{"id":{"repo_id":"buffalo","oai_identifier":"oai:ubir.buffalo.edu:10477/86847"},"canonical_url":"https://search.dev.ndltd.org/etd/buffalo/oai:ubir.buffalo.edu:10477/86847","repository":{"repo_id":"buffalo","name":"Buffalo","base_url":"https://ubir.buffalo.edu/oai/request"},"display":{"title":"Flame Aerosol Synthesis of Metal-containing Nanomaterials","abstract":"Ph.D.","abstract_html":"Ph.D.","abstract_has_math":false,"creators":["Mohammadi, Mohammadmoein; 0000-0003-3458-4190"],"institution":"State University of New York at Buffalo","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Swihart, Mark","Chemical and Biological Engineering"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-02-25T23:23:24Z","date_published":"2025-02-25T23:23:24Z","updated_at":"2026-07-27T19:05:37Z","subjects":["nanotechnology","materials science","chemical engineering"],"languages":["eng"],"rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10477/86847","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Swihart, Mark","Chemical and Biological Engineering"]},{"key":"dc:creator","label":"Author","values":["Mohammadi, Mohammadmoein; 0000-0003-3458-4190"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-02-25T23:23:24Z","2020","2020-08-09 00:38:38"]},{"key":"dc:publisher","label":"Institution","values":["State University of New York at Buffalo"]},{"key":"dc:type","label":"Dc Type","values":["Text","Dissertation"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["nanotechnology","materials science","chemical engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/10477/86847"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Ph.D.","This dissertation highlights the production and applications of metal-containing nanomaterials synthesized by an aerosol flame-driven process. Nanomaterials with controlled sizes, compositions, and morphologies were produced by a rapid, continuous flame-based process known as the high temperature reducing jet (HTRJ) reactor. In this process, metallic nanomaterials were produced from low-cost metal salt precursors using the hot combustion product gases of a hydrogen-rich flame. In this dissertation, we advanced the capabilities of this process by functionalizing metallic nanoparticles in situ using an organic molecule for direct dispersion as nanoparticle inks (nano-inks), or by embedding them in a carbonaceous or metal oxide matrix in one step. ‎Chapter 1 introduces aerosol processes, particle formation mechanisms, and methods for making nanomaterials. Flame processes are further discussed and the HTRJ process is described. In ‎Chapter 2, a novel technique for the synthesis of conductive metal nano-inks is introduced. Nickel-silver conductive nano-inks were produced using an in situ functionalization method. A liquid atomization apparatus was coupled with the HTRJ reactor to spray an organic molecule into the reactor effluent after the particle formation zone. Octylamine was atomized to cap nanoparticles as they form, which made the functionalized nanopowders dispersible in common organic solvents. Films fabricated from nano-inks were conductive without any post processing. Samples containing 50 wt % (65 at %) Ni provided an electrical conductivity of 5.14×104 S m-1 and 4.22×105 S m-1 without sintering and after thermal annealing in an inert environment, respectively. This technique can eliminate the need for thermal post-processing of printed conductive patterns while reducing the silver content of conductive inks. Thus, it can be used a promising alternative to current silver inks produced by multi-step, time-consuming solution-phase methods. In ‎Chapter 3, we introduce a general recipe for the synthesis of multicomponent metal-decorated crumpled reduced graphene oxide balls (M-CGBs). Binary and ternary M-CGB nanocomposites including CoNi-CGB, CoPd-CGB, CoNiFe-CGB and CoNiPd-CGB were produced. The HTRJ process enabled the decoration of CGB with sub-4 nm transition metal nanoparticles that cannot be synthesized easily by other methods. As a representative application of these nanomaterials, in ‎Chapter 4, we demonstrate the use of Pd-CGB nanocomposites for H2 detection in air at room temperature. Sensors made from Pd-CGB were sensitive to a wide range of H2 concentrations (0.01-2%) with relatively faster response and recovery compared to state of the art Pd-graphene-based sensors. Moreover, the HTRJ process provided single-step, continuous production of Pd-CGB nanocomposites which is advantageous relative to other Pd-graphene materials made by multi-step methods. In ‎‎Chapter 5, we present the synthesis of supported nickel-based nanocatalysts for the dry reforming of methane (DRM) reaction. For the initial screening, nickel catalysts with various supports were produced by the HTRJ process. The most active one, magnesia-supported nickel nanocatalyst (NiMgO-F), was further studied. The NiMgO-F catalyst showed higher activity, especially at low temperature, compared with those prepared by conventional methods such as wet-impregnation and co-precipitation. It remained active throughout a 50 h stability test. Although addition of various promoters and co-catalysts did not improve the activity of NiMgO-F catalyst, this study showed the capability of the HTRJ process to produce multicomponent nanocatalysts for the DRM reaction and any other catalytic reaction. A summary and suggestions for future work in the flame-based synthesis of nanomaterials are presented in ‎Chapter 6.","**To request an accessible version of the file(s) associated with this item, contact library@buffalo.edu. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.**"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Flame Aerosol Synthesis of Metal-containing Nanomaterials"]}]}],"canonical_facts":{"dc:contributor":["Swihart, Mark","Chemical and Biological Engineering"],"dc:creator":["Mohammadi, Mohammadmoein; 0000-0003-3458-4190"],"dc:date":["2025-02-25T23:23:24Z","2020","2020-08-09 00:38:38"],"dc:description":["Ph.D.","This dissertation highlights the production and applications of metal-containing nanomaterials synthesized by an aerosol flame-driven process. Nanomaterials with controlled sizes, compositions, and morphologies were produced by a rapid, continuous flame-based process known as the high temperature reducing jet (HTRJ) reactor. In this process, metallic nanomaterials were produced from low-cost metal salt precursors using the hot combustion product gases of a hydrogen-rich flame. In this dissertation, we advanced the capabilities of this process by functionalizing metallic nanoparticles in situ using an organic molecule for direct dispersion as nanoparticle inks (nano-inks), or by embedding them in a carbonaceous or metal oxide matrix in one step. ‎Chapter 1 introduces aerosol processes, particle formation mechanisms, and methods for making nanomaterials. Flame processes are further discussed and the HTRJ process is described. In ‎Chapter 2, a novel technique for the synthesis of conductive metal nano-inks is introduced. Nickel-silver conductive nano-inks were produced using an in situ functionalization method. A liquid atomization apparatus was coupled with the HTRJ reactor to spray an organic molecule into the reactor effluent after the particle formation zone. Octylamine was atomized to cap nanoparticles as they form, which made the functionalized nanopowders dispersible in common organic solvents. Films fabricated from nano-inks were conductive without any post processing. Samples containing 50 wt % (65 at %) Ni provided an electrical conductivity of 5.14×104 S m-1 and 4.22×105 S m-1 without sintering and after thermal annealing in an inert environment, respectively. This technique can eliminate the need for thermal post-processing of printed conductive patterns while reducing the silver content of conductive inks. Thus, it can be used a promising alternative to current silver inks produced by multi-step, time-consuming solution-phase methods. In ‎Chapter 3, we introduce a general recipe for the synthesis of multicomponent metal-decorated crumpled reduced graphene oxide balls (M-CGBs). Binary and ternary M-CGB nanocomposites including CoNi-CGB, CoPd-CGB, CoNiFe-CGB and CoNiPd-CGB were produced. The HTRJ process enabled the decoration of CGB with sub-4 nm transition metal nanoparticles that cannot be synthesized easily by other methods. As a representative application of these nanomaterials, in ‎Chapter 4, we demonstrate the use of Pd-CGB nanocomposites for H2 detection in air at room temperature. Sensors made from Pd-CGB were sensitive to a wide range of H2 concentrations (0.01-2%) with relatively faster response and recovery compared to state of the art Pd-graphene-based sensors. Moreover, the HTRJ process provided single-step, continuous production of Pd-CGB nanocomposites which is advantageous relative to other Pd-graphene materials made by multi-step methods. In ‎‎Chapter 5, we present the synthesis of supported nickel-based nanocatalysts for the dry reforming of methane (DRM) reaction. For the initial screening, nickel catalysts with various supports were produced by the HTRJ process. The most active one, magnesia-supported nickel nanocatalyst (NiMgO-F), was further studied. The NiMgO-F catalyst showed higher activity, especially at low temperature, compared with those prepared by conventional methods such as wet-impregnation and co-precipitation. It remained active throughout a 50 h stability test. Although addition of various promoters and co-catalysts did not improve the activity of NiMgO-F catalyst, this study showed the capability of the HTRJ process to produce multicomponent nanocatalysts for the DRM reaction and any other catalytic reaction. A summary and suggestions for future work in the flame-based synthesis of nanomaterials are presented in ‎Chapter 6.","**To request an accessible version of the file(s) associated with this item, contact library@buffalo.edu. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.**"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/10477/86847"],"dc:language":["eng"],"dc:publisher":["State University of New York at Buffalo"],"dc:rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"dc:subject":["nanotechnology","materials science","chemical engineering"],"dc:title":["Flame Aerosol Synthesis of Metal-containing Nanomaterials"],"dc:type":["Text","Dissertation"]},"updated_at":"2026-07-27T19:05:37Z"}