The Northeast Complex Fluids and Soft Matter Workshop brings together researchers working on the science and engineering of complex fluids and soft matter, including polymers, granular materials, biomaterials, colloids, foams, and liquid crystals. This informal workshop will bring together researchers to exchange ideas and foster collaborations. The workshops host a mix of invited talks, short presentations, and networking time.
The 6th Northeast Complex Fluids and Soft Matter (NCS) workshop will be held at Stevens Institute of Technology in Hoboken, NJ on January 13th, 2017. The NCS workshop is a one-day event hosted bi-annually at research universities in the NJ/NY/CT area. Previous workshops were held at Rutgers University, City College of New York, New Jersey Institute of Technology, Stony Brook University, and NYU Tandon.
Registration is free; however, in order to participate registration is required by January 9th, 2017, using the form below. Please indicate on the registration form if you wish to participate in a presentation (oral or poster). Short talks will be approximately eight minutes in length.
Lunch will be provided for all attendees.
If the form below is not loading, please use this link to register.
Click title to expand abstract.
The pioneering work of Landau, Levich and Derjaguin (LLD) has remained the founding of the coating theory for more than half a century. When a solid substrate is withdrawn from a liquid reservoir, a film is deposited on the substrate whose thickness is uniquely selected by the substrate speed, according to the LLD theory. However, when the contact angle is finite, i.e. for a partially wetting substrate, the film only forms above a critical speed. Here we investigate this transition using direct and adaptive computations of Navier-Stokes equations with surface tension. We demonstrate the scale dependence of the computations that arises from applying mesh refinement near the contact line, a consequence of the well-known contact line singularity resolved through a numerical slip. We show how this scaling depends on the contact angle, mesh size, and the viscosity ratio. We then propose a procedure for realizing grid-independent solutions. The proposed numerical model can be thought of as a large scale computation in an asymptotic matching procedure. This is a joint work with Stéphane Zaleski (UPMC).
I will present a new system of nanoparticles grafted with ion-containing long polymer chains at low graft density regime to explore their potentials as polyelectrolyte membranes. Polystyrene-b-poly(styrene sulfonate) grafted superparamagnetic nanoparticles form side-by-side aggregated strings and retain their structures in ionic liquid, 1-hexyl-3-methylimidazolium bis(trifluormethylsulfonyl)imide. Transmission electron tomography results revealed that these aggregates are monolayers of particles at low sulfonations and planar-like networks at 3 mol % sulfonation in the ionic liquid. Organization of magnetic nanoparticles with the polymer grafting approach is shown, for the first time, to enhance conductivity upon incorporation of an ionic liquid.
The sustained operation of colloidal machines – that is, dynamic assemblies of colloidal components that perform useful functions – requires a steady input of energy, which must be delivered remotely and converted efficiently into useful motions. In this context, we have developed an electric motor that operates efficiently at small scales using electrostatic forces powered by steady electric (or electrochemical) currents. The underlying mechanism – termed contact charge electrophoresis (CCEP) – relies on the electrostatic actuation of conductive particles or droplets, which are repeatedly charged by contact with biased electrodes. In contrast to traditional forms of electrophoresis or dielectrophoresis, CCEP allows for rapid and sustained particle motions driven by low power DC voltages, which make it an ideal mechanism for powering the active components of small machines (e.g., mobile microfluidic technologies). This talk will describe the basic physics underlying CCEP motions and present several strategies for rectifying these motions to achieve useful functions such as microfluidic droplet generation, transport, and mixing.
Microrheology is a set of maturing methods and techniques with unique capabilities to aid our understanding of a material's rheological properties or help in the design of new materials. Microrheology uses the movement of colloidal particles in a material, essentially as tiny, "embedded rheometers." The operating regime of microrheology favors samples that are softer and more delicate than those that have played important roles in the development of the field---polymers, glassy liquids, elastomers---these lie outside the operating range of most microrheology methods. But microrheology opens a wide range of samples and conditions which may be difficult, if not impossible, to measure by conventional rheometry. From the studies of Heilbronn, Freundlich, and Seifriz in the early 20th century on, particles have been used to measure rheology in small sample volumes. Today, particle tracking, single-particle interferometry, magnetic bead, and laser tweezer microrheology typically require sample volumes between ~1 and 10 microliters. This opens up many scarce and expensive materials to rheological characterization. Formulations of protein therapeutics and emerging biomaterials are just two examples. Because the acquisition times are short, the small sample dimensions facilitate rapid mass and heat transfer, and the methods can harness microfluidics for sample preparation and manipulation, microrheology enables rapid screening of conditions and compositions to capture the "genome" of a material. Microrheology is growing in its versatility and importance for characterizing and engineering complex fluids.
Foam injection into the subsurface is performed to improve gas mobility control during the extraction of residual oil or remediation of contaminated sites. Foam improves the gas mobility control as the gas viscosity is increased through its dispersion into a liquid phase. Finer the bubbles the lower the gas apparent viscosity (or foam viscosity) and the better is the sweep efficiency. A chemical surfactant is generally used to maintain an optimal foam texture (number of bubbles for unit volume). However, it can be desorbed making the foam coarser.
Here, we present an experimental and modeling study on the effect of nanoparticles on foam stability. Nanoparticles are adsorbed onto the bubble interface irreversibly and, therefore, they are expected to keep the desired texture of the foam for the entire time of an application. In this work, we use silica nanoparticles in conjunction with a surfactant to study the transport behavior of a CO2 foam in a porous medium. Employing selected surfactant and nanoparticle concentrations to the foam under the conditions of a deep formation, foam viscosity is of one order of magnitude larger than when only a surfactant is used, suggesting a better control of the mobility of the foam. The flow was described by a mechanistic population balance model (PBE) coupled with the fractional flow equation and constitutive equations for foam generation and destruction based on lamella division and bubble coalescence mechanisms, respectively, developed for a surfactant-stabilized foam. Experiments and theory agree well and the validated model allowed to predict the evolution of the foam under various conditions of interest.
Download schedule .PDF here.
|8:15-8:55 a.m.||Breakfast and Registration||Babbio Center, Room 122. Registration and poster setup in atrium outside room 122.|
|8:55-9:00 a.m.||Welcome Remarks||Mo Dehghani, Vice Provost of Research|
|9:00-9:30 a.m.||Pinar Akcora, Stevens Institute of Technology||"Dispersion of ion-containing polymer grafted nanoparticles in ionic liquids"|
|9:30-10:00 a.m.||Kyle Bishop,Columbia University||"Contact charge electrophoresios for powering colloidal machines"|
|10:00-10:20 a.m.||Coffee Break|
|10:20-11:50 a.m.||Short Presentations I: Experiments|
|1||Wei Xu, Stevens Institute of Technology||"Low-voltage droplet manipulation via tunable wetting on smart polymers"|
|2||Xiaoyi Hu, Stony Brook University||"Destabilization of viscosity stratifications in microfluidic channel: interfacial waves and droplets"|
|3||Dong Song, Stevens Institute of Technology||"A comparison between static de-icing and dynamic anti-icing properties of superhydrophobic surfaces"|
|4||Lin Lei, Rutgers University||"Morphological control of melting gel materials by electrospray"|
|5||Madhu Majji, City College of New York||"Inertial migration in Taylor-Couette flow"|
|6||Siqi Du, Rutgers University||"Deterministic lateral displacement systems with anchored-liquid obstacles"|
|7||David Gagnon, University of Pennsylvania||"Swimming in complex fluids"|
|8||Tianxing Ma, Rutgers University||"Focused laser spike dewetting of metallic thin films"|
|9||Ivana Seric, New Jersey Institute of Technology||"Explicit demonstration of the role of Marangoni effect in the breakup of nanoscale liquid filaments"|
|11:50-1:20 p.m.||Lunch and Poster Presentations||Babbio Atrium|
|1:20-1:50 p.m.||Shahriar Afkhami, New Jersey Institute of Technology||"Large scale simulation of forced dewetting"|
|1:50-2:20 p.m.||Joel Koplik,City University of New York||"Nanoparticles at interfaces"|
|2:20-2:40 p.m.||Coffee Break|
|2:40-3:40 p.m.||Short Presentations II: Theory and Simulations|
|1||Salman Sohrabi, Lehigh University||"Efficient Capture and Release of Cells through a Micro-patterned Surface"|
|2||Abbas Fakhari, University of Notre Dame||"Numerical simulation of partial coalescence cascade"|
|3||Sheng Mao, Princeton University||"Particle aggregation during receptor-mediated endocytosis"|
|4||Pejman Sanaei, New Jersey Institute of Technology||"Modeling Branching Pore Structures in Membrane Filters"|
|5||Siddhartha Sarkar, Princeton University||"Elastic multipole method for describing deformations of 2D solid structures"|
|6||Tianya Yin, Rutgers University||"Molecular dynamics simulation of particle re-entrainment induced by a moving liquid-liquid interface"|
|3:40-4:00 p.m.||Coffee Break|
|4:00-4:30 p.m.||Eric Furst, University of Delaware||"Microrheology for soft materials discovery and characterization"|
|4:30-5:00 p.m.||Valentina Prigiobbe,Stevens Institute of Technology||"Nanoparticle-stabilized foam transport in porous media"|
Students may set up their posters upon arrival in Babbio Atrium and leave them up all day. Students should stand by their posters to receive questions from attendees starting at 12:45 p.m.