Piotr Korczyk, Ph.D., Dr. Habil.

Department of Biosystems and Soft Matter (ZBiMM)
Division of Modelling in Biology and Medicine (PMBM)
position: assistant professor
telephone: (+48) 22 826 12 81 ext.: 413
room: 312
e-mail: pkor
personal site: http://pmbm.ippt.pan.pl/web/Piotr_Korczyk

Doctoral thesis
2008-11-27Drobnoskalowa turbulencja w procesie mieszania chmury z otoczeniem - model laboratoryjny 
supervisor -- Prof. Tomasz Kowalewski, Ph.D., Dr. Habil., IPPT PAN
618
 
Habilitation thesis
2017-02-23Mechaniczne podstawy zastosowania kropel jako mikroreaktorów chemicznych w pasywnych układach mikroprzepływowych 
Recent publications
1.Korczyk P.M., Dolega M.E., Jakieła S., Jankowski P., Makulska S., Garstecki P., Scaling up the throughput of synthesis and extraction in droplet microfluidic reactors, Journal of Flow Chemistry, ISSN: 2062-249X, DOI: 10.1556/JFC-D-14-00038, Vol.5, No.2, pp.110-118, 2015
Abstract:

Conducting reactions in droplets in microfluidic chips offers several highly attractive characteristics, among others, increased yield and selectivity of chemical syntheses. The use of droplet microfluidic systems in synthetic chemistry is, however, hampered by the intrinsically small throughput of micrometric channels. Here, we verify experimentally the potential to increase throughput via an increase of the scale of the channels.We use the results of these experiments characterizing the processes of (1) generation of droplets, (2) mixing in droplets, (3) inter-phase extraction, and (4) the yield of synthesis of pyrrole, to postulate a number of guidelines for scaling up the throughput of microfluidic droplet systems. In particular, we suggest the rules for maximizing the throughput via an increase of the size of the channels and via parallelization to optimize the throughput of synthesis against the cost of fabrication of the chips and against the kinetic requirements of specific reactions.

Keywords:

flow chemistry, microfluidics, synthesis, emulsions, droplets

Affiliations:
Korczyk P.M.-IPPT PAN
Dolega M.E.-Université Grenoble Alpes (FR)
Jakieła S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Jankowski P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Makulska S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
2.Kor M., Korczyk P.M., Addai-Mensah J., Krasowska M., Beattie D.A., Carboxymethylcellulose Adsorption on Molybdenite: The Effect of Electrolyte Composition on Adsorption, Bubble–Surface Collisions, and Flotation, LANGMUIR, ISSN: 0743-7463, DOI: 10.1021/la503248e, Vol.30, No.40, pp.11975-11984, 2014
Abstract:

The adsorption of carboxymethylcellulose polymers on molybdenite was studied using spectroscopic ellipsometry and atomic force microscopy imaging with two polymers of differing degrees of carboxyl group substitution and at three different electrolyte conditions: 1 × 10–2 M KCl, 2.76 × 10–2 M KCl, and simulated flotation process water of multicomponent electrolyte content, with an ionic strength close to 2.76 × 10–2 M. A higher degree of carboxyl substitution in the adsorbing polymer resulted in adsorbed layers that were thinner and with more patchy coverage; increasing the ionic strength of the electrolyte resulted in increased polymer layer thickness and coverage. The use of simulated process water resulted in the largest layer thickness and coverage for both polymers. The effect of the adsorbed polymer layer on bubble–particle attachment was studied with single bubble–surface collision experiments recorded with high-speed video capture and image processing and also with single mineral molybdenite flotation tests. The carboxymethylcellulose polymer with a lower degree of substitution resulted in almost complete prevention of wetting film rupture at the molybdenite surface under all electrolyte conditions. The polymer with a higher degree of substitution prevented rupture only when adsorbed from simulated process water. Molecular kinetic theory was used to quantify the effect of the polymer on the dewetting dynamics for collisions that resulted in wetting film rupture. Flotation experiments confirmed that adsorbed polymer layer properties, through their effect on the dynamics of bubble–particle attachment, are critical to predicting the effectiveness of polymers used to prevent mineral recovery in flotation.

Keywords:

flotation, bubble, adsorption

Affiliations:
Kor M.-University of South Australia (AU)
Korczyk P.M.-other affiliation
Addai-Mensah J.-University of South Australia (AU)
Krasowska M.-other affiliation
Beattie D.A.-University of South Australia (AU)
3.Guzowski J., Jakieła S., Korczyk P.M., Garstecki P., Custom tailoring multiple droplets one-by-one, LAB ON A CHIP, ISSN: 1473-0197, DOI: 10.1039/c3lc50841b, Vol.13, pp.4308-4311, 2013
Abstract:

We report automated generation of arbitrary sequences of multiple microdroplets with online and individual control over the number of cores and volumes of all the constituents (cores and shells) of each of the multiple droplets. We show that a given sequence of volumes of the cores always folds to the same final three-dimensional architecture. The method presents the first proof-of-concept for the ability to design the three-dimensional structure of multiple droplets. We discuss the potential use of the technique in the formulation of predetermined distribution of drug release capsules and for automated generation of functional chemical microdroplet networks.

Keywords:

multiple droplets, microfluidics

Affiliations:
Guzowski J.-other affiliation
Jakieła S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Korczyk P.M.-IPPT PAN
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
4.Korczyk P.M., Derzsi L., Jakieła S., Garstecki P., Microfluidic traps for hard-wired operations on droplets, LAB ON A CHIP, ISSN: 1473-0197, DOI: 10.1039/c3lc50347j, Vol.13, pp.4096-4102, 2013
Abstract:

We present microfluidic modules (traps) that allow us to lock, shift, dose and merge micro-aliquots of liquid precisely. The precision is hard-wired into the geometry of the device: small values of the capillary number guarantee reproducibility of operation over a range of rates of flow that need not be controlled precisely. The modules can be integrated into systems that perform complicated protocols on micro-droplets while not requiring precision in forcing the flow.

Keywords:

microfluidics, droplets

Affiliations:
Korczyk P.M.-IPPT PAN
Derzsi L.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Jakieła S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
5.Churski K., Nowacki M., Korczyk P.M., Garstecki P., Simple modular systems for generation of droplets on demand, LAB ON A CHIP, ISSN: 1473-0197, DOI: 10.1039/c3lc50340b, Vol.13, pp.3689-3697, 2013
Abstract:

This report provides practical guidelines for the use of inexpensive electromagnetic valves characterized by large dead volumes (tens to hundreds of μL) for the generation of small (nL) droplets on demand in microfluidic chips. We analyze the role of the ratio of resistances and of the elastic capacitance of the fluidic connectors between the reservoir of the liquid, the valve and the microfluidic chip in the reliable and precise formation of micro droplets on demand. We also demonstrate and examine the use of conventional electromagnetic squeeze valves in the generation of small droplets on demand with a similar set of design rules.

Keywords:

microfluidics, droplets

Affiliations:
Churski K.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Nowacki M.-other affiliation
Korczyk P.M.-IPPT PAN
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
6.Węgrzyn J., Samborski A., Reissig L., Korczyk P.M., Błoński S., Garstecki P., Microfluidic architectures for efficient generation of chemistry gradations in droplets, MICROFLUIDICS AND NANOFLUIDICS, ISSN: 1613-4982, DOI: 10.1007/s10404-012-1042-3, Vol.14, No.1, pp.235-245, 2013
Abstract:

We demonstrate a strategy for construction of high-throughput microfluidic systems generating gradations of chemistry in micro-droplets. The productivity of the systems that we propose is limited only by the maximum rate of the droplet formation, and does not need to be limited by the rate of mixing. Multilayer polycarbonate chips transform two miscible input streams A and B into N streams of droplets, containing mixtures [A]i, [B]i. Exemplary devices generate linear ([B]i ∝ i) and logarithmic gradations (ln[B]i ∝ i). We also analyze the use of the same strategy for the generation of concentration gradation in the streams of droplets comprising mixtures of liquids of different viscosities. The devices preserve the required distribution of compositions, while allowing the volume of the droplets to be tuned over almost two orders of magnitude (i.e. between 3 and 80 nL).

Keywords:

Microfluidics, Generation of gradients, Droplet, Viscosity

Affiliations:
Węgrzyn J.-other affiliation
Samborski A.-other affiliation
Reissig L.-Nagoya University (JP)
Korczyk P.M.-IPPT PAN
Błoński S.-IPPT PAN
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
7.van Steijn V., Korczyk P.M., Derzsi L., Abate A.R., Weitz D.A., Garstecki P., Block-and-break generation of microdroplets with fixed volume, BIOMICROFLUIDICS, ISSN: 1932-1058, DOI: 10.1063/1.4801637, Vol.7, pp.024108-1-8, 2013
Abstract:

We introduce a novel type of droplet generator that produces droplets of a volume set by the geometry of the droplet generator and not by the flow rates of the liquids. The generator consists of a classic T-junction with a bypass channel. This bypass directs the continuous fluid around the forming droplets, so that they can fill the space between the inlet of the dispersed phase and the exit of the bypass without breaking. Once filled, the dispersed phase blocks the exit of the bypass and is squeezed by the continuous fluid and broken off from the junction. We demonstrate the fixed-volume droplet generator for (i) the formation of monodisperse droplets from a source of varying flow rates, (ii) the formation of monodisperse droplets containing a gradation of solute concentration, and (iii) the parallel production of monodisperse droplets.

Keywords:

droplet generator, droplets, microfluidics

Affiliations:
van Steijn V.-Delft University of Technology (NL)
Korczyk P.M.-IPPT PAN
Derzsi L.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Abate A.R.-University of California, Berkeley (US)
Weitz D.A.-Harvard University (US)
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
8.Jakieła S., Korczyk P.M., Makulska S., Cybulski O., Garstecki P., Discontinuous Transition in a Laminar Fluid Flow: A Change of Flow Topology inside a Droplet Moving in a Micron-Size Channel, PHYSICAL REVIEW LETTERS, ISSN: 0031-9007, DOI: 10.1103/PhysRevLett.108.134501, Vol.108, No.13, pp.134501-1-5, 2012
Abstract:

Even at moderate values of Reynolds number [e.g., Re=O(1) ] a curved interface between liquids can induce an abrupt transition between topologically different configurations of laminar flow. Here we show for the first time direct evidence of a sharp transition in the speed of flow of a droplet upon a small increase of the value of the capillary number above a threshold and the associated change of topology of flow. The quantitative results on the dependence of the threshold capillary number on the contrast of viscosities and on the direction of transition cannot be explained by any of the existing theories and call for a new description.

Keywords:

speed of droplets, microfluidics, droplets

Affiliations:
Jakieła S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Korczyk P.M.-IPPT PAN
Makulska S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Cybulski O.-other affiliation
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
9.Guzowski J., Korczyk P.M., Jakieła S., Garstecki P., The structure and stability of multiple micro-droplets, SOFT MATTER, ISSN: 1744-683X, DOI: 10.1039/c2sm25838b, Vol.8, pp.3269-3278, 2012
Abstract:

Microfluidic droplet-on-demand systems allow the controllable construction of multiple droplets of previously unattainable morphologies. Guided by the diagrams of the possible topologies of double droplets we investigate in detail the vistas to control the morphology of Janus droplets. We also explore and control new morphologies of multiple Janus droplets, i.e., arbitrarily long chains of alternating immiscible segments. Theoretical calculations together with the control offered by the use of automation allow the design of both the topology and the geometry (e.g. curvatures of the interfaces) of the multiple droplets. The ability to rationally design convex–convex, convex–concave and concave–convex segments may be useful in material science, while the ability to tune the distances between the interfaces in the chains of droplets may have applications in designing artificial biochemical signalling networks.

Keywords:

multiple droplets, microfluidics

Affiliations:
Guzowski J.-other affiliation
Korczyk P.M.-IPPT PAN
Jakieła S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
10.Sikora M., Dieter A., Korczyk P.M., Prodi-Schwab A., Szymczak P., Cieplak M., Geometrical and electrical properties of indium tin oxide clusters in ink dispersions, LANGMUIR, ISSN: 0743-7463, DOI: 10.1021/la203886b, Vol.28, No.2, pp.1523-1530, 2012
Abstract:

The analysis of the TEM images of indium tin oxide (ITO) clusters in ink solutions deposited from ink dispersions reveals that their geometry arises from a diffusion limited cluster aggregation (DLCA) process. We model films of ITO clusters as built through deposition of DLCA clusters made of primary spherical nanoparticles of 13 nm in diameter.
The deposition is then followed by a further compactification process that imitates sintering. We determine the conductivity of the sintered films by mapping the problem to that of the resistor network in which the contact regions between the touching spheres provide the dominant electric resistance. For a given volume fraction, conductivity of the sintered films is shown to be larger than that for the randomly packed spheres. However, the larger a typical radius of gyration of the clusters the smaller the enhancement. We also provide numerical tests for the routines used in the interpretation of the TEM images.

Keywords:

cluster aggregation, ITO

Affiliations:
Sikora M.-other affiliation
Dieter A.-other affiliation
Korczyk P.M.-IPPT PAN
Prodi-Schwab A.-other affiliation
Szymczak P.-University of Warsaw (PL)
Cieplak M.-other affiliation
11.Korczyk P.M., Kowalewski T.A., Malinowski Sz.P., Turbulent mixing of clouds with the environment: Small scale two phase evaporating flow investigated in a laboratory by particle image velocimetry, PHYSICA D-NONLINEAR PHENOMENA, ISSN: 0167-2789, DOI: 10.1016/j.physd.2011.11.003, Vol.241, pp.288-296, 2012
Abstract:

In this report, experiments mimicking some aspects of cloud-clear-air mixing in a laboratory chamber are discussed. A saturated plume containing small droplets of water (a surrogate of an atmospheric cloud) is mixed with unsaturated environmental air in order to study effect of evaporative cooling at the interfaces between cloudy and clear air filaments on small-scale turbulence. Two components of the turbulent velocity at a small scale are determined using particle imaging velocimetry of the cloud droplets. Enhanced velocity fluctuations between the Kolmogorov (η ≈ 0.8 mm) and Taylor (λ ≈ 8 mm) microscales are observed.
The characteristic feature of these microscales is anisotropy with a preferred vertical direction. A straightforward dependence of the observed effects on the relative humidity of the environment indicates the importance of buoyancy production by evaporative cooling. This conclusion is in agreement with previous numerical experiments described in the literature and suggests that, under certain conditions, effects similar to the above may influence the smallest scales of turbulence in natural clouds.

Keywords:

Small-scale turbulence, Atmospheric turbulence, Evaporative cooling, Cloud-clear-air mixing

Affiliations:
Korczyk P.M.-IPPT PAN
Kowalewski T.A.-IPPT PAN
Malinowski Sz.P.-other affiliation
12.Korczyk P.M., Cybulski O., Makulska A., Garstecki P., Effects of unsteadiness of the rates of flow on the dynamics of formation of droplets in microfluidic systems, LAB ON A CHIP, ISSN: 1473-0197, DOI: 10.1039/C0LC00088D, Vol.11, No.1, pp.173-175, 2011
Abstract:

Oscillations of the input rates of flow have a significant impact on the dynamics of formation of droplets in microfluidic systems and on the quality of generated emulsions.

Keywords:

microfluidics, T-junction, droplet generation, syringe pump

Affiliations:
Korczyk P.M.-IPPT PAN
Cybulski O.-other affiliation
Makulska A.-other affiliation
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
13.Guzowski J., Korczyk P.M., Jakieła S., Garstecki P., Automated high-throughput generation of droplets, LAB ON A CHIP, ISSN: 1473-0197, DOI: 10.1039/c1lc20595a, Vol.11, No.21, pp.3593-3595, 2011
Abstract:

We report a microfluidic technique for high-throughput generation of droplets of nanolitre volume in parallel channels with online control of the volumes, volume fraction and distribution of droplet volumes with the use of two external valves.

Keywords:

microfluidics, droplet generation, droplets

Affiliations:
Guzowski J.-other affiliation
Korczyk P.M.-IPPT PAN
Jakieła S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
14.Jakieła S., Makulska S., Korczyk P.M., Garstecki P., Speed of flow of individual droplets in microfluidic channels as a function of the capillary number, volume of droplets and contrast of viscosities, LAB ON A CHIP, ISSN: 1473-0197, DOI: 10.1039/c1lc20534j, Vol.11, No.21, pp.3603-3608, 2011
Abstract:

Droplet microfluidic techniques offer an attractive compromise between the throughput (of i.e. reactions per second) and the number of input/output controls needed to control them. Reduction of the number of controls follows from the confinement to essentially one-dimensional flow of slugs in channels which—in turn—relies heavily on the speed of flow of droplets. This speed is a complicated function of numerous parameters, including the volume of droplets (or length L of slugs), their viscosity μd, viscosity μc and rate of flow of the continuous phase, interfacial tension and geometry of the cross-section of the channel. Systematic screens of the impact of these parameters on the speed of droplets remain an open challenge. Here we detail an automated system that screens the speeds of individual droplets at a rate of up to 2000 experiments per hour, with high precision and without human intervention. The results of measurements in channels of square cross-section (of width w = 360 μm) for four different values of the contrast of viscosities λ = μd/μc = 0.3, 1, 3, and 33, wide ranges of values of the capillary number Ca ∈ (10−4, 10−1), and wide ranges of lengths of droplets l = L/w ∈ (0.8, 30) show that the speed of droplets depends significantly both on l and on λ. The dependence on Ca is very strong for λ > 1, while it is less important both for λ ≤ 1 and for λ ≫ 1.

Keywords:

microfluidics, capillary flow, droplets

Affiliations:
Jakieła S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Makulska S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Korczyk P.M.-IPPT PAN
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
15.Szymborski T., Korczyk P.M., Hołyst R., Garstecki P., Ionic polarization of liquid-liquid interfaces; dynamic control of the rate of electro-coalescence, APPLIED PHYSICS LETTERS, ISSN: 0003-6951, DOI: 10.1063/1.3629783, Vol.99, pp.094101-1-4, 2011
Abstract:

Electrostatic forces are the strongest interactions in soft matter physics, yet they are usually screened by ions present in the solutions. Here we demonstrate that the extent of ionic polarization of liquid-liquid interfaces can be dynamically controlled via appropriate choice of the strength and frequency of the external electric field. Results of microfluidic experiments on electro-coalescence of droplets of aqueous solutions of salt provide guidelines for optimization of the process.

Keywords:

electro-coalescence, droplets, microfluidics

Affiliations:
Szymborski T.-other affiliation
Korczyk P.M.-IPPT PAN
Hołyst R.-other affiliation
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
16.Churski K., Korczyk P., Garstecki P., High-throughput automated droplet microfluidic system for screening of reaction conditions, LAB ON A CHIP, ISSN: 1473-0197, DOI: 10.1039/b925500a, Vol.10, pp.816-818, 2010
Abstract:

We demonstrate a new droplet on demand (DOD) technique and an integrated system for scanning of arbitrary combinations of 3 miscible solutions in ∼1.5 μL droplets at 3 Hz. The DOD system uses standard electromagnetic valves that are external to the microfluidic chip. This feature makes up for modularity, simplicity of assembly and compatibility with virtually any microfluidic chip and yields an on-chip footprint of less than 1 mm2. A novel protocol for formation of DOD enables generation of an arbitrarily large range of volumes of droplets at a maximum operational frequency of ∼30 Hz. The integrated system that we demonstrate can be used to scan up to 10000 conditions of chemical and biochemical reactions per hour using ∼10 mL of solutions in total.

Keywords:

microfluidics, automation, droplet on demand, droplet

Affiliations:
Churski K.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Korczyk P.-IPPT PAN
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
17.Malinowski Sz., Andrejczuk M., Grabowski W., Korczyk P., Smolarkiewicz P., Kowalewski T.A., Laboratory and modeling studies of cloud-clear air interfacial mixing: anisotropy of small-scale turbulence due to evaporative cooling, NEW JOURNAL OF PHYSICS, ISSN: 1367-2630, DOI: 10.1088/1367-2630/10/7/075020, Vol.10, pp.75020-15, 2008
Abstract:

Small-scale mixing between cloudy air and unsaturated clear air is investigated in numerical simulations and in a laboratory cloud chamber. Despite substantial differences in physical conditions and some differences in resolved scales of motion, results of both studies indicate that small-scale turbulence generated through cloud–clear air interfacial mixing is highly anisotropic. For velocity fluctuations, numerical simulations and cloud chamber observations demonstrate that the vertical velocity variance is up to a factor of two larger than the horizontal velocity variance. The Taylor microscales calculated separately for the horizontal and vertical directions also indicate anisotropy of turbulent eddies. This anisotropy is attributed to production of turbulent kinetic energy (TKE) by buoyancy forces due to evaporative cooling of cloud droplets at the cloud–clear air interface. Numerical simulations quantify the effects of buoyancy oscillations relative to the values expected from adiabatic and isobaric mixing, standardly assumed in cloud physics. The buoyancy oscillations result from microscale transport of liquid water due to the gravitational sedimentation of cloud droplets. In the particular modeling setup considered here, these oscillations contribute to about a fifth of the total TKE production.

Keywords:

laboratory cloud formation, TKE of cloud air, microscale cloud turbulence

Affiliations:
Malinowski Sz.-other affiliation
Andrejczuk M.-other affiliation
Grabowski W.-other affiliation
Korczyk P.-IPPT PAN
Smolarkiewicz P.-other affiliation
Kowalewski T.A.-IPPT PAN
18.Kowalewski T.A., Błoński S., Korczyk P., Eksperymentalna analiza przeplywów w skali mikro i nano, Wybrane zagadnienia przepływów i wymiany ciepła, Vol.6, pp.127-149, 2008
Keywords:

mikroprzepływy, eksperymentalna mechanika płynów

Affiliations:
Kowalewski T.A.-IPPT PAN
Błoński S.-IPPT PAN
Korczyk P.-IPPT PAN
19.Błoński S., Korczyk P., Kowalewski T.A., Analysis of turbulence in a micro-channel emulsifier, INTERNATIONAL JOURNAL OF THERMAL SCIENCES, ISSN: 1290-0729, DOI: 10.1016/j.ijthermalsci.2007.01.028, Vol.46, pp.1123-1141, 2007
Abstract:

Turbulent flow of water in an 1 mm long and 0.4 mm high gap of an emulsifier is investigated experimentally using micro-PIV technique and compared with numerical predictions. The purpose of the investigations is to develop a procedure for well-controlled generation of mono-disperse suspension of micro-droplets. The micro-flow measurements are based on epi-fluorescence illumination and high-speed imaging. The experimental data are compared with the numerical results obtained using direct simulation and turbulent flow model. From the turbulent modelling (k−ε) was found that, the maximum of turbulent energy dissipation rate takes place mainly in the micro-channel gap. However, measured and directly simulated (DNS) velocity fields indicate that flow turbulization is delayed and develops shortly behind the gap. Experimental and numerical results are used to predict droplet dimension of two different oil emulsions. Very low amount of oil-phase fraction in investigated emulsions justifies us to use flow characteristics evaluated for pure water to predict mean diameter of oil droplets. These predictions are validated using experimental data on statistics of droplets size.

Keywords:

Micro-flow, Micro-PIV, Particle Image Velocimetry, Turbulence, Micro-channel, Emulsion

Affiliations:
Błoński S.-IPPT PAN
Korczyk P.-IPPT PAN
Kowalewski T.A.-IPPT PAN
20.Korczyk P., Malinowski S.P., Kowalewski T.A., Mixing of cloud and clear air in centimeter scales observed in laboratory by means of Particle Image Velocimetry, ATMOSPHERIC RESEARCH, ISSN: 0169-8095, DOI: 10.1016/j.atmosres.2005.09.009, Vol.82, pp.173-182, 2006
Abstract:

Cloudy air, containing small water droplets, undergoes mixing with the unsaturated environment inside the cloud chamber in the process resembling smallest scales of entrainment and mixing in real clouds. Particle Image Velocimetry (PIV) applied to images from the chamber interior is used to investigate dynamics of the process in scales from 1.2 mm to few centimeters. A special algorithm, allowing for investigation of droplets motion, is developed, tested and adapted to the experimental data. Two velocity components retrieved in the vertical cross-section through the chamber interior indicate anisotropy of small-scale turbulent motions, with the preferred vertical direction. This result confirms earlier numerical studies, indicating that evaporation of cloud droplets at the cloud – clear air interface may substantially influence the small-scale turbulence in clouds.

Keywords:

Atmospheric turbulence, Turbulence in clouds, Small-scale turbulence, Laboratory investigations of atmospheric turbulence, Particle Image Velocimetry

Affiliations:
Korczyk P.-IPPT PAN
Malinowski S.P.-other affiliation
Kowalewski T.A.-IPPT PAN

List of recent monographs
1.
91
Korczyk P., Drobnoskalowa turbulencja w procesie mieszania chmury z otoczeniem – model laboratoryjny, IPPT Reports on Fundamental Technological Research, 4, pp.1-131, 2008
List of chapters in recent monographs
1.
240
Kowalewski T.A., Błoński S., Korczyk P., Wybrane zagadnienia przepływu płynów i wymiany ciepła, rozdział: Eksperymentalna analiza przepływów w skali mikro i nano, Oficyna Wydawnicza Politechniki Warszawskiej (Warszawa), Suchecki W. (Eds.), pp.127-149, 2008

Conference papers
1.Malinowski S.P., Górska A., Kowalewski T.A., Korczyk P., Błoński S., Kumala W., Small-scale mixing at cloud top observed in a laboratory cloud chamber - preliminary results, 13th AMS Conference on Cloud Physics, 2010-06-28/07-02, Portland (US), Vol.P1.22, pp.1-4, 2010
Keywords:

small-scale turbulence, cloud, cloud droplets, evaporation

Affiliations:
Malinowski S.P.-other affiliation
Górska A.-other affiliation
Kowalewski T.A.-IPPT PAN
Korczyk P.-IPPT PAN
Błoński S.-IPPT PAN
Kumala W.-University of Warsaw (PL)

Conference abstracts
1.Korczyk P.M., Microfluidic traps - a new tool for precise manipulation on small droplets, KKNM, 4th National Conference on Nano- and Micromechanics, 2014-07-08/07-10, Wrocław (PL), pp.21-22, 2014
Keywords:

microfluidics, droplets

Affiliations:
Korczyk P.M.-IPPT PAN
2.Korczyk P.M., Van Steijn V., Błoński S., Kowalewski T.A., Garstecki P., Mechanism of generation of droplets in a T-junction for low capillary numbers, XXI FMC, XXI Fluid Mechanics Conference, 2014-06-15/06-18, Kraków (PL), pp.117, 2014
Keywords:

microfluidics, lab on a chip, droplets, T-junction

Affiliations:
Korczyk P.M.-IPPT PAN
Van Steijn V.-Delft University of Technology (NL)
Błoński S.-IPPT PAN
Kowalewski T.A.-IPPT PAN
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
3.Korczyk P.M., Jakieła S., Derzsi L., Garstecki P., Microfluidic traps for precise operations on droplets, III National Conference of Nano and Micromechanics, 2012-07-04/07-06, Warszawa (PL), pp.139, 2012
Abstract:

Techniques operating on droplets and treating them as single reactors are very promising due to their advantage: i) lack of dispersion, ii) fast mixing, iii) superior control on kinetics of reactions, iv) easy to paralelization v) small volume The challenge is to control the size and the content of each droplet simultaneously.
We present concept of microfluidic modules that taking advantage of the capillary back pressure allow to trap, dose and realize precise portion of liquid. The precision is encrypted in the geometry of the device and large mismatch of shear stresses and capillary forces. This mismatch guaranties reproducibility over a wide range of rates of flow that need not be controlled precisely. We also demonstrate that these modules allow to built systems that perform complicated protocols precisely while nor precise control.

Keywords:

microfluidics, droplets

Affiliations:
Korczyk P.M.-IPPT PAN
Jakieła S.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Derzsi L.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)