BIOMOLECULAR SCIENCES

Angela Brown, ChBE Research Puiblication

Epigallocatechin gallate alters leukotoxin secretion and Aggregatibacter actinomycetemcomitans virulence

Angela Brown, En Hyung Chang

We and others have previously shown that epigallocatechin gallate (EGCg) inhibits the activity of an important virulence factor, leukotoxin (LtxA), produced by the oral bacterium Aggregatibacter actinomycetemcomitans, suggesting the potential use of this molecule as an anti-virulence strategy to treat periodontal infections. Here, we sought to better understand the effects of EGCg on toxin secretion and A. actinomycetemcomitans pathogenicity in a co-culture model.

Anand Jagota

Length of mucin-like domains enhances cell-Ebola virus adhesion by increasing binding probability

Xinyu Cui, Nicole Lapinski, Xiaohui (Frank) Zhang, Anand Jagota

Ebola and other viruses often stick to cells in the first stage of infection through spike-like protrusions.  Here, for the Ebola virus, we develop coarse-grained molecular models to study how the properties of the  protrusions affect adhesion.  This work will help identify potential therapies.

Kelly M. Schultz

Human mesenchymal stem cell-engineered length scale dependent rheology of the pericellular region measured with bi-disperse multiple particle tracking microrheology

John A.McGlynn, Kilian J.Druggan, Kiera J.Croland, Kelly M. Schultz

Human mesenchymal stem cell (hMSC) remodeling is a complex process across many length scales: single cross-links break on the nanometer scale, cellular extensions pull material and degrade paths through the scaffold to enable motility on the micrometer scale and bulk scaffold degradation occurs on macroscopic scales. We measure length scale dependent material properties during cell-mediated remodeling of the pericellular region using techniques developed in our laboratory, namely bi-disperse multiple particle tracking microrheology (MPT) and MPT. By characterizing evolving length scale dependent material properties, new materials can be designed which better mimic native tissue and instruct cell behavior.

ENERGY AND ENVIRONMENT

Jonas Baltrusaitis, ChBE Research Puiblication

Surface chemistry of hydroxyapatite for sustainable n-butanol production from bio-ethanol

Jonas Baltrusaitis, Daniyal Kiani

Understanding the catalyst surface chemistry is of paramount importance for the accelerated development of structure-activity/selectivity relationships that form the basis for the rational design and optimization of catalysts at large. Here, we highlight the state-of-the-art understanding regarding the surface chemistry of hydroxyapatite (HAp)—a catalyst that enables the production of value-added alcohols from bio-ethanol.

Mark A. Snyder, Christopher J. Kiely, and Steven McIntosh

Tailored Coupling of Biomineralized CdS Quantum Dots to rGO to Realize Ambient Aqueous Synthesis of a High-Performance Hydrogen Evolution Photocatalyst

John Sakizadeh, Joseph P. Cline, Mark A. Snyder, Christopher J. Kiely, and Steven McIntosh

We establish a green, biomineralization route for the efficient synthesis of nanostructured CdS-rGO photocatalysts. These materials can be utilized to directly generate hydrogen fuel from water using sunlight.

Elsa Reichmanis

Data Science Guided Experiments Identify Conjugated Polymer Solution Concentration as a Key Parameter in Device Performance

Rahul Venkatesh, Yulong Zheng, Campbell Viersen, Aaron Liu, Carlos Silva, Martha Grover, Elsa Reichmanis

A data science approach identified polymer solution concentration as a key parameter that helps to define the electronic performance of semiconducting polymers. The results will accelerate the design and development of sustainable materials and processes for flexible devices in applications ranging from energy storage and conversion to ubiquitous sensors for the IoT (Internet of Things).

Israel Wachs and Jonas Baltrusaitis

New Mechanistic and Reaction Pathway Insights for Oxidative Coupling of Methane (OCM) over Supported Na2WO4/SiO2 Catalysts

Sagar Sourav, Yixiao Wang, Daniyal Kiani, Jonas Baltrusaitis, Rebecca R. Fushimi, Israel E. Wachs

Oxidative coupling of methane is a catalytic chemistry whereby methane from shale gas can be converted into valuable products such as ethylene and Ethane. By carefully controlling the synthesis of a promising catalyst, viz. Na2WO4/SiO2, and by using sophisticated spectroscopic techniques, we gained new insights into how the catalyst functions (i.e. the active site and reaction mechanism). Our results provide directions on how to discover new and improved catalysts.

Mark Snyder

Scalable Biomineralization of CdS Quantum Dots by Immobilized Cystathionine γ-Lyase

Nur Koncuy Ozdemir, Joseph P. Cline, Christopher J. Kiely, Steven McIntosh, and Mark A. Snyder

Facile enzyme immobilization on inexpensive supports enables sustainable, green nanomanufacturing of remarkably consistent CdS quantum dots by regenerable enzymatic biomineralization.
 
Bin Zhang and Israel E. Wachs   
 
The specific oxide support was found to control the number of activated sites (Al2O3 ≫ ZrO2 > CeO2 > TiO2 > SiO2) and propylene metathesis activity (Al2O3 ≫ ZrO2 ≫ TiO2 ∼ CeO2 ∼ SiO2), revealing that the oxide support cation is a potent ligand for the surface ReOx sites. This new fundamental insight allows for tuning the catalytic activity of supported ReOx sites for olefin metathesis.
 
Jun-Kun Lai, Nicholas R. Jaegers, Bar Mosevitzky Lis, Mingyu Guo, Michael E. Ford, Eric Walter, Yong Wang, Jian Zhi Hu, and Israel E. Wachs
 
Blurb: The catalyst structural and chemical changes occurring during activation and aging of supported VOx-WOx/TiO2 catalysts for selective catalytic reduction (SCR) of NOx with NH3 were investigated. The surface and bulk changes during activation and aging were monitored with a suite of in situ catalyst characterization studies. It was found that surface structural changes that enhance the concentration of surface NH4+* species, primarily associated with the surface VOx sites, are related to the efficient performance of supported VOx-WOx/TiO2 catalysts for the SCR reaction.

MATERIALS AND INTERFACES

Mark A. Snyder, Christopher J. Kiely, and Steven McIntosh

Tailored Coupling of Biomineralized CdS Quantum Dots to rGO to Realize Ambient Aqueous Synthesis of a High-Performance Hydrogen Evolution Photocatalyst

John Sakizadeh, Joseph P. Cline, Mark A. Snyder, Christopher J. Kiely, and Steven McIntosh

We establish a green, biomineralization route for the efficient synthesis of nanostructured CdS-rGO photocatalysts. These materials can be utilized to directly generate hydrogen fuel from water using sunlight.

Elsa Reichmanis

Data Science Guided Experiments Identify Conjugated Polymer Solution Concentration as a Key Parameter in Device Performance

Rahul Venkatesh, Yulong Zheng, Campbell Viersen, Aaron Liu, Carlos Silva, Martha Grover, Elsa Reichmanis

A data science approach identified polymer solution concentration as a key parameter that helps to define the electronic performance of semiconducting polymers. The results will accelerate the design and development of sustainable materials and processes for flexible devices in applications ranging from energy storage and conversion to ubiquitous sensors for the IoT (Internet of Things).

Jonas Baltrusaitis, Israel Wachs

New Mechanistic and Reaction Pathway Insights for Oxidative Coupling of Methane (OCM) over Supported Na2WO4/SiO2 Catalysts

Sagar Sourav, Yixiao Wang, Daniyal Kiani, Jonas Baltrusaitis, Rebecca R. Fushimi, Israel E. Wachs

Oxidative coupling of methane is a catalytic chemistry whereby methane from shale gas can be converted into valuable products such as ethylene and Ethane. By carefully controlling the synthesis of a promising catalyst, viz. Na2WO4/SiO2, and by using sophisticated spectroscopic techniques, we gained new insights into how the catalyst functions (i.e. the active site and reaction mechanism). Our results provide directions on how to discover new and improved catalysts.

James F. Gilchrist

Chemical vs. mechanical microstructure evolution in drying colloid and polymer coatings

Thitiporn Kaewpetch & James F. Gilchrist

This study watches the structural rearrangement of particles within a drying film using 3D high speed confocal laser scanning microscopy.  The structural evolution is tied to the particle interactions and the drying conditions and has applications from industrial and automotive coatings to development of thin films for pharmaceutical drug delivery.

Kelly M. Schultz

Human mesenchymal stem cell-engineered length scale dependent rheology of the pericellular region measured with bi-disperse multiple particle tracking microrheology

John A. McGlynn, Kilian J. Druggan, Kiera J. Croland, Kelly M. Schultz

Human mesenchymal stem cell (hMSC) remodeling is a complex process across many length scales: single cross-links break on the nanometer scale, cellular extensions pull material and degrade paths through the scaffold to enable motility on the micrometer scale and bulk scaffold degradation occurs on macroscopic scales. We measure length scale dependent material properties during cell-mediated remodeling of the pericellular region using techniques developed in our laboratory, namely bi-disperse multiple particle tracking microrheology (MPT) and MPT. By characterizing evolving length scale dependent material properties, new materials can be designed which better mimic native tissue and instruct cell behavior.

Mark Snyder

Scalable Biomineralization of CdS Quantum Dots by Immobilized Cystathionine γ-Lyase

Nur Koncuy Ozdemir, Joseph P. Cline, Christopher J. Kiely, Steven McIntosh, and Mark A. Snyder

Facile enzyme immobilization on inexpensive supports enables sustainable, green nanomanufacturing of remarkably consistent CdS quantum dots by regenerable enzymatic biomineralization.

Active Material Interfacial Chemistry and Its Impact on Composite Magnetite Electrodes

Miguel Gonzalez, Krysten Minnici, Bailey Risteen, Lei Wang, Lisa M. Housel, Genesis D. Renderos, Kenneth J. Takeuchi, Esther S. Takeuchi, Amy C. Marschilok, Thomas F. Fuller, and Elsa Reichmanis

Rechargeable lithium-ion batteries continue to emerge as the primary energy storage medium for a variety of applications, including consumer products and automotive vehicles. Our research aims to elucidate key surface chemistry and interfacial interactions between the components of composite electrodes to identify necessary physical and chemical properties for future high-capacity storage solutions.

 
Kedar Joshia, James F. Gilchrist

This work investigates colloidal self-assembly and crystallization in convective deposition in the presence of surfactant.  We show that added SDS alters the flow patterns inside the thin film through Marangoni-driven surface stress, which then alters the time for the assembly. The added surfactant can permit more reliable conditions for monolayer coatings.

 
Chong Shen, Zhiyu Jiang, Lanfang Li, James F. Gilchrist, and H. Daniel Ou-Yang 
 
This paper describes the use of electric and magnetic fields to control the direction and speed of induced-charge electrophoresis (ICEP) driven metallic Janus microrobots. A direct current (DC) magnetic field applied in the direction perpendicular to the electric field maintains the linear movement of particles in a 2D plane. Phoretic force spectroscopy (PFS), a phase-sensitive detection method to detect the motions of phoretic particles, is used to characterize the frequency-dependent phoretic mobility and drag coefficient of the phoretic force.

SYSTEMS, COMPUTATION & SIMULATIONS

Srinivas Rangarajan, ChBE Research Puiblication

Computing a Global Degree of Rate Control for Catalytic Systems

Srinivas Rangarajan, Huijie Tian

In this paper, we discuss the concept and properties of variance-based global sensitivity analysis, as an expansion of local sensitivity metrics (such as the degree of rate control), for modeling and design of catalytic reaction systems.

Elsa Reichmanis

Data Science Guided Experiments Identify Conjugated Polymer Solution Concentration as a Key Parameter in Device Performance

Rahul Venkatesh, Yulong Zheng, Campbell Viersen, Aaron Liu, Carlos Silva, Martha Grover, Elsa Reichmanis

A data science approach identified polymer solution concentration as a key parameter that helps to define the electronic performance of semiconducting polymers. The results will accelerate the design and development of sustainable materials and processes for flexible devices in applications ranging from energy storage and conversion to ubiquitous sensors for the IoT (Internet of Things).

Mayuresh Kothare

Experimental design of a “Snap-on” and standalone single-bed oxygen concentrator for medical applications

Rama Rao Vemula, Matthew D. Urich & Mayuresh V. Kothare

Recent demand for medical oxygen has grown exponentially due to the recent COVID-19 pandemic. To this end, a novel single-bed, “Snap-on” and standalone, medical oxygen concentrator design based on a rapid pressure swing adsorption process was investigated for continuous oxygen supply.

 

 
Huijie Tian and Srinivas Rangarajan
 
Mean field microkinetic models are commonly employed to model catalytic reaction systems; such models often make the incorrect approximation that the adsorbates on a catalyst surface are uniformly distributed (hence the “mean field” nature of the model). The alternative method, called the kinetic Monte Carlo (kMC) simulations, are more accurate in this aspect but are more computationally intensive. In this work, we show that, at the limit of fast diffusion of adsorbates, lattice Monte Carlo simulations can be combined with machine learning to build a new type of model, viz. “neural network modified microkinetic model (NN-MK)” that are more accurate than the mean field models but not as computationally intensive as kMC. This new approach can be used to build more reliable models of catalytic systems.

 

 
Christopher Rzepa, Daniel W. Siderius, Harold W. Hatch, Vincent K. Shen, Srinivas Rangarajan, and Jeetain Mittal
 
It has been previously shown that alkanes adsorb in microporous siliceous and aluminum-containing zeolites in such a way that their entropy (upon adsorption) is reduced by a constant fraction of their free (gas phase) value. Such linear relations are valuable in computationally discovering the ideal zeolite for gas adsorption, separation, and catalysis. Using Monte Carlo simulations, in this work, we showed that such relations extend to several other classes of molecules such as olefins, cyclic hydrocarbons, biomass oxygenates, and other heteroatom containing molecules like thiols. This points to the existence of a universal relation that can relate the adsorbate structure and zeolite topology with thermochemical properties.