Bulletin of the American Physical Society
APS March Meeting 2018
Volume 63, Number 1
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session H57: Soft Matter in Industrial ApplicationsFocus
|
Hide Abstracts |
Sponsoring Units: GSOFT Chair: Jie Ren, Merck & Co., Inc. Room: LACC 518 |
Tuesday, March 6, 2018 2:30PM - 3:06PM |
H57.00001: How Sand Gets to the Bottom of the Sea: Turbidity Currents and Deep Water Oil and Gas Reservoirs Invited Speaker: Thomas Halsey Subaqueous turbidity currents may be the dominant mechanism by which sediments are moved from continents into the deep ocean; these flows are critical in the formation of submarine canyons and corresponding submarine fans. Sediments deposited in these settings can, under the right circumstances, assume economic importance as deep water oil and gas reservoirs. In 1986 Parker, Fukushima, and Pantin introduced a depth-averaged mechanical model for these currents, intending to identify the circumstances under which the erosion of underlying material by a turbidity current could lead to an “auto-igniting” sustainable flow. We use a simplified version of their model to map a global regime diagram for these flows as a function of the Richardson and Rouse numbers of the flows; in different segments of this diagram the flows are predominantly depositional, erosional, or bypass in nature. We identify those features of microscopic erosion, deposition, and clear-water entrainment physics that control these large-scale stratigraphic properties. |
Tuesday, March 6, 2018 3:06PM - 3:18PM |
H57.00002: The Use of Molecular Simulations to Construct and Study Organic Pores and Fluids Present in Shale Reservoirs Felipe Perez Valencia, Deepak Devegowda In this work, we use molecular simulations to create molecular models of organic matter found in shales (the so-called kerogen) to study the spatial distribution and flow of fluids in unconventional reservoirs. The models account for the chemical functionality of kerogen with the corresponding degree of thermal maturity and the densities are consistent with reported experimental data. For overmature kerogen, the models serve as rigid frameworks for the study of adsorption of pure CH4 and CO2 using Monte Carlo simulations. For mature kerogen, we study the spatial distribution of a mixture of hydrocarbons (representative of a volatile oil), asphaltenes/resins, water, and carbon dioxide in organic pores using equilibrium molecular dynamics. We then employ these models as rigid frameworks for the investigation of flow of liquid dodecane through organic matter using nonequilibrium molecular dynamics. All the simulations are run at typical reservoir conditions. |
Tuesday, March 6, 2018 3:18PM - 3:30PM |
H57.00003: Predictive Drug Release Modeling from Micro-Structural Imaging of Long-Acting Pharmaceutical Devices Daniel Skomski, Roberto Irizarry, Antong Chen, Ryan Teller, Seth Forster, Megan Mackey, Li Li, Zhen Liu, Stephanie Barrett, Wei Xu For pharmaceutical products, long-acting release formulations that achieve continual drug release over many months or years are desirable for disease prevention and treatment through improvements in patient compliance. A major challenge in the development of these long-acting formulations is that they require lengthy and costly clinical trials. To reduce development timelines, it is of interest to pioneer methods that can preemptively assess the suitability of different formulations to inform on process parameter optimization and batch consistency. To help address these challenges, predictive tools that can generate theoretical drug release profiles are needed. However, drug release from long-acting formulations is mechanistically complex and is mediated not only by composition, but also the macro- and micro-structure of the device. Thus, there is a pressing need to characterize the intricate pharmaceutical structures to enable sophisticated predictive modeling solutions. A novel approach to predictive drug release modeling is presented that combines 3D micro-imaging and diffusional models to simulate drug transport through a pharmaceutical device. An example of an in-line product is discussed and these tools are being applied to guide formulation of development candidate LAPs. |
Tuesday, March 6, 2018 3:30PM - 3:42PM |
H57.00004: Optimizing Constriction Flow with Submerged Granular Hoppers Juha Koivisto, Marko Korhonen, Antti Puisto, Mikko Alava, Carlos Ortiz, Douglas Durian In granular hoppers, discrete particles flow out small hole due to gravity. Usually the role of air is considered negligible on both discharge rate and clogging probability. However, this is not so for hoppers submerged in a viscous fluid like water. Our experiments [1] and simulations [2] show a counterintuitive terminal surge, where the discharge rate increases as the hopper empties. This is accompanied and caused by a fluid-is-faster effect whereby the interstitial fluid flows downwards faster than the grains. For applications, this raises the possibility to (i) tune the discharge rate by pumping fluid through the medium at controlled rate, (ii) prevent clogging, and (iii) maximize throughput. |
Tuesday, March 6, 2018 3:42PM - 3:54PM |
H57.00005: Hyperuniformity with no fine tuning in sheared sedimenting suspensions Jikai Wang, Jennifer Schwarz, Joseph Paulsen Particle suspensions, present in many natural and industrial settings, typically contain aggregates and other microstructures that can complicate flow behaviors and damage processing equipment. Recent work found that applying uniform periodic shear near a critical transition can reduce fluctuations in the local particle concentration across all length scales, leading to a hyperuniform state. However, this strategy for homogenization requires fine tuning of the strain amplitude. Here we show that in a model of sedimenting particles under periodic shear, there is a well-defined regime at low sedimentation speed where hyperuniform density fluctuations automatically occur. Our simulations and theoretical arguments show that hyperuniformity is lost beyond a finite lengthscale that is set by vertical density gradients. Nonetheless, this lengthscale can be made arbitrarily large simply by slowing the sedimentation rate. |
Tuesday, March 6, 2018 3:54PM - 4:06PM |
H57.00006: Microfluidic double emulsions and microparticles for the delivery of hydrophilic active pharmaceutical ingredients. Marine Truchet, Patrick Tabeling, Jean-Pierre Burnouf Encapsulation of active pharmaceutical ingredients (API) is widely used in the pharmaceutical industry to control their release over several days or weeks. |
Tuesday, March 6, 2018 4:06PM - 4:18PM |
H57.00007: Advanced Polymeric Architectures for Biomedical Applications Victoria Piunova This presentation will discuss the design and synthesis of gel-core star polymers as drug delivery vehicles and antimicrobial agents. Well-defined, multi-armed star polymers have been prepared by an “arm first” synthetic approach. Strategies to introduce core and/or peripheral functionality into the gel-core star polymers have been taken to tailor the properties of the carriers. A combination of molecular simulations and experimental results provides insight into the mechanism of star polymer formation and cargo encapsulation. |
Tuesday, March 6, 2018 4:18PM - 4:30PM |
H57.00008: Mesoscale Model For The Self-Assembly And Cross-Linking Dynamics of HPV Virus-Like Particles Oleksandr Zavalov, Roberto Irizarry, Matthew Flamm, Ryan Marek We present a novel Kinetic Monte Carlo modeling strategy to simulate the assembly and maturation of Human Papillomavirus (HPV) virus-like particles (VLPs) across a wide range of experimental conditions. The approach allows for the concurrent tracking of capsomeres during their assembly into HPV capsids and the formation of stabilizing intercapsomeric disulfide bonds (“L1 cross-linking”) in the real-time scale. The dynamical cross-linking process has been introduced in the model by using the mechanistic probability rules between involved L1 cysteine residues. The model incorporates real experimental data from an in vitro assembly system and the detailed information of VLP geometrical structure. We checked on the hypothesis related to important factors affecting the rates of capsid initiation, HPV VLP growth and cross-linking. The objective of this study was to leverage the model to advance the mechanistic understanding of the assembly and particle maturation process in order to screen for and prioritize process optimization strategies. |
Tuesday, March 6, 2018 4:30PM - 4:42PM |
H57.00009: Drying inhomogeneity of waterborne latex particles Hao Huang, H Daniel Ou-Yang, Willie Lau, Mohamed El-Aasser Waterborne latex (polymer particles suspended in water) forms a polymeric coating after being dried. Contrary to ideally uniform drying, particles in real latexes distribute inhomogeneously in space during drying. This can undermine performances of coatings, such as drying front, cracking, delamination and skin layer formation. To understand drying inhomogeneity, we develop “OCT-Gravimetry- Video” method by combining optical coherence tomography (OCT), analytical balance and video camera together to monitor the drying process. Microscopic images by OCT give the spatial distribution of particles and the internal structure of coating. Water evaporation rates measured by gravimetry and film’s appearance by video are correlated with OCT results. We use this method to study the mechanism of skin layer formation, during which the film dries early on top and forms an impermeable skin that extends the film drying time considerably. Water-soluble additives, that can delay coalescence, were found able to reduce the drying time dramatically. |
Tuesday, March 6, 2018 4:42PM - 4:54PM |
H57.00010: Measuring friction on soft substrates Raisa Rudge, Elke Scholten, Joshua Dijksman The relative motion of two interfaces induces dissipation that we experience as friction. Friction is a complex phenomena that involves many length and time scales. Importantly, friction depends on the composition of the two interfaces sliding with respect to each other. It has been challenging to measure between soft substrates such as hydrogels. We describe a methodology to measure friction between hydrogels of arbitrary composition and discuss how this method reveals nontrivial frictional properties, even for example in the rate independent sliding regime. We link the frictional properties of hydrogels to their surface roughness as obtained with cryo-SEM. |
Tuesday, March 6, 2018 4:54PM - 5:06PM |
H57.00011: Salt Comets in Hand Sanitizer: Salt-Induced Microgel Collapse Arash Nowbahar, Art O'Connor, Vincent Mansard, Patrick Spicer, Todd Squires Yield stress fluids have seen widespread use, with many industrial and consumer products relying on this property for functionality, such as in toothpastes, hair gel, and paint. While some applications employ colloidal gels, e.g. clay particles, others use colloidal glasses such as microgel particles that swell and jam. For example, hand sanitizer is a form of alcohol that sits without falling from the user’s hands due to its yield stress. In this work, we propose a simple experiment that takes advantage of a gel’s yield stress to understand the dynamics of microgel collapse in the presence of salt. The sedimentation of salt particles in hand sanitizer is studied with a diffusion-relaxation model and corroborated with microfluidic experiments, thus revealing a timescale for microgel collapse. |
Tuesday, March 6, 2018 5:06PM - 5:18PM |
H57.00012: Granular Temperature and Competing Dilatational Effects in High Velocity Shear Flows of Angular Mineral Grains Stephanie Taylor, Emily Brodsky Granular temperature may control high-speed granular flows, yet it is difficult to measure in laboratory experiments, particularly when using nonuniform, angular, polydisperse samples. We show that acoustic energy captures the anticipated behavior of granular temperature as a function of grain mass in aspherical mineral sand shear flows. We also find that granular temperature (through its proxy acoustic energy) is nearly linearly proportional to inertial number, and total dilation is proportional to acoustic energy raised to the power 0.6 ± 0.2, representing a combined effect of shear zone dilation, which image analysis shows is linearly proportional to granular temperature, and sub-shear compaction caused by vibration of non-moving grains. This demonstrates a dual role for acoustic vibrations in shear flows. Granular temperature can dilate a flow and simultaneously vibrate the bed, causing a competing compaction. We also find that despite the theoretical dependence of granular temperature on coefficient of restitution, granular temperature and dilation to be most dependent on grain mass. Angular grains of geologically relevant minerals with differing strength and elasticity exhibit effectively the same relationships between granular temperature, dilation and inertial number. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700