{"id":{"repo_id":"must-thes","oai_identifier":"oai:scholarsmine.mst.edu:doctoral_dissertations-3818"},"canonical_url":"https://search.dev.ndltd.org/etd/must-thes/oai:scholarsmine.mst.edu:doctoral_dissertations-3818","repository":{"repo_id":"must-thes","name":"Missouri University of Science and Technology","base_url":"https://scholarsmine.mst.edu/do/oai/"},"display":{"title":"Polyurea aerogels: From nanoscopic to macroscopic properties","abstract":"\"The morphology of a material is intrinsically a qualitative property and in order to relate nanomorphology to synthetic conditions, it is necessary to express nano/micro-structure quantitatively. In this context, polyurea aerogels were chosen as a model system with demonstrated potential for rich nanomorphology and being guided by a statistical Design-of-Experiments model, a large array of materials (208) with identical chemical composition, but quite different nanostructures were prepared. By reflecting upon the SEM images, it was realized that our first pre-verbal impression about a nanostructure is related to its openness and texture; the former is quantified by porosity (Π), and the latter is related to the contact angle (θ) of water droplets resting on the material. Herewith, the θ/Π ratio is referred to as the K-index, and it was noticed that all polyurea aerogel samples could be put in eight K-index groups with separate nanomorphologies. The K-index was validated as a morphology predictor by compressing samples to different strains: as porosity decreases, contact angle decreases proportionally, and the K-index remains constant. The predictive power of the K-index was demonstrated with new PUAs prepared in eight binary solvents. Finally, using response surface methodology, K-indexes and other material properties of interest were correlated to synthetic conditions, thus enabling synthesis of materials with prescribed properties at a time. The second part of this dissertation focuses on polyurea aerogels consisting of different arrangements of nanoparticles (1.2 ≤ K-index ≤ 1.5). SAXS, XRD and SEM have demonstrated that these nanostructures consist of similar-size primary particles. A model for the formation of these nanoparticles through Molecular Dynamic simulations is suggested\"--Abstract, page iv.","abstract_html":""The morphology of a material is intrinsically a qualitative property and in order to relate nanomorphology to synthetic conditions, it is necessary to express nano/micro-structure quantitatively. In this context, polyurea aerogels were chosen as a model system with demonstrated potential for rich nanomorphology and being guided by a statistical Design-of-Experiments model, a large array of materials (208) with identical chemical composition, but quite different nanostructures were prepared. By reflecting upon the SEM images, it was realized that our first pre-verbal impression about a nanostructure is related to its openness and texture; the former is quantified by porosity (Π), and the latter is related to the contact angle (θ) of water droplets resting on the material. Herewith, the θ/Π ratio is referred to as the K-index, and it was noticed that all polyurea aerogel samples could be put in eight K-index groups with separate nanomorphologies. The K-index was validated as a morphology predictor by compressing samples to different strains: as porosity decreases, contact angle decreases proportionally, and the K-index remains constant. The predictive power of the K-index was demonstrated with new PUAs prepared in eight binary solvents. Finally, using response surface methodology, K-indexes and other material properties of interest were correlated to synthetic conditions, thus enabling synthesis of materials with prescribed properties at a time. The second part of this dissertation focuses on polyurea aerogels consisting of different arrangements of nanoparticles (1.2 ≤ K-index ≤ 1.5). SAXS, XRD and SEM have demonstrated that these nanostructures consist of similar-size primary particles. A model for the formation of these nanoparticles through Molecular Dynamic simulations is suggested"--Abstract, page iv.","abstract_has_math":false,"creators":["Taghvaee, Tahereh"],"institution":"Missouri University of Science and Technology","degree_name":"Ph. D. in Chemistry","degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":null,"date_issued":"","date_published":null,"updated_at":"2026-07-24T03:18:34Z","subjects":["Aerogels","Contact angle","K-index","Morphology","Polyurea","SEM","Chemistry","Materials Science and Engineering","Polymer Chemistry"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsmine.mst.edu/doctoral_dissertations/2813","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Taghvaee, Tahereh"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:type","label":"Dc Type","values":["Dissertation - Open Access"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. 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In this context, polyurea aerogels were chosen as a model system with demonstrated potential for rich nanomorphology and being guided by a statistical Design-of-Experiments model, a large array of materials (208) with identical chemical composition, but quite different nanostructures were prepared. By reflecting upon the SEM images, it was realized that our first pre-verbal impression about a nanostructure is related to its openness and texture; the former is quantified by porosity (Π), and the latter is related to the contact angle (θ) of water droplets resting on the material. Herewith, the θ/Π ratio is referred to as the K-index, and it was noticed that all polyurea aerogel samples could be put in eight K-index groups with separate nanomorphologies. The K-index was validated as a morphology predictor by compressing samples to different strains: as porosity decreases, contact angle decreases proportionally, and the K-index remains constant. The predictive power of the K-index was demonstrated with new PUAs prepared in eight binary solvents. Finally, using response surface methodology, K-indexes and other material properties of interest were correlated to synthetic conditions, thus enabling synthesis of materials with prescribed properties at a time. The second part of this dissertation focuses on polyurea aerogels consisting of different arrangements of nanoparticles (1.2 ≤ K-index ≤ 1.5). SAXS, XRD and SEM have demonstrated that these nanostructures consist of similar-size primary particles. A model for the formation of these nanoparticles through Molecular Dynamic simulations is suggested\"--Abstract, page iv."]},{"key":"dc:title","label":"Title","values":["Polyurea aerogels: From nanoscopic to macroscopic properties"]}]}],"canonical_facts":{"dc:creator":["Taghvaee, Tahereh"],"dc:description.abstract":["\"The morphology of a material is intrinsically a qualitative property and in order to relate nanomorphology to synthetic conditions, it is necessary to express nano/micro-structure quantitatively. In this context, polyurea aerogels were chosen as a model system with demonstrated potential for rich nanomorphology and being guided by a statistical Design-of-Experiments model, a large array of materials (208) with identical chemical composition, but quite different nanostructures were prepared. By reflecting upon the SEM images, it was realized that our first pre-verbal impression about a nanostructure is related to its openness and texture; the former is quantified by porosity (Π), and the latter is related to the contact angle (θ) of water droplets resting on the material. Herewith, the θ/Π ratio is referred to as the K-index, and it was noticed that all polyurea aerogel samples could be put in eight K-index groups with separate nanomorphologies. The K-index was validated as a morphology predictor by compressing samples to different strains: as porosity decreases, contact angle decreases proportionally, and the K-index remains constant. The predictive power of the K-index was demonstrated with new PUAs prepared in eight binary solvents. Finally, using response surface methodology, K-indexes and other material properties of interest were correlated to synthetic conditions, thus enabling synthesis of materials with prescribed properties at a time. The second part of this dissertation focuses on polyurea aerogels consisting of different arrangements of nanoparticles (1.2 ≤ K-index ≤ 1.5). SAXS, XRD and SEM have demonstrated that these nanostructures consist of similar-size primary particles. A model for the formation of these nanoparticles through Molecular Dynamic simulations is suggested\"--Abstract, page iv."],"dc:identifier":["https://scholarsmine.mst.edu/doctoral_dissertations/2813"],"dc:subject":["Aerogels","Contact angle","K-index","Morphology","Polyurea","SEM","Chemistry","Materials Science and Engineering","Polymer Chemistry"],"dc:title":["Polyurea aerogels: From nanoscopic to macroscopic properties"],"dc:type":["Dissertation - Open Access"],"thesis:degree_name":["Ph. D. in Chemistry"],"thesis:institution_name":["Missouri University of Science and Technology"]},"updated_at":"2026-07-24T03:18:34Z"}