1016\/j.nanoen.2016.05.020","article-title":"Transparent and haze wood composites for highly efficient broadband light management in solar cells","volume":"26","author":"Zhu","year":"2016","journal-title":"Nano Energy"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1016\/j.biortech.2015.08.085","article-title":"A review on alkaline pretreatment technology for bioconversion of lignocellulosic biomass","volume":"199","author":"Kim","year":"2016","journal-title":"Bioresour. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"10274","DOI":"10.1021\/acssuschemeng.8b06635","article-title":"Chemical study of kraft lignin during alkaline delignification of E. urophylla x E. grandis hybrid in low and high residual effective alkali","volume":"7","author":"Ribeiro","year":"2019","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2000251","DOI":"10.1002\/adsu.202000251","article-title":"Delignified wood from understanding the hierarchically aligned cellulosic structures to creating novel functional materials: A review","volume":"5","author":"Kumar","year":"2021","journal-title":"Adv. Sustain. Syst."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"12977","DOI":"10.1021\/acs.iecr.0c02110","article-title":"Detailed modeling of kraft pulping chemistry. Delignification","volume":"59","author":"Fearon","year":"2020","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Kleme\u0161, J.J. (2013). 25\u2014Applications of process integration methodologies in the pulp and paper industry. Handbook of Process Integration (PI), Woodhead Publishing.","DOI":"10.1533\/9780857097255"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Jardim, J.M., Hart, P.W., Lucia, L.A., Jameel, H., and Chang, H.-m. (2022). The effect of the kraft pulping process, wood species, and pH on lignin recovery from black liquor. Fibers, 10.","DOI":"10.3390\/fib10020016"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1016\/j.carbon.2019.01.035","article-title":"From waste to wealth: From kraft lignin to free-standing supercapacitors","volume":"145","author":"Schlee","year":"2019","journal-title":"Carbon"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Mariani, A., and Malucelli, G. (2022). Transparent wood-based materials: Current state-of-the-art and future perspectives. Materials, 15.","DOI":"10.3390\/ma15249069"},{"key":"ref_30","unstructured":"Born, M., and Wolf, E. (1999). 1.5. Reflection and refraction of a plane wave. Principles of Optics, Cambridge University Press. [7th ed.]."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1007\/BF00309677","article-title":"The current potential of plastination","volume":"175","author":"Tiedemann","year":"1987","journal-title":"Anat. Embryol."},{"key":"ref_32","unstructured":"von Hagens, G. (1981). Animal and vegetal tissues permanently preserved by synthetic resin impregnation. (US-4205059-A), U.S. Patent."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"35451","DOI":"10.1021\/acsami.9b11816","article-title":"Thickness dependence of optical transmittance of transparent wood: Chemical modification effects","volume":"11","author":"Chen","year":"2019","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_34","first-page":"66","article-title":"Accurate Transmission measurements of translucent materials","volume":"42","author":"Tirpak","year":"2008","journal-title":"Photonics Spectra"},{"key":"ref_35","unstructured":"Stamm, A.J. (1964). Wood and Cellulose Science, Ronald Press Company."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"403","DOI":"10.1007\/s00226-015-0700-5","article-title":"Composition and structure of balsa (Ochroma pyramidale) wood","volume":"49","author":"Borrega","year":"2015","journal-title":"Wood Sci. Technol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s10853-009-3874-0","article-title":"Review: Current international research into cellulose nanofibres and nanocomposites","volume":"45","author":"Eichhorn","year":"2010","journal-title":"J. Mater. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1094","DOI":"10.1039\/C7TA09973H","article-title":"Towards centimeter thick transparent wood through interface manipulation","volume":"6","author":"Li","year":"2018","journal-title":"J. Mater. Chem. A"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"403","DOI":"10.1515\/hfsg.1992.46.5.403","article-title":"Transparent Wood\u2014A New Approach in the functional study of wood structure","volume":"46","author":"Fink","year":"1992","journal-title":"Holzforschung"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1958","DOI":"10.1016\/j.compscitech.2009.04.017","article-title":"Optically transparent wood\u2013cellulose nanocomposite as a base substrate for flexible organic light-emitting diode displays","volume":"69","author":"Okahisa","year":"2009","journal-title":"Compos. Sci. Technol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1600834","DOI":"10.1002\/adom.201600834","article-title":"Luminescent transparent wood","volume":"5","author":"Li","year":"2017","journal-title":"Adv. Opt. Mater."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1700057","DOI":"10.1002\/adom.201700057","article-title":"Lasing from organic dye molecules embedded in transparent wood","volume":"5","author":"Vasileva","year":"2017","journal-title":"Adv. Opt. Mater."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"46914","DOI":"10.1021\/acsami.0c12505","article-title":"Transparent wood biocomposites by fast UV-curing for reduced light-scattering through wood\/thiol\u2013ene interface design","volume":"12","author":"Johansson","year":"2020","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"6061","DOI":"10.1021\/acssuschemeng.8b06248","article-title":"Optically transparent wood substrate for perovskite solar cells","volume":"7","author":"Li","year":"2019","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1907511","DOI":"10.1002\/adfm.201907511","article-title":"A clear, strong, and thermally insulated transparent wood for energy efficient windows","volume":"30","author":"Mi","year":"2020","journal-title":"Adv. Funct. Mater."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"34777","DOI":"10.1021\/acsami.0c06494","article-title":"Transparent wood composites fabricated by impregnation of epoxy resin and W-Doped VO2 nanoparticles for application in energy-saving windows","volume":"12","author":"Zhang","year":"2020","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"eabd7342","DOI":"10.1126\/sciadv.abd7342","article-title":"Solar-assisted fabrication of large-scale, patternable transparent wood","volume":"7","author":"Xia","year":"2021","journal-title":"Sci. Adv."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"843","DOI":"10.1007\/s00107-019-01431-w","article-title":"House model with 2\u20135 cm thick translucent wood walls and its indoor light performance","volume":"77","author":"Li","year":"2019","journal-title":"Eur. J. Wood Wood Prod."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"4086","DOI":"10.1002\/cssc.201801826","article-title":"Large-size transparent wood for energy-saving building applications","volume":"11","author":"Wang","year":"2018","journal-title":"ChemSusChem"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"9993","DOI":"10.1021\/acsnano.9b00089","article-title":"Clear wood toward high-performance building materials","volume":"13","author":"Jia","year":"2019","journal-title":"ACS Nano"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1038\/nmeth.2089","article-title":"NIH Image to ImageJ: 25 years of image analysis","volume":"9","author":"Schneider","year":"2012","journal-title":"Nature Methods"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"2838","DOI":"10.1039\/C8SM02290A","article-title":"Reversible water driven chirality inversion in cellulose-based helices isolated from Erodium awns","volume":"15","author":"Almeida","year":"2019","journal-title":"Soft Matter"},{"key":"ref_53","first-page":"149","article-title":"Effect of hot water treatment on the structure and properties of cork","volume":"22","author":"Rosa","year":"1990","journal-title":"Wood Fiber Sci."},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Berlanga-Del Pozo, M., Gallardo-Guerrero, L., and Gandul-Rojas, B. (2020). Influence of alkaline treatment on structural modifications of clorophyll pigments in NaOH-treated table olives preserved without fermentation. Foods, 9.","DOI":"10.3390\/foods9060701"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1080\/00393630.2015.1137695","article-title":"Chemical bleaching of wood: An investigation into the bleaching of mahogany, walnut, rosewood, padauk, and purpleheart","volume":"62","author":"Herstedt","year":"2017","journal-title":"Stud. Conserv."},{"key":"ref_56","first-page":"406","article-title":"Kraft pulp bleaching with hydrogen peroxide and pancreatic acid","volume":"54","author":"Potucek","year":"2000","journal-title":"Chem. Pap."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1080\/02773818808070668","article-title":"Solid state analysis of plant polymers by FTIR","volume":"8","author":"Abbott","year":"1988","journal-title":"J. Wood Chem. Technol."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"344","DOI":"10.1002\/1097-0282(2000)57:6<344::AID-BIP40>3.0.CO;2-#","article-title":"Quantitation of aliphatic suberin in Quercus suber L. cork by FTIR spectroscopy and solid-state 13C-NMR spectroscopy","volume":"57","author":"Lopes","year":"2000","journal-title":"Biopolymers"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1063\/1.1698419","article-title":"Scattering by an inhomogeneous solid","volume":"20","author":"Debye","year":"1949","journal-title":"J. Appl. Phys."},{"key":"ref_60","unstructured":"Matyjaszewski, K., and M\u00f6ller, M. (2012). 2.14\u2014Combined small-angle scattering for characterization of hierarchically structured polymer systems over nano-to-micron meter: Part II theory. Polymer Science: A Comprehensive Reference, Elsevier."}],"container-title":["Macromol"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2673-6209\/5\/2\/17\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:12:21Z","timestamp":1760029941000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2673-6209\/5\/2\/17"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,4,8]]},"references-count":60,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2025,6]]}},"alternative-id":["macromol5020017"],"URL":"https:\/\/doi.org\/10.3390\/macromol5020017","relation":{},"ISSN":["2673-6209"],"issn-type":[{"type":"electronic","value":"2673-6209"}],"subject":[],"published":{"date-parts":[[2025,4,8]]}}}