Bulletin of the American Physical Society
APS March Meeting 2023
Volume 68, Number 3
Las Vegas, Nevada (March 5-10)
Virtual (March 20-22); Time Zone: Pacific Time
Session N33: Microscopic Self-Assembly II |
Hide Abstracts |
Sponsoring Units: DSOFT Chair: Tine Curk, Johns Hopkins University Room: Room 225 |
Wednesday, March 8, 2023 11:30AM - 11:42AM Author not Attending |
N33.00001: Exploring hydrodynamic effects in colloidal self-assembly using multiparticle collision dynamics (MPCD) simulations Ying-Shuo Peng, Talid Sinno Crystal nucleation is an important phenomenon within the broader context of colloidal self-assembly. Yet, most computational studies of colloidal crystallization have largely ignored the role of hydrodynamic interactions (HI) during nucleation, growth, and dissolution. Recent studies, however, have indicated that HI between particles, even in a quiescent liquid medium, may play a significant role during assembly, potentially impacting crystal growth kinetics [1] and gelation [2]. Jenkins et al. [3], and later Lee et al. [4] also showed that hydrodynamic correlations mediate diffusionless transformation pathways in a floppy colloidal crystal comprised of DNA-functionalized particles. |
Wednesday, March 8, 2023 11:42AM - 11:54AM |
N33.00002: Coiled coil peptide 'bundlemers': model nanoparticles for electrostatically-driven interparticle assembly Yi Shi, Rui Guo, Christopher J Kloxin, Jeffrey G Saven, Darrin J Pochan Computationally designed peptide coiled coils, also named "bundlemers", provide unique opportunities to exactly specify the display of exterior surface amino acid side chains thus offering direct, local control of electrostatic interactions between bundlemers in solution. In this study, highly ordered nanostructures were observed in the presence of particular multivalent couterions in solutions of specifically charged bundlemers. The solutions and final assemblies were characterized by small-angle scattering methods and transmission electron microscopy, respectively. Distinctive assembly morphologies were achieved by various counterions such as multivalent molecular ions, polyelectrolytes, and biomolecules. More importantly, the impact of peptide sequence, and the inherent surface charge anisotropy and patterning, was investigated owing to the inherent programmability of computational design. Two categories of bundlemers were studied: Bundlemers with only positively charged residues ('single-charged' bundlemers) and bundlemers with both positively and negatively charged residues ('mix-charged' bundlemers). Single-charged bundlemers revealed a selection of counterions that induced colloidal crystal-like structures while mix-charged bundlemers formed amorphous aggregates in solution. |
Wednesday, March 8, 2023 11:54AM - 12:06PM |
N33.00003: Single Molecule Magnet and Magnetic Tunnel Junction-based Molecular Spintronics Devices: A Method of Harnessing Exotic Properties of Molecular Nanostructure Pawan Tyagi, Andrew Grizzle, Eva Mutunga Molecules are quantum structures that can be mass-produced with unique optical, magnetic, and transport characteristics molecule-based devices may govern the advancement of logic and memory devices for next-generation computers and may be suitable for quantum computation. However, the biggest challenge is to connect two or three metal electrodes to the molecule(s) and develop a robust and versatile device fabrication technology that can be adopted for commercial-scale mass production. Utilizing tunnel junction as a testbed for making molecular devices solve many critical problems [1]. We focused on producing magnetic tunnel junction-based molecular devices (MTJMSD). This talk will show that an MTJMSD evolves when molecules are bridged along the exposed side edges of a tunnel junctio. With the MTJMSD approach, many unprecedented advantages become available to devise researchers. MTJMSD enables the connection between ferromagnetic electrodes and a variety of molecules with the spin state. For the first time, the MTJMSD approach enabled magnetic measurements and conventional transport studies[1]. Magnetic studies showed that molecules could transform the magnetic[2] and transport properties of the MTJs[3] at room temperature. Molecules' strong impact on ferromagnetic electrodes produced several orders of resistance changes at room temperature. An MTJMSD approach is a high-yield method and can be mass-produced with the conventional microfabrication tools present in typical labs. Our MTJMSD approach also allows numerous control experiments to provide a deep understanding of device mechanisms. This talk will demonstrate two types of control experiments to prove that we successfully made a molecular device. The first control experiment is the reversible impact of making and breaking molecular channels on the overall charge transport. We also performed ferromagnetic resonance before and after damaging the tunnel barrier and damaging the molecular channels by using plasma. In addition, this talk will discuss how the MTJMSD approach is suitable for making light and biochemical sensors, as molecules are present in the open region. |
Wednesday, March 8, 2023 12:06PM - 12:18PM |
N33.00004: Leveraging Curvature to Drive Non-Trivial Corona Morphologies for Anisotropic Particles Tommy Waltmann, Thi Vo, Sharon C Glotzer Nanoparticles can self-assemble into materials with unique optical, electronic, and thermal properties if their shape and interactions are judiciously designed. Previous theoretical works that consider how the shape of the ligand shell around a nanoparticle affects interparticle interactions have successfully predicted experimentally realized assemblies [1]. Here we simulate nanoparticles with a range of core shapes and with ligand shells whose shape varies with the number and length of the ligands as well as with core shape. We focus our study on designing ligand-grafted nanoparticles that are experimentally realizable today but whose synthesis and assembly have not yet been reported. We find that the partitioning of ligands to high curvature regions of the nanoparticle core is a primary driver for effective shape, resulting in nontrivial ligand shell morphologies that we are able to self-assemble into novel structures in hard particle monte carlo simulations. Our findings may help to guide future design and synthesis of nanoparticles for self-assembly. |
Wednesday, March 8, 2023 12:18PM - 12:30PM |
N33.00005: Tunable colloids with dipolar and depletion interactions: towards field-switchable crystals and gels. Anand Yethiraj Micron-scale colloids undergoing Brownian motion are wonderful model experimental systems to understand how atoms crystallize or fail to crystallize. Depletion forces, induced by non-adsorbing polymer, can be used to make new classes of partially ordered or disordered gel-like materials. Dipolar forces, induced by an external electric field, can be used to make ordered crystalline structures. |
Wednesday, March 8, 2023 12:30PM - 12:42PM |
N33.00006: Many-Body Potential for Simulating Self-Assembly of Polymer-Grafted Nanoparticles in a Polymer Matrix Yilong Zhou, Sigbjørn L Bore, Francesco Paesani, Gaurav Arya Many-body effects (interactions) play a key role in promoting low-dimensional assembly of polymer-grafted nanoparticles (NPs) in polymer melts or at interfaces. However, capturing such interactions in molecular dynamics simulations and understanding their effects on self-assembly remain challenging because explicit modeling of the polymers is highly computationally expensive even using coarse-grained models. In this work, we introduce a general machine learning (ML) approach to develop an analytical three-body potential that can describe the many-body interactions between polymer-grafted NPs in a polymer matrix. Our approach involves the use of permutational invariant polynomials to fit the Morse-transformations of interparticle distances. The developed potential reduces the computational cost by several orders of magnitude and thus allows us to explore NP assembly at large length and time scales. We show that the developed three-body potential can reproduce the previously discovered phases including 1d strings and 2d hexagonal sheet and help discover many interesting phases like network strings, small clusters, and gel phases. The roles of three-body contributions on the formation of those phases are also elucidated. Overall, our work suggests the usefulness of machine learning in dealing with complex problems in polymer nanocomposites and in predicting new types of NP assemblies is promising. |
Wednesday, March 8, 2023 12:42PM - 12:54PM |
N33.00007: Capitalizing on Aggregation to Chaperon NPs Across Fluid Interfaces Yuchen Fu, Yu CHAI, Thomas P Russell The transfer of nanoparticles (NPs) from one liquid phase to a second immiscible phase is important in the synthesis, processing, and modification of nanoparticles. However, aggregation of NPs in the solution has long been considered as an undesirable phenomenon, which is regarded as a sign of failure for NPs transfer to another phase. Here, we take advantage of the aggregation to realize a ligand-induced NP transfer. Using oppositely charged amphiphilic polymers, we show that mono-disperse NPs that aggregate in an aqueous phase can be transferred to an oil phase where the aggregates are effectively dissolved, delivering NPs that disperse in the oil phase. This new transfer path challenges the conventional conception of the unsuccessful phase transfer due to NPs aggregation. By jamming the NP-polymer assembly at the liquid/liquid interface, the transfer process can be inhibited. The charged amphiphilic polymers effectively act as chaperons for the NP transfer and provide a unique way to manipulate the dispersion and distribution of the NPs in two immiscible liquids when they are brought into contact. |
Wednesday, March 8, 2023 12:54PM - 1:06PM |
N33.00008: Annular patches leading to the formation of spherical shell and icosahedral structures VIKKI A VARMA In this work, we have proposed a simple potential, leading to the formation of mono-dispersed spherically closed shell, with tuned sizes. We found nucleation rate and kinetics as the key factor deciding theyield of closed shells. High yield of perfectly closed shells have been observed for the shells having smaller size. While yield reduces with increasing the size. The behaviour shown is similar to the biological systems such as viruses. Constituents particles are found unable to get trapped inside the shell, at low volume fraction regime. Structural properties have been found to be independent of the shape and size of the hard-core, except in terms of kinetics. Icosahedral-symmetry have found to be as not the only minimum potential-energy configuration. We found structural rearrangement playing an important role behind closing the shell. Which is also the deciding factor behind the size of the shell for a particular set of potential parameters. |
Wednesday, March 8, 2023 1:06PM - 1:18PM |
N33.00009: Self-assembly of polymers at the interface between two poor solvents Sai ZHAO, Yu CHAI, Yao Liu Interfacially inactive materials do not assemble a liquid surface/interface unless they interact with interfacially active species, e.g., hydrophilic silica nanoparticles assembling at the water-oil interface with the help of surfactant molecules. Here, we show that polymers can spontaneously assemble at an interface between two poor solvents with the help of a good solvent. Polyacrylonitrile (PAN) is not soluble in toluene or water. Dimethyl sulfoxide (DMSO) is a good solvent for PAN and is miscible with toluene and water. We found that by adding a mixture of PAN and DMSO in toluene, PDMS spontaneously diffused across the liquid interface and dissolved in water. During this process, the interfacially inactive material, PAN, is trapped at the interface between toluene and water, therefore forming a solid interfacial film. By conducting various in situ measurements, such as in situ liquid-liquid atomic force microscopy measurements, interfacial tension measurements, etc., we systematically studied the formation and structure of this self-assembled interfacial layer and further explored their use in 3-dimensional all liquid print and thin film fabrication. |
Wednesday, March 8, 2023 1:18PM - 1:30PM |
N33.00010: Organic Field Effect Transistors (OFETs) Fabricated from Phenothiazine-TCNQ Yuri Chung Charge transfer cocrystals have interesting applications in the field of organic electronics due to their |
Wednesday, March 8, 2023 1:30PM - 1:42PM Author not Attending |
N33.00011: Cyclic and Constant Shear SeSP-Doped Disk Packings John A Ryan Superellipse sector particles (SeSPs) are generalizations of an ellipse that define shapes ranging from circles to rods to concave particles. We explore constant and cyclic simple shear of quasi-2-dimensional packings of disks and SeSPs in an annular-planar Couette cell. The packing is sheared quasi-statically and is affected by gravity and a constant pressure. An array of six cameras around the cell offers a 360° view, allowing tracking of the motion of the particles around the entire shear cell. We investigate how the SeSPs affect changes in the packing by quantifying reversibility of motion, shear velocity profiles, mean-squared displacements, and other structure measurements such as pair correlation. We compare how these values change under constant versus cyclic simple shear. Results have implications for industrial and pharmaceutical processes that involve irregular-shaped particle matter. |
Wednesday, March 8, 2023 1:42PM - 1:54PM Author not Attending |
N33.00012: Effective Viscosity and Force Moments of a Hot Particles Suspension Osher Arbib
|
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