Francisco J. Galindo-Rosales

Francisco J. Galindo-Rosales
University of Porto | UP

PhD

About

89
Publications
16,084
Reads
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1,226
Citations
Citations since 2016
52 Research Items
957 Citations
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
Introduction
My research interests lie on the field of Rheology and Colloids: Master Thesis and PhD Thesis at Universidad de Málaga and postdoc at K.U. Leuven to study about the dispersion quality of fillers in nanocomposites. Since 2010, I work at the Transport Phenomena Research Center (CEFT) in the University of Porto and I have extending my expertise towards Microfluidics, Extensional Flows, Porous Media, cork composites and fluid-structure interactions. galindo[at]fe.up.pt curro[at]galindorosales.com
Additional affiliations
December 2013 - present
University of Porto
Position
  • Research Assistant
May 2010 - December 2013
University of Porto
Position
  • PostDoc Position
October 2008 - February 2010
KU Leuven
Position
  • PostDoc Position

Publications

Publications (89)
Article
We find and study the viscoelastic transition in transonic flow focusing when polymers of low molecular weights are dissolved in water at the appropriate concentration. This phenomenon is explained in terms of the coil-stretch transition of the polymers crossing the tapering meniscus, where the airstream produces very large strain rates. The result...
Article
Material extrusion is an additive manufacturing process in which material is selectively dispensed through a nozzle. In this work, we are focused on fused filament fabrication (FFF) and we intend to analyze the melt flow patterns generated by a commercial version of polycarbonate, modelled by means of a viscoelastic model (Giesekus) based on rheolo...
Article
Full-text available
It is a common practice to add rheology modifiers to functional inks, such as graphene inks, to optimize the rheological properties so that they can be printed with a certain printing technique. This practice may lead to inks formulations with poorer electrical, optical, and mechanical performance upon its application, which are of paramount import...
Article
Full-text available
Microbots have been considered powerful tools in minimally invasive medicine. In the last few years, the topic has been highly studied by researchers across the globe to further develop the capabilities of microbots in medicine. One of many applications of these devices is performing surgical procedures inside the human circulatory system. It is ex...
Article
Full-text available
This study represents a pioneering work on the extensional magnetorheological properties of human blood analogue fluids loaded with magnetic microparticles. Dynabeads M-270 particles were dispersed in Newtonian and viscoelastic blood analogue fluids at 5% wt. Capillary breakup experiments were performed, with and without the influence of an externa...
Preprint
Full-text available
We find and study the viscoelastic transition in transonic flow focusing when polymers of low molecular weights are dissolved in water at the appropriate concentration. This phenomenon is explained in terms of the coil-stretch transition of the polymers crossing the tapering meniscus, where the airstream produces very large strain rates. The result...
Preprint
Full-text available
Rotational rheometers are extremely sensitive instruments that are able to provide very accurate measurements of low values of different material functions, such as viscosity and viscoelastic moduli, under certain ideal flow conditions. Nevertheless, they fail in providing reliable data for the viscosity when measured at short time scales due to ei...
Article
Motivated by the recent developments in the research of untethered microrobots for performing minimally invasive procedures inside blood vessels, we have devised a novel microfluidic experiment for studying the haemodynamics around different types of cylinders confined inside a straight, long, 270×100μm channel. Two test sections are studied: flow...
Article
The present works contributes with a rheological characterization of the most commonly used polymers and solvents to formulate amorphous solid dispersions by means of spray drying process: copovidone, hydroxypropyl methylcellulose (HPMC), hydroxypropyl methylcellulose acetate succinate (HPMCAS) and a copolymer of methacrylic acid and methyl methacr...
Article
Full-text available
This is the supplementary information of the research paper “Haemodynamics around confined microscopic cylinders” by Rodrigues et al. [1]. The critical overlap concentration of entanglement of polymer coils indicates whether a polymer solution is dilute or semidilute. Here, the reader will find the determination of c* for xanthan gum aqueous soluti...
Preprint
Full-text available
A nonlinear block-coupled Finite Volume methodology is developed for large displacement and large strain regime. The new methodology uses the same normal and tangential face derivative discretisations found in the original fully coupled cell-centred Finite Volume solution methodology for linear elasticity, meaning that existing block-coupled implem...
Article
We study both numerically and experimentally the breakup of a viscoelastic liquid bridge formed between two parallel electrodes. The polymer solutions and applied voltages are those commonly used in electrospinning and near-field electrospinning. We solve the leaky-dielectric finitely extensible nonlinear elastic-Peterlin (FENE-P) model to describe...
Article
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
Full-text available
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle...
Article
This work presents a simple model of the flow generated in microchannels when the upper lid has a vertical deformation that depends on time and space. This model is able to capture the dynamics of the flow generated for two fundamental cases: full displacement of the upper lid and the flow generated by an impactor. The results for these cases have...
Preprint
Full-text available
We study both numerically and experimentally the breakup of a viscoelastic liquid bridge between two parallel electrodes. We solve the leaky-dielectric FENE-P model to describe the dynamical response of the liquid bridge under isothermal conditions. The results show that the surface charge screens the inner electric field perpendicular to the free...
Preprint
Full-text available
Dense suspensions of model hard-sphere-like colloids, with different particle sizes, are examined experimentally in the glass state, under shear and extensional rheology. Under steady shear flow we detect Discontinuous Shear Thickening (DST) above a critical shear rate. Start-up shear experiments show stress overshoots in the vicinity of the onset...
Article
Full-text available
In this study, we propose a new way of optimising the formulation of ferrofluids for oil-spill clean-up processes, based on the rheological behaviour under extensional flow and magnetic fields. Different commercial ferrofluids (FFs), consisting of a set of six ferrofluids with different magnetic saturation and particle concentration, were character...
Article
Over the last three decades, a variety of additive manufacturing techniques have gradually gained maturity and will potentially play an important role in future manufacturing industries. Among them, direct ink writing has attracted significant attention from both material and tissue engineering areas, where the colloidal ink is extruded and dispens...
Article
Full-text available
In this paper, we present a preliminary study and conceptual idea concerning 3D printing water-sensitive glass, using a borosilicate glass with high alkali and alkaline oxide contents as an example in direct ink writing. The investigated material was prepared in the form of a glass frit, which was further ground in order to obtain a fine powder of...
Preprint
In this paper, we present a preliminary study and conceptual idea concerning 3D printing water-sensitive glass by exemplifying with a borosilicate glass with high alkali and alkaline oxide contents using direct ink writing. The investigated material was prepared in the form of a glass frit, which was further ground in order to obtain a fine powder...
Chapter
As a branch of direct 3D printing technique, Robocasting is a promising candidate to fulfil multiple material printing [1]. Currently, the Robocasting community commonly utilizes small amplitude oscillatory shear (SAOS) tests to evaluate the printability and stiffness of the pastes for Robocasting, while large amplitude oscillatory shear (LAOS) tes...
Chapter
This preliminary numerical investigation is carried out in order to assess the usefulness of a new variant of the sliding cylinder approach to determine “instantaneous” viscosity under unsteady flow conditions. A fixed cylindrical reservoir is considered with a coaxial inner cylinder which is sliding into the liquid with different time dependent ve...
Chapter
How does flow inside a microfluidic device behave when passing by a pressure tap? Will its natural state be disrupted by any means? We seek to answer these questions and assess the consequences (if any) of attaching pressure taps to microchannels. To do so, streakline photography was performed for flow patterns visualisation in the close proximity...
Chapter
When performing extensional ER tests for the characterization of electro-rheological fluids, the time between applying the electric field and triggering the experiment (delay time) plays an important role in ER behaviour of the sample. The current study investigates the delay time effect in extensional ER characterization. The ER sample used in the...
Article
Full-text available
This work introduces a novel design of a fixture to be adapted to the commercial version of the capillary breakup extensional rheometer (CaBER), here termed as an extensional magneto-rheological fixture (ExMRFx), that allows the characterization of magnetic fluids under uniaxial extensional flow. The fixture consists of four solenoids that generate...
Book
This book presents the proceedings of IBEREO 2019. This conference addresses the most recent trends in rheology with a special emphasis on both basic science and industrial applications. Papers presented cover different perspectives, like experimental, theoretical and numerical. Topics include Microfluidics and microrheology, Food, Cosmetics and Ph...
Article
Full-text available
Uniaxial extensional flow is a canonical flow typically used in rheological characterization to provide complementary information to that obtained by imposing simple shear flow. In spite of the importance of having a full rheological characterization of complex fluids, publications on the rheological characterization of mobile liquids under extensi...
Article
Full-text available
A new electrorheological cell for the Capillary Breakup Extensional Rheometer (Haake™ CaBER 1™, Thermo Scientific) allowing the analysis of the rheological properties of complex fluids under the simultaneous application of an extensional flow and an electric field has been developed and tested. In this study, the add-on is described in full detail...
Technical Report
Full-text available
I would like to share with you that we are currently equipped in our research group with magnetorheological and electrorheological cells (both patents pending) specifically designed to work with the Capillary BreakUp Extensional Rheometer (CaBER). If you are interested in collaborating with us, please send me a message. "Capillary Breakup Extension...
Article
In this paper we analyse the jet of non-Newtonian power law fluids emerging from a tube with a diameter D and impinging on a flat plate, which is receiving from the other side a constant heat flux. To that end, different numerical simulations have been carried out with the one dimensional fully developed axisymmetric velocity profile used as bounda...
Article
Full-text available
Fused Filament Fabrication is an extrusion deposition technique in which a thermoplastic filament is melted, pushed through a nozzle and deposited to build, layer-by-layer, custom 3D geometries. Despite being one of the most widely used techniques in 3D printing, there are still some challenges to be addressed. One of them is the accurate control o...
Article
Full-text available
Measuring fluid pressure in microchannels is difficult and constitutes a challenge to even the most experienced of experimentalists. Currently, to the best of the authors’ knowledge, no optimal solution are being used for the design of pressure taps, nor guidelines concerning their shape and its relation with the accuracy of the readings. In an att...
Chapter
In this chapter, a numerical study and assessment of the mixing efficiency of a novel microfluidic device for mixing two fluids are presented. The device under study consists of a two-dimensional straight microchannel with a square pillar centered across the channel. The main fluid flows through the microchannel from the main inlet to the outlet, w...
Chapter
Complex fluids are everywhere, literally, just need to look around you, or even closer, inside your own body. These fluids are named complex because when they flow, they do not hold a linear relationship between the rate of deformation and the stress tensors, and consequently the Newton’s law of viscosity is not suitable for them. In this chapter,...
Article
Full-text available
The development of engineered systems for energy dissipation (or absorption) during impacts or vibrations is an increasing need in our society, mainly for human protection applications, but also for ensuring the right performance of different sort of devices, facilities or installations. In the last decade, new energy dissipating composites based o...
Patent
The present disclosure relates to the customization of a composite layer material for absorbing or dissipating mechanical energy under impacts or vibrations. The composite layer material comprises at least a support layer of a resilient material, said support layer having recessed fluid-tight microchannels comprising a fluid, wherein the channel se...
Article
A new experimental setup for the study of the flow dynamics around 3D microbot prototypes in a straight microchannel has been developed. The ultimate aim of this work is focused on the analysis of the morphology of different microbot prototypes to get a better insight of their efficiency when they swim through the main conduits of the human circula...
Article
Full-text available
The interest in the development of blood analogues has been increasing recently as a consequence of the increment in the number of experimental hemodynamic studies and the difficulties associated with the manipulation of real blood in vitro because of ethical, economical or hazardous issues. Although one-phase Newtonian and non-Newtonian blood anal...
Conference Paper
Axial migration of individual red blood cells (RBCs) is a well known effect that happens in microchannels with dimensions below 300 μm. This effect is known as the Fåhræus-Lindqvist effect gives place to a cell free layer (CFL) of plasma located around the walls of the microchannel [1]. Several flow studies regarding the CFL measurement exist in in...
Article
This work presents a technique and develops an apparatus that allows the application of homogeneous external magnetic fields (parallel or perpendicular to the deformation axis) to a fluid sample undergoing extensional flow kinematics while measuring the filament thinning using the commercial version of the capillary breakup extensional rheometer (H...
Article
Many artificial and natural fluids contain macromolecules, particles or droplets that impart complex flow behaviour to the fluid. This complex behaviour results in a non-linear relationship between stress and deformation standing in between Newton’s law of viscosity for an ideal viscous liquid and Hooke’s law for an ideal elastic material. Such non...
Article
Full-text available
Flow velocimetry measurements are made on a non-shear-banding wormlike micellar solution within high-aspect-ratio rectilinear microchannels over a wide range of imposed steady flow rates. At the lowest and highest flow rates tested, Newtonian-like velocity profiles are measured. However, at intermediate flow rates the velocity field never stabilize...
Article
Microfluidic cross-slot devices can generate wide regions of vorticity-free strong extensional flow near the stagnation point, resulting in large extensional deformation and orientation of the microstructure of complex fluids, with possible applications in extensional rheometry and hydrodynamic stretching of single cells or molecules. Standard cros...
Article
Full-text available
A gelation process was seen to occur when Boger fluids made from aqueous solutions of polyacrylamide (PAA) and NaCl flowed through porous media with certain characteristics. As these viscoelastic fluids flow through a porous medium, the pressure drop across the bed varies linearly with the flow rate, as also happens with Newtonian fluids. Above a c...
Article
Extensional flows and the underlying stability/instability mechanisms are of extreme relevance to the efficient operation of inkjet printing, coating processes and drug delivery systems, as well as for the generation of micro droplets. The development of an extensional rheometer to characterize the extensional properties of low viscosity fluids has...
Article
A new apparent viscosity function for shear thickening fluids has been recently published [1], which is able to cover the three characteristic regions typically exhibited by these materials (thinning/thickening/thinning). The proposed function was shown to provide an excellent fitting to several independent data sets used. However, although its for...
Article
In this work we focus on the development of low viscosity Boger fluids and assess their elasticity analyzing the flow through a microfluidic hyperbolic contraction. Rheological tests in shear and extensional flows were carried out in order to evaluate the effect of the addition of a salt (NaCl) to dilute aqueous solutions of polyacrylamide at 400,...
Chapter
Process engineering deals with the processing of large quantities of materials and they must be transported from one unit operation to another within the processing environment. This is commonly made through pipelines, where occurs a dissipation of energy due essentially to frictional losses against the inside wall of the pipe and changes in the in...
Article
Full-text available
The properties of filled polymers and nanocomposites are strongly linked to the adequate dispersion of the solid phase into a polymeric matrix. However, obtaining the degree of dispersion within a polymer composite system is far from trivial. Typical methods for microstructural analysis such as electron and optical microscopy or scattering methods...
Article
AbstractA new apparent viscosity function for shear thickening fluids is proposed, contemplating the three characteristic regions typically exhibited by these materials: slight shear thinning at low shear rates, followed by a sharp viscosity increase over a threshold shear rate value (critical shear rate), and a subsequent pronounced shear thinning...
Article
Full-text available
In this study, two microfluidic devices are proposed as simplified 1-D microfluidic analogues of a porous medium. The objectives are twofold: firstly to assess the usefulness of the microchannels to mimic the porous medium in a controlled and simplified manner, and secondly to obtain a better insight about the flow characteristics of viscoelastic f...