{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/90828"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/90828","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Coalescence-induced nanodroplet jumping","abstract":"Made available in DSpace on 2016-07-07T20:35:12Z (GMT). No. of bitstreams: 2 CHA-THESIS-2016.pdf: 2224018 bytes, checksum: 497c21f5ec14cea688f8b206e81b1b44 (MD5) LICENSE.txt: 4210 bytes, checksum: b076c2ca76ed752c030fdb8c95f208df (MD5) Previous issue date: 2016-04-28","abstract_html":"Made available in DSpace on 2016-07-07T20:35:12Z (GMT). No. of bitstreams: 2 CHA-THESIS-2016.pdf: 2224018 bytes, checksum: 497c21f5ec14cea688f8b206e81b1b44 (MD5) LICENSE.txt: 4210 bytes, checksum: b076c2ca76ed752c030fdb8c95f208df (MD5) Previous issue date: 2016-04-28","abstract_has_math":false,"creators":["Cha, Hyeongyun"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Miljkovic, Nenad"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-07-07T20:35:12Z","date_published":"2016-07-07T20:35:12Z","updated_at":"2026-07-22T22:26:34Z","subjects":["jumping-droplet","coalescence","condensation","nanodroplet","heat transfer"],"languages":["en"],"rights":["Copyright 2016 Hyeongyun Cha"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/90828","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Miljkovic, Nenad"]},{"key":"dc:creator","label":"Author","values":["Cha, Hyeongyun"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2016-07-07T20:35:12Z","2018-07-08T09:15:33Z","2016-04-28","2016-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"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":["jumping-droplet","coalescence","condensation","nanodroplet","heat transfer"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2016 Hyeongyun Cha"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/90828"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Made available in DSpace on 2016-07-07T20:35:12Z (GMT). No. of bitstreams: 2 CHA-THESIS-2016.pdf: 2224018 bytes, checksum: 497c21f5ec14cea688f8b206e81b1b44 (MD5) LICENSE.txt: 4210 bytes, checksum: b076c2ca76ed752c030fdb8c95f208df (MD5) Previous issue date: 2016-04-28","U of I Only Restriction Lifted for Item 93181 on 2018-07-08T09:15:33Z.","Water vapor condensation on superhydrophobic surfaces has received much attention in recent years due to the ability of such surfaces to shed microscale water droplets via coalescence-induced droplet jumping, resulting in heat transfer, anti-icing, and self-cleaning performance enhancement. Here, we report for the first time the coalescence-induced removal of water nanodroplets (𝑅 ≈ 500 nm) from superhydrophobic carbon nanotube (CNT) surfaces. The two-droplet coalescence time is measured for varying droplet Ohnesorge numbers, confirming that coalescence prior to jumping is governed by capillary-inertial dynamics. By varying the conformal hydrophobic coating thickness on the CNT surface, the minimum jumping droplet radius was shown to increase with increasing solid fraction and decreasing apparent advancing contact angle, indicating that hydrodynamic limitations stemming from viscous dissipation do not limit the minimum droplet jumping size even for the smallest nanostructure length scale (≤ 100 nm) and surface adhesion. Rather, a surface interaction mechanism stemming from the evolved droplet morphology plays the defining role in limiting the minimum size for jumping. The outcomes of this work demonstrate the ability to passively shed nanometric water droplets, which has the potential to further increase the efficiency of systems that can harness jumping droplets for a wide range of energy and water applications.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-05-01","The student, Hyeongyun Cha, accepted the attached license on 2016-04-27 at 15:42.","The student, Hyeongyun Cha, submitted this Thesis for approval on 2016-04-27 at 15:51.","This Thesis was approved for publication on 2016-04-28 at 16:01.","DSpace SAF Submission Ingestion Package generated from Vireo submission #9487 on 2016-07-07 at 13:50:51","Embargo set by: Seth Robbins for item 93181 Lift date: 2018-07-07T20:35:34Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Coalescence-induced nanodroplet jumping"]}]}],"canonical_facts":{"dc:contributor":["Miljkovic, Nenad"],"dc:creator":["Cha, Hyeongyun"],"dc:date":["2016-07-07T20:35:12Z","2018-07-08T09:15:33Z","2016-04-28","2016-05"],"dc:description":["Made available in DSpace on 2016-07-07T20:35:12Z (GMT). No. of bitstreams: 2 CHA-THESIS-2016.pdf: 2224018 bytes, checksum: 497c21f5ec14cea688f8b206e81b1b44 (MD5) LICENSE.txt: 4210 bytes, checksum: b076c2ca76ed752c030fdb8c95f208df (MD5) Previous issue date: 2016-04-28","U of I Only Restriction Lifted for Item 93181 on 2018-07-08T09:15:33Z.","Water vapor condensation on superhydrophobic surfaces has received much attention in recent years due to the ability of such surfaces to shed microscale water droplets via coalescence-induced droplet jumping, resulting in heat transfer, anti-icing, and self-cleaning performance enhancement. Here, we report for the first time the coalescence-induced removal of water nanodroplets (𝑅 ≈ 500 nm) from superhydrophobic carbon nanotube (CNT) surfaces. The two-droplet coalescence time is measured for varying droplet Ohnesorge numbers, confirming that coalescence prior to jumping is governed by capillary-inertial dynamics. By varying the conformal hydrophobic coating thickness on the CNT surface, the minimum jumping droplet radius was shown to increase with increasing solid fraction and decreasing apparent advancing contact angle, indicating that hydrodynamic limitations stemming from viscous dissipation do not limit the minimum droplet jumping size even for the smallest nanostructure length scale (≤ 100 nm) and surface adhesion. Rather, a surface interaction mechanism stemming from the evolved droplet morphology plays the defining role in limiting the minimum size for jumping. The outcomes of this work demonstrate the ability to passively shed nanometric water droplets, which has the potential to further increase the efficiency of systems that can harness jumping droplets for a wide range of energy and water applications.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-05-01","The student, Hyeongyun Cha, accepted the attached license on 2016-04-27 at 15:42.","The student, Hyeongyun Cha, submitted this Thesis for approval on 2016-04-27 at 15:51.","This Thesis was approved for publication on 2016-04-28 at 16:01.","DSpace SAF Submission Ingestion Package generated from Vireo submission #9487 on 2016-07-07 at 13:50:51","Embargo set by: Seth Robbins for item 93181 Lift date: 2018-07-07T20:35:34Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/90828"],"dc:language":["en"],"dc:rights":["Copyright 2016 Hyeongyun Cha"],"dc:subject":["jumping-droplet","coalescence","condensation","nanodroplet","heat transfer"],"dc:title":["Coalescence-induced nanodroplet jumping"],"dc:type":["text"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:34Z"}