News & EventsDepartment Events
Events
-
May16
EVENT DETAILS
Abstract: While classical elasticity theory describes the mechanical deformation of solids without any reference whatsoever to the atomic constituents of matter, modern lattice dynamics provides quantitative ways to compute elastic constants in terms of atomic-scale configurations and interactions. Within this framework, the fundamental problem is reduced to evaluating forces and configurations in MD simulations. Nonetheless, for real solids (incl. crystals with defects and grain boundaries, non-centrosymmetric crystals, heated crystals, glasses), the elasticity is dominated by relaxational atomic motions that are not included in standard (Born-Huang) lattice dynamics [1-4]. These atomic motions are referred to, in the current literature, as “nonaffine motions”: they are associated with incompatible deformations, and are ubiquitous in real-life materials. In general, since they stem from the relaxation of local interatomic forces due to the lack of inversion symmetry, the nonaffine motions are linked to a significant decrease (softening) of the elastic constants, in particular the shear modulus. For example, nonaffine motions can quantitatively explain the mechanics of diverse systems such as the jamming transition and marginal elasticity of granular packings [2] as well as the experimentally observed elastic constants of α-quartz [3]. Nonaffine motions can also explain the frequency-dependent viscoelasticity of disordered materials such as polymer glass [4]. This is because, on long time scales, the relaxational nonaffine motions dominate the mechanical response (the zero-frequency plateau modulus), whereas, at high external oscillation frequencies, they become gradually less significant compared to the affine or Born modulus. A recent atomistic implementation of this principle, called NALD (Nonaffine Lattice Dynamics), provides a new way to solve the time-scale bridging problem of materials mechanics [5,6], whereby traditional atomistic MD simulations are strongly limited by the simulation time-step, and its predictions are confined to deformation frequencies/time-scales that are too high to be accessible experimentally. Because NALD leverages the direct diagonalization of the Hessian matrix of the solid, it is perfectly feasible for the atomic-level description of the mechanical properties of nanostructured materials, in combination with the state of the art in interatomic forces and interactions. Finally, NALD also provides a way to quantitatively define topological defects in glassy materials akin to dislocations in crystals [7]. These well-defined topological defects have recently been observed experimentally for the first time in glasses [8] and are potentially the game changer for the hitherto elusive mechanism of plastic deformation and failure of glassy materials [9].
[1] J. C. Slonczewski and H. Thomas, Phys. Rev. B 1, 3599 (1970)
[2] A. Zaccone and E. Scossa-Romano, Phys. Rev. B 83, 184205 (2011)
[3] B. Cui, A. Zaccone, D. Rodney, J. Chem. Phys. 151, 224509 (2019)
[4] A. Zaccone “Theory of Disordered Solids”, Springer Monograph (2023)
[5] R. M. Elder, A. Zaccone, T. W. Sirk, ACS Macro Letters 8, 9, 1160–1165 (2019)
[6] V. Vaibhav, T. W. Sirk, A. Zaccone, Macromolecules 57, 23, 10885–10893 (2024)
[7] M. Baggioli, I. Kriuchevskyi, T. W. Sirk, A. Zaccone, Phys. Rev. Lett. 127, 015501 (2021)
[8] V. Vaibhav, A. Bera, A. C. Y. Liu, M. Baggioli, P. Keim & A. Zaccone, Nature Communications 16, 55 (2025)
[9] A. Bera, et al. PNAS Nexus, 3, 9, pgae315 (2024); A. Bera, A. Zaccone, M. Baggioli, https://arxiv.org/abs/2407.20631v1.
Alessio Zaccone received his Ph.D. from the Department of Chemistry of ETH Zurich in 2010. From 2010 till 2014 he was an Oppenheimer Research Fellow at the Cavendish Laboratory, University of Cambridge. After being on the faculty of Technical University Munich (2014–2015) and of University of Cambridge (2015–2018), he has been a full professor and chair of theoretical physics in the Department of Physics at the University of Milano. Awards include the ETH Silver Medal, the 2020 Gauss Professorship of the Göttingen Academy of Sciences, the Fellowship of Queens' College Cambridge, and an ERC Consolidator grant "Multimech". Research contributions include the exact solution to the jamming transition problem of granular matter (Zaccone & Scossa-Romano PRB 2011), the analytical solution to the random close packing problem in 2d and 3d (Zaccone PRL 2022), the theory of colloidal aggregation processes in shear flows (Zaccone et al PRE 2009), the theory of crystal nucleation under shear flow (Mura & Zaccone PRE 2016), the theoretical prediction of boson-like peaks in the vibrational spectra of crystals and glasses (Milkus & Zaccone PRB 2016; Baggioli & Zaccone PRL 2019), the molecular-level theory of the glass transition in polymers (Zaccone & Terentjev PRL 2013), the theoretical, computational and experimental discovery of topological defects in glasses (Baggioli, Kriuchevskyi, Sirk, Zaccone PRL 2021; Vaibhav et al. Nature Comm. 2025), and the theoretical predictions of superconductivity enhancement effects due to phonon anharmonicity (Setty, Baggioli, Zaccone PRB 2020) and thin-film confinement (Travaglino & Zaccone JAP 2023). Research interests range from the statistical physics of disordered systems (random packings, materials mechanics, granular packings, glasses and the glass transition, colloids, nonequilibrium thermodynamics) to solid-state physics and superconductivity.
TIME Friday, May 16, 2025 at 11:00 AM - 12:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
-
May16
EVENT DETAILS
TBA
TIME Friday, May 16, 2025 at 2:00 PM - 3:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
-
May19
EVENT DETAILS
TBA
TIME Monday, May 19, 2025 at 11:00 AM - 12:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
-
May21
EVENT DETAILS
TBA
TIME Wednesday, May 21, 2025 at 11:00 AM - 12:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
-
May23
EVENT DETAILS
Abstract: Anaerobic Membrane Bioreactor (AnMBR) is a promising technology for sustainable domestic wastewater (DWW) treatment, enabling energy, water, and nutrients recovery at low biomass production rates. However, membrane fouling remains a major challenge, increasing costs and limiting long-term performance. While fouling is often attributed to biomass components like extracellular polymeric substances (EPS), the mechanisms linking biomass responses to operational conditions and fouling remain poorly understood. This study presents a mechanistic framework for AnMBR fouling, demonstrating how changes in organic loading rate (OLR) and coagulant addition influence sludge rheology, sludge dewaterability, EPS hydration and viscoelasticity, and ultimately affecting membrane fouling propensity. Parallel investigations at lab- and pilot-scale AnMBR systems treating real DWW provide a unique comparison between controlled and real-world conditions. Our integrated microscale-to-macroscale approach captures the complexity of biomass behavior. On the microscale, EPS hydration and viscoelasticity were analyzed using quartz crystal microbalance with dissipation (QCM-D) and localized surface plasmon resonance (LSPR). On the macroscale, dynamic rheometry, sludge volume index (SVI), and capillary suction time (CST) quantified biomass stability and dewaterability, while optical coherence tomography (OCT) and scanning electron microscopy (SEM) revealed biomass floc structure and fouling layer formation. Our findings provide an expansive explanation of how OLR and coagulant addition affect biomass destabilization and membrane fouling in AnMBR for DWW treatment, paving the way for improved fouling mitigation strategies and contributing to more stable and cost-effective AnMBR operations.
Bio- Moshe Herzberg is a full professor at the Zuckerberg Institute for Water Research in Ben-Gurion University of the Negev, ISRAEL, appointed as a faculty member, since 2007. Prof. Herzberg did his postdoctoral training in Yale University and received both a PhD in Agricultural Engineering and BSc in Chemical Engineering from the Technion, the Israel Institute of Technology. Prof. Herzberg’s research interests focus on microbial biofilms, biofouling and fouling of membranes, interfacial processes that relate to membrane separation and “anti-fouling” modified-membranes. Prof. Herzberg is an author of 90 scientific publications and more than 140 presentations and seminars. He serves as a co-leader of the CoWERC, the US-Israel Collaborative Water-Energy Research Center. Prof. Herzberg is currently performing an enhanced synergistic collaboration with different scientists and industries around the world, from Jordan, Italy, the united-states, and Israel.
TIME Friday, May 23, 2025 at 2:00 PM - 3:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
-
May28
EVENT DETAILS
TBA
TIME Wednesday, May 28, 2025 at 11:00 AM - 12:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
-
May30
EVENT DETAILS
Abstract
The use of nanomaterials has become a rapidly growing approach for advanced water treatment technologies, but the continued emergence of highly oxidation-resistant micropollutants, such as per- and polyfluoroalkyl substances (PFAS), calls for transformative strategies that move beyond recent oxidation-based remediation practices. Alternative reduction-based approaches utilizing aqueous electrons (eaq−, Eo = −2.9 V)—one of the most reactive nucleophilic species—are emerging as a promising solution for efficient PFAS breakdown. Herein, we leverage nanoconfinement engineering to enable a new water treatment approach—plasmon-mediated advanced reduction processes (PARPs)—for efficient, chemical-free PFAS destruction at room temperature. We first present novel nanoreactor designs that engineer the ‘nanoconfinement effect’, i.e. unique aggregation-induced interparticle interactions that are inaccessible by typical unconfined, bulk-phase nanomaterials. We demonstrate that the precisely controlled nanoconfinement of plasmonic nanoparticles can generate highly reactive reducing species under UV irradiation, capable of breaking even the strong C–F bonds in PFAS. The nanoreactor we developed achieved 81.5% mineralization of perfluorooctanoic acid (PFOA) after 24 hours of UV irradiation in pure water at room temperature, compared to only 16.6% mineralization by UV photolysis. Further reaction monitoring under various conditions and multimodal NMR-guided investigation were conducted to elucidate PFAS degradation mechanisms and pathways. We further explored the potential of PARPs for the chemical-free remediation of nitrate, a prevalent oxyanion pollutant that is resistant to conventional oxidation-based treatments. Our findings highlight the transformative promise of nanoconfinement engineering to catalyze innovation in environmental nanotechnology and extend the frontier of advanced reduction processes for water treatment.
Bio- Haklae Lee is a PhD student in the Environmental Engineering & Science program and a member of the Gray Lab in the Department of Civil and Environmental Engineering at Northwestern University. He holds a B.S. and M.S. in Environmental Engineering from Pusan National University in South Korea. His work focuses on the design and engineering of nano-sized reactors for efficient and more sustainable remediation of emerging contaminants from wastewater. He uses mesoporous silica to spatially confine various metal nanoparticles within multi-layered nanoreactors, enabling unique features such as multifunctional compartments and nanoconfinement effects for previously unexplored environmental applications.
TIME Friday, May 30, 2025 at 2:00 PM - 3:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
-
Jun4
EVENT DETAILS
TBA
TIME Wednesday, June 4, 2025 at 11:00 AM - 12:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
-
Jun15
EVENT DETAILSmore info
2024-2025 Commencement Ceremony
TIME Sunday, June 15, 2025
CONTACT Office of the Registrar nu-registrar@northwestern.edu EMAIL
CALENDAR University Academic Calendar
-
Jun16
EVENT DETAILS
McCormick School of Engineering PhD Hooding and Master's Degree Recognition Ceremony. The most up to date information can be found on our graduation webpage.
TIME Monday, June 16, 2025 at 9:00 AM - 11:00 AM
LOCATION 2705 Ashland Ave
CONTACT Northwestern Engineering Events northwestern-engineering-events@northwestern.edu EMAIL
CALENDAR McCormick School of Engineering and Applied Science
-
Jun16
EVENT DETAILSmore info
McCormick School of Engineering Undergraduate Convocation. The most up to date information can be found on our graduation webpage.
TIME Monday, June 16, 2025 at 2:00 PM - 4:00 PM
LOCATION 2705 Ashland Ave
CONTACT Northwestern Engineering Events northwestern-engineering-events@northwestern.edu EMAIL
CALENDAR McCormick School of Engineering and Applied Science