{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T19:49:01Z","timestamp":1773172141030,"version":"3.50.1"},"reference-count":35,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2023,9,25]],"date-time":"2023-09-25T00:00:00Z","timestamp":1695600000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"FCT and IFIMUP","doi-asserted-by":"publisher","award":["UIDB\/04968\/2020"],"award-info":[{"award-number":["UIDB\/04968\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT and IFIMUP","doi-asserted-by":"publisher","award":["UIDP\/04968\/2020"],"award-info":[{"award-number":["UIDP\/04968\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT and IFIMUP","doi-asserted-by":"publisher","award":["Circular2B\u201437_CALL#2"],"award-info":[{"award-number":["Circular2B\u201437_CALL#2"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT and IFIMUP","doi-asserted-by":"publisher","award":["SFRH\/BD\/148785\/2019"],"award-info":[{"award-number":["SFRH\/BD\/148785\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"name":"European Economic Area Financial Mechanism EEA","award":["UIDB\/04968\/2020"],"award-info":[{"award-number":["UIDB\/04968\/2020"]}]},{"name":"European Economic Area Financial Mechanism EEA","award":["UIDP\/04968\/2020"],"award-info":[{"award-number":["UIDP\/04968\/2020"]}]},{"name":"European Economic Area Financial Mechanism EEA","award":["Circular2B\u201437_CALL#2"],"award-info":[{"award-number":["Circular2B\u201437_CALL#2"]}]},{"name":"European Economic Area Financial Mechanism EEA","award":["SFRH\/BD\/148785\/2019"],"award-info":[{"award-number":["SFRH\/BD\/148785\/2019"]}]},{"DOI":"10.13039\/501100001871","name":"FCT\u2014Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UIDB\/04968\/2020"],"award-info":[{"award-number":["UIDB\/04968\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT\u2014Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UIDP\/04968\/2020"],"award-info":[{"award-number":["UIDP\/04968\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT\u2014Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["Circular2B\u201437_CALL#2"],"award-info":[{"award-number":["Circular2B\u201437_CALL#2"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT\u2014Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["SFRH\/BD\/148785\/2019"],"award-info":[{"award-number":["SFRH\/BD\/148785\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Buildings"],"abstract":"<jats:p>Energy consumption for building cooling is directly related to incident solar radiation. Therefore, solutions of high reflectivity, while keeping color comfort, are being actively researched. Here, finite-difference time-domain (FDTD) simulations were used to investigate the influence of nanoparticle and core\u2013shell additives on coating reflection and color. Different TiO2 and CuO nanoparticle mixings were tested, with relative concentrations varying from 0 to 20% of each on acrylic. The same compounds were used to define core\u2013shells with a varied inner radius (0\u201330 nm) for both TiO2 and CuO as the core and shell. The numerical simulations demonstrate that mixing CuO with TiO2 enables dark colors while maintaining the overall reflectance. The reflectance results for the core\u2013shell structure are comparable with those of the nanoparticles when CuO is the core, while a more pronounced color change is originated when CuO is the shell.<\/jats:p>","DOI":"10.3390\/buildings13102437","type":"journal-article","created":{"date-parts":[[2023,9,26]],"date-time":"2023-09-26T02:31:29Z","timestamp":1695695489000},"page":"2437","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Reflectance and Color Tuning in TiO2-CuO Nanoparticle Composition Mixing"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1007-3919","authenticated-orcid":false,"given":"Catarina","family":"Dias","sequence":"first","affiliation":[{"name":"IFIMUP, Departamento de F\u00edsica e Astronomia, Faculdade de Ci\u00eancias, Universidade do Porto, Rua do Campo Alegre s\/n, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6934-490X","authenticated-orcid":false,"given":"Rita C.","family":"Veloso","sequence":"additional","affiliation":[{"name":"IFIMUP, Departamento de F\u00edsica e Astronomia, Faculdade de Ci\u00eancias, Universidade do Porto, Rua do Campo Alegre s\/n, 4169-007 Porto, Portugal"},{"name":"CONSTRUCT-LFC, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0494-3009","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Ventura","sequence":"additional","affiliation":[{"name":"IFIMUP, Departamento de F\u00edsica e Astronomia, Faculdade de Ci\u00eancias, Universidade do Porto, Rua do Campo Alegre s\/n, 4169-007 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,9,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3343","DOI":"10.1016\/j.egyr.2023.02.015","article-title":"Latest advancements and challenges of technologies and methods for accelerating the sustainable energy transition","volume":"9","author":"Buonomano","year":"2023","journal-title":"Energy Rep."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"123290","DOI":"10.1016\/j.energy.2022.123290","article-title":"Characterizing regional building energy consumption under joint climatic and socioeconomic impacts","volume":"245","author":"Duan","year":"2022","journal-title":"Energy"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1016\/j.solener.2015.04.004","article-title":"NIR-reflecting properties of new paints for energy-efficient buildings","volume":"116","author":"Cozza","year":"2015","journal-title":"Sol. Energy"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1016\/j.solener.2004.04.005","article-title":"Passive cooling of outdoor urban spaces. The role of materials","volume":"77","author":"Doulos","year":"2004","journal-title":"Sol. Energy"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Kamel, E., and Memari, A. (2022). Residential Building Envelope Energy Retrofit Methods, Simulation Tools, and Example Projects: A Review of the Literature. Buildings, 12.","DOI":"10.3390\/buildings12070954"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/j.enbuild.2004.05.006","article-title":"State of the art in thermal insulation materials and aims for future developments","volume":"37","author":"Papadopoulos","year":"2005","journal-title":"Energy Build."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/j.rser.2018.12.040","article-title":"A review and evaluation of thermal insulation materials and methods for thermal energy storage systems","volume":"103","author":"Villasmil","year":"2019","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"19791","DOI":"10.1007\/s10853-021-06560-3","article-title":"Nanomaterials with high solar reflectance as an emerging path towards energy-efficient envelope systems: A review","volume":"56","author":"Veloso","year":"2021","journal-title":"J. Mater. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3085","DOI":"10.1016\/j.solener.2010.12.023","article-title":"Using advanced cool materials in the urban built environment to mitigate heat islands and improve thermal comfort conditions","volume":"85","author":"Santamouris","year":"2011","journal-title":"Sol. Energy"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"998","DOI":"10.1016\/j.matpr.2021.10.470","article-title":"Impact of light-colored paint materials on discomfort in a building for hot-dry climate","volume":"52","author":"Rawat","year":"2022","journal-title":"Mater. Today Proc."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"792","DOI":"10.1016\/j.renene.2020.07.109","article-title":"Recent development and research priorities on cool and super cool materials to mitigate urban heat island","volume":"161","author":"Santamouris","year":"2020","journal-title":"Renew. Energy"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"127826","DOI":"10.1016\/j.jclepro.2021.127826","article-title":"NIR reflective pigments for cool roof applications: A comprehensive review","volume":"313","author":"Rosati","year":"2021","journal-title":"J. Clean. Prod."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/S1352-2310(97)00182-9","article-title":"Practical issues for using solar-reflective materials to mitigate urban heat islands","volume":"32","author":"Bretz","year":"1998","journal-title":"Atmos. Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1016\/j.buildenv.2018.10.017","article-title":"Laboratorial investigation on optical and thermal properties of cool pavement nano-coatings for urban heat island mitigation","volume":"147","author":"Xie","year":"2019","journal-title":"Build. Environ."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Mourou, C., Zamorano, M., Ruiz, D.P., and Mart\u00edn-Morales, M. (2022). Cool Surface Strategies with an Emphasis on the Materials Dimension: A Review. Appl. Sci., 12.","DOI":"10.3390\/app12041893"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/j.enbuild.2013.03.051","article-title":"Optical properties across the solar spectrum and indoor thermal performance of cool white coatings for building energy efficiency","volume":"63","author":"Song","year":"2013","journal-title":"Energy Build."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1126\/science.aat9513","article-title":"Hierarchically porous polymer coatings for highly efficient passive daytime radiative cooling","volume":"362","author":"Mandal","year":"2018","journal-title":"Science"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Taha, H., Sailor, D., and Akbari, H. (1992). High-Albedo Materials for Reducing Building Cooling Energy Use.","DOI":"10.2172\/7000986"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1016\/j.solmat.2004.11.013","article-title":"Solar spectral optical properties of pigments\u2014Part II: Survey of common colorants","volume":"89","author":"Levinson","year":"2005","journal-title":"Sol. Energy Mater. Sol. Cells"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1016\/j.enbuild.2013.11.058","article-title":"Economic comparison of white, green, and black flat roofs in the United States","volume":"71","author":"Sproul","year":"2014","journal-title":"Energy Build."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"105590","DOI":"10.1016\/j.porgcoat.2020.105590","article-title":"Dispersion state of TiO2 pigment particles studied by ultra-small-angle X-ray scattering revealing dependence on dispersant but limited change during drying of paint coating","volume":"142","author":"Hamieau","year":"2020","journal-title":"Prog. Org. Coat."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1016\/j.dyepig.2014.04.028","article-title":"Solar spectral optical properties of rutile TiO2 coated mica-titania pigments","volume":"109","author":"Gao","year":"2014","journal-title":"Dyes Pigment."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/j.jallcom.2014.07.191","article-title":"Effect of titanium dioxide (TiO2) on largely improving solar reflectance and cooling property of high density polyethylene (HDPE) by influencing its crystallization behavior","volume":"617","author":"Wang","year":"2014","journal-title":"J. Alloys Compd."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"122833","DOI":"10.1016\/j.ijheatmasstransfer.2022.122833","article-title":"A novel model of mixed-particle coating for accurate performance quantifications at varying composition percentages","volume":"191","author":"Gao","year":"2022","journal-title":"Int. J. Heat Mass Transf."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"109523","DOI":"10.1016\/j.enbuild.2019.109523","article-title":"A black near-infrared reflective coating based on nano-technology","volume":"205","author":"You","year":"2019","journal-title":"Energy Build."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.solmat.2016.03.023","article-title":"Cool black roof impacts into the cooling and heating load demand of a residential building in various climates","volume":"152","author":"Baneshi","year":"2016","journal-title":"Sol. Energy Mater. Sol. Cells"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.solener.2021.06.061","article-title":"Experimental study of optical and cooling performances of CuO and TiO2 near-infrared reflective blending coatings","volume":"225","author":"You","year":"2021","journal-title":"Sol. Energy"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2373","DOI":"10.1021\/cr100449n","article-title":"Core\/Shell Nanoparticles: Classes, Properties, Synthesis Mechanisms, Characterization, and Applications","volume":"112","author":"Chaudhuri","year":"2012","journal-title":"Chem. Rev."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1071\/CH17626","article-title":"Synthesis, Characterization, and Optical Properties of Near-Infrared Reflecting Composite Inorganic Pigments Composed of TiO2\/CuO Core\u2013Shell Particles","volume":"71","author":"Yao","year":"2018","journal-title":"Aust. J. Chem."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1016\/j.enbuild.2014.05.008","article-title":"Thermal performance of reflective materials applied to exterior building components\u2014A review","volume":"80","author":"Arce","year":"2014","journal-title":"Energy Build."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"569","DOI":"10.1016\/j.enbuild.2017.09.085","article-title":"Experimental thermal evaluation of building roofs with conventional and reflective coatings","volume":"158","year":"2018","journal-title":"Energy Build."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"687","DOI":"10.1016\/j.cpc.2009.11.008","article-title":"Meep: A flexible free-software package for electromagnetic simulations by the FDTD method","volume":"181","author":"Oskooi","year":"2010","journal-title":"Comput. Phys. Commun."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"112296","DOI":"10.1016\/j.enbuild.2022.112296","article-title":"Oversight of radiative properties of coatings pigmented with TiO2 nanoparticles","volume":"271","author":"Dias","year":"2022","journal-title":"Energy Build."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"10070","DOI":"10.1038\/s41598-017-09413-9","article-title":"Customized binary and multi-level HfO2-x-based memristors tuned by oxidation conditions","volume":"7","author":"He","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2965","DOI":"10.1016\/j.jeurceramsoc.2017.03.020","article-title":"Synthesis and coloration of highly dispersed NiTiO3@TiO2 yellow pigments with core-shell structure","volume":"37","author":"He","year":"2017","journal-title":"J. Eur. Ceram. Soc."}],"container-title":["Buildings"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-5309\/13\/10\/2437\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:58:01Z","timestamp":1760129881000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-5309\/13\/10\/2437"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,9,25]]},"references-count":35,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2023,10]]}},"alternative-id":["buildings13102437"],"URL":"https:\/\/doi.org\/10.3390\/buildings13102437","relation":{},"ISSN":["2075-5309"],"issn-type":[{"value":"2075-5309","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,9,25]]}}}