{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/84394"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/84394","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Structural Characterization of Sulfur-Based Monomolecular Thin Films: I. Langmuir-Blodgett Films Derived From Multisulfur Heterocycles. II. Second Harmonic Generation Studies of Alkanethiolates on Ag and Au","abstract":"Optical second-harmonic generation (SHG) has been used as a very sensitive surface probe to study metal-electrolyte interfaces at potentials within the double layer charging region. In this work, the potential dependence of second harmonic (SH) signal from metal/thin film/electrolyte systems have been studied. Self-assembled monolayers (SAMs) of alkanethiolates have been prepared on Ag and Au surfaces, both SHG and AC impedance measurements of the Ag-alkanethiolate-electrolyte systems have been performed for alkanethiols with different chain lengths. The capacitance of the alkanethiolate SAMs is found inversely proportional to the chain length of the alkanethiol. For both Au and Ag electrodes, the SH signal is found less sensitive to the potential change after alkane-thiolate monolayer formation. The coverage dependent SH signal intensity from Au-alkanethiolate-electrolyte systems has been measured. Ozonolysis is used to obtain partially covered hexadecanethiolate (HDT) monolayers on Au surfaces, with the coverage being controlled by the ozone exposure time and monitored by surface plasmon resonance (SPR) technique. A linear relationship between the film coverage and SH intensity has been observed.","abstract_html":"Optical second-harmonic generation (SHG) has been used as a very sensitive surface probe to study metal-electrolyte interfaces at potentials within the double layer charging region. In this work, the potential dependence of second harmonic (SH) signal from metal/thin film/electrolyte systems have been studied. Self-assembled monolayers (SAMs) of alkanethiolates have been prepared on Ag and Au surfaces, both SHG and AC impedance measurements of the Ag-alkanethiolate-electrolyte systems have been performed for alkanethiols with different chain lengths. The capacitance of the alkanethiolate SAMs is found inversely proportional to the chain length of the alkanethiol. For both Au and Ag electrodes, the SH signal is found less sensitive to the potential change after alkane-thiolate monolayer formation. The coverage dependent SH signal intensity from Au-alkanethiolate-electrolyte systems has been measured. Ozonolysis is used to obtain partially covered hexadecanethiolate (HDT) monolayers on Au surfaces, with the coverage being controlled by the ozone exposure time and monitored by surface plasmon resonance (SPR) technique. A linear relationship between the film coverage and SH intensity has been observed.","abstract_has_math":false,"creators":["Zhang, Yang"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Bohn, Paul W."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T22:14:16Z","date_published":"2015-09-25T22:14:16Z","updated_at":"2026-07-22T22:26:23Z","subjects":["Engineering, Materials Science"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI9812821"],"render_values":[{"text":"(MiAaPQ)AAI9812821","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/84394","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Bohn, Paul W."]},{"key":"dc:creator","label":"Author","values":["Zhang, Yang"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T22:14:16Z","10000-01-01","1997"]},{"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":["Engineering, Materials Science"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/84394","(MiAaPQ)AAI9812821"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Optical second-harmonic generation (SHG) has been used as a very sensitive surface probe to study metal-electrolyte interfaces at potentials within the double layer charging region. In this work, the potential dependence of second harmonic (SH) signal from metal/thin film/electrolyte systems have been studied. Self-assembled monolayers (SAMs) of alkanethiolates have been prepared on Ag and Au surfaces, both SHG and AC impedance measurements of the Ag-alkanethiolate-electrolyte systems have been performed for alkanethiols with different chain lengths. The capacitance of the alkanethiolate SAMs is found inversely proportional to the chain length of the alkanethiol. For both Au and Ag electrodes, the SH signal is found less sensitive to the potential change after alkane-thiolate monolayer formation. The coverage dependent SH signal intensity from Au-alkanethiolate-electrolyte systems has been measured. Ozonolysis is used to obtain partially covered hexadecanethiolate (HDT) monolayers on Au surfaces, with the coverage being controlled by the ozone exposure time and monitored by surface plasmon resonance (SPR) technique. A linear relationship between the film coverage and SH intensity has been observed.","Made available in DSpace on 2015-09-25T22:14:16Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9812821.pdf: 3492454 bytes, checksum: cb54b46404f59588cf22218c211b237d (MD5) Previous issue date: 1997","Embargo set by: Seth Robbins for item 85675 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","135 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1997."]},{"key":"dc:title","label":"Title","values":["Structural Characterization of Sulfur-Based Monomolecular Thin Films: I. Langmuir-Blodgett Films Derived From Multisulfur Heterocycles. II. Second Harmonic Generation Studies of Alkanethiolates on Ag and Au"]}]}],"canonical_facts":{"dc:contributor":["Bohn, Paul W."],"dc:creator":["Zhang, Yang"],"dc:date":["2015-09-25T22:14:16Z","10000-01-01","1997"],"dc:description":["Optical second-harmonic generation (SHG) has been used as a very sensitive surface probe to study metal-electrolyte interfaces at potentials within the double layer charging region. In this work, the potential dependence of second harmonic (SH) signal from metal/thin film/electrolyte systems have been studied. Self-assembled monolayers (SAMs) of alkanethiolates have been prepared on Ag and Au surfaces, both SHG and AC impedance measurements of the Ag-alkanethiolate-electrolyte systems have been performed for alkanethiols with different chain lengths. The capacitance of the alkanethiolate SAMs is found inversely proportional to the chain length of the alkanethiol. For both Au and Ag electrodes, the SH signal is found less sensitive to the potential change after alkane-thiolate monolayer formation. The coverage dependent SH signal intensity from Au-alkanethiolate-electrolyte systems has been measured. Ozonolysis is used to obtain partially covered hexadecanethiolate (HDT) monolayers on Au surfaces, with the coverage being controlled by the ozone exposure time and monitored by surface plasmon resonance (SPR) technique. A linear relationship between the film coverage and SH intensity has been observed.","Made available in DSpace on 2015-09-25T22:14:16Z (GMT). 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Second Harmonic Generation Studies of Alkanethiolates on Ag and Au"],"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":"2026-07-22T22:26:23Z"}