{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/70392"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/70392","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Polysilicic Acid Esters as Precursors to New Ceramic Materials","abstract":"Two simple siloxane ester chains, (Si$\\sb2$O) (OCH$\\sb3$)$\\sb6$ and (Si$\\sb3$O$\\sb2$) (OCH$\\sb3$)$\\sb8$, and a polysilicic acid ester based on the cubic (Si$\\sb8$O$\\sb $) core, (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$ were prepared. Synthesis of the di- and trisiloxane esters was achieved by reaction of their commercially available chlorosiloxane precursors with either CH$\\sb3$ONO or HC(OCH$\\sb3$)$\\sb3$. Similar reactions of (Si$\\sb8$O$\\sb $) Cl$\\sb8$, prepared by photochlorination of (Si$\\sb8$O$\\sb $) H$\\sb8$, with CH$\\sb3$ONO or HC(OCH$\\sb3$)$\\sb3$ produce (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$. $\\sp{29}$Si NMR spectroscopy was used to confirm the structure of each ester, and in the case of (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$, the structure was determined by single-crystal X-ray analysis.","abstract_html":"Two simple siloxane ester chains, (Si$\\sb2$O) (OCH$\\sb3$)$\\sb6$ and (Si$\\sb3$O$\\sb2$) (OCH$\\sb3$)$\\sb8$, and a polysilicic acid ester based on the cubic (Si$\\sb8$O$\\sb $) core, (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$ were prepared. Synthesis of the di- and trisiloxane esters was achieved by reaction of their commercially available chlorosiloxane precursors with either CH$\\sb3$ONO or HC(OCH$\\sb3$)$\\sb3$. Similar reactions of (Si$\\sb8$O$\\sb $) Cl$\\sb8$, prepared by photochlorination of (Si$\\sb8$O$\\sb $) H$\\sb8$, with CH$\\sb3$ONO or HC(OCH$\\sb3$)$\\sb3$ produce (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$. $\\sp{29}$Si NMR spectroscopy was used to confirm the structure of each ester, and in the case of (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$, the structure was determined by single-crystal X-ray analysis.","abstract_has_math":true,"creators":["Millar, Dean Michael"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Klemperer, Walter G."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-15T23:19:08Z","date_published":"2014-12-15T23:19:08Z","updated_at":"2026-07-22T22:26:02Z","subjects":["Chemistry, Inorganic","Engineering, Materials Science"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8803141"],"render_values":[{"text":"(UMI)AAI8803141","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/70392","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Klemperer, Walter G."]},{"key":"dc:creator","label":"Author","values":["Millar, Dean Michael"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-15T23:19:08Z","10000-01-01","1987"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Chemistry, Inorganic","Engineering, Materials Science"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/70392","(UMI)AAI8803141"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Two simple siloxane ester chains, (Si$\\sb2$O) (OCH$\\sb3$)$\\sb6$ and (Si$\\sb3$O$\\sb2$) (OCH$\\sb3$)$\\sb8$, and a polysilicic acid ester based on the cubic (Si$\\sb8$O$\\sb $) core, (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$ were prepared. Synthesis of the di- and trisiloxane esters was achieved by reaction of their commercially available chlorosiloxane precursors with either CH$\\sb3$ONO or HC(OCH$\\sb3$)$\\sb3$. Similar reactions of (Si$\\sb8$O$\\sb $) Cl$\\sb8$, prepared by photochlorination of (Si$\\sb8$O$\\sb $) H$\\sb8$, with CH$\\sb3$ONO or HC(OCH$\\sb3$)$\\sb3$ produce (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$. $\\sp{29}$Si NMR spectroscopy was used to confirm the structure of each ester, and in the case of (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$, the structure was determined by single-crystal X-ray analysis.","The behavior of these silicic acid esters towards polymerization by hydrolysis-condensation was investigated by $\\sp{29}$Si NMR spectroscopy. Spectra obtained demonstrated that for (Si$\\sb2$O) (OCH$\\sb3$)$\\sb6$ and (Si$\\sb3$O$\\sb2$) (OCH$\\sb3$)$\\sb8$, monomer degradation had occurred, although at low rates. Similar experiments following the behavior of (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb3$ showed that these reactions appeared to proceed without cage degradation.","Solid-state NMR techniques were used to follow the later stages of gelation and drying. $\\sp{29}$Si FTMAS and CPMAS NMR experiments showed that gels prepared from Si(OCH$\\sb3$)$\\sb4$, (Si$\\sb2$O) (OCH$\\sb3$)$\\sb6$, and (Si$\\sb3$O$\\sb2$) (OCH$\\sb3$)$\\sb8$ exhibited similar distributions of Q$\\sp2$, Q$\\sp3$, and Q$\\sp4$ sites. The observance of Q silicon centers demonstrated that degradation of the (Si$\\sb8$O$\\sb $) cage had occurred. Further distinctions between the gels were made based on spin-lattice relaxation (T$\\sb1$) values for the Q$\\sb4$ silicons.","A series of (Si$\\sb8$O$\\sb $) -based molecules bearing a single reactive site were synthesized in order to study the condensation behavior of the Q$\\sp3$- (Si$\\sb8$O$\\sb $) centers. (Si$\\sb8$O$\\sb $) (OSi(CH$\\sb3$)$\\sb3$) $\\sb7$H was prepared from (Si$\\sb8$O$\\sb $) H$\\sb8$ by reaction with (CH$\\sb3$)$\\sb3$NO and excess (CH$\\sb3$)$\\sb3$SiCl. Reaction of this monosilane with (CH$\\sb3$)$\\sb3$SnOCH$\\sb3$ produced (Si$\\sb8$O$\\sb $) (OSi(CH$\\sb3$)$\\sb3$) $\\sb7$OSn(CH$\\sb3$)$\\sb3$ with essentially quantitative conversion. Hydrolysis of the stannoxy adduct with HCl yielded the stable, crystalline monosilicic acid (Si$\\sb8$O$\\sb $) OSi(CH$\\sb3$)$\\sb3$) $\\sb7$OH. Silicic acid self-condensation was found to be catalyzed by bases but not by acids. No evidence of cage degraded products were observed. The monosilicic acid was found to readily react with (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$ to yield the mixed dimer ((CH$\\sb3$)$\\sb3$SiO) $\\sb7$ (Si$\\sb8$O$\\sb $) O (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb7$. All monomeric and dimeric products were fully characterized by MS and NMR techniques.","Made available in DSpace on 2014-12-15T23:19:08Z (GMT). No. of bitstreams: 1 8803141.pdf: 4582101 bytes, checksum: f7de76c726c1c4e091008f66f787b3c8 (MD5) Previous issue date: 1987","Embargo set by: Seth Robbins for item 70558 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","162 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1987."]},{"key":"dc:title","label":"Title","values":["Polysilicic Acid Esters as Precursors to New Ceramic Materials"]}]}],"canonical_facts":{"dc:contributor":["Klemperer, Walter G."],"dc:creator":["Millar, Dean Michael"],"dc:date":["2014-12-15T23:19:08Z","10000-01-01","1987"],"dc:description":["Two simple siloxane ester chains, (Si$\\sb2$O) (OCH$\\sb3$)$\\sb6$ and (Si$\\sb3$O$\\sb2$) (OCH$\\sb3$)$\\sb8$, and a polysilicic acid ester based on the cubic (Si$\\sb8$O$\\sb $) core, (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$ were prepared. Synthesis of the di- and trisiloxane esters was achieved by reaction of their commercially available chlorosiloxane precursors with either CH$\\sb3$ONO or HC(OCH$\\sb3$)$\\sb3$. Similar reactions of (Si$\\sb8$O$\\sb $) Cl$\\sb8$, prepared by photochlorination of (Si$\\sb8$O$\\sb $) H$\\sb8$, with CH$\\sb3$ONO or HC(OCH$\\sb3$)$\\sb3$ produce (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$. $\\sp{29}$Si NMR spectroscopy was used to confirm the structure of each ester, and in the case of (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$, the structure was determined by single-crystal X-ray analysis.","The behavior of these silicic acid esters towards polymerization by hydrolysis-condensation was investigated by $\\sp{29}$Si NMR spectroscopy. Spectra obtained demonstrated that for (Si$\\sb2$O) (OCH$\\sb3$)$\\sb6$ and (Si$\\sb3$O$\\sb2$) (OCH$\\sb3$)$\\sb8$, monomer degradation had occurred, although at low rates. Similar experiments following the behavior of (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb3$ showed that these reactions appeared to proceed without cage degradation.","Solid-state NMR techniques were used to follow the later stages of gelation and drying. $\\sp{29}$Si FTMAS and CPMAS NMR experiments showed that gels prepared from Si(OCH$\\sb3$)$\\sb4$, (Si$\\sb2$O) (OCH$\\sb3$)$\\sb6$, and (Si$\\sb3$O$\\sb2$) (OCH$\\sb3$)$\\sb8$ exhibited similar distributions of Q$\\sp2$, Q$\\sp3$, and Q$\\sp4$ sites. The observance of Q silicon centers demonstrated that degradation of the (Si$\\sb8$O$\\sb $) cage had occurred. Further distinctions between the gels were made based on spin-lattice relaxation (T$\\sb1$) values for the Q$\\sb4$ silicons.","A series of (Si$\\sb8$O$\\sb $) -based molecules bearing a single reactive site were synthesized in order to study the condensation behavior of the Q$\\sp3$- (Si$\\sb8$O$\\sb $) centers. (Si$\\sb8$O$\\sb $) (OSi(CH$\\sb3$)$\\sb3$) $\\sb7$H was prepared from (Si$\\sb8$O$\\sb $) H$\\sb8$ by reaction with (CH$\\sb3$)$\\sb3$NO and excess (CH$\\sb3$)$\\sb3$SiCl. Reaction of this monosilane with (CH$\\sb3$)$\\sb3$SnOCH$\\sb3$ produced (Si$\\sb8$O$\\sb $) (OSi(CH$\\sb3$)$\\sb3$) $\\sb7$OSn(CH$\\sb3$)$\\sb3$ with essentially quantitative conversion. Hydrolysis of the stannoxy adduct with HCl yielded the stable, crystalline monosilicic acid (Si$\\sb8$O$\\sb $) OSi(CH$\\sb3$)$\\sb3$) $\\sb7$OH. Silicic acid self-condensation was found to be catalyzed by bases but not by acids. No evidence of cage degraded products were observed. The monosilicic acid was found to readily react with (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb8$ to yield the mixed dimer ((CH$\\sb3$)$\\sb3$SiO) $\\sb7$ (Si$\\sb8$O$\\sb $) O (Si$\\sb8$O$\\sb $) (OCH$\\sb3$)$\\sb7$. All monomeric and dimeric products were fully characterized by MS and NMR techniques.","Made available in DSpace on 2014-12-15T23:19:08Z (GMT). No. of bitstreams: 1 8803141.pdf: 4582101 bytes, checksum: f7de76c726c1c4e091008f66f787b3c8 (MD5) Previous issue date: 1987","Embargo set by: Seth Robbins for item 70558 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","162 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1987."],"dc:identifier":["http://hdl.handle.net/2142/70392","(UMI)AAI8803141"],"dc:subject":["Chemistry, Inorganic","Engineering, Materials Science"],"dc:title":["Polysilicic Acid Esters as Precursors to New Ceramic Materials"],"dc:type":["text"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:02Z"}