Experimental Analysis of Multiple Emulsion Compound Droplet Dynamics in a Stenosed Microchannel

Experimental Analysis of Multiple Emulsion Compound Droplet Dynamics in a Stenosed Microchannel | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF correspondence Experimental Analysis of Multiple Emulsion Compound Droplet Dynamics in a Stenosed Microchannel Kumar Amit, Ashwani Assam, Abhishek Raj This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8608391/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The dynamics of (O/W)/O multiple emulsion droplets navigating through stenosed microchannels are critical for understanding droplet behaviour in confined geometries, with implications for drug delivery, controlled emulsification, and biomedical modelling. This study explores how factors such as flow rate ratio ( \(\:{Q}_{r}\) ), droplet size (both inner and outer), channel wall compliance, and the inherent size variation of the inner droplets influence the transit phenomena. Experimental results reveal that the size and transit time of the compound droplets varies exponentially with an increase in flow rate ratio ( \(\:3\:\le\:\:{Q}_{r}\le\:\:5\) ). Material optimization showed that Xanthan gum (XG) concentration ( \(\:0.16\--0.2\%\:\) w/v) and intermediate oil concentrations ( \(\:\sim15\%\) v/v) were found to stabilize the inner emulsions while maintaining consistent droplet behaviour. For larger inner droplets (0.65 ≤ \(\:{D}_{i,\:max}^{*}\) ≤ 1.11), mean transit times (for droplet passage through stenosed microchannel) were \(\:52.27\:\pm\:\:1.07\) ms, approximately 8% higher than for smaller droplets ( \(\:0.21\le\:{D}_{i,\:max}^{*}\) \(\:\le\:0.25\) ) at 48.35 ± 0.96 ms. Crucially, wall compliance significantly altered droplet behaviour, leading to earlier droplet formation and consistently longer transit times due to curvature effects arising from wall deformation. The compliant channel exhibits a maximum \(\:{t}_{total}\) increase of 35.07% compared to the rigid channel at \(\:{Q}_{r}=\:3.333\) . Additionally, this work practical preparation method for mineral oil emulsions using an XG+DI solution, which enables stable, foam-free visualization and controlled encapsulation. This novel preparation technique, combined with experimental insights, highlights the importance of both internal droplet structure and wall compliance in microfluidic droplet dynamics. Full Text Additional Declarations No competing interests reported. Supplementary Files Multimedia2EffectofLargerInnerDropletsonTotalTransitTime.mp4 Multimedia1dropletgenerationrigidcompliant.mp4 Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8608391","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"correspondence","associatedPublications":[],"authors":[{"id":602252876,"identity":"df3e642c-c07d-425f-9358-727f08f3f61b","order_by":0,"name":"Kumar Amit","email":"","orcid":"","institution":"Indian Institute of Technology Patna","correspondingAuthor":false,"prefix":"","firstName":"Kumar","middleName":"","lastName":"Amit","suffix":""},{"id":602252877,"identity":"21427e31-56dc-48a2-afd7-da3b724d5f47","order_by":1,"name":"Ashwani Assam","email":"","orcid":"","institution":"Indian Institute of Technology Patna","correspondingAuthor":false,"prefix":"","firstName":"Ashwani","middleName":"","lastName":"Assam","suffix":""},{"id":602252878,"identity":"58141378-80a3-4ed7-a7e2-beeac08829fa","order_by":2,"name":"Abhishek Raj","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAtklEQVRIiWNgGAWjYJACgw8GEjAmkVoMZxhISJCmhZmHgUGCsDIY4J99+EGxTYFFnTkD88MPDAV3CGuROJdmYJwDdJhlA5uxBIPBMyKsOcMA0WJwgMEM6JfDhHXIn2H/YGwB1sL+jTgtBmd4DIwZwFp4iLTF8AxPgWGPgYTkzmaeYokEYrTInWHfZvDjTx2/OXv7xg8f/hChBQjYwPFnwAwkEojSAIzJB2AtRKoeBaNgFIyCEQgA+4wtxMF2lrQAAAAASUVORK5CYII=","orcid":"","institution":"Indian Institute of Technology Patna","correspondingAuthor":true,"prefix":"","firstName":"Abhishek","middleName":"","lastName":"Raj","suffix":""}],"badges":[],"createdAt":"2026-01-15 08:23:28","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8608391/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8608391/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104406035,"identity":"4ec017ca-c908-4332-a304-335c813f3ccd","added_by":"auto","created_at":"2026-03-11 12:24:38","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2005536,"visible":true,"origin":"","legend":"","description":"","filename":"07JanManuscriptWithoutnumericalpaperemulsionencapsulatedcompounddroplet.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8608391/v1_covered_2f512ab4-337a-4258-9c89-a77841936ece.pdf"},{"id":104332315,"identity":"b87c782c-0293-46e0-8317-719a276cd6d6","added_by":"auto","created_at":"2026-03-10 15:13:24","extension":"mp4","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":4800750,"visible":true,"origin":"","legend":"","description":"","filename":"Multimedia2EffectofLargerInnerDropletsonTotalTransitTime.mp4","url":"https://assets-eu.researchsquare.com/files/rs-8608391/v1/0601bcf418ff80ccf924d8f6.mp4"},{"id":104332317,"identity":"84896b59-a783-4dab-aa75-cfdaa1096361","added_by":"auto","created_at":"2026-03-10 15:13:25","extension":"mp4","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":36403844,"visible":true,"origin":"","legend":"","description":"","filename":"Multimedia1dropletgenerationrigidcompliant.mp4","url":"https://assets-eu.researchsquare.com/files/rs-8608391/v1/649d6e3a62fa78cdf8de51af.mp4"}],"financialInterests":"No competing interests reported.","formattedTitle":"Experimental Analysis of Multiple Emulsion Compound Droplet Dynamics in a Stenosed Microchannel","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8608391/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8608391/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe dynamics of (O/W)/O multiple emulsion droplets navigating through stenosed microchannels are critical for understanding droplet behaviour in confined geometries, with implications for drug delivery, controlled emulsification, and biomedical modelling. This study explores how factors such as flow rate ratio (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{Q}_{r}\\)\u003c/span\u003e\u003c/span\u003e), droplet size (both inner and outer), channel wall compliance, and the inherent size variation of the inner droplets influence the transit phenomena. Experimental results reveal that the size and transit time of the compound droplets varies exponentially with an increase in flow rate ratio (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:3\\:\\le\\:\\:{Q}_{r}\\le\\:\\:5\\)\u003c/span\u003e\u003c/span\u003e). Material optimization showed that Xanthan gum (XG) concentration (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:0.16\\--0.2\\%\\:\\)\u003c/span\u003e\u003c/span\u003ew/v) and intermediate oil concentrations (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\sim15\\%\\)\u003c/span\u003e\u003c/span\u003e v/v) were found to stabilize the inner emulsions while maintaining consistent droplet behaviour. For larger inner droplets (0.65 \u0026le; \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{D}_{i,\\:max}^{*}\\)\u003c/span\u003e\u003c/span\u003e \u0026le; 1.11), mean transit times (for droplet passage through stenosed microchannel) were \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:52.27\\:\\pm\\:\\:1.07\\)\u003c/span\u003e\u003c/span\u003e ms, approximately 8% higher than for smaller droplets (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:0.21\\le\\:{D}_{i,\\:max}^{*}\\)\u003c/span\u003e\u003c/span\u003e \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\le\\:0.25\\)\u003c/span\u003e\u003c/span\u003e) at 48.35 \u0026plusmn; 0.96 ms. Crucially, wall compliance significantly altered droplet behaviour, leading to earlier droplet formation and consistently longer transit times due to curvature effects arising from wall deformation. The compliant channel exhibits a maximum \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{t}_{total}\\)\u003c/span\u003e\u003c/span\u003e increase of 35.07% compared to the rigid channel at \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{Q}_{r}=\\:3.333\\)\u003c/span\u003e\u003c/span\u003e. Additionally, this work practical preparation method for mineral oil emulsions using an XG+DI solution, which enables stable, foam-free visualization and controlled encapsulation. This novel preparation technique, combined with experimental insights, highlights the importance of both internal droplet structure and wall compliance in microfluidic droplet dynamics.\u003c/p\u003e","manuscriptTitle":"Experimental Analysis of Multiple Emulsion Compound Droplet Dynamics in a Stenosed Microchannel","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-10 15:13:19","doi":"10.21203/rs.3.rs-8608391/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"49478a1d-161d-41e0-a10a-2f8c0b18401f","owner":[],"postedDate":"March 10th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-10T15:13:19+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-10 15:13:19","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8608391","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8608391","identity":"rs-8608391","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}