Dutcher Group

The Dutcher Lab at the University of Guelph is seeking qualified MSc and PhD candidates to work on the application of machine learning (ML) and artificial intelligence (AI) to the analysis of large databases of infrared (IR) spectra collected in IR microscopy images of polymers. The goal in this work is to ultimately understand the degradation and failure mechanisms of polymers used in water transport applications, in collaboration with our industrial partner HeatLink.

We are looking for applicants who are excited to contribute to the forefront of the application of ML and AI strategies to the analysis of large databases, an emerging area at the intersection of physical and data science. Our recent use of a β-variational autoencoder (β-VAE) approach is particularly promising [1-3]. In this neural network-based approach, a very large number of IR spectra are used to train an encoder that forces the input spectra through an information bottleneck. By doing this, we can identify a small number of important generative factors called latent dimensions that are responsible for most of the measured variance in the dataset. New spectra from high resolution IR images collected on our in-house, state-of-the-art Bruker LUMOS II infrared microscope can then be analyzed using the β-VAE model to classify and track the spatial distribution of different modes of degradation in the polymers and identify new features in the data. Further insights can be achieved by using dimensionally reduced features, learned by β-VAE and other approaches, as inputs into clustering (k-means, hierarchical, and density based) and classification (support vector machines, k-nearest neighbours, and logistic regression) models.

HeatLink: https://www.heatlink.com

[1] M. Grossutti, J. D’Amico, J. Quintal, H. MacFarlane, A. Quirk and J.R. Dutcher. Deep Learning and Infrared Spectroscopy: Representation Learning with a β-Variational Autoencoder. J. Phys. Chem. Lett. 13, 5787 (2022).
[2] M. Grossutti, J. D’Amico, J. Quintal, H. MacFarlane, W.C. Wareham, A. Quirk and J.R. Dutcher. Deep Generative Modeling of Infrared Images Provides Signature of Cracking in Cross-Linked Polyethylene Pipe. ACS Appl. Mater. Interfaces 15, 22532 (2023).
[3] J. D’Amico, M. Grossutti and J.R. Dutcher, Deep Learning Analysis of the Propagation of Stabilizing Additive Hydrolysis in a Cross-Linked Polyethylene Pipe. ACS Appl. Polym. Mater. 6, 534 (2024).

Position Requirements and Expectations

• Completed or close to completing a Bachelors or Masters degree in physics, physical chemistry or a related field of physical science
• Interest and strong motivation to work at the forefront of the application of machine learning techniques to physical science data
• Strong analytical skills and the ability to think critically and creatively
• Strong problem-solving skills and work ethic
• Excellent hands-on laboratory skills including the use of advanced instrumentation
• Ability to work safely and responsibly in a laboratory
• Ability to apply sophisticated data analysis techniques to experimental data
• Ability to program in Python and work with large databases
• Ability to work effectively in a team environment
• Strong oral and written communication skills
   

Start Date

The anticipated start date is in Fall 2025.
 

Application Process

Interested applicants should send a cover letter, CV and the names of up to three referees to (dutcher@uoguelph.ca). In your cover letter, you should highlight your relevant previous experience and training. Review of applications will begin immediately and continue until all positions are filled. Only applicants selected for an interview will be contacted. The Dutcher Lab and the University of Guelph are committed to building a diverse and inclusive community. All qualified applicants are invited to apply, but we particularly welcome applications from individuals that identify with groups traditionally underrepresented in the physical sciences, and we will strive to hire individuals who share our commitment to equity, diversity and inclusion.

The Dutcher Lab at the University of Guelph is seeking qualified MSc and PhD candidates to work on the characterization of new nanomaterials based on phytoglycogen (PG), a highly branched glucose polymer produced as compact, soft, hairy nanoparticles in the kernels of sweet corn. Not only are PG nanoparticles useful for applications in personal care and biomedicine, but they also provide an ideal system for studying the physics of soft nanoparticles. The Dutcher Lab uses a wide variety of techniques to characterize the structure, morphology, hydration and mechanical properties of PG nanoparticles, and our data show dramatic changes to the particle properties with simple modifications to the particles. One of the important measurements is called rheology, in which the mechanical properties of aqueous dispersions of PG nanoparticles are measured as a function of particle concentration [1,2]. At high concentrations, in which the particles are forced into contact, these measurements reveal the nature of the interaction between PG nanoparticles and, more generally, provide insight into the nature of the soft colloidal glass transition. Recently, we have shown that partially digesting PG particles using dilute acids produces smaller, less dense particles and significantly changes the interactions between the particles at high concentrations so that, surprisingly, the soft colloidal glass transition can be studied on experimental timescales [2].

We are looking for applicants who are excited to contribute to the forefront of investigating novel properties of soft nanoparticles. This work will involve performing simple chemical and physical modifications to PG nanoparticles, such as attaching chemical groups to the outer surface of the particles that add charge and/or hydrophobicity, and then measuring the mechanical properties of aqueous dispersions of the modified PG nanoparticles using a state-of-the-art rheometer. These data will be used together with data from other techniques such as atomic force microscopy, multi-angle light scattering and advanced computer simulations to achieve an understanding of how the interactions between PG particles change with modifications of the particles. This work should lead to new applications of natural, safe, sustainable PG nanoparticles.

[1] H. Shamana et al., Soft Matter 14, 6496 (2018).
[2] H. Shamana and J.R. Dutcher, Biomacromolecules 23, 2040 (2022).

Position Requirements and Expectations

• Completed or close to completing a Bachelors or Masters degree in physics, physical chemistry or a related field of physical science
• Interest and strong motivation to work at the forefront of the physics of soft nanoparticles
• Strong analytical skills and the ability to think critically and creatively
• Strong problem-solving skills and work ethic
• Excellent hands-on laboratory skills including the use of advanced instrumentation
• Ability to work safely and responsibly in a laboratory
• Ability to apply sophisticated data analysis techniques to experimental data
• Ability to program in Python and work with large databases
• Ability to work effectively in a team environment
• Strong oral and written communication skills
   

Start Date

The anticipated start date is in Fall 2025.
 

Application Process

Interested applicants should send a cover letter, CV and the names of up to three referees to (dutcher@uoguelph.ca). In your cover letter, you should highlight your relevant previous experience and training. Review of applications will begin immediately and continue until all positions are filled. Only applicants selected for an interview will be contacted. The Dutcher Lab and the University of Guelph are committed to building a diverse and inclusive community. All qualified applicants are invited to apply, but we particularly welcome applications from individuals that identify with groups traditionally underrepresented in the physical sciences, and we will strive to hire individuals who share our commitment to equity, diversity and inclusion.

We study a novel polysaccharide called phytoglycogen that is produced as dense, compact nanoparticles in the kernels of sweet corn. The natural polymer particles have a special dendritic or tree-like architecture that imparts special properties. Because of their unique physical properties as well as their biocompatibility, non-toxicity and digestibility, the particles have distinct advantages for use in applications involving the human body, such as personal care, nutrition, and biomedicine.

To study the properties of these nanoparticles, we use a wide range of experimental techniques that includes small angle neutron scattering (SANS), atomic force microscopy (AFM), infrared (IR) spectroscopy, ellipsometry, rheology, dynamic light scattering (DLS), and size exclusion chromatography-multiangle light scattering (SEC-MALS). The results of our measurements of the structure, morphology, hydration, and mechanical properties have shown that native phytoglycogen nanoparticles are soft, hairy, porous, and hydrated. We also use computational techniques such as dynamic self-consistent field theory to model native and modified phytoglycogen nanoparticles and their interaction with other small molecules.  

Important things that we have learned:

• Phytoglycogen nanoparticles are compact with a uniform density throughout the interior of the particles.
• Phytoglycogen nanoparticles are “hairy”: they have short chains that extend from the outer surface of the particles.
• Hydration water within phytoglycogen nanoparticles is well ordered and has slower dynamics than bulk water.
• Swelling of films of phytoglycogen nanoparticles is consistent with hydration forces acting between chains within the particles.
• Increasing the concentration of phytoglycogen nanoparticles in water produces a colloidal glass transition.
• Pressing on individual nanoparticles with an AFM tip shows that hydrated particles are soft and easily deformed. 
• There is an intimate link between the amount of hydration water within the particles and their bulk modulus and Young’s modulus. 

We can also modify phytoglycogen nanoparticles in several useful ways: 

• We can reduce the size and stiffness of the particles through partial digestion (hydrolysis either with acids or enzymes) and by using high shear extrusion. Acid hydrolysis of the particles produces decreases in the size and stiffness of the particles. Acid hydrolysis of the particles produces a qualitative change in their colloidal glass transition as the particles are forced into contact in high concentration dispersions. High shear extrusion of the particles produces a decrease in size and also changes the density and stiffness of the particles.
• We can add charged groups to the particles. Adding a positive charge to the particles can produce an increase in the stiffness of the particles. 
• We can add hydrophobic groups to change their interaction with water. High levels of modification with a charged, hydrophobic compound (octenyl succinic anhydride) result in the formation of hydrophobic “seeds” on the outer surface of the particles described by the raspberry model.
• We can associate bioactive compounds with the particles for bioactive and drug delivery applications. 

In our current research, we are investigating new ways to modify phytoglycogen nanoparticles to produce novel properties and identify new applications, and we are developing computer simulations of phytoglycogen nanoparticles using the technique of dynamic self-consistent field theory. This work involves collaborations with Prof. Rob Wickham (Guelph), Prof. Jon Nickels (Cincinnati), Dr. John Katsaras (Oak Ridge National Laboratory) and Prof. Mario Martinez (Aarhus). 

This safe, natural nanotechnology is being commercialized by our spinoff company, Mirexus Biotechnologies, which is working with customers to develop innovative products for personal care applications. 

Machine learning is revolutionizing the analysis of large databases. We are contributing to this revolution through our application of deep learning to the analysis of infrared spectra. 

We are studying cross-linked polyethylene (PEX-a) pipe, which you likely have as the water lines in your house. Commercial pipe formulations include additives that offer enhanced protection against degradation processes such as oxidation and UV-degradation. We use infrared (IR) microscopy to measure local changes to the polyethylene and the additives with in-service use at elevated temperature and pressure.

We place the pipes in an in-house water recirculation system that allows us to produce accelerated ageing of the pipes at different temperatures and environmental conditions. Aggressive ageing of the pipes can produce cracks in the pipes that ultimately leads to pipe failure. Our work is focused on understanding the formation and growth of cracks so that the lifetime of PEX-a pipe can be extended. 

Important things that we have learned:

• We have used a deep learning approach based on a beta-variational autoencoder to identify the underlying physicochemical changes associated with ageing of PEX-a pipe, including the characteristic signature of cracks that formed at the inner surface of pipes.
• We used principal component analysis of infrared microscopy data to quantify the hydrolysis of stabilizing additives with ageing of PEX-a pipes. 
• We used principal component analysis of infrared spectroscopy data to classify different formulations of PEX-a pipe.

• N. van Heijst, P. Whiting and J.R. Dutcher. Solubilization of Hydrophobic Astaxanthin in Water by Physical Association with Phytoglycogen Nanoparticles. Biomacromolecules 25, 4110 (2024).
• B. Morling, S. Luyben, J.R. Dutcher and R.A. Wickham. Efficient Modeling of High-Generation Dendrimers in Solution Using Dynamical Self-Consistent Field Theory. Macromolecules 57, 4617 (2024).
• J. D’Amico, M. Grossutti and J.R. Dutcher. Deep Learning Analysis of the Propagation of Stabilizing Additive Hydrolysis in a Cross-Linked Polyethylene Pipe. ACS Appl. Polym. Mater. 6, 534 (2024).
• R.R.B. Long, O.M.N. Bullingham, B. Baylis, J.B. Shaftoe, J.R. Dutcher and T.E. Gillis. The influence of triiodothyronine on the immune response and extracellular matrix remodeling during zebrafish heart regeneration. Comp. Biochem. Physiol. A Mol. Integr. Physiol., in press.
• M. Guo, K. Xu, J. Yee, J.R. Dutcher, M.M. Martinez and L. Roman. Comparative rheology and antioxidant potential of high-methoxyl sugar acid gels of unrefined powder and acid-extracted pectin from two hawthorn (Crataegus pinnatifida) fruit cultivars. LWT 203, 116331 (2023).
• M. Grossutti, J. D’Amico, J. Quintal, H. MacFarlane, W.C. Wareham, A. Quirk and J.R. Dutcher. Deep Generative Modeling of Infrared Images Provides Signature of Cracking in Cross-Linked Polyethylene Pipe. ACS Appl. Mater. Interfaces (2023), DOI: 10.1021/acsami.3c02564.
• F. Nasrollahzadeh, L. Roman, K. Skov, L.M.A. Jakobsen, B.M. Trinh, E.D. Tsochatzis, T. Mekonnen, M. Corredig, J.R. Dutcher and M.M. Martinez. A comparative investigation of seed storage protein fractions: The synergistic impact of molecular properties and composition on anisotropic structuring. Food Hydrocolloids, 137, 108400 (2023).
• K. Charlesworth, N. van Heijst, A. Maxwell, B. Baylis, M. Grossutti, J.J. Leitch and J.R. Dutcher. Binding Affinity of Concanavalin A to Native and Acid-Hydrolyzed Phytoglycogen Nanoparticles. Biomacromolecules 23, 4778 (2022).
• L. Roman, B. Baylis, K. Klinger, J. de Jong, John R. Dutcher and M.M. Martinez. Changes to fine structure, size and mechanical modulus of phytoglycogen nanoparticles subjected to high-shear extrusion. Carbohydr. Polym. 298, 120080 (2022).
• M. Grossutti, J. D’Amico, J. Quintal, H. MacFarlane, A. Quirk and J.R. Dutcher. Deep Learning and Infrared Spectroscopy: Representation Learning with a \(\beta -\)Variational Autoencoder. J. Phys. Chem. Lett. 13, 5787 (2022).
• H. Shamana and J.R. Dutcher. Transition in the Glassy Dynamics of Melts of Acid-Hydrolyzed Phytoglycogen Nanoparticles. Biomacromolecules 23, 2040 (2022).
• F. Nasrollahzadeh, L. Roman, V.J. Shiva Swaraj, K.V. Ragavan, N.P. Vidal, J.R. Dutcher and M.M. Martinez. Hemp (Cannabis sativa L.) protein concentrates from wet and dry industrial fractionation: Molecular properties, nutritional composition, and anisotropic structuring. Food Hydrocolloids 131, 107755 (2022).
• A.K. Luu, R.E. Macdonald, R. Parg, J.R. Dutcher and A.M. Viloria-Petit. A preliminary comparison of two different polyacrylamide hydrogel fabrication methods demonstrate differences in stiffness measurements and adhesion abilities of osteosarcoma cells. Med. Res. Arch. 10, 3 (2022).
• M. Grossutti, M. Hiles, J. D’Amico, W.C. Wareham, B. Morling, S. Graham and J.R. Dutcher. Quantifying stabilizing additive hydrolysis and kinetics through principal component analysis of infrared spectra of cross-linked polyethylene pipe. Polym. Degrad. Stab. 200, 109963 (2022).
• B. Baylis, E. Shelton, M. Grossutti and J.R. Dutcher. Force Spectroscopy Mapping of the Effect of Hydration on the Stiffness and Deformability of Phytoglycogen Nanoparticles, Biomacromolecules 22, 2985 (2021).
• M. Grossutti and J.R. Dutcher. Correlation of mechanical and hydration properties of soft phytoglycogen nanoparticles, Carbohydr. Polym. 251, 116980 (2021).
• M. Grossutti and J.R. Dutcher. Hydration Water Structure, Hydration Forces, and Mechanical Properties of Polysaccharide Films, Biomacromolecules 21, 4871 (2020).
• J. Simmons, J.D. Nickels, M. Michalski, M. Grossutti, H. Shamana, C.B. Stanley, A.L. Schwan, J. Katsaras, and J.R. Dutcher. Structure, Hydration, and Interactions of Native and Hydrophobically Modified Phytoglycogen Nanoparticles, Biomacromolecules 21, 4053-4062 (2020).
• T. Hoffmann, G.V. Lowry, S. Ghoshal, N. Tufenkji, D. Brambilla, J.R. Dutcher, L.M. Gilbertson, J.P. Giraldo, J.M. Kinsella, M.P. Landry, W. Lovell, R. Naccache, M. Paret, J.A. Petersen, J.M. Unrine, J.C. White and K.J. Wilkinson. Technology readiness and overcoming barriers to sustainably implement nanotechnology-enabled plant agriculture, Nature Food 1, 416-425 (2020).
• M. Hiles, M. Grossutti and J.R. Dutcher. Classifying Formulations of Crosslinked Polyethylene Pipe by Applying Machine-Learning Concepts to Infrared Spectra. Journal of Polymer Science: Polymer Physics 57, 1255-1262 (2019).
• J.R. Dutcher. Membranes stick to one dimension, Nature 563, 481-482 (2018), doi: 10.1038/d41586-018-07261-9.
• H. Shamana, M. Grossutti, E. Papp-Szabo, c. Miki and J.R. Dutcher. Unusual Polysaccharide Rheology of Aqueous Dispersions of Soft Phytoglycogen Nanoparticles, Soft Matter 14, 6496-6505 (2018).
• V. Giacintucci, C.D. Di Mattia, G. Sacchetti, F. Flamminii, A.J. Gravelle, B. Baylis, J.R. Dutcher, A.G. Marangoni and P. Pittia. Ethylcellulose oleogels with extra virgin olive oil: the role of oil minor components on microstructure and mechanical strength, Food Hydrocolloids 84, 508-514 (2018).
• J.R. Dutcher. Fundamental science and discoveries at the interface of microbiology and physics, Can. J. Microbiol. 64, 639-641 (2018).
• M. Grossutti, E. Bergmann, B. Baylis and J.R. Dutcher. Equilibrium swelling, interstitial forces and water structuring in phytoglycogen nanoparticle films, Langmuir 33, 2810-2816 (2017).
• M. Grossutti, C. Miki and J.R. Dutcher. Phytoglycogen Nanoparticles: 1. Key properties relevant to its use as a natural moisturizing ingredient, H & PC Today 12, 47-51 (2017).
• J.R. Dutcher, M. Grossutti, J. Atkinson, B. Baylis, H. Shamana, E. Bergmann, J. Nickels and J. Katsaras. Phytoglycogen Nanoparticles: Exciting Science and Promising Technologies From Nature, Phys. Canada 73, 91-94 (2017).
• M. Grossutti and J.R. Dutcher. Correlation Between Chain Architecture and Hydration Water Structure in Polysaccharides, Biomacromolecules 17, 1198-1204 (2016).
• J.D. Nickels, J. Atkinson, E. Papp-Szabo, C. Stanley, S.O. Diallo, S. Perticaroli, B. Baylis, P. Mahon, G. Ehlers, J. Katsaras and J.R. Dutcher. Structure and Hydration of Highly-Branched, Monodisperse Phytoglycogen Nanoparticles, Biomacromolecules 17, 735-743 (2016).
• J. Shi, D. Jiang, J.R. Dutcher and X. Qin. Thickness-dependent mobility in tetracene thin-film field-effect-transistors, J. Vac. Sci. Technol. B33, 050604 (2015).
• N. Couto, S.R. Schooling, J.R. Dutcher and J. Barber. Proteome Profiles of Outer Membrane Vesicles and Extracellular Matrix of Pseudomonas aeruginosa Biofilms, J. Proteome Res. 14, 420-222 (2015).
• S. Lu, M. Giuliani, H. Harvey, L.L. Burrows, R.A. Wickham and J.R. Dutcher. Nanoscale Pulling of Type IV Pili Reveals Their Flexibility and Adhesion to Surfaces over Extended Lengths of the Pili, Biophys. J. 108, 2865-2875 (2015).
• A.K. Zetzl, A. Gravelle, M. Kurylowicz, J.R. Dutcher, S. Barbut and A.G. Marangoni. Microstructure of ethylcellulose oleogels and its relationship to mechanical properties, Food Structure 2, 27-40 (2014).
• A. Raegen, K. Reiter, A. Dion, A.J. Clarke, J. Lipkowski and J.R. Dutcher. Advances in surface plasmon resonance imaging enable quantitative tracking of nanoscale changes in thickness and roughness, Anal. Chem. 86, 3346-3354 (2014).
• M. Kurylowicz, H. Paulin, J. Mogyoros, M. Giuliani and J.R. Dutcher. The Effect of Nanoscale Surface Curvature on the Oligomerization of Surface-Bound Proteins, J. R. Soc. Interface 11, 20130818 (2014).
• S. Lu, G. Walters, R. Parg and J.R. Dutcher. Nanomechanical Response of Bacterial Cells to Cationic Antimicrobial Peptides, Soft Matter 10, 1806-1815 (2014).
• J. Wang, A. Quirk, J. Lipkowski, J.R. Dutcher and A.J. Clarke. Direct in Situ Observation of Synergism between Cellulolytic Enzymes during the Biodegradation of Crystalline Cellulose Fibers, Langmuir 29, 14997-15005 (2013).
• R.F. Moscaritolo, M. Kinley, A. Raegen, M. Giuliani, R. White, C. Kelly, L.L. Burrows and J.R. Dutcher. Quantifying the Dynamics of Bacterial Crowd Surfing, Physics in Canada, 69, 137-139 (2013).
• J.J. Leitch, C. Brosseau, S. Roscoe, K. Bessonov, J.R. Dutcher and J. Lipkowski. Electrochemical and PM-IRRAS Characterization of Cholera Toxin Binding at a Model Biological Membrane, Langmuir 29, 965-976 (2013).
• L.N. Rahman, F. McKay, M. Giuliani, A. Quirk, B.A. Moffatt, G. Harauz and J.R. Dutcher. Interactions of Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 with membranes at cold and ambient temperatures - Surface morphology and single-molecule force measurements show phase separation, and reveal tertiary and quaternary associations, BBA - Biomembranes 1828, 967-980 (2013).
• M. Kurylowicz, M. Giuliani and J.R. Dutcher. Using Nanoscale Substrate Curvature to Control the Dimerization of a Surface-Bound Protein, ACS Nano 6, 10571-10580 (2012).
• S.G. Allen, O. Tanchak, A. Quirk, A.N. Raegen, K. Reiter, R. Whitney, A.J. Clarke, J. Lipkowski and J.R. Dutcher. Surface Plasmon Resonance Imaging of the Enzymatic Degradation of Cellulose Microfibrils , Anal. Methods 4, 3238-3245 (2012).
• J. Wang, A. Quirk, J. Lipkowski, J.R. Dutcher, C. Hill, A. Mark and A.J. Clarke. Real-Time Observation of the Swelling and Hydrolysis of a Single Crystalline Cellulose Fiber Catalyzed by Cellulase 7B from Trichoderma reesei, Langmuir 28, 9664-9672 (2012).
• J.J. Leitch, J. Collins, A.K. Friedrich, U. Stimming, J.R. Dutcher and J. Lipkowski. Infrared Studies of the Potential Controlled Adsorption of Sodium Dodecyl Sulfate at the Au(111) Electrode Surface, Langmuir 28, 2455-2464 (2012).
• L.N. Rahman, G.S.T. Smith, V.V. Bamm, J.A.M. Voyer-Grant, B.A. Moffatt, J.R. Dutcher and G. Harauz. Phosphorylation of Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 facilitates cation-induced conformational changes and actin assembly, Biochemistry 50, 9587-9604 (2011).
• A. Touhami, M. Alexander, M. Kurylowicz, C. Gram, M. Corredig and J.R. Dutcher. Probing Protein Conformations at the Oil Droplet-Water Interface Using Single-Molecule Force Spectroscopy, Soft Matter 7, 10274-10284 (2011).
• C. Kelly, M. Giuiliani and J.R. Dutcher. Precise Measurement of Min Protein Oscillations in Bacterial Cells Using TIRF Microscopy, Physics in Canada 67, 185-187 (2011).
• T. Laredo, J.R. Dutcher and J. Lipkowski. Electric field driven changes of a Gramicidin containing lipid bilayer supported on a Au(111) surface, Langmuir 27, 10072-10087 (2011).
• B.C. Bryksa, P. Bhaumik, E. Magracheva, D.C. De Moura, M. Kurylowicz, A. Zdanov, J.R. Dutcher, A. Wlodawer and R.Y. Yada. Structure and mechanism of the saposin-like domain of a plant aspartic proteinase, J. Biol. Chem. 286, 28265-28275 (2011).
• V. Vadillo-Rodriguez and J.R. Dutcher. Viscoelasticity of the Bacterial Cell Envelope, Soft Matter 7, 4101-4110 (2011).
• L.N. Rahman, V.V. Bamm, J.A.M. Voyer, G.S.T. Smith, L. Chen, M.W. Yaish, B.A. Moffatt, J.R. Dutcher and G. Harauz. Zinc induces disorder-to-order transitions in free and membrane-associated Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 - A solution CD and solid-state ATR-FTIR study, Amino Acids 40, 1485-1502 (2011).
• L.N. Rahman, L. Chen, S. Nazim, V.V. Bamm, M.W.F. Yaish, B.A. Moffatt, J.R. Dutcher and G. Harauz. Interactions of intrinsically disordered Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 with membranes - Synergistic effects of lipid composition and temperature on secondary structure, Biochem. Cell Biol. 88, 791-807 (2010).
• A. Quirk, J. Lipkowski, C. Vandenende, D. Cockburn, A. Clarke, J.R. Dutcher and S.G. Roscoe. Direct Visualization of Enzymatic Digestion of a Single fiber of Native Cellulose in Aqueous Environment by Atomic Force Microscopy, Langmuir 26, 5007-5013 (2010).
• Graham S.T. Smith, Lin Chen, Vladimir V. Bamm, John R. Dutcher and George Harauz. The interaction of zinc with membrane-associated 18.5 kDa myelin basic protein (MBP) - an attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopic study, Amino Acids 39, 739-750 (2010).
• J.-B. Fiche, T. Laredo, O. Tanchak, J. Lipkowski, J.R. Dutcher and R.Y. Yada. Influence of an electric field on oriented films of DMPC/gramicidin bilayers: a circular dichroism study, Langmuir 26, 1057-1066 (2010).
• V. Vadillo-Rodriguez and J.R. Dutcher. Dynamic Viscoelastic Behavior of Individual Gram-Negative Bacterial Cells, Soft Matter 5, 5012-5019 (2009).
• P. Lau, T. Lindhout, T.J. Beveridge, J.R. Dutcher and J.S. Lam. Differential lipopolysaccharide core capping leads to quantitative and correlated modifications of mechanical and structural properties in Pseudomonas aeruginosa biofilms, J. Bacteriol. 191, 6618-6631 (2009).
• V. Vadillo-Rodriguez, S. Schooling and J.R. Dutcher. In Situ Characterization of Differences in the Viscoelastic Response of Individual Gram-Negative and Gram-Positive Bacterial Cells, J. Bacteriol. 191, 5518-5525 (2009).
• J. Leitch, J. Kunze, J.D. Goddard, A.L. Schwan, R.J. Faragher, R. Naumann, W. Knoll, J.R. Dutcher and J. Lipkowski. In Situ PM-IRRAS Studies of an Archaea Analogue Thiolipid Assembled on a Au(111) Electrode Surface, Langmuir 25, 10354-10363 (2009).
• S. Sek, T. Laredo, J.R. Dutcher and J. Lipkowski. Molecular resolution imaging of an antibiotic peptide in a lipid matrix, JACS 131, 6439-6444 (2009).
• P. Lau, J.R. Dutcher, T.J. Beveridge and J.S. Lam. Absolute quantitation of bacterial biofilm adhesion and viscoelasticity by microbead force spectroscopy, Biophys. J. 96, 2935-2948 (2009).
• A. Touhami and J.R. Dutcher. pH-Induced Changes in Adsorbed beta-Lactoglobulin Molecules Measured Using Atomic Force Microscopy, Soft Matter 5, 220-227 (2009).
• O. Stukalov, A.A. Korenevsky, T.J. Beveridge and J.R. Dutcher. Use of Atomic Force Microscopy and Transmission Electron Microscopy for Correlative Studies of Bacterial Capsules, Appl. Environ. Microbiol. 74, 5457-5465 (2008).
• V. Vadillo-Rodriguez, T.J. Beveridge and J.R. Dutcher. Surface Viscoelasticity of Individual Gram-Negative Bacterial Cells Studied Using Atomic Force Microscopy, J. Bacteriol., 190, 4225-4232 (2008).
• J.R. Dutcher and M.D. Ediger. Glassy Surfaces Not So Glassy, Science, 319, 577-578 (2008).
• T. Laredo, J. Leitch, M. Chen, I.J. Burgess, J.R. Dutcher and J. Lipkowski. Measurement of the Charge Number Per Adsorbed Molecule and Packing Densities of Self-Assembled Long-Chain Monolayers of Thiols, Langmuir, 23, 6205-6211 (2007).
• C.A. Murray and J.R. Dutcher. Effect of Changes in Relative Humidity and Temperature on Ultrathin Chitosan Films, Biomacromolecules 7, 3460-3465 (2006).
• C.B. Roth, A. Pound, S.W. Kamp, C.A. Murray and J.R. Dutcher. Molecular Weight Dependence of the Glass Transition Temperature of Freely-Standing Poly(Methyl Methacrylate) Films, Eur. Phys. J. E 20, 441-448 (2006).
• J. Kunze, J. Leitch, A.L. Schwann, R.J. Faragher, R. Naumann, S. Schiller, W. Knoll, J.R. Dutcher J. Lipkowski. A New Method to Measure Packing Densities of Self-Assembled Thiolipid Monolayers, Langmuir, 22, 5509 (2006).
• C.B. Roth and J.R. Dutcher. Hole Growth as a Micro-Rheological Probe to Measure the Viscosity of Polymers Confined to Thin Films, special issue on Dynamics of Confined Polymers, J. Polym. Sci.: Polym. Phys. 44, 3011-3021 (2006).
• O. Stukalov, C.A. Murray, A. Jacina and J.R. Dutcher. Relative Humidity Control for Atomic Force Microscopes, Rev. Sci. Instrum. 77, 033704-1 - 033704-6 (2006) (featured in Virtual Journal of Nanoscale Science and Technology, April 2006).
• C.B. Roth, B. Deh, B.G. Nickel and J.R. Dutcher. Evidence for Convective Constraint Release in Hole Growth in Freely-Standing Polystyrene Films, Phys. Rev. E 72, 021802-1 - 021802-12 (2005).
• C.B. Roth and J.R. Dutcher. Hole Growth in Freely-Standing Polystyrene Films Probed using a Differential Pressure Experiment, Phys. Rev. E 72, 021803-1 - 021803-9 (2005).
• J. Bante, C.A. Murray, J.R. Dutcher and J.-J. Alvarado-Gil. A Novel Integrated System for Analysis of Thermal Depth Profiles, Proc. of SPIE 5776, 485 (2005).
• C.B Roth and J.R. Dutcher. Glass Transition and Chain Mobility in Thin Polymer Films, J. Electroanal. Chem. 584, 13 (2005).
• C.A. Murray, S.W. Kamp, J.M. Thomas and J.R. Dutcher. Onset and Manipulation of Self-Assembled Morphology in Freely-Standing Polymer Trilayer Films, Phys. Rev. E 69, 061612-1 - 061612-11 (2004) (featured in Virtual Journal of Nanoscale Science and Technology, July 2004).
• C.B Roth and J.R. Dutcher. Mobility on Different Length Scales in Thin Polymer Films, in Soft Materials: Structure and Dynamics, eds. J.R. Dutcher and A.G. Marangoni (Marcel Dekker, 2004).
• C.B Roth and J.R. Dutcher. Glass Transition Temperature of Freely-Standing Films of Atactic Poly(methyl methacrylate), Eur. Phys. J. E 12, s01, 024 (2003).
• B. Frick, K. Dalnoki-Veress, J. Forrest, J. Dutcher, C. Murray and A. Higgins. First Inelastic Neutron Scattering Studies on Thin Free Standing Polymer Films, Eur. Phys. J. E 12, s01, 022 (2003).
• M. Wübbenhorst, C.A. Murray and J.R. Dutcher. Dielectric Relaxations in Ultrathin Isotactic PMMA Films and PS-PMMA-PS Trilayer Films, Eur. Phys. J. E 12, s01, 025 (2003).
• K. Dalnoki-Veress, J.R. Dutcher and J.A. Forrest. Dynamics and Pattern Formation in Thin Polymer Films, Physics in Canada 59, 75-84 (2003).
• C.B. Roth, B.G. Nickel, J.R. Dutcher and K. Dalnoki-Veress. Differential Pressure Experiment to Probe Hole Growth in Freely-Standing Polymer Films, Rev. Sci. Instrum. 74, 2796-2804 (2003).
• M. Wübbenhorst, C.A. Murray, J.A. Forrest and J.R. Dutcher. Dielectric Relaxations in Ultrathin Films of PMMA: Assessing the Length Scale of Cooperativity in the Dynamic Glass Transition, Proceedings of the International Symposium of Electrets (ISE-11), Melbourne Australia (2002).
• C. Gigault, K. Dalnoki-Veress and J.R. Dutcher. Changes in the Morphology of Self-Assembled Polystyrene Microsphere Monolayers Produced By Annealing, J. Colloid Inter. Sci. 243, 143-155 (2001).
• K. Dalnoki-Veress, B. Frick, J. Forrest, J.R. Dutcher, C. Murray and A. Higgins. First Inelastic Neutron Scattering Studies on Thin Free Standing Polymer Films, Institut Laue-Langevin (ILL) Millenium Symposium Technical Report (2001).
• K. Dalnoki-Veress, C. Murray, C. Gigault and J.R. Dutcher. Molecular Weight Dependence of Reductions in the Glass Transition Temperature of Thin Freely-Standing Polymer Films, Phys. Rev. E 63, 031801-1 - 031801-10 (2001).
• K. Dalnoki-Veress, J.A. Forrest, P.-G. de Gennes and J.R. Dutcher. Glass Transition Reductions in Thin Freely-Standing Polymer Films: A Scaling Analysis of Chain Confinement Effects [invited], J. Phys. IV France 10, Pr7-221 - Pr7-226 (2000). 
• John R. Dutcher, K. Dalnoki-Veress, B.G. Nickel and C.B. Roth. Instabilities in Thin Polymer Films: From Pattern Formation to Rupture [invited], Macromol. Symp. 159, 143-150 (2000). 
• A.P. Hitchcock, T. Tyliszczak, I. Koprinarov, H. Stover, W.H. Li, Y.M. Heng, K. Murti, P. Gerroir, J. R. Dutcher, K. Dalnoki-Veress and H.W. Ade. X-ray Microscopy: Proceedings of the Sixth International Conference, Eds. W. Meyer-Ilse, T. Warwick and D. Attwood (American Institute of Physics Press, 2000), pp. 231-234.
• K. Dalnoki-Veress, B.G. Nickel and J.R. Dutcher. Dispersion-Driven Morphology of Mechanically-Confined Polymer Films, Phys. Rev. Lett. 82, 1486-1489 (1999). 
• K. Dalnoki-Veress, B.G. Nickel, C. Roth and J.R. Dutcher. Hole Formation and Growth in Freely-Standing Polystyrene Films, Phys. Rev. E 59, 2153-2156 (1999). 
• J.R. Dutcher, K. Dalnoki-Veress and J.A. Forrest. Optical Probes of the Glass Transition in Thin Polymer Films, book chapter in "Supramolecular Structure in Confined Geometries", ed. G. Warr and S. Manne (American Chemical Society Press, 1998), V. 736, pp. 127-139.
• J.A. Forrest, K. Dalnoki-Veress and J.R. Dutcher. Brillouin Light Scattering Studies of the Mechanical Properties of Thin Freely-Standing Polystyrene Films, Phys. Rev. E 58, 6109-6114 (1998). 
• K. Dalnoki-Veress, J.A. Forrest and J.R. Dutcher. Mechanical Confinement Effects on the Phase Separation Morphology of Polymer Blend Thin Films, Phys. Rev. E 57, 5811-5817 (1998). 
• C. Gigault and J.R. Dutcher. Analysis of a Simple Method for the Reduction of Phonon Peak Broadening in Surface Brillouin Light Scattering, Appl. Opt. 37, 3318-3323 (1998).
• J.A. Forrest, K. Dalnoki-Veress and J.R. Dutcher. Interface and Chain Confinement Effects on the Glass Transition Temperature of Thin Polymer Films, Phys. Rev. E 56, 5705-5716 (1997). 
• K. Dalnoki-Veress, J.A. Forrest, J.R. Stevens and J.R. Dutcher. Phase Separation Morphology of Spincoated Polymer Blend Thin Films, Physica A 239, 87-94 (1997). 
• K. Dalnoki-Veress, J.A. Forrest, J.R. Stevens and J.R. Dutcher. Phase Separation Morphology of Thin Films of Polystyrene/Polyisoprene Blends, J. Polym. Sci. Part B: Polym. Phys. 34, 3017-3024 (1996). 
• J.A. Forrest, A.C. Rowat, K. Dalnoki-Veress, J.R. Stevens and J.R. Dutcher. Brillouin Light Scattering Studies of the Mechanical Properties of Polystyrene/Polyisoprene Multilayered Thin Films, J. Polym. Sci. Part B: Polym. Phys. 34, 3009-3016 (1996). 
• J.A. Forrest, K. Dalnoki-Veress, J.R. Stevens and J.R. Dutcher. Effect of Free Surfaces on the Glass Transition Temperature of Thin Polymer Films, Phys. Rev. Lett. 77, 2002-2005 (1996); 77, 4108 (1996). 
• J.A. Forrest, K. Dalnoki-Veress, J.R. Dutcher, A.C. Rowat and J.R. Stevens. Brillouin Light Scattering Determination of the Glass Transition in Thin, Freely-Standing Polystyrene Films. Proc. Mater. Res. Soc. Symp. 407, 131-136 (1996). 

• Atomic force microscopes
• Self-nulling ellipsometer
• Rheometer
• Differential scanning calorimeter
• Thermogravimetric analyzer
• SEC-MALS system
• Surface plasmon resonance imaging system
• Optical microscopes
• Dynamic light scattering spectrometer
• Attenuated total reflection FTIR spectrometer
• Accelerated ageing recirculation system
• UV-Vis-NIR Spectrophotometer
• Nanodrop Spectrophotometer
• Refractometer
• Contact angle instrument
• Infrared microscope

• Spincoater
• Glove box
• Laminar flow cabinet
• Ultrapure water facility
• Vacuum ovens
• UV/ozone cleaner
• Plasma cleaner
• CO2
• snow cleaner
• Microtome
• High temperature oven
• Langmuir trough
• Microbiology facilities

• Ultrafiltration system
• Vacuum oven
• Centrifuge
• Spray dryer
• Lyophilizer