{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/111315"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/111315","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Generation of Titanium Dioxide Parts using Cellulose Nanocrystal Aerogel Hard Templates","abstract":"This project studies the generation of crystalline mesoporous structured titanium dioxide (TiO2) using cellulose nanocrystal (CNC) aerogel hard templates for photocatalytic and biomaterial applications. Suspensions of CNCs in water varying in solid loading from 20 mg/mL to 100 mg/mL were prepared and frozen at three different temperatures (-20 °C, -40 °C, or -80 °C) using four combinations of hollow cylindrical molds and mold plates with different thermal conductivities (stainless-steel or glass) placed on different heat conductive and insulative substrates (aluminum, polystyrene foam and cardboard). Frozen samples were then freeze dried to sublimate the ice and render a multiscale and mesoporous structure with a variety of microstructural features, including lamellar sheeting, flakes, ribbons, or striations. Ceramic green bodies are then produced by reacting Titanium isopropoxide with water through several different processes to generate amorphous TiO2 either in-situ in the CNC aerogel or as a suspension for infiltration under varying pressure. Green bodies are dried at room temperature, and the extent of ceramic coating of the template is visually determined using SEM imaging. Once dried, crystalline TiO2 are produced through a two-step heat treatment with a CNC burnout at 270 °C and crystallization and sintering at 500 °C, 600 °C, or 1000 °C. The final crystallinity and phase composition is examined using XRD, and the final porosity is determined using BET. Results have shown the ability to satisfactorily coat aerogels under 10 mm in one dimension with TiO2. These samples have been successfully heat-treated to produce both anatase and rutile phase TiO2 while maintaining the macrostructure of the CNC aerogel. Multiscale porosity has been achieved, and samples heat treated at 1000 °C have achieved structural integrity.","abstract_html":"This project studies the generation of crystalline mesoporous structured titanium dioxide (TiO2) using cellulose nanocrystal (CNC) aerogel hard templates for photocatalytic and biomaterial applications. Suspensions of CNCs in water varying in solid loading from 20 mg/mL to 100 mg/mL were prepared and frozen at three different temperatures (-20 °C, -40 °C, or -80 °C) using four combinations of hollow cylindrical molds and mold plates with different thermal conductivities (stainless-steel or glass) placed on different heat conductive and insulative substrates (aluminum, polystyrene foam and cardboard). Frozen samples were then freeze dried to sublimate the ice and render a multiscale and mesoporous structure with a variety of microstructural features, including lamellar sheeting, flakes, ribbons, or striations. Ceramic green bodies are then produced by reacting Titanium isopropoxide with water through several different processes to generate amorphous TiO2 either in-situ in the CNC aerogel or as a suspension for infiltration under varying pressure. Green bodies are dried at room temperature, and the extent of ceramic coating of the template is visually determined using SEM imaging. Once dried, crystalline TiO2 are produced through a two-step heat treatment with a CNC burnout at 270 °C and crystallization and sintering at 500 °C, 600 °C, or 1000 °C. The final crystallinity and phase composition is examined using XRD, and the final porosity is determined using BET. Results have shown the ability to satisfactorily coat aerogels under 10 mm in one dimension with TiO2. These samples have been successfully heat-treated to produce both anatase and rutile phase TiO2 while maintaining the macrostructure of the CNC aerogel. Multiscale porosity has been achieved, and samples heat treated at 1000 °C have achieved structural integrity.","abstract_has_math":false,"creators":["Custer, Faulkner Paine"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Materials Science and Engineering","degree_department":"Materials Science and Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Tallon Galdeano, Carolina","Foster, Earl Johan"],"committee_members":["Morris, Amanda"],"year":2021,"date_issued":"2021-01-27","date_published":"2021-01-27","updated_at":"2026-07-22T22:18:39Z","subjects":["Cellulose Nanocrystals","Titania","Porous Ceramics"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:28641"],"render_values":[{"text":"vt_gsexam:28641","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/111315","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Tallon Galdeano, Carolina","Foster, Earl Johan"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Morris, Amanda"]},{"key":"dc:contributor.department","label":"Department","values":["Materials Science and Engineering"]},{"key":"dc:creator","label":"Author","values":["Custer, Faulkner Paine"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2022-07-22T06:00:07Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-07-22T06:00:07Z"]},{"key":"dc:date.issued","label":"Date","values":["2021-01-27"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science and Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Cellulose Nanocrystals","Titania","Porous Ceramics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:28641"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/111315"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This project studies the generation of crystalline mesoporous structured titanium dioxide (TiO2) using cellulose nanocrystal (CNC) aerogel hard templates for photocatalytic and biomaterial applications. Suspensions of CNCs in water varying in solid loading from 20 mg/mL to 100 mg/mL were prepared and frozen at three different temperatures (-20 °C, -40 °C, or -80 °C) using four combinations of hollow cylindrical molds and mold plates with different thermal conductivities (stainless-steel or glass) placed on different heat conductive and insulative substrates (aluminum, polystyrene foam and cardboard). Frozen samples were then freeze dried to sublimate the ice and render a multiscale and mesoporous structure with a variety of microstructural features, including lamellar sheeting, flakes, ribbons, or striations. Ceramic green bodies are then produced by reacting Titanium isopropoxide with water through several different processes to generate amorphous TiO2 either in-situ in the CNC aerogel or as a suspension for infiltration under varying pressure. Green bodies are dried at room temperature, and the extent of ceramic coating of the template is visually determined using SEM imaging. Once dried, crystalline TiO2 are produced through a two-step heat treatment with a CNC burnout at 270 °C and crystallization and sintering at 500 °C, 600 °C, or 1000 °C. The final crystallinity and phase composition is examined using XRD, and the final porosity is determined using BET. Results have shown the ability to satisfactorily coat aerogels under 10 mm in one dimension with TiO2. These samples have been successfully heat-treated to produce both anatase and rutile phase TiO2 while maintaining the macrostructure of the CNC aerogel. Multiscale porosity has been achieved, and samples heat treated at 1000 °C have achieved structural integrity."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Titanium Dioxide (TiO2) is a common material in today's world used in a range of applications including pigments, sunscreens, and thin films. It is a chemically and physically stable material, making it ideal for some biomedical applications including bone and cell growth scaffolds. TiO2 is also photocatalytic and has been used in photovoltaic cells and water decontamination systems to take advantage of this property. While TiO2 has been effectively implemented in these applications, the multiscale, controllable porous structure required for these applications has proven complicated to generate. To help improve this process, cellulose nanocrystal (CNC) aerogels were investigated as tunable hard templates for porous TiO2. Controlled ice templating through alteration of the freezing conditions followed by freeze drying provided a reliable method for the production CNC aerogels with repeatable micro and macrostructures. Testing multiple methods for coating the template in TiO2 led to the successful replication of the template in a ceramic part. The final TiO2 exhibited multiscale porosity with micro and macrostructures matching those of the CNC aerogel template. These parts can be tailored to fit a desired application by controlling the structure of the aerogel."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Generation of Titanium Dioxide Parts using Cellulose Nanocrystal Aerogel Hard Templates"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Tallon Galdeano, Carolina","Foster, Earl Johan"],"dc:contributor.committeemember":["Morris, Amanda"],"dc:contributor.department":["Materials Science and Engineering"],"dc:creator":["Custer, Faulkner Paine"],"dc:date.accessioned":["2022-07-22T06:00:07Z"],"dc:date.available":["2022-07-22T06:00:07Z"],"dc:date.issued":["2021-01-27"],"dc:description.abstract":["This project studies the generation of crystalline mesoporous structured titanium dioxide (TiO2) using cellulose nanocrystal (CNC) aerogel hard templates for photocatalytic and biomaterial applications. Suspensions of CNCs in water varying in solid loading from 20 mg/mL to 100 mg/mL were prepared and frozen at three different temperatures (-20 °C, -40 °C, or -80 °C) using four combinations of hollow cylindrical molds and mold plates with different thermal conductivities (stainless-steel or glass) placed on different heat conductive and insulative substrates (aluminum, polystyrene foam and cardboard). Frozen samples were then freeze dried to sublimate the ice and render a multiscale and mesoporous structure with a variety of microstructural features, including lamellar sheeting, flakes, ribbons, or striations. Ceramic green bodies are then produced by reacting Titanium isopropoxide with water through several different processes to generate amorphous TiO2 either in-situ in the CNC aerogel or as a suspension for infiltration under varying pressure. Green bodies are dried at room temperature, and the extent of ceramic coating of the template is visually determined using SEM imaging. Once dried, crystalline TiO2 are produced through a two-step heat treatment with a CNC burnout at 270 °C and crystallization and sintering at 500 °C, 600 °C, or 1000 °C. The final crystallinity and phase composition is examined using XRD, and the final porosity is determined using BET. Results have shown the ability to satisfactorily coat aerogels under 10 mm in one dimension with TiO2. These samples have been successfully heat-treated to produce both anatase and rutile phase TiO2 while maintaining the macrostructure of the CNC aerogel. Multiscale porosity has been achieved, and samples heat treated at 1000 °C have achieved structural integrity."],"dc:description.abstractgeneral":["Titanium Dioxide (TiO2) is a common material in today's world used in a range of applications including pigments, sunscreens, and thin films. It is a chemically and physically stable material, making it ideal for some biomedical applications including bone and cell growth scaffolds. TiO2 is also photocatalytic and has been used in photovoltaic cells and water decontamination systems to take advantage of this property. While TiO2 has been effectively implemented in these applications, the multiscale, controllable porous structure required for these applications has proven complicated to generate. To help improve this process, cellulose nanocrystal (CNC) aerogels were investigated as tunable hard templates for porous TiO2. Controlled ice templating through alteration of the freezing conditions followed by freeze drying provided a reliable method for the production CNC aerogels with repeatable micro and macrostructures. Testing multiple methods for coating the template in TiO2 led to the successful replication of the template in a ceramic part. The final TiO2 exhibited multiscale porosity with micro and macrostructures matching those of the CNC aerogel template. These parts can be tailored to fit a desired application by controlling the structure of the aerogel."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:28641"],"dc:identifier.uri":["http://hdl.handle.net/10919/111315"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Cellulose Nanocrystals","Titania","Porous Ceramics"],"dc:title":["Generation of Titanium Dioxide Parts using Cellulose Nanocrystal Aerogel Hard Templates"],"dc:type":["Thesis"],"thesis:degree_discipline":["Materials Science and Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:18:39Z"}