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Search Publications by: Anthony Kotula (Fed)

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Displaying 1 - 25 of 33

Evaluating Models That Predict Epoxy Conversion Using Rheological Properties

April 15, 2024
Author(s)
Stian Romberg, Paul Roberts, Chad R. Snyder, Anthony Kotula
Simultaneous rheology and conversion measurements of neat and composite epoxy resins reveal that conventional models neither accurately nor fully describe the relationship between rheology and conversion. We find that models predicting thermoset conversion

Toward pluripotent materials through tempering of dynamic covalent polymer networks

February 2, 2024
Author(s)
Anthony Kotula, Nicholas Boynton, Joseph Dennis, Neil Dolinski, Charlie Lindberg, Garrett Grocke, Stephanie Vivod, Shrayesh Patel, Stuart Rowan
Pluripotency is defined as a system not fixed as to its developmental potentialities. While stem cells and pluripotent materials have heretofore been synonymous, a synthetic analog would lead to significant advancements in materials design for resource

Connecting Molecular Exchange Dynamics to Stress Relaxation in Phase-Separated Dynamic Covalent Networks

January 22, 2024
Author(s)
Neil Dolinski, Ran Tao, Nicholas Boynton, Anthony Kotula, Charlie Lindberg, Kyle Petersen, Aaron M. Forster, Stuart Rowan
A suite of phase separated dynamic covalent networks based on highly tunable dynamic benzalcyanoacetate (BCA) thia-Michael acceptors are investigated. In situ kinetic studies on small molecule model systems are used in conjunction with macroscopic

Trace Water Effects on Crystalline 1-Ethyl-3-methylimidazolium Acetate

May 16, 2023
Author(s)
Ashlee Aiello, John Hoffman, Anthony Kotula, Lucas Flagg, Ruipeng Li, Jeremiah Woodcock
Spontaneous room temperature crystallization of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) was observed upon removal of trace water. To ensure that this observation was not produced by trace water or other contaminants, sample purity was confirmed

Mechanical Regulation of Oral Epithelial Barrier Function

April 25, 2023
Author(s)
Eun Jin Lee, Paul Salipante, Anthony Kotula, Dana Graves, Stella Alimperti, Yoontae Kim
Epithelial cell function is modulated by mechanical forces imparted by the extracellular environment. The transmission of forces onto the cytoskeleton by modalities such as mechanical stress and matrix stiffness is necessary to address by the development

Reaction-Induced Phase Separation (RIPS) in Amine-Cured Epoxy/Epoxy Thermosets.2. Visualization of Heterogeneity using Fluorescence Lifetime Imaging Microscopy (FLIM)

February 25, 2023
Author(s)
Jeremiah Woodcock, Stephan J. Stranick, Anthony Kotula, Gale A. Holmes
The strategic integration of a rhodamine-spirolactam (RS) mechanophore into a transparent bis-epoxide/bis-epoxide/amine and corresponding bis-epoxide/amine networks has revealed, for the first time using fluorescence lifetime imaging microscopy (FLIM)

Crystallization Kinetics in an Immiscible Polyolefin Blend

December 12, 2022
Author(s)
Derek Huang, Anthony Kotula, Chad R. Snyder, Kalman Migler
Motivated by the problem of brittle mechanical behavior in recycled blends of high density polyethylene (HDPE) and isotactic polypropylene (iPP), we employ optical microscopy, rheo-Raman, and differential scanning calorimetry (DSC) to measure the

Time-gated Raman spectroscopy of recovered plastics

July 1, 2022
Author(s)
Anthony Kotula, Sara Orski, Kayla Brignac, Jennifer Lynch, Bryan Heilala
Raman spectroscopy is a powerful non-destructive technique for the identification and characterization of plastics. The technique often has limited use due to fluorescence emission, which often occurs in polymer samples containing colorants or that have

Engineering 3D Printed Scaffolds with Tunable Hydroxyapatite

June 15, 2022
Author(s)
Yoontae Kim, Eun Jin Lee, Anthony Kotula, Shozo Takagi, Laurence C. Chow, Styliani Alimperti
Bone grafting is a surgical procedure to bone repair due to trauma or diseases in the craniofacial and dental area. Current limitations of autogenous and allogeneic grafts are often associated with reduced host-graft integration due to geometrical confor

Percolation implications in the rheology of crystallization

October 26, 2020
Author(s)
Anthony P. Kotula, Kalman D. Migler
The rheology of polymer crystallization is an old problem that often defies explanation due to the complex interrelationships between crystallization and flow properties. Although separate measurements of rheology and crystallinity can give some

Rheology of Crystallizing LLDPE

October 8, 2020
Author(s)
Marat Andreev, David Nicholson, Anthony Kotula, Jonathan D. Moore, Jaap Den Doelder, Gregory C. Rutledge
Polymer crystallization occurs in many plastic manufacturing processes, from injection molding to film blowing. Linear low-density polyethylene (LLDPE) is one of the most commonly processed polymers, wherein the type and extent of short chain branching

Precision, Tunable Deuterated Polyethylene via Polyhomologation

July 22, 2019
Author(s)
Wesley Farrell, Sara Orski, Anthony Kotula, Kathryn Beers, Daniel Baugh
Polyhomologation (also known as "C1 polymerization") of a deuterated ylide has been performed, which yields linear polyethylene of high deuterium content. Copolymerization with the protonated analog allows for the preparation of sta-tistical copolymers, in

Measuring & Predicting Crystal Morphology in Fused Deposition Modeling

June 19, 2019
Author(s)
Claire McIlroy, Jonathan Seppala, Anthony Kotula
Semi-crystalline polymer melts are commonly used in fused deposition modeling. Although flows have a profound effect on polymer crystallization, the relationship between typical fused deposition modeling (FDM) deformation rates and printed-part crystal

Polymer Additive Manufacturing: Confronting Complexity

June 19, 2019
Author(s)
Anthony P. Kotula, Jonathan E. Seppala, Chad R. Snyder
Since its development and commercialization in the 1980s, polymer additive manufacturing (AM) has become a disruptive technology. In this chapter we describe the ever-increasing demands for polymer AM in industry, academia, and government, as well as the

Preface

June 19, 2019
Author(s)
Jonathan E. Seppala, Anthony P. Kotula, Chad R. Snyder

Flow-induced crystallization during materials extrusion additive manufacturing

September 10, 2018
Author(s)
Lily Northcutt, Sara Orski, Kalman D. Migler, Anthony Kotula
Material extrusion additive manufacturing processes force molten polymer through a printer nozzle at high (> 100 s-1) wall shear rates prior to cooling and crystallization. These high shear rates can lead to flow-induced crystallization in common polymer