Botto Research Group

My group is interested in fundamental aspects of microscale fluid mechanics and transport phenomena in multiphase systems. My name is Lorenzo Botto, and I am leading the group since 2013.  I have recently joined the Process & Energy Department of TU Delft, Faculty of Mechanical, Maritime and Materials Engineering. I was at Queen Mary University of London until Oct. 1 2019. For any enquiries you can reach me at l.botto “at” tudelft.nl.

Much of my group’s research focuses on topics at the interface between classical fluid mechanics and materials science.

These include the flow properties of carbon materials (particularly graphene), the mechanisms of formation of solid-stabilised emulsions, the formation of fibers from spun liquids, and the fluid dynamics of naturally-occurring fragile flocs. The underpinning science is to be found in the classical fields of multiphase flow dynamics of dispersed systems (particles, colloids) and wetting (surface tension) phenomena.

The mission of the group is to provide rigorous analysis and underpinning fluid dynamics science that can support the development of advanced materials, and the accurate characterisation of naturally-occurring materials. I am particularly interested in developing liquid-based processing methods to produce energy materials on large scales.

A second line of research is what I like to define as Fluid Dynamics for Society. Topics where society benefits directly, rather than via the knowledge support that typically the academic world gives to industrial research. Examples of this line of research are the development of engineering tools to “democratise” COVID dispersion simulation, enabling everyone with a modest exposure to CFD to create meaningful simulations; my research on the fluid dynamics of sedimentation, towards improved predictive models to understand morphological changes in rivers due to sediment transport; and my research on liquid repellency of textiles.

Recent contributions from my group are:

•  the development of mathematical models to predict the liquid-phase exfoliation of graphene
•  the discovery of flow induced alignment in graphene particles due to slip
• the development of the FIPI method for the efficient simulation of 3-phase/3-component flow problems relevant to particle-stabilised interfaces
• the elucidation of the interaction of liquids with textiles for smart-textiles applications through flow visualisation and X-Ray imaging
• improvements in our understanding of droplet interactions mediated by elasto-capillarity and transport problems in self-assembled membranes

Most recently, we have also contributed to the first accurate simulation of sedimentation of a river floc accounting for the actual geometry of a REAL floc (including the geometry associated to inorganic particles, organic components and living matter) . This work is done in collaboration with the School of Geography at QMUL, and is achieved by combining Stokesian dynamics simulations with imaging obtained by focused ion beam nanotomography, a technique typically used to image extremely fragile biomaterials.

Thanks to support from the European Research Council we have initiated an ambitious research line on the hydrodynamics of graphene and other flexible 2D nanomaterials. Recent contributions in this area are pioneering research on flow-induced dispersion of graphene particles and slip-mediated graphene particle orientation in shear flow.

The ERC project FlexNanoFlow aims to understand the  dynamics of 2D nanomaterials in sheared liquids, how nanosheets deform, break and orient themselves in complex flows, for applications such as coating, printing, and nanocomposites manufacturing.

My group uses primarily simulation and theory. However our studies often starts from experimental observations. We are building our own experimental lab, and collaborate extensively with experimentalists in the UK and abroad. We collaborate with fluid mechanicians, soft matter physics,  colloids and interface scientists, and materials engineers. 

Current research areas are:

• graphene hydrodynamics: modelling deformation and dispersion of 2D nanomaterials in sheared liquids
• fundamentals of dispersed multiphase flows, including drops, particulate suspensions, and powders;
• modelling of particle-laden drops,  bubbles and emulsions, for applications to materials science (e.g. nanoparticle stabilised polymer blends) and chemical engineering;
• micromechanics of and solute transport in biological and bioengineered materials, including cell mechanics and transport in gels for regenerative medicine; 
• capillary deformation of drops on deformable substrates (“soft wetting”);
• fluidisation of pharmaceutical drug powders in inhaler devices;
• liquid transport in textiles via X-ray microscopy.

Funding

ERC Starting Grant Project “FLEXNANOFLOW”  (from 2017-04-01 to 2022-03-31)

2D nanomaterials hold immense technological promise thanks to extraordinary intrinsic properties such as ultra-high conductivity, strength and unusual semiconducting properties. Our understanding of how these extremely thin and flexible objects are processed in flow is however inadequate, and this is hindering progress towards true market applications. When processed in liquid environments to make nanocomposites, conductive coatings and energy storage devices, 2D nanomaterials tend to fold and break owing to strong shear forces produced by the mechanical agitation of the liquid. This can lead to poorly-oriented, crumpled sheets of small lateral size and therefore of low intrinsic value. Orientation is also a major issue, as ultra-flexible materials are difficult to extend and align. In this project, we will develop nanoscale fluid-structure simulation techniques to capture with unprecedented resolution the unsteady deformation and fracture dynamics of single and multiple sheets in response to the complex hydrodynamic load produced by shearing flows. In addition, we will demonstrate via simulations new strategies to exploit capillary forces to structure 2D nanomaterials into 3D constructs of desired morphology. To guide the simulations and explore a wider parameter space than allowed in computations, we will develop conceptually new experiments on “scaled-up 2D nanomaterials”. The simulations will include continuum treatments and atomistic details, and will be analysed within the theoretical framework of microhydrodynamics and non-linear solid mechanics. By uncovering the physical principles governing flow-induced deformation of 2D nanomaterials, this project will have a profound impact on our ability to produce and process 2D nanomaterials on large scales.

Several PhD and postdoctoral positions are available for this project. If you are interested in joining my group, feel free to contact me at l.botto@qmul.ac.uk.

A graphene ink: how does it flow? [Image’s copyright: EnerAge Inc.]

RECENT NEWS

• Gannian Zhang has successfully defended his PhD thesis, which focused on wetting of liquid-repellent textiles
• Ms. Claire Savonnet is visiting the group from École nationale supérieure des mines de Saint-Étienne, to perform a research project during the Summer. Welcome Claire!
•  Dr. Srinivasa Ramisetti, working in University of Leeds with Prof. Dognsheng Wen, has visited the group and given a talk on “Slip flow over nano-structured surfaces & nano gas films”. Dr. Ramisetti’s visit has been supported by a UK Fluids Short Research Visit grant
• 9/5/2018 – Lorenzo Botto’s talk at Euromech Colloquium “NUMERICAL SIMULATIONS OF FLOWS WITH PARTICLES, BUBBLES AND DROPLETS”, in Venice, Italy. Seminar title:“3-phase flows with particles: the FIPI method for the fast simulation of particle-drop and particle-bubble interactions”
•  our group member Jake Bewick has won Best 3rd Year Project Student award at the QMUL Industrial Liaison Forum meeting for his thesis on modelling of cell buckling . Jake has been a fantastic student.
•  PhD student Gannian Zhang has won the 2018 Best Student Presentation award at the SEMS PhD Student Forum with his presentation on “Drop impact on textiles” (work done in collaboration with Rafael Castrejon Pita and the UK Defence Science and Technology Laboratory).