A Digital Twin of the Coaxial Lamination Mixer for the Systematic Study of Mixing Performance and the Prediction of Precipitated Nanoparticle Properties
The synthesis of nanoparticles in microchannels promises the advantages of small size, uniform shape and narrow size distribution. However, only with insights into the mixing processes can the most suitable designs and operating conditions be systematically determined. Coaxial lamination mixers (CLM...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-11-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/13/12/2076 |
| _version_ | 1797456227501867008 |
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| author | Songtao Cai Peer Erfle Andreas Dietzel |
| author_facet | Songtao Cai Peer Erfle Andreas Dietzel |
| author_sort | Songtao Cai |
| collection | DOAJ |
| description | The synthesis of nanoparticles in microchannels promises the advantages of small size, uniform shape and narrow size distribution. However, only with insights into the mixing processes can the most suitable designs and operating conditions be systematically determined. Coaxial lamination mixers (CLM) built by 2-photon polymerization can operate long-term stable nanoparticle precipitation without fouling issues. Contact of the organic phase with the microchannel walls is prevented while mixing with the aqueous phase is intensified. A coaxial nozzle allows 3D hydrodynamic focusing followed by a sequence of stretch-and-fold units. By means of a digital twin based on computational fluid dynamics (CFD) and numerical evaluation of mixing progression, the influences of operation conditions are now studied in detail. As a measure for homogenization, the mixing index (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>MI</mi></mrow></semantics></math></inline-formula>) was extracted as a function of microchannel position for different operating parameters such as the total flow rate and the share of solvent flow. As an exemplary result, behind a third stretch-and-fold unit, practically perfect mixing (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>MI</mi><mo>></mo><mn>0.9</mn><mo stretchy="false">)</mo></mrow></semantics></math></inline-formula> is predicted at total flow rates between 50 µL/min and 400 µL/min and up to 20% solvent flow share. Based on <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>MI</mi></mrow></semantics></math></inline-formula> values, the mixing time, which is decisive for the size and dispersity of the nanoparticles, can be determined. Under the conditions considered, it ranges from 5 ms to 54 ms. A good correlation between the predicted mixing time and nanoparticle properties, as experimentally observed in earlier work, could be confirmed. The digital twin combining CFD with the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>MI</mi></mrow></semantics></math></inline-formula> methodology can in the future be used to adjust the design of a CLM or other micromixers to the desired total flow rates and flow rate ratios and to provide valuable predictions for the mixing time and even the properties of nanoparticles produced by microfluidic antisolvent precipitation. |
| first_indexed | 2024-03-09T16:05:12Z |
| format | Article |
| id | doaj.art-72e0385008a3415bbea925d69e74db86 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-09T16:05:12Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
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| series | Micromachines |
| spelling | doaj.art-72e0385008a3415bbea925d69e74db862023-11-24T16:43:45ZengMDPI AGMicromachines2072-666X2022-11-011312207610.3390/mi13122076A Digital Twin of the Coaxial Lamination Mixer for the Systematic Study of Mixing Performance and the Prediction of Precipitated Nanoparticle PropertiesSongtao Cai0Peer Erfle1Andreas Dietzel2Institute of Microtechnology, Technische Universität Braunschweig, 38124 Braunschweig, GermanyInstitute of Microtechnology, Technische Universität Braunschweig, 38124 Braunschweig, GermanyInstitute of Microtechnology, Technische Universität Braunschweig, 38124 Braunschweig, GermanyThe synthesis of nanoparticles in microchannels promises the advantages of small size, uniform shape and narrow size distribution. However, only with insights into the mixing processes can the most suitable designs and operating conditions be systematically determined. Coaxial lamination mixers (CLM) built by 2-photon polymerization can operate long-term stable nanoparticle precipitation without fouling issues. Contact of the organic phase with the microchannel walls is prevented while mixing with the aqueous phase is intensified. A coaxial nozzle allows 3D hydrodynamic focusing followed by a sequence of stretch-and-fold units. By means of a digital twin based on computational fluid dynamics (CFD) and numerical evaluation of mixing progression, the influences of operation conditions are now studied in detail. As a measure for homogenization, the mixing index (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>MI</mi></mrow></semantics></math></inline-formula>) was extracted as a function of microchannel position for different operating parameters such as the total flow rate and the share of solvent flow. As an exemplary result, behind a third stretch-and-fold unit, practically perfect mixing (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>MI</mi><mo>></mo><mn>0.9</mn><mo stretchy="false">)</mo></mrow></semantics></math></inline-formula> is predicted at total flow rates between 50 µL/min and 400 µL/min and up to 20% solvent flow share. Based on <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>MI</mi></mrow></semantics></math></inline-formula> values, the mixing time, which is decisive for the size and dispersity of the nanoparticles, can be determined. Under the conditions considered, it ranges from 5 ms to 54 ms. A good correlation between the predicted mixing time and nanoparticle properties, as experimentally observed in earlier work, could be confirmed. The digital twin combining CFD with the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>MI</mi></mrow></semantics></math></inline-formula> methodology can in the future be used to adjust the design of a CLM or other micromixers to the desired total flow rates and flow rate ratios and to provide valuable predictions for the mixing time and even the properties of nanoparticles produced by microfluidic antisolvent precipitation.https://www.mdpi.com/2072-666X/13/12/2076digital twincoaxial lamination mixer (CLM)3D hydrodynamic flow focusingmixing timemixing indexnanoparticle precipitation |
| spellingShingle | Songtao Cai Peer Erfle Andreas Dietzel A Digital Twin of the Coaxial Lamination Mixer for the Systematic Study of Mixing Performance and the Prediction of Precipitated Nanoparticle Properties Micromachines digital twin coaxial lamination mixer (CLM) 3D hydrodynamic flow focusing mixing time mixing index nanoparticle precipitation |
| title | A Digital Twin of the Coaxial Lamination Mixer for the Systematic Study of Mixing Performance and the Prediction of Precipitated Nanoparticle Properties |
| title_full | A Digital Twin of the Coaxial Lamination Mixer for the Systematic Study of Mixing Performance and the Prediction of Precipitated Nanoparticle Properties |
| title_fullStr | A Digital Twin of the Coaxial Lamination Mixer for the Systematic Study of Mixing Performance and the Prediction of Precipitated Nanoparticle Properties |
| title_full_unstemmed | A Digital Twin of the Coaxial Lamination Mixer for the Systematic Study of Mixing Performance and the Prediction of Precipitated Nanoparticle Properties |
| title_short | A Digital Twin of the Coaxial Lamination Mixer for the Systematic Study of Mixing Performance and the Prediction of Precipitated Nanoparticle Properties |
| title_sort | digital twin of the coaxial lamination mixer for the systematic study of mixing performance and the prediction of precipitated nanoparticle properties |
| topic | digital twin coaxial lamination mixer (CLM) 3D hydrodynamic flow focusing mixing time mixing index nanoparticle precipitation |
| url | https://www.mdpi.com/2072-666X/13/12/2076 |
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