Ralph Colby

About

Ralph H. Colby received his B.S. in Materials Science and Engineering from Cornell University in 1979. After working for two years at the General Electric Company in rheology research and process development, he attended Northwestern University, where he earned his M.S. and Ph.D. in Chemical Engineering in 1983 and 1985, respectively. His graduate research focused on the rheology of linear polybutadiene melts and solutions, including a 15-month period as a visiting scholar at Exxon Research and Engineering Company. He then worked for ten years at the Eastman Kodak Company's Corporate Research Laboratories, conducting rheology research on linear polymer melts and solutions, miscible polymer blends, block copolymers, randomly branched polymers, polymer gels, liquid crystalline polymers, polyelectrolytes, proteins, surfactants, and colloidal suspensions. In 1995, Dr. Colby joined Pennsylvania State University as an Associate Professor of Materials Science and Engineering and was promoted to Professor in 2000. He teaches undergraduate courses on Polymer Processing and graduate courses on Polymer Physics. Dr. Colby has authored over 130 publications and published a textbook titled 'Polymer Physics' in 2003. His research group focuses on understanding the dynamics of interesting liquids at a molecular level, particularly viscoelastic polymer liquids, liquid crystals, and surfactants, using mechanical rheology, dielectric spectroscopy, neutron and x-ray scattering, and optical…

Research topics

• Chemistry
• Materials science
• Polymer chemistry
• Composite material
• Quantum mechanics
• Physical chemistry
• Chemical engineering
• Chemical physics
• Organic chemistry
• Physics

Selected publications

• Room Temperature to 150 <b>°</b>C Lithium Metal Batteries Enabled by a Rigid Molecular Ionic Composite Electrolyte

  Advanced Energy Materials · 2021 · 54 citations

  Abstract Molecular ionic composites (MICs), made from ionic liquids and a rigid‐rod polymer poly(2,2′‐disulfonyl‐4,4′‐benzidine terephthalamide) (PBDT), are a new type of rigid gel electrolyte that combine fast ion transport with high thermal stability and mechanical strength. In this work, a MIC electrolyte membrane is prepared that is composed of PBDT, lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), and 1‐butyl‐1‐methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (Pyr 14 TFSI) in a mass…

  DOI

• Rheology of Entangled Polyelectrolyte Solutions

  Macromolecules · 2021 · 45 citations

  Senior authorCorresponding

  Polyelectrolyte solution dynamics have been carefully studied experimentally and theoretically for unentangled solutions and thought to be reasonably well understood. While theoretical models have been proposed for entangled polyelectrolyte solutions, there have been limited experimental data published to justify any understanding of entangled polyelectrolyte solution rheology. Herein, we study entangled nearly monodisperse carefully dialyzed cesium polystyrene sulfonate (Mn = 2.83 × 106 g/mol)…

  DOI

• Fiber spinning from polymer solutions

  Journal of Rheology · 2023-11-01 · 14 citations

  articleOpen access1st authorCorresponding

  The thinning of a cylinder of a polymer solution in a volatile solvent is argued to be controlled by solvent diffusion through a dense polymer layer at the cylinder surface. This naturally leads to the exponential time dependence of cylinder radius that is observed in experiments using a fast camera, such as capillary breakup extensional rheometry (CaBER). The relaxation time is controlled by the thickness of the dense (and often glassy) polymer layer and the diffusion coefficient of solvent thr…

  PublisherOA PDFDOI

• Water-Driven Sol–Gel Transition in Native Cellulose/1-Ethyl-3-methylimidazolium Acetate Solutions

  ACS Macro Letters · 2024-01-29 · 11 citations

  articleOpen access

  The addition of water to native cellulose/1-ethyl-3-methylimidazolium acetate solutions catalyzes the formation of gels, where polymer chain–chain intermolecular associations act as cross-links. However, the relationship between water content (Wc), polymer concentration (Cp), and gel strength is still missing. This study provides the fundamentals to design water-induced gels. First, the sol–gel transition occurs exclusively in entangled solutions, while in unentangled ones, intramolecular associ…

  PublisherOA PDFDOI

• Enhancing the dielectric constant of zwitterionic liquids via dipole moment and anion chemistry

  The Journal of Chemical Physics · 2024-07-01 · 11 citations

  articleOpen access

  The dielectric constant is a critical parameter in many energy-related applications. Typically, increasing the dielectric constant of soft materials involves adding high dielectric constant polar liquids or inorganic fillers, but there are limitations to this approach due to safety concerns with volatile and flammable solvents and the agglomeration of inorganic fillers. An alternative approach is to add zwitterionic liquids that exhibit exceptionally high dielectric constants with negligible vol…

  PublisherOA PDFDOI

Recent grants

• First Principles Design of Ionomers for Facile Ion Transport

  NSF · $313k · 2009–2013

• Collaborative: Viscoelasticity of Nanoparticle Dispersed Polymer Melts: Experiment and Simulation

  NSF · $553k · 2010–2016

• Energy materials based on single-ion conducting polymers mixed with zwitterions

  NSF · $634k · 2018–2023

Frequent coauthors

• Gary L. Leal

  University of California, Santa Barbara

  469 shared

• A. Jeffrey Giacomin

  University of Nevada, Reno

  468 shared

• Albert Co

  323 shared

• Albert Co

  152 shared

• Sanat K. Kumar

  Columbia University

  50 shared

• James Runt

  Pennsylvania State University

  45 shared

• Quan Chen

  Huaiyin Institute of Technology

  44 shared

• U Hyeok Choi

  42 shared

Labs

• Ralph Colby LabPI

Awards & honors

• Penn State Faculty Scholar Medals for Outstanding Achievemen…
• Bingham Medal, Society of Rheology (2012)
• American Chemical Society Fellowship

Similar researchers at Pennsylvania State University

• Long-Qing Chenh-150
• Zi-Kui Liuh-92
• Tarasankar DebRoyh-81