IPR Student Seminars

Dr. Pengxiang Si November 20, 2020 @ 1 pm.


Polyurethanes (PUs) are a class of versatile polymers; their structure and morphology can be readily tailored to exhibit various mechanical, physical, chemical and biological properties. PUs have been employed in a variety of industrial applications including foams, coatings, textiles, machinery, sporting, transportation, vehicles and construction. Water-based PU was developed to reduce the usage of volatile organic compounds (VOCs) in the synthesis of conventional solvent based PU, and exhibits advantages of superior material properties (e.g. flexibility, stretchability, elasticity, mechanical strength), processability (e.g. 3D printing, inkjet printing, screen printing, spray coating, molding) and sustainability (e.g. low VOCs, degradable). Water-based PU combines the superior mechanical properties of PU with the excellent stability of colloids. The current research trend of PU is shifting from traditional industrial applications to state-of-the-art fields such as soft and wearable electronics, energy storage devices, biosensors, actuators, photovoltaic devices and stimuli-responsive materials. Due to the existence of a variety of functional groups such as urethane, aliphatic or aromatic hydrocarbons, esters, ethers, amides and urea, water-based PU can be physically or chemically incorporated with functional materials to form PU colloidal composites towards various applications.

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Remi Casier December 3, 2020 @ 1pm

The Hierarchy of Protein Folding


Proteins are biological macromolecules composed of linear polypeptide chains. Often, a specific three-dimensional arrangement of the constituting polypeptide chains is required to provide the protein a biological function. Despite all the advancements in protein science, a simple, yet fundamental question remains: How do proteins fold so quickly? A polypeptide chain has near infinite conformational space, yet many proteins are capable of rapidly navigating from a structureless state to their native conformation on the order of milliseconds to seconds. Therefore, it is clear that proteins cannot exhaustively probe their entire conformational space, and instead must somehow explore a more limited conformational space as they fold.

This presentation will provide an introduction to the concepts involved in protein folding. It will cover the underlying physical forces governing folding, the experimental evidence used to understand the folding behavior of proteins on a macroscopic and microscopic scale, and how the microscopic behavior of proteins can circumvent the time-scale folding problem.


Remi Casier obtained his BSc in honours chemistry in 2013 followed by his MSc in polymer chemistry in 2015 from the University of Waterloo. Under the supervision of Prof. Jean Duhamel, Remi is currently pursuing his PhD in polymer science. Currently, his research focuses on using advanced fluorescence techniques to probe the conformational state and internal dynamics of polypeptides in solution in order to provide insight to the dynamic behavior of proteins.

Damin Kim February 25th, 2021 @ 1pm

Discussion on some Polysaccharides: Their Structures, Properties, and Applications


Polysaccharides are natural polymers that can be divided into two categories depending on whether they are used for storage or structure. Animals and plants can store glucose as a primary energy source by polymerizing it into polysaccharides. Many different polysaccharides are also present in cell walls, where they serve as structural components. As polysaccharides play important roles in many fields, carbohydrate chemistry has been the focus of intense research for decades. The fundamental study of a polysaccharide begins by characterizing its structure. Different structural models have been proposed for some polysaccharides. In turn, these structural models help better understand the properties of polysaccharides and their applications. The fact, that polysaccharides are abundant, cost effective, and biodegradable, combined with current environmental concerns increases the demand for replacing synthetic polymers with polysaccharides. The hydroxyl groups of polysaccharides provide an easy route for chemical modification with a variety of functional groups to reinforce the properties of polysaccharides in a controlled manner and widen their range of industrial applications.

The structures, properties, and applications of some polysaccharides will be discussed in the presentation. Various techniques including acid hydrolysis, enzyme treatment, and methylation will be reviewed since these techniques were applied to determine the fundamental structures of polysaccharides. The different building blocks of polysaccharides will be presented as they lead to different structures and, ultimately, properties, that are unique for each polysaccharide. As a result, different polysaccharides can be used in various fields depending on the properties desired for a given application. The current industrial use of polysaccharides will be reviewed and some current research on polysaccharides will be presented.

About the speaker

Damin Kim received her B.Sc in Chemistry with specialization in Material Chemistry from the University of Waterloo in 2014. She then joined the Duhamel Laboratory for her graduate studies. She completed her MSc thesis in 2016, which focused on the characterization of hydrophobically modified starch nanoparticles. She is now finalizing her PhD thesis, which expanded her MSc research to characterize various polysaccharides using different fluorescence techniques. Damin Kim has had many opportunities to present her work at various conferences and she has received a few internal graduate scholarships from the University of Waterloo.

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Janine Thoma Friday March 12th at 1pm

PEGylation and Polymeric Brushes for Drug Delivery


PEGylation has been utilized since the late 1970s in the biomedical industry to confer water solubility, non-immunogenicity, and targeted tissue delivery to hydrophobic and/or toxic drug molecules. Through careful drug and peptide-conjugate engineering, researchers have been able to use PEGylation in the preparation of many FDA approved drugs over the last 30 years to treat different diseases including severe combined immunodeficiency, acute lymphoblastic leukemia, febrile neutropenia, and Crohn’s disease. Unfortunately, with the increased use of PEG with drug and peptide conjugates, there has been reports of patients generating anti-PEG antibodies causing an autoimmune response. Researchers have determined that by introducing PEG via a branched architecture reduces the autoimmune response induced by anti-PEG antibodies. This presentation aims to briefly introduce and discuss PEGylation as well as the physiological considerations, that need to be considered, when designing a drug or peptide conjugate. Finally, the incorporation of PEG into different polymeric bottle brush (PBB) drug conjugates will be explored and three specific research articles will be discussed in more detail.

About the Speaker

Janine Thoma is currently pursuing her PhD in polymer chemistry studying the backbone and sidechain dynamics of polymers with branched architectures in solution using fluorescence under the supervision of Prof. Jean Duhamel. She received her BSc in biochemistry from the University of Waterloo in 2015 and then began her MSc in the Duhamel lab. In 2016 she transferred directly into the PhD program. In 2018 and 2019 she was awarded a Nanofellowship from the Waterloo Institute for Nanotechnology (WIN) and in 2020 she won the Institute of Polymer Research (IPR) award as well as the Graduate Student Excellence Award from the department of chemistry. Currently she is working on probing the backbone conformation and determining the persistence length of poly(oligo(ethylene glycol) methacrylate) (PEGMA) polymers in solution.

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Jiaxin Xu Friday March 26th at 1pm



Nanogels are described as hydrophilic three-dimensional crosslinked polymeric particles that can absorb large amounts of water or physiological fluids while maintaining their internal network. As a distinctive class of material that combines both the properties of hydrogels and nanomaterials, nanogels provide long term colloidal stability and biocompatibility. Due to the advantages and unique properties mentioned above, nanogels can be easily tailored and applied in many fields, such as drug delivery systems, controlled release, tissue engineering, and environmental remediation applications. In this presentation, nanogels will be introduced based on different types of classifications, synthesis methods and, applications. Emulsion polymerization, a traditional method employed for nanogel fabrication, will be introduced too. A pH responsive, methacrylic acid and ethyl acrylate (MAA/EA) crosslinked nanogel will be used as an example for elucidating different characterization techniques, including: Dynamic light scattering/ static light scattering (DLS/SLS), Zeta potential measurement, Transmission electron microscopy and potentiometric-conductometric titration.

About the Speaker

Jiaxin (Sara) Xu is currently pursuing her PhD in chemical engineering (water institute) studying the development of versatile nanogel hybrid materials applied for drinking water purification, antimicrobial/bioimaging, and catalytic systems under the supervision of Professor Michael Tam. She received her BSc at Dalian Jiaotong University in Chemical and Software engineering (2009-2014) and then her MSc with Professor Leonardo Simon for the evaluation of mechanical properties of recycled polyamide-cellulose fiber composites (2015-2016). She started her PhD studies with Professor Xianshe Feng and Zhongchao Tan for membrane-based flue gas denitrification and desulfurization projects. From 2018 she transferred to Professor Tam’s lab perusing her PhD studies on beta-cyclodextrin functionalized magnetic particles applied for drinking water purification. She was a speaker at the 2017 American Filtration and Separations Society conference and presented at the UW Research Spotlight: the Grand River Watershed workshop. She received a University of Waterloo Graduate Scholarship in 2020, and Ontario Graduate Scholarship and President’s Graduate Scholarship in 2020-2021.

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