双乳液滴内核可控包裹与融合机制及实验研究
发布时间：2019-04-03 08:50
【摘要】：液滴微流控作为一种新的流体控制技术可以在液滴内实现纳升级别的微反应,已然成为微尺度上生物和化学反应及其过程检测的有效手段。液滴作为微反应器,能够有效控制扩散、加速混合、提高检测灵敏度,其应用范围涉及到单细胞分析、药物筛选、个人洗护等多学科交叉领域。然而,单乳液滴在壁面润湿、界面扰动等外界因素作用下易产生样品泄露,造成交叉污染,且不易进行多组分液滴操控。双乳液滴独特的核-壳结构能够有效保护内核液滴中的反应样品及反应产物,同时避免有害反应产物对外界环境的污染,且多核双乳液滴为多组分液滴的精准操控提供了重要载体。液滴微流控芯片是一个研究平台,其目的是为各领域的应用提供方法。但是,微尺度下的反应具有高度的多样化,单一的液滴微流控系统很难满足多样化的微反应需求。因此,需要多种微液滴形式及操控方法实现不同条件下的微反应器功能,从而去满足多样化的微反应需求。本文针对上述问题展开。从微纳尺度流体流动角度出发,根据微通道内两相流的基本理论,分析了液滴的形成及水包油包水(Water-in-Oil-in-Water,W/O/W)型双核双乳液滴内核电融合机理。建立了基于共轴流法的液滴生成仿真模型,对影响液滴生成大小及频率的关键因素进行了模拟分析,为液滴生成玻璃微流控芯片的设计提供支撑;建立了交流电场中W/O/W双核双乳液滴的受力及仿真二维模型,对内核液滴在极化作用下的电场力和流体动力进行分析,得出电场频率、电压幅值、内核电导率与内核液滴电融合之间的影响关系,为后续实验研究奠定理论基础。从简单实用角度考虑,设计了一种玻璃毛细管微流控芯片系统,在不需要停止实验和更换溶液的情况下,实现了W/O/W双乳液滴中两种不同试剂的“一步”定比例包裹,在大量节省试剂的条件下可以完成多工况的纳升级微反应;根据质量守恒方程,推导了双乳液滴大小及壳厚与各相流体流速的关系式,作为实验验证,合成了具有不同大小,不同壳厚,且具有高度均匀性的双乳液滴;通过对双乳液滴的PDMS(polydimethylsiloxane)外壳进行恒温固化,成功将双乳液滴转换成了具有一定机械强度的微囊泡结构,并对其进行了长达7个月的时间耐久性检测,确保其内部包裹物可以长时间储存和观察;最后,利用酶催化反应和中和反应验证了此方法在多工况微反应器中应用的可行性。从灵活可控角度考虑,设计并搭建了用于生成包含两个不同内核的W/O/W双乳液滴实验平台,通过调节内核液滴与外界介质中的盐浓度差异,研究了渗透压作用下双核双乳液滴的膨胀和形变规律,包括两内核在不同渗透压作用下随时间等速膨胀后的融合和非等速膨胀后的单一内核破裂。利用渗透压诱导实现了双乳液滴中分别含有Ca Cl2和Na2CO3溶液的两个内核液滴融合,进而实现了其内部溶液的混合及CaCO3生成反应,验证了渗透压诱导内核融合的双核双乳液滴作为纳升级微反应器的可行性。尤其是在没有电能的恶劣条件下,仅仅通过盐浓度的差异,就可以实现纳升级微反应。从即时操控角度考虑,利用交流电场的极化作用实现了连续流中W/O/W双核双乳液滴的内核液滴即时融合,研究了连续流流速、电场频率、电压幅值、内核溶液电导率等对大批量双核双乳液滴内核液滴融合效率的影响关系。通过合理调节各参数,连续流中W/O/W双核双乳液滴的内核液滴融合效率可以达到95%以上,为大样本需求的纳升级微反应提供技术支持。另外,通过酶催化的葡萄糖检测反应和水凝胶微粒合成及包裹酵母菌细胞的实验,验证了内核电融合的双核双乳液滴作为即时操控型纳升级微反应器的可行性。
[Abstract]:Microfluidic as a new kind of fluid control technology can realize the micro-reaction of nano-upgrading in the liquid drop, and has become an effective means of biological and chemical reaction in micro-scale and its process detection. The liquid drops act as micro-reactors, can effectively control the diffusion, accelerate the mixing, and improve the detection sensitivity, and the application range of the liquid drops relates to the cross-cutting fields of single-cell analysis, drug screening, personal care and the like. However, that single-emulsion drop is easy to generate sample leakage under the action of wall surface wetting, interface disturbance and other external factors, so that the cross-contamination is caused, and the multi-component liquid drop control is not easy to be carried out. The unique core-shell structure of the double-emulsion liquid drops can effectively protect the reaction sample and the reaction product in the inner core liquid drop, and meanwhile, the pollution of the harmful reaction product to the external environment is avoided, and the multi-core double-emulsion liquid drop is an important carrier for precise control of the multi-component liquid drop. The droplet micro-fluidic chip is a research platform, the purpose of which is to provide a method for the application of each field. However, the micro-scale reaction has a high degree of diversification, and a single droplet micro-flow control system is difficult to meet the diversified micro-reaction requirements. Therefore, the micro-reactor function under different conditions is realized by the form of a plurality of micro-droplets and the control method, so that the diversified micro-reaction requirements can be met. This paper is based on the above-mentioned problems. According to the basic theory of the two-phase flow in the micro-channel, the electric fusion mechanism of the water-in-water-in-Water (W/ O/ W) dual-core double-emulsion droplet is analyzed based on the basic theory of the two-phase flow in the micro-channel. The simulation model of the droplet generation based on the co-axial flow method is established, and the key factors that influence the size and frequency of the droplet generation are simulated and analyzed, and a support is provided for the design of the liquid drop generating glass micro-fluidic chip, and the force and the simulation two-dimensional model of the W/ O/ W dual-core double-emulsion liquid drop in the alternating-current electric field are established, The influence of the electric field frequency, the amplitude of the voltage, the electrical conductivity of the inner core and the electric fusion of the inner core is obtained, and the theoretical basis for the subsequent experimental research is obtained. from a simple and practical point of view, a glass capillary micro-fluidic chip system is designed, and the "one step" of two different reagents in the W/ O/ W double-emulsion liquid drop is realized under the condition of not stopping the experiment and changing the solution, According to the mass conservation equation, the relation between the size of the double-emulsion liquid drop and the shell thickness and the fluid flow rate of each phase is deduced, and the double-emulsion liquid drops are transformed into a micro-capsule structure with a certain mechanical strength by performing constant-temperature curing on the PDMS (polydimethylsiloxane) shell of the double-emulsion liquid drop, And finally, the feasibility of the application of the method in a multi-working condition micro-reactor is verified by using the enzyme catalysis reaction and the neutralization reaction. In this paper, we design and set up a W/ O/ W double-emulsion drop experiment platform for generating two different cores from a flexible and controllable angle. By adjusting the difference of the salt concentration between the inner core and the external medium, the expansion and deformation of the dual-core double-emulsion liquid drop under the influence of the osmotic pressure are studied. Comprises the fusion of the two cores under different osmotic pressure and the single core rupture after the non-constant-speed expansion. By using osmotic pressure induction, the two core liquid droplets containing the solution of Ca 2 and Na2CO3 in the double-emulsion liquid droplet were fused, and then the mixing of the internal solution and the reaction of CaCO3 formation were realized, and the feasibility of the dual-core double-emulsion liquid droplet fused by the osmotic pressure-inducing core as a nano-upgrading micro-reactor was verified. In particular, the nano-upgrading micro-reaction can be realized only by the difference of the salt concentration under the severe conditions of no electric energy. The instantaneous fusion of W/ O/ W dual-core double-emulsion droplets in continuous flow is realized by the polarization effect of the AC electric field from the point of view of the real-time operation. The continuous flow velocity, the frequency of the electric field and the amplitude of the voltage are studied. The effect of the electrical conductivity of the core solution on the droplet fusion efficiency of the large-scale dual-core double-emulsion liquid droplet. By reasonably adjusting each parameter, the fusion efficiency of the inner core of the W/ O/ W dual-core double-emulsion liquid drop in the continuous flow can reach more than 95%, and technical support is provided for the nano-upgrading micro-reaction of the large sample requirement. In addition, by enzyme-catalyzed glucose test and water-gel particle synthesis and the experiments of the yeast cells, the feasibility of the dual-core dual-emulsion liquid drop as an immediate control type micro-reactor was verified.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O35
本文编号：2453082
[Abstract]:Microfluidic as a new kind of fluid control technology can realize the micro-reaction of nano-upgrading in the liquid drop, and has become an effective means of biological and chemical reaction in micro-scale and its process detection. The liquid drops act as micro-reactors, can effectively control the diffusion, accelerate the mixing, and improve the detection sensitivity, and the application range of the liquid drops relates to the cross-cutting fields of single-cell analysis, drug screening, personal care and the like. However, that single-emulsion drop is easy to generate sample leakage under the action of wall surface wetting, interface disturbance and other external factors, so that the cross-contamination is caused, and the multi-component liquid drop control is not easy to be carried out. The unique core-shell structure of the double-emulsion liquid drops can effectively protect the reaction sample and the reaction product in the inner core liquid drop, and meanwhile, the pollution of the harmful reaction product to the external environment is avoided, and the multi-core double-emulsion liquid drop is an important carrier for precise control of the multi-component liquid drop. The droplet micro-fluidic chip is a research platform, the purpose of which is to provide a method for the application of each field. However, the micro-scale reaction has a high degree of diversification, and a single droplet micro-flow control system is difficult to meet the diversified micro-reaction requirements. Therefore, the micro-reactor function under different conditions is realized by the form of a plurality of micro-droplets and the control method, so that the diversified micro-reaction requirements can be met. This paper is based on the above-mentioned problems. According to the basic theory of the two-phase flow in the micro-channel, the electric fusion mechanism of the water-in-water-in-Water (W/ O/ W) dual-core double-emulsion droplet is analyzed based on the basic theory of the two-phase flow in the micro-channel. The simulation model of the droplet generation based on the co-axial flow method is established, and the key factors that influence the size and frequency of the droplet generation are simulated and analyzed, and a support is provided for the design of the liquid drop generating glass micro-fluidic chip, and the force and the simulation two-dimensional model of the W/ O/ W dual-core double-emulsion liquid drop in the alternating-current electric field are established, The influence of the electric field frequency, the amplitude of the voltage, the electrical conductivity of the inner core and the electric fusion of the inner core is obtained, and the theoretical basis for the subsequent experimental research is obtained. from a simple and practical point of view, a glass capillary micro-fluidic chip system is designed, and the "one step" of two different reagents in the W/ O/ W double-emulsion liquid drop is realized under the condition of not stopping the experiment and changing the solution, According to the mass conservation equation, the relation between the size of the double-emulsion liquid drop and the shell thickness and the fluid flow rate of each phase is deduced, and the double-emulsion liquid drops are transformed into a micro-capsule structure with a certain mechanical strength by performing constant-temperature curing on the PDMS (polydimethylsiloxane) shell of the double-emulsion liquid drop, And finally, the feasibility of the application of the method in a multi-working condition micro-reactor is verified by using the enzyme catalysis reaction and the neutralization reaction. In this paper, we design and set up a W/ O/ W double-emulsion drop experiment platform for generating two different cores from a flexible and controllable angle. By adjusting the difference of the salt concentration between the inner core and the external medium, the expansion and deformation of the dual-core double-emulsion liquid drop under the influence of the osmotic pressure are studied. Comprises the fusion of the two cores under different osmotic pressure and the single core rupture after the non-constant-speed expansion. By using osmotic pressure induction, the two core liquid droplets containing the solution of Ca 2 and Na2CO3 in the double-emulsion liquid droplet were fused, and then the mixing of the internal solution and the reaction of CaCO3 formation were realized, and the feasibility of the dual-core double-emulsion liquid droplet fused by the osmotic pressure-inducing core as a nano-upgrading micro-reactor was verified. In particular, the nano-upgrading micro-reaction can be realized only by the difference of the salt concentration under the severe conditions of no electric energy. The instantaneous fusion of W/ O/ W dual-core double-emulsion droplets in continuous flow is realized by the polarization effect of the AC electric field from the point of view of the real-time operation. The continuous flow velocity, the frequency of the electric field and the amplitude of the voltage are studied. The effect of the electrical conductivity of the core solution on the droplet fusion efficiency of the large-scale dual-core double-emulsion liquid droplet. By reasonably adjusting each parameter, the fusion efficiency of the inner core of the W/ O/ W dual-core double-emulsion liquid drop in the continuous flow can reach more than 95%, and technical support is provided for the nano-upgrading micro-reaction of the large sample requirement. In addition, by enzyme-catalyzed glucose test and water-gel particle synthesis and the experiments of the yeast cells, the feasibility of the dual-core dual-emulsion liquid drop as an immediate control type micro-reactor was verified.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O35
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