PARISlab research group at UCLA

Group of Prof. Bauchy

Our research group focuses on improving materials of engineering and industrial relevance. Our goal is to understand composition-nano/micro-structure-properties relationships in materials at a fundamental level. To this end, we use a computational physical/material science approach, supported by experiments.

In strong collaboration with the Laboratory for the Chemistry of Construction (LC2) Materials, we work at establishing a new paradigm in civil engineering by modeling materials at different scales – from atoms to continuum – to improve their performance and sustainability.

Open positions

  • Summer 2017PhD

    Ph.D. Student Position

    Mesoscale simulations of gel/colloids/granular materials.

  • Any timeInternship

    Undergraduate Internship

    Research internships in various areas are possible at any time in the year.

  • Mid-2017Post-PhD

    Postdoc Positions

    1. Design/fabrication of advanced cementitious composites
    2. Design and optimization of CO2 utilization processes

Contact us to apply to an open position and join the PARISlab!

Funding

  • National Science Fundation 2016

    Collaborative Research: Elucidating the Physical Origins of Creep in Cementitious Materials Towards Improved Prediction and Prescription of Creep-Resistant Binders

    UCLA–TAMU

  • Department of Energy 2016

    The Influences of Neutron Irradiation on Aggregate Induced Degradation of Concrete

    UCLA-ASU-ORNL-NIST-INL-EPRI

  • Corning Inc. 2015

    Mixed-ion effect in silicate glasses

    UCLA

Awards received by PARISlab members

  • 2017
    Glass Age Scholarship – Xin Li
    The Glass Age Scholarship is awarded to one student at the collegiate level, providing an opportunity to work closely with Corning scientists on a research project to help guide academic glass science research.

    Xin Li is a M.S. student in the Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab) at the University of California, Los Angeles – she is the 2017-2018 Glass Age Scholar. She will be working collaboratively with Corning Incorporated scientists and UCLA engineers to continue research in glass science and highlight the importance of research at the academic level.

    Glass Age Scholarship 2017/2018

  • 2017
    Alfred R. Cooper Scholars Award - Yushu Hu
    The Alfred R. Cooper Scholars Award recognizes an undergraduate student who has demonstrated excellence in research, engineering, and/or study in glass science or technology. It is awarded by the Glass & Optical Materials Division of The American Ceramic Society. This undergraduate award is named in honor of the late Professor Alfred R. Cooper, Jr., member of the faculty at Case Western Reserve University and a prominent contributor to the understanding of many glass phenomena and glass problems.

    2017 Cooper Award

  • 2017
    Norbert J. Kreidl Award - Yingtian Yu
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    The Norbert J. Kreidl Award for Young Scholars is attributed by the American Ceramic Society and recognizes research excellence in glass science.

    Title: Stretched exponential relaxation of glasses: Origin of the mixed alkali effect

    Abstract: Although it is commonly believed that as frozen supercooled liquids, glasses should continue to flow over the years (e.g., in the case of the stained glass windows of medieval cathedrals), the dramatic increase of their viscosity below the glass transition temperature suggests the contrary—that their relaxation time is on the order of 1032 years at room temperature. A recent study conducted by Mauro et al. reported the intriguing dynamics of the relaxation of a commercial Corning® Gorilla Glass® at room temperature, over 1.5 years. We report a novel atomistic simulation method that allows us to directly access the long-term (years) dynamics of glass relaxation at room temperature. Based on the simulation of a series of mixed alkali silicate glasses, we demonstrate that room temperature relaxation is a direct consequence of the mixed alkali effect. Although both volume and energy feature a stretched exponential relaxation, our results reveal a bifurcation of the stretching exponents, with b = 3/5 and 3/7 for energy and volume relaxation, respectively. Relaxation occurs through the diffusion of local stressed structural instabilities inside the atomic network, which anneal each other when a compressed atomic unit meets one that is under tension. The driving force for this diffusion-trap relaxation mechanism is at a maximum when the concentrations of each alkali atom equals each other, which arises from a balance between the concentration of each alkali atom and the magnitude of the local stress that they undergo.

    2017 Norbert J. Kreidl Award

  • 2017
    GOMD Poster award – Yingtian Yu
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    Award received at the GOMD meeting for the poster “Origin of the Mixed Modifier Effect on Hardness”
  • 2017
    GOMD Travel Grant – Yingtian Yu
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    Travel grant to attend the GOMD 2017 meeting of the American Ceramic Society in Waikoloa, Hawaii.
  • 2016
    GOMD Poster award – Mengyi Wang
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    Award received at the GOMD meeting for the poster “Topological control on the dissolution of borosilicate glasses”
  • 2016
    GOMD Travel Grant – Mengyi Wang
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    Travel grant to attend the GOMD 2016 meeting of the American Ceramic Society in Madison.
  • 2015
    Glass Age Scholarship – Mengyi Wang
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    The Glass Age Scholarship is awarded to one student at the collegiate level, providing an opportunity to work closely with Corning scientists on a research project to help guide academic glass science research.

    Mengyi Wang is a M.S. student in the Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab) at the University of California, Los Angeles – she is the 2015-2016 Glass Age Scholar. Wang was selected for her academic research proposal, which spanned multiple areas of interest to the glass science industry, as part of Corning’s Glass Age Scholarship Program. She will be working collaboratively with Corning Incorporated scientists and UCLA engineers to continue research in glass science and highlight the importance of research at the academic level.

  • 2014
    Future Leader Nomination - The American Ceramic Society
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    The nomation to the Future Leader Program (FLP) recognises exemplary work and potential as a future leader in the ceramics and glass industry.

    2014 Future Leader Program

  • 2012
    Norbert J. Kreidl Award - The American Ceramic Society
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    The Norbert J. Kreidl Award for Young Scholars is attributed by the American Ceramic Society and recognizes research excellence in glass science.

    Topological Constraints and Rigidity of Network Glasses from Molecular Dynamics Simulations

    Topological constraint theory provides an interesting means to understand the important microscopic physics governing the thermal, mechanical and rheological properties of glasses with changing compositions, while filtering out unnecessary details that ultimately do not affect its macroscopic properties. It has been successful in predicting compositional trends in covalent network-forming glasses such as chalcogenides. Its application appears however more challenging in iono-covalent glasses such as silicates where neighbors/bonds and angles need to be properly defined. Here we derive such constraints for different alkali silicates using an atomic scale approach (Molecular Dynamics, MD) combined with partial bond angle distributions (PBAD). The latter allows having access to the second moments (standard deviations) of the distributions. Large (small) standard deviations correspond to large (small) angular excursions around a mean value, and are identified as broken (intact) bond-bending constraints. A similar procedure is used for bond-stretching constraints. Systems examined include glassy and liquid disilicate 2SiO2-M2O (LS2, NS2, KS2). In the glass, MD constraint counting closely matches Maxwell enumeration of constraints using the octet binding (8-N) rule. Results show that the standard deviations of the partial bond angle distributions increase with temperature and suggest a softening of bond-bending constraints. A bimodal bonding oxygen distribution is obtained for T>Tg, and the fraction of thermally activated broken bond-bending constraints computed as a function of temperature. As a preliminary work, pressure effects are also presented. Overall, these results provide a microscopic rationale for extending constraint counting from chalcogenides to complex oxides, and also a numerical basis for recent functional forms of temperature-dependent constraints proposed from energy landscape approaches.

    2012 Norbert J. Kreidl Award

Featured publications

Evidence for Anomalous Dynamic Heterogeneities in Isostatic Supercooled Liquids

Papers
M Micoulaut, M Bauchy
Physical Review Letters 118 (14), 145502
Publication year: 2017

Compositional thresholds and anomalies in connection with stiffness transitions in network glasses

Papers
M Bauchy, M Micoulaut, M Boero, C Massobrio
Physical review letters 110 (16), 165501
Publication year: 2013

Combinatorial molecular optimization of cement hydrates

Papers
KJVVRJMP M.J. Abdolhosseini Qomi, K.J. Krakowiak, M. Bauchy, K.L. Stewart, R ...
Nature Communications 5
Publication year: 2014

Rigidity transition in materials: hardness is driven by weak atomic constraints

Papers
M Bauchy, MJA Qomi, C Bichara, FJ Ulm, RJM Pellenq
Physical review letters 114 (12), 125502
Publication year: 2015

Stretched Exponential Relaxation of Glasses at Low Temperature

Papers
Y Yu, M Wang, D Zhang, B Wang, G Sant, M Bauchy
Physical Review Letters 115, 165901
Publication year: 2015

Mesoscale texture of cement hydrates

Papers
K Ioannidou, KJ Krakowiak, M Bauchy, CG Hoover, E Masoero, S Yip, ...
Proceedings of the National Academy of Sciences 113 (8), 2029-2034
Publication year: 2016