Technical Seminars

Fall 2019 Solvay Seminar Series

She-min Heh looks at the camera. The image is a circular crop with an orange dotted circle around the photo for style.

Prof. Ximin He

UCLA

Assistant Professor, Materials Science and Engineering

"Bioinspired Adaptive Materials based on Smart Hydrogels: Sensing, Solar Harvesting, and Soft Robotics"

Date

Wednesday, September 4

Time

11:15 AM - 12:15 PM

Location

Fralin Auditorium

Ximin He is an assistant professor of Materials Science and Engineering at University of California, Los Angeles (UCLA) and Faculty of California Nanosystems Institute (CNSI). Dr. He was postdoctoral research fellow in Wyss Institute of Bioinspired Engineering and School of Engineering and Applied Science at Harvard University. Dr. He received her PhD in Chemistry from University of Cambridge. Dr. He’s research focuses biologically inspired functional smart materials, chemical and biological sensors, actuators with broad applications in materials science, biomedicine, environment, and energy. She has authored/co-authored papers in leading archival journals, book chapters and has a number of patents. Dr. He is the recipient of many young scientist awards including the National Science Foundation CAREER award, Air Force Office of Scientific Research Young Investigator Program (AFOSR YIP) award, CIFAR Global Scholar, International Society of Bionic Engineering (ISBE) Outstanding Youth Award, Hellman Fellows Award, and UCLA Faculty Career Development Award. Her research on bioinspired homeostatic materials and chemo-mechanical molecule separation have garnered a number of regional and international awards and was featured in >100 international news outlets.

From the cellular level up to the body system level, living organisms are able to sense and adapt to local environment for various functions, from detecting and transporting molecules in the complex bio-fluids to harvesting energy from the environment and generate motions to keep alive. These graceful capabilities arise from the coordination of the chemo-mechanical actions, such as the molecular configuration changes and micro/macroscopic mechanical motions. Stimuli-responsive hydrogels are a class of synthetic materials that can change their volume and physical properties in response to environmental cues including temperature, light, and specific molecules. Inspired by these unique abilities, we have developed a series of dynamic material systems based on hydrogels. This presentation will introduce several novel functionalities that this broad-based platform has demonstrated, ranging from beetle-inspired ultrafast colorimetric sensing of chemical and biological species (Adv. Mater. 2018), autonomous sorting of target molecules in complex biofluids or wastewater (Nat. Chem. 2015), and plant-mimetic adaptive light tracking and harvesting, as well as self-sensing actuators for soft robotics (Sci. Robotics 2019). Overall, the environment-adaptive, dynamic material systems would have broad impacts in areas ranging from wearable sensors to smart devices that regulate energy usage and fully autonomous soft robots.

Nick Stephanopoulos looks at the camera. The image is a circular crop with an orange dotted circle around the photo for style.

Prof. Nick Stephanopoulos

Arizona State University

Assistant Professor,  School of Molecular Sciences and the Biodesign Institute’s Center for Molecular Design and Biomimetics

"Hybrid Self-Assembled Nanomaterials from Proteins, Peptides, and DNA"

Date

Wednesday, September 11

Time

11:15 AM - 12:15 PM

Location

Fralin Auditorium

Nicholas Stephanopoulos was born in Athens, Greece, but grew up outside of Boston, Massachusetts. He obtained his A.B. in chemistry from Harvard University, followed by a one-year stint to earn a Master’s in chemical engineering at MIT. He then pursued doctoral studies at the University of California, Berkeley, working with Prof. Matthew Francis. His research focused on using site-specific bioconjugation chemistry to modify viral capsid nano-scaffolds, in order to create materials for energy, biomedicine, and nanotechnology. After earning his PhD in 2010, he went to Northwestern University for postdoctoral studies, supported by both NIH Ruth Kirschtein and International Institute for Nanotechnology fellowships, working with Prof. Samuel Stupp on self-assembling peptide nanomaterials and their applications to regenerative medicine.

At both Berkeley and Northwestern, Prof. Stephanopoulos became interested in integrating proteins and peptides with DNA nanotechnology. In 2015, he began his independent career at Arizona State University, with a goal to merge these molecules into a new class of hybrid nanomaterials, with applications across a range of fields. He is currently an assistant professor in the School of Molecular Sciences and the Biodesign Institute’s Center for Molecular Design and Biomimetics, with affiliate appointments in Biomedical Engineering and Chemical Engineering. Since coming to ASU, Prof. Stephanopoulos has received a number of accolades, including the 2016 Air Force (AFOSR) Young Investigator Award, the 2018 NSF CAREER, and the 2018 NIH Director's New Innovator Award.

The ability to design materials that mimic the complexity and functionality of biological systems is a long standing goal of nanotechnology, with applications in medicine, energy, and fundamental science. Biological molecules such as proteins, peptides, and DNA possess a rich palette of self-assembly motifs and chemical functional diversity, and are attractive building blocks for the synthesis of such nanomaterials. In this talk, we will describe research in creating hybrid materials that incorporate proteins and peptides with DNA nanotechnology to create cages, nanofibers, and 3D crystals with a high degree of programmability and nanoscale resolution. Key to these endeavors will be (bio)molecular design, organic chemistry for linking components in a site-specific fashion, and the tuning of multiple self-assembly "modes" to create hybrid structures. Although the talk will focus on the fundamental chemistry and self-assembly of these systems, we will also discuss potential applications in areas such as targeted cargo delivery, biomaterials for regenerative medicine, and synthesis of virus- and antibody-mimetic nanostructures.

Jacinta Conrad looks at the camera. The image is a circular crop with an orange dotted circle around the photo for style.

Prof. Jacinta Conrad

University of Houston

Frank M Tiller Professor of Chemical and Biomolecular Engineering

"Transport of Nanoparticles through Complex, Crowded Fluids"

Date

Wednesday, September 18

Time

11:15 AM - 12:15 PM

Location

Kelly Hall 310

Jacinta Conrad is a physical scientist studying transport and dynamics within soft, complex materials and matrices. Using a broad range of microscopy, rheology, scattering, and computational methods, her group seeks to understand how microscale particles, including colloids, nanoparticles, bacteria, viruses, and proteins, explore and/or transport through confined and crowded environments containing polymers, macromolecules, or other dispersed species. Insights gained from fundamental studies of these non-equilibrium processes inform the design of new materials for preventing fouling and corrosion, for remediating environmental damage, and for sensitively diagnosing disease. She earned an SB in Mathematics from the University of Chicago and MA and PhD degrees in Physics from Harvard. She worked as a postdoctoral associate in MatSe at Illinois before starting her faculty position at the University of Houston (UH). Currently, she is the Frank M. Tiller Associate Professor of Chemical Engineering at UH and serves as an Associate Editor for ACS Applied Nano Materials.

Transport of nanoparticles affects applications ranging from targeted drug delivery to enhanced oil recovery to processing of nanocomposite materials. In each of these applications, nanoparticles must be transported through a complex fluid to reach the desired target, whether a cancerous tumor, the oil-water interface, or a polymer melt. For large particles, the surrounding medium is effectively homogeneous across the surface of the particle, so that the transport properties can be directly related to the bulk fluid properties. For nanoparticles, however, the particle size is comparable to the length scales of heterogeneities in the fluid so that the particle dynamics decouple from bulk properties and are poorly understood. Here, we combine microscopy and scattering experiments with molecular simulation to investigate how nanoparticles transport through two models of complex fluids: polymer solutions, which model viscoelastic liquids, and supercooled and glassy colloidal liquids, which model crowded suspensions. In each setting, we probe how the dynamics of the nanoparticles are coupled to relaxations of the surrounding liquid. The physics elucidated in these studies will grant better control over the transport and dispersion of nanoparticles through complex, heterogeneous materials.

Rebekka Klausen looks at the camera. The image is a circular crop with an orange dotted circle around the photo for style.

Prof. Rebekka Klausen

Johns Hopkins University

Associate Professor, Chemistry

"Building Block Strategies to Functional Polymers"

Date

Wednesday, September 25

Time

11:15 AM - 12:15 PM

Location

Kelly Hall 310

Dr. Rebekka S. Klausen grew up in Brookline, MA. She graduated cum laude from Boston College in 2005, where she did research in the laboratory of Dr. Steven D. Bruner. Dr. Klausen completed her doctoral research under the supervision of Dr. Eric N. Jacobsen at the Department of Chemistry and Chemical Biology at Harvard University (2005-2011), where she carried out mechanistic studies on a thiourea and Brønsted acid co-catalyzed Pictet–Spengler reaction. She carried out postdoctoral research with Dr. Colin Nuckolls at the Columbia University Department of Chemistry (2011-2013) on the topic of single molecule electronics.

Dr. Klausen initiated her independent research program at the Johns Hopkins University Department of Chemistry in 2013, where she is now an Associate Professor with tenure. Research in the Klausen Group focuses on bottom-up synthetic approaches to macromolecular materials to enable atomic-level structural precision and control of materials properties. Two current projects in her laboratory are (1) the use of vinyl boranes as a versatile platform for functional polymers and (2) conjugated materials inspired by crystalline silicon.

This talk highlights frontiers in materials science – nonplanar electronics, atomically precise functional polymers, and control of hierarchical structure – and describes synthetic approaches to next generation materials. The discussion will provide insight into how the Klausen Research Group deploys strategic chemical synthesis to identify fundamentally new materials with transformative potential, as well as to refine advanced materials through an understanding of structure-property-performance relationships. Key topics include (1) the design and synthesis of poly(cyclosilane)s, conjugated polymers inspired by the semiconductor crystalline silicon, and (2) the discovery of an innovative synthetic platform to poly(vinyl alcohol)s with atomic-level control of composition, sequence, and stereoregularity. 

Michael Bartlett looks at the camera. The image is a circular crop with an orange dotted circle around the photo for style.

Prof. Michael Bartlett

Iowa State University

Assistant Professor, Materials Science and Engineering

"Multifunctional Soft Materials for Electronics and Adhesives"

Date

Wednesday, October 2

Time

11:15 AM - 12:15 PM

Location

Kelly Hall 310

Michael Bartlett is an Assistant Professor of Materials Science and Engineering at Iowa State University. His research investigates and creates soft multifunctional materials and interfaces with highly tunable mechanical and functional properties for deformable electronics and soft robotics, adaptive materials, and ‘smart’ adhesives. He received his BSE in Materials Science and Engineering from the University of Michigan in 2008 and completed his Ph.D. in Polymer Science and Engineering at the University of Massachusetts Amherst in 2013 studying bio-inspired adhesion. After obtaining his Ph.D. he worked as a Senior Research Engineer in the Corporate Research Laboratory at 3M and as a Postdoctoral Fellow at Carnegie Mellon University before joining Iowa State in 2016.  His research has resulted in publications, patents, media coverage through outlets such as the Discovery Channel, and awards including a DARPA Young Faculty Award, a 3M Non-Tenured Faculty Award, and an Outstanding Faculty Award from the Iowa State Engineering Student Council (student nominated). More at: www.mse.iastate.edu/bartlett.

Multifunctional soft materials and interfaces create intriguing new opportunities to enhance performance through adaptable and programmable properties.  I will discuss two examples of this approach, one that utilizes material composition through liquid-solid hybrid composites for soft machines and deformable electronics and another inspired by kirigami, the art of paper cutting, where material structures are manipulated to create materials with tunable functionality.  For hybrid composites, I will present an all-soft matter approach that combines soft elastomers with dispersions of liquid-phase eutectic Ga-In (EGaIn) metal alloy microdroplets.  Experimental and theoretical investigations show that liquid metal droplets incorporated into elastomers enables exceptional combinations of soft elasticity and electrical and thermal properties with extreme toughness, autonomously self-healing circuits, and mechanically triggered stiffness tuning. For kirigami, I will present a framework for designing materials with highly tunable mechanical and adhesive properties.  This is demonstrated with hybrid cut architectures to create highly tunable mechanical properties, stretchable conductors, and rapid magnetoactive soft actuators which elongate to 330 % strain in ~0.1 s.  Furthermore, by incorporating kirigami-inspired structures at interfaces, we can enhance adhesive force by a factor of ∼100 across a spatially patterned sheet while tuning adhesion in different directions for high capacity yet easy release interfaces.  These approaches provide model systems to study fundamental material properties while enabling electronic skins, soft robots, and ‘smart’ adhesives for a variety of soft matter systems.

An-Chang Shi looks at the camera. The image is a circular crop with an orange dotted circle around the photo for style.

Prof. An-Chang Shi

McMaster University

Professor, Physics and Astronomy

"Non-Classical Ordered Phases of Block Copolymers"

Date

Wednesday, October 9

Time

11:15 AM - 12:15 PM

Location

Kelly Hall 310

An-Chang Shi is a professor of physics at McMaster University. He received B.Sc. in physics from Fudan University in 1982 and Ph.D. in physics from University of Illinois at Urbana-Champaign in 1988. From 1988 to 1892 he was a Post-Doctoral Fellow and Research Associate at McMaster University. He joined Xerox Research Centre of Canada as a Member of Research Staff in 1992 and moved to McMaster University as an Associate Professor in 1999. He was promoted to Professor in 2004. He received a Premier’s Research Excellent Award in 2000 and was elected to Fellow of American Physical Society in 2010. His has worked on a wide range of topics in condensed matter physics, including crystal shapes, superconductivity and soft matter theory. His current research focuses on the development of theoretic models and methods for polymeric system, the investigation of phase diagrams of block copolymers, and the study of kinetic pathways of transitions between stable and metastable phases.

The observation of ordered phases in hard-condensed matter systems such as metallic alloys has a long history in materials physics. In recent years, intricate periodic and aperiodic order has emerged in a host of soft matter systems including supramolecular assemblies, surfactants and block copolymers. The emergence of complex ordered phases in these diverse systems underscores the universality of emergent order in condensed matter. Due their rich phase behavior, block copolymers provide an ideal system to study the origins and stability of periodic and aperiodic order in condensed matter physics. In particular, recent experimental and theoretical studies have revealed that non-classical ordered phases, such as the Frank-Kasper phases and quasicrystals, could be self-assembled from block copolymers as equilibrium or metastable morphologies. We have examined the occurrence of complex spherical packing phases in block copolymer systems using the self-consistent field theory and showed that a key mechanism of forming complex spherical phases is the conformational asymmetry of the blocks. Furthermore, we have predicted that the segregation of different polymeric species in block copolymer blends provides another mechanism to stabilize spherical packing phases with very different sized-spherical domains. In my presentation, I will summarize recent theoretical and experimental progresses on this fascinating topic and discuss possible future research directions.

Stuart Rowan, wearing glasses and a blue collared shirt, smiles and looks at the camera..

Prof. Stuart Rowan

University of Chicago

Barry L. MacLean Professor for Molecular Engineering Innovation and Enterprise

"Design and Synthesis of Adaptive Polymeric Materials"

Date

Wednesday, October 30

Time

11:15 AM - 12:15 PM

Location

Kelly Hall 310

Stuart J. Rowan is currently the Barry L. MacLean Professor of Molecular Engineering and Professor of Chemistry at the University of Chicago, where he moved in 2016. He also has a staff appointment at Argonne National Labs. Prior to this he was the Kent H. Smith Professor of Engineering in the Department of Macromolecular Science and Engineering at Case Western Reserve University. Stuart was born in Edinburgh, Scotland and grew up in Troon, Aryshire on Scotland’s west coast.  He received his B.Sc. (Hons.) in Chemistry in 1991 from the University of Glasgow and stayed there for graduate school in the laboratory of Dr David D. MacNicol, receiving his Ph.D. in 1995. In 1994 he moved to the Chemistry Department at the University of Cambridge to work with Prof. Jeremy K. M. Sanders FRS. He moved across the Atlantic (and the continental U.S.) to continue his postdoctoral studies with Prof. Sir J. Fraser Stoddart FRS at the University of California, Los Angeles in 1998. In 1999 he was appointed as an Assistant Professor to the Department of Macromolecular Science and Engineering at Case Western Reserve University in Cleveland, Ohio, was promoted to Associate Professor with tenure in 2005 and became a Full Professor in 2008. He is a NSF CAREER awardee, received the Morley Medal (ACS) in 2013, the CWRU Distinguished University Award in 2015, and the Herman Mark Scholar Award (ACS) in 2015. He is an ACS Fellow, an ACS POLY Fellow and a Fellow of the Royal Society of Chemistry. He is Editor-in-Chief of ACS Macro Letters, and on the editorial advisory board for Chemical Science, ACS Applied Polymer Materials and J. Macromolecular Sci, Pure & Applied Chem. His research interests include investing the use of dynamic chemistry (covalent and non-covalent) in the construction and properties of structurally dynamic and adaptive polymeric materials. His group works on supramolecular polymers, self-healing materials, active/responsive adhesives, stimuli-responsive material and nanocomposites, metal-containing polymers, gels, biomaterials, and developing new synthetic methods for the construction of complex polymeric architectures. 

Nature uses adaptive/responsive materials in a wide range of situations. Many of these materials use reversible bonds and interactions to induce the response. Such dynamic bonds can be defined as any class of bond that selectively undergoes reversible breaking and reformation, usually under equilibrium conditions. The incorporation of dynamic bonds (which can be either covalent or non-covalent) allows access to structurally dynamic polymers and adaptive composites. Such materials can exhibit macroscopic responses upon exposure to an environmental stimulus, on account of a rearrangement of the polymeric architecture.  In such systems, the nature of the dynamic bond not only dictates which stimulus the material will be responsive to but also plays a role in the response itself. Thus, such a design concept represents a molecular level approach to the development of new stimuli-responsive/adaptive materials. We have been interested in the potential of such systems to access new material platforms and have developed a range of new mechanically stable, structurally dynamic polymer and nanocomposite films that change their properties in response to a given stimulus, such as temperature, light or specific chemicals. Such adaptive materials have been targeted toward applications that include healable plastics, responsive liquid crystalline polymers, adhesives, chemical sensors, mechanically dynamic films, and shape memory materials. Our latest results in these areas will be discussed.

Michael Bortner looks at the camera. The image is a circular crop with an orange dotted circle around the photo for style.

Prof. Michael Bortner

Virginia Tech

Assistant Professor, Chemical Engineering

"Additive Manufacturing of Moisture Responsive Cellulose Nanocrystal Polymer Composites"

Date

Wednesday, December 4

Time

11:15 AM - 12:15 PM

Location

Kelly Hall 310

Michael J. Bortner is an assistant professor in Chemical Engineering at Virginia Tech and part of the Virginia Tech Advanced Manufacturing Team (AMT) and the Macromolecules Innovation Institute (MII). His research is in the areas of polymer and composite rheology, and structure-process-property relationships.  He earned his B.S. in Chemical Engineering with a Polymer Option at Penn State, and his Ph.D. in Chemical Engineering at Virginia Tech.  Mike spent 10 years in industry focusing on manufacturing process development for novel polymer nanocomposites. His current research efforts at Virginia Tech are focused on development of materials and process technologies, and computational methodologies, to advance the state of the art in 1) polymer based additive manufacturing, 2) cellulose nanocrystals: production, characterization and CNC/polymer composite materials development, and 3) fiber reinforced polymer matrix composites.

Improving material selection for additive manufacturing (AM), otherwise known as 3D printing, has gained significant attention in recent years. Several researchers and companies have been pushed by consumers and industry to stretch the capabilities of the most common form of AM, known as fused filament fabrication (FFF), which involves extrusion of a polymer filament in a layer-by-layer fashion. FFF was originally developed as a prototyping tool and is now progressively challenged each day to produce end use parts for a wide variety of applications.

We have built on the development of a smart mechanically dynamic thermoplastic urethane/cellulose nanocrystal (TPU/CNC) composite, one which can respond to changes in environment simply by moisture exposure, to potentially increase design freedom and realize opportunities for expansion of FFF into new functional products. TPU/CNC composites have been documented to change modulus significantly upon exposure to moisture through decoupling of CNC hydrogen bonding and disruption of the mechanically percolating network. However, the effects of processing on the mechanical response of the composites is not well documented or understood.

In this seminar, we investigate the interplay between processing and structure-property relationships for 3-D printed TPU/CNC composites. We evaluate the impact of melt processing parameters on moisture induced mechanical modulus change following 1) TPU/CNC filament production from a masterbatched, solvent cast composite and 2) subsequent FFF of TPU/CNC filament into functional parts. The interplay between thermal history and shear induced particle orientation are investigated to determine effects on the dynamic modulus change upon moisture exposure. Further, we analyze the impact of geometry on moisture diffusion kinetics, and reversibility of the mechanical modulus change. We present the impact of FFF process parameters on the mechanical response of 3D printed parts, including the ability for the printed composite parts to change and/or hold their shape upon exposure to moisture and/or drying. Finally, we will discuss our preliminary findings on the moisture diffusion mechanisms and their role in the mechanical switching process. These analyses help us understand how processing influences the structure and behavior of the composite, notably on its ability to mechanically adapt upon moisture exposure. This information is critical to successfully realize the ability to design and 3D print complex, mechanically moisture responsive composite structures.



Fall 2019 Solvay Seminar Series At A Glance

Speaker, Institution

Seminar Title

Date

Prof. Ximin He
UCLA

"Bioinspired Adaptive Materials based on Smart Hydrogels: Sensing, Solar Harvesting, and Soft Robotics"

September 4, 2019
11:15 AM – 12:15 PM
Fralin Auditorium

Prof. Nick Stephanopoulos
Arizona State University
"Hybrid Self-Assembled Nanomaterials from Proteins, Peptides, and DNA"

September 11, 2019
11:15 AM – 12:15 PM
Fralin Auditorium

Prof. Jacinta Conrad
University of Houston

"Transport of Nanoparticles Through Complex, Crowded Fluids"

September 18, 2019
11:15 AM – 12:15 PM
Kelly Hall 310

Prof. Rebekka Klausen
Johns Hopkins University

"Building Block Strategies to Functional Polymers"

September 25, 2019
11:15 AM – 12:15 PM
Kelly Hall 310

Prof. Michael Bartlett
Iowa State University

"Multifunctional Soft Materials for Electronics and Adhesives"

October 2, 2019
11:15 AM – 12:15 PM
Kelly Hall 310

Prof. An-Chang Shi
McMaster University

"Non-Classical Ordered Phases of Block Copolymers" October 9, 2019
11:15 AM – 12:15 PM
Kelly Hall 310
Prof. Stuart Rowan
University of Chicago
"Design and Synthesis of Adaptive Polymeric Materials"
October 30, 2019
11:15 AM – 12:15 PM
Kelly Hall 310

MII Technical Conference and Review

Full Agenda November 4-6, 2019
Inn at Virginia Tech and Skelton Conference Center
Prof. Michael Bortner
Virginia Tech
"Additive Manufacturing of Moisture Responsive Cellulose Nanocrystal Polymer Composites" December 4, 2019
11:15 AM – 12:15 PM
Kelly Hall 310