Y型微通道内双重乳液流动破裂机理
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摘要
基于体积分数法建立了Y型微通道中双重乳液流动非稳态理论模型,数值模拟研究了Y型微通道内双重乳液破裂情况,详细分析了双重乳液流经Y型微通道时的流场信息以及双重乳液形变参数演化特性,定量地给出了双重乳液流动破裂的驱动以及阻碍作用,揭示了双重乳液破裂流型的内在机理.研究结果表明:流经Y型微通道时,双重乳液受上游压力驱动产生形变,形变过程中乳液两端界面张力差阻碍双重乳液形变破裂,两者正相关;隧道的出现将减缓双重乳液外液滴颈部收缩速率以及沿流向拉伸的速率,并减缓了内液滴沿流向拉伸的速率,其对于内液滴颈部收缩速率影响不大;隧道破裂和不破裂工况临界线可以采用幂律关系式l~*=βCa~b进行预测,隧道破裂和阻塞破裂工况临界线可以采用线性关系l~*=α描述;与单乳液运动相图相比,双重乳液运动相图各工况的分界线关系式系数α和β均相应增大.
A scheme of passive breakup of generated droplet into two daughter droplets in a microfluidic Y-junction is characterized by the precisely controlling the droplet size distribution. Compared with the T-junction, the microfluidic Y-junction is very convenient for droplet breakup and successfully applied to double emulsionbreakup. Therefore, it is of theoretical significance and engineering value for fully understanding the double emulsion breakup in a Y-junction. However, current research mainly focuses on the breakup of single phase droplet in the Y-junction. In addition, due to structural complexity, especially the existence of the inner droplet,more complicated hydrodynamics and interface topologies are involved in the double emulsion breakup in a Y-junction than the scenario of the common single phase droplet. For these reasons, an unsteady model of a double emulsion passing through microfluidic Y-junction is developed based on the volume of fluid method and numerically analyzed to investigate the dynamic behavior of double emulsion passing through a microfluidic Y-junction. The detailed hydrodynamic information about the breakup and non-breakup is presented, together with the quantitative evolutions of driving and resistance force as well as the droplet deformation characteristics, which reveals the hydrodynamics underlying the double emulsion breakup. The results indicate that the three flow regimes are observed when double emulsion passes through a microfluidic Y-junction:obstructed breakup, tunnel breakup and non-breakup; as the capillary number or initial length of the double emulsion decreases, the flow regime transforms from tunnel breakup to non-breakup; the upstream pressure and the Laplace pressure difference between the forefront and rear droplet interfaces, which exhibit a correspondence relationship, are regarded as the main driving force and the resistance to double emulsion breakup through a microfluidic Y-junction; the appearance of tunnels affects the double emulsion deformation, resulting in the slower squeezing speed and elongation speed of outer droplet as well as the slower squeezing speed of inner droplet; the critical threshold between breakup and non-breakup is approximately expressed as a power-law formula l~*= βCa~b , while the threshold between tunnel breakup and obstructed breakup is approximately expressed as a linear formula l~*=α; comparing with the phase diagram for single phase droplet, the coefficients α and β of the boundary lines between the different regimes in phase diagram for double emulsion are both increased.
A scheme of passive breakup of generated droplet into two daughter droplets in a microfluidic Y-junction is characterized by the precisely controlling the droplet size distribution. Compared with the T-junction, the microfluidic Y-junction is very convenient for droplet breakup and successfully applied to double emulsionbreakup. Therefore, it is of theoretical significance and engineering value for fully understanding the double emulsion breakup in a Y-junction. However, current research mainly focuses on the breakup of single phase droplet in the Y-junction. In addition, due to structural complexity, especially the existence of the inner droplet,more complicated hydrodynamics and interface topologies are involved in the double emulsion breakup in a Y-junction than the scenario of the common single phase droplet. For these reasons, an unsteady model of a double emulsion passing through microfluidic Y-junction is developed based on the volume of fluid method and numerically analyzed to investigate the dynamic behavior of double emulsion passing through a microfluidic Y-junction. The detailed hydrodynamic information about the breakup and non-breakup is presented, together with the quantitative evolutions of driving and resistance force as well as the droplet deformation characteristics, which reveals the hydrodynamics underlying the double emulsion breakup. The results indicate that the three flow regimes are observed when double emulsion passes through a microfluidic Y-junction:obstructed breakup, tunnel breakup and non-breakup; as the capillary number or initial length of the double emulsion decreases, the flow regime transforms from tunnel breakup to non-breakup; the upstream pressure and the Laplace pressure difference between the forefront and rear droplet interfaces, which exhibit a correspondence relationship, are regarded as the main driving force and the resistance to double emulsion breakup through a microfluidic Y-junction; the appearance of tunnels affects the double emulsion deformation, resulting in the slower squeezing speed and elongation speed of outer droplet as well as the slower squeezing speed of inner droplet; the critical threshold between breakup and non-breakup is approximately expressed as a power-law formula l~*= βCa~b , while the threshold between tunnel breakup and obstructed breakup is approximately expressed as a linear formula l~*=α; comparing with the phase diagram for single phase droplet, the coefficients α and β of the boundary lines between the different regimes in phase diagram for double emulsion are both increased.
引文
[1]Shum H C,Bandyopadhyay A,Bose S,Weitz D A 2009Chem.Mater.21 5548
[2]Chen H S,Zhao Y J,Li J,Guo M,Wan J D,Weitz D A,Stone H A 2011 Lab Chip 11 2312
[3]Kim S H,Kim J W,Cho J C,Weitz D A 2011 Lab Chip 113162
[4]Wang J,Sun L,Zou M,Gao W,Liu C,Shang L,Gu Z,Zhao Y 2017 Sci.Adv.3 e1700004
[5]Kim J H,Jeon T Y,Choi T M,Shim T S,Kim S H,Yang SM 2014 Langmuir 30 1473
[6]McClements D J,Li Y 2010 Adv.Colloid Interface Sci.159213
[7]Zhang Y,Chan H F,Leong K W 2013 Adv.Drug Del.Rev.65 104
[8]Teh S Y,Lin R,Hung L H,Lee A P 2008 Lab Chip 8 198
[9]Seemann R,Brinkmann M,Pfohl T,Herminghaus S 2012Rep.Prog.Phys.75 016601
[10]Shang L R,Cheng Y,Zhao Y J 2017 Chem.Rev.117 7964
[11]Choi C H,Kim J,Nam J O,Kang S M,Jeong S G,Lee C S2014 Chemphyschem 15 21
[12]Vladisavljevic G T,Al Nuumani R,Nabavi S A 2017Micromachines 8 75
[13]Cubaud T 2009 Phys.Rev.E 80 026307
[14]Link D R,Anna S L,Weitz D A,Stone H A 2004 Phys.Rev.Lett.92 054503
[15]de Menech M 2006 Phys.Rev.E 73 031505
[16]Jullien M C,Ching M J T M,Cohen C,Menetrier L,Tabeling P 2009 Phys.Fluids 21 072001
[17]Leshansky A M,Pismen L M 2009 Phys.Fluids 21 023303
[18]Afkhami S,Leshansky A M,Renardy Y 2011 Phys.Fluids 23022002
[19]Leshansky A M,Afkhami S,Jullien M C,Tabeling P 2012Phys.Rev.Lett.108 264502
[20]Hoang D A,Portela L M,Kleijn C R,Kreutzer M T,van Steijn V 2013 J.Fluid Mech.717 R4
[21]Samie M,Salari A,Shafii M B 2013 Phys.Rev.E 87 053003
[22]Chen B,Li G J,Wang W M,Wang P 2015 Appl.Therm.Eng.88 94
[23]Chen Y P,Deng Z L 2017 J.Fluid Mech.819 401
[24]Yamada M,Doi S,Maenaka H,Yasuda M,Seki M 2008 J.Colloid Interface Sci.321 401
[25]Carlson A,Do Quang M,Amberg G 2010 Int.J.Multiphase Flow 36 397
[26]Abate A R,Weitz D A 2011 Lab Chip 11 1911
[27]Liang H,Chai Z H,Shi B C 2016 Acta Phys.Sin.65 204701(in Chinese)[梁宏,柴振华,施保昌2016物理学报65 204701]
[28]Wang Y,Minh D Q,Amberg G 2016 Phys.Fluids 28 033103
[29]Zheng M M,Ma Y L,Jin T M,Wang J T 2016 Microfluid.Nanofluid.20 107
[30]Ma Y L,Zheng M M,Bah M G,Wang J T 2018 Chem.Eng.Sci.179 104
[31]Chen Y P,Gao W,Zhang C B,Zhao Y J 2016 Lab Chip 161332
[32]Chen Y P,Liu X D,Shi M H 2013 Appl.Phys.Lett.102051609
[33]Bashir S,Rees J M,Zimmerman W B 2014 Int.J.Multiphase Flow 60 40
[34]Chen Y P,Wu L Y,Zhang L 2015 Int.J.Heat Mass Transfer82 42
[35]Nabavi S A,Gu S,Vladisavljevic G T,Ekanem E E 2015 J.Colloid Interface Sci.450 279
[36]Nabavi S A,Vladisavljevic G T,Gu S,Ekanem E E 2015Chem.Eng.Sci.130 183
[37]Azarmanesh M,Farhadi M,Azizian P 2016 Phys.Fluids 28032005
[38]Fu Y H,Zhao S F,Bai L,Jin Y,Cheng Y 2016 Chem.Eng.Sci.146 126
[39]Liu X D,Wu L Y,Zhao Y J,Chen Y P 2017 Colloids Surf.Physicochem.Eng.Aspects 533 87
[40]Chen Y P,Liu X D,Zhao Y J 2015 Appl.Phys.Lett.106141601
[41]Zhang C B,Yu C,Liu X D,Jin O,Chen Y P 2016 Acta Phys.Sin.65 204704(in Chinese)[张程宾,于程,刘向东,金瓯,陈永平2016物理学报65 204704]
[42]Liu X D,Wang C Y,Zhao Y J,Chen Y P 2018 Chem.Eng.Sci.183 215
[43]Liu X D,Wang C Y,Zhao Y J,Chen Y P 2018 Int.J.Heat Mass Transfer 121 377
[44]Brackbill J U,Kothe D B,Zemach C 1992 J.Comput.Phys.100 335
[45]Gueyffier D,Li J,Nadim A,Scardovelli R,Zaleski S 1999 J.Comput.Phys.152 423
[46]Taylor G I 1934 Proc.Roy.Soc.London Series A 146 501
[2]Chen H S,Zhao Y J,Li J,Guo M,Wan J D,Weitz D A,Stone H A 2011 Lab Chip 11 2312
[3]Kim S H,Kim J W,Cho J C,Weitz D A 2011 Lab Chip 113162
[4]Wang J,Sun L,Zou M,Gao W,Liu C,Shang L,Gu Z,Zhao Y 2017 Sci.Adv.3 e1700004
[5]Kim J H,Jeon T Y,Choi T M,Shim T S,Kim S H,Yang SM 2014 Langmuir 30 1473
[6]McClements D J,Li Y 2010 Adv.Colloid Interface Sci.159213
[7]Zhang Y,Chan H F,Leong K W 2013 Adv.Drug Del.Rev.65 104
[8]Teh S Y,Lin R,Hung L H,Lee A P 2008 Lab Chip 8 198
[9]Seemann R,Brinkmann M,Pfohl T,Herminghaus S 2012Rep.Prog.Phys.75 016601
[10]Shang L R,Cheng Y,Zhao Y J 2017 Chem.Rev.117 7964
[11]Choi C H,Kim J,Nam J O,Kang S M,Jeong S G,Lee C S2014 Chemphyschem 15 21
[12]Vladisavljevic G T,Al Nuumani R,Nabavi S A 2017Micromachines 8 75
[13]Cubaud T 2009 Phys.Rev.E 80 026307
[14]Link D R,Anna S L,Weitz D A,Stone H A 2004 Phys.Rev.Lett.92 054503
[15]de Menech M 2006 Phys.Rev.E 73 031505
[16]Jullien M C,Ching M J T M,Cohen C,Menetrier L,Tabeling P 2009 Phys.Fluids 21 072001
[17]Leshansky A M,Pismen L M 2009 Phys.Fluids 21 023303
[18]Afkhami S,Leshansky A M,Renardy Y 2011 Phys.Fluids 23022002
[19]Leshansky A M,Afkhami S,Jullien M C,Tabeling P 2012Phys.Rev.Lett.108 264502
[20]Hoang D A,Portela L M,Kleijn C R,Kreutzer M T,van Steijn V 2013 J.Fluid Mech.717 R4
[21]Samie M,Salari A,Shafii M B 2013 Phys.Rev.E 87 053003
[22]Chen B,Li G J,Wang W M,Wang P 2015 Appl.Therm.Eng.88 94
[23]Chen Y P,Deng Z L 2017 J.Fluid Mech.819 401
[24]Yamada M,Doi S,Maenaka H,Yasuda M,Seki M 2008 J.Colloid Interface Sci.321 401
[25]Carlson A,Do Quang M,Amberg G 2010 Int.J.Multiphase Flow 36 397
[26]Abate A R,Weitz D A 2011 Lab Chip 11 1911
[27]Liang H,Chai Z H,Shi B C 2016 Acta Phys.Sin.65 204701(in Chinese)[梁宏,柴振华,施保昌2016物理学报65 204701]
[28]Wang Y,Minh D Q,Amberg G 2016 Phys.Fluids 28 033103
[29]Zheng M M,Ma Y L,Jin T M,Wang J T 2016 Microfluid.Nanofluid.20 107
[30]Ma Y L,Zheng M M,Bah M G,Wang J T 2018 Chem.Eng.Sci.179 104
[31]Chen Y P,Gao W,Zhang C B,Zhao Y J 2016 Lab Chip 161332
[32]Chen Y P,Liu X D,Shi M H 2013 Appl.Phys.Lett.102051609
[33]Bashir S,Rees J M,Zimmerman W B 2014 Int.J.Multiphase Flow 60 40
[34]Chen Y P,Wu L Y,Zhang L 2015 Int.J.Heat Mass Transfer82 42
[35]Nabavi S A,Gu S,Vladisavljevic G T,Ekanem E E 2015 J.Colloid Interface Sci.450 279
[36]Nabavi S A,Vladisavljevic G T,Gu S,Ekanem E E 2015Chem.Eng.Sci.130 183
[37]Azarmanesh M,Farhadi M,Azizian P 2016 Phys.Fluids 28032005
[38]Fu Y H,Zhao S F,Bai L,Jin Y,Cheng Y 2016 Chem.Eng.Sci.146 126
[39]Liu X D,Wu L Y,Zhao Y J,Chen Y P 2017 Colloids Surf.Physicochem.Eng.Aspects 533 87
[40]Chen Y P,Liu X D,Zhao Y J 2015 Appl.Phys.Lett.106141601
[41]Zhang C B,Yu C,Liu X D,Jin O,Chen Y P 2016 Acta Phys.Sin.65 204704(in Chinese)[张程宾,于程,刘向东,金瓯,陈永平2016物理学报65 204704]
[42]Liu X D,Wang C Y,Zhao Y J,Chen Y P 2018 Chem.Eng.Sci.183 215
[43]Liu X D,Wang C Y,Zhao Y J,Chen Y P 2018 Int.J.Heat Mass Transfer 121 377
[44]Brackbill J U,Kothe D B,Zemach C 1992 J.Comput.Phys.100 335
[45]Gueyffier D,Li J,Nadim A,Scardovelli R,Zaleski S 1999 J.Comput.Phys.152 423
[46]Taylor G I 1934 Proc.Roy.Soc.London Series A 146 501