(6ko) Exploring the Structure of Gradient Double Network Gels

Gradient materials exhibit a continuous variation in any of their physical or chemical properties. For example, tendons, fibrous tissues found in our bodies, illustrate naturally occurring gradient materials; they exhibit a continuous change in modulus, which helps to achieve efficient connectivity between soft muscle tissues and hard bones. Mimicking such gradients using synthetic polymers networks with tunable stiffness will have a tremendous impact on the development of medical implants. The research program that I envision to develop will explore new methods for generating tough gradient hydrogels. The strategy will be to synthesize double network hydrogels (DN) and elastomers by incorporating degradable network strands, wherein the first network can be degraded under acidic conditions while maintaining the second network intact. Such a system will also allow for complete characterization of DN strands after their formation by selective degradation of either one of the two networks to examine the network properties of the remaining gel. After gaining fundamental insights into the structure of DN, the project will focus on the development of gradient DN (gDN), demonstrating a continuous variation in network density and modulus. A key advantage of gDN is that a single specimen can be used to investigate the effect (e.g., elasticity or molecular concentration) of varying a given parameter systematically.

I am also interested in developing versatile synthetic routes for creating functional hydrogels reinforced with nanoparticles (e.g., activated carbon and magnetic particles) and lignin which will have various industrial applications (e.g., catalysis, water purification, and electronics). The strategy is to synthesize polymerizable resins incorporating nanoparticles and crosslinkers that can be printed through digital stereolithography (DSLA) using visible light. DSLA affords high-quality surface finish, dimensional accuracy, and a wide range of compatible materials that enable the fabrication of large-scale

3D objects. Having a strong background in polymer chemistry, polymer physics, and biology, I am confident that I can independently attain financial support from government and private agencies. The interdisciplinary nature of my research interest would draw potential funding from NIH (NIEHS, NIBIB), NSF (BMAT, CMMT, EBMS, POLY), ONR and many industries (e.g., Eastman Chemical Company).

Teaching Interests:

My passion for research, teaching, and learning is what motivated me to consider a career in academia. Teaching students and witnessing how their understanding and scientific thinking develops is extremely rewarding. I think the process occurs not only when mentoring a student, but also every time a student internalizes concepts in a classroom. Beyond the transfer of knowledge, through teaching I wish to develop students’ abilities to analyze information, engage in critical thinking and ensure retention of materials.

I am qualified to teach any undergraduate major courses in Chemical Engineering:

• Chemical Engineering Thermodynamics, Reaction Engineering, Reaction Kinetics
• Computer-Aided Chemical Engineering, Principles of Chemical Engineering
• Material and Energy Balances, Materials Science
• Chemistry for Engineers, Macromolecular Science and Engineering
• Biomaterials, Polymer Science and Technology

For graduate students, considering my previous experiences, I can teach the following courses:

• Polymer Chemistry, Polymer Physics, Polymer at Interfaces
• Proteins at Interfaces, Biomaterials
• Spectroscopic methods for Molecular Characterization,
• Surface-Analytical Techniques for Soft Matters

Selected Publications

• C. K. Pandiyarajan, Jan Genzer, “Thermally Activated One-Pot, Simultaneous Radical and Condensation Reactions Generate Surface-Anchored Network Layers from Common Polymers”, Macromolecules 2019, 52, 700−707 (Link).
• Joachim Jelken, C. K. Pandiyarajan, Jan Genzer, Nino Lomadze, Svetlana Santer, “Polymer Nano- Membranes with Reversible Tunable Pore Size”, ACS Appl. Mater. Interfaces 2018, 10, 30844-30851 (Link).
• C. K. Pandiyarajan, Jan Genzer, “Effect of Network Density in Surface-Anchored Poly (N-isopropyl acrylamide) Hydrogels on Adsorption of Fibrinogen”, Langmuir 2017, 33, 1974-1983 (Link).
• C. K. Pandiyarajan, Oswald Prucker, Jürgen Rühe, “Humidity Driven Swelling of the Surface- Attached Poly (N-alkylacrylamide) Networks”, Macromolecules 2016, 49, 8254-8264 (Link).
• C. K. Pandiyarajan, Michael Rubinstein, Jan Genzer, “Surface-Anchored Poly (N-isopropyl acrylamide) Orthogonal Gradient Networks”, Macromolecules 2016, 49, 5076-5083 (Link).
• C. K. Pandiyarajan, “Biofunctionalized Hydrogels for Tissue Engineering”, Advanced Science News: Regenerative Medicines 2016 (Link).
• Ke Li, C. K. Pandiyarajan, Oswald Prucker, Jürgen Rühe, “On the Lubrication Mechanism of Surfaces Covered with Surface-Attached Hydrogels”, Macromolecular Chemistry and Physics 2016, 217, 526-536 (Link).
• C. K. Pandiyarajan, Oswald Prucker, Barbara Zieger, Jürgen Rühe, “Influence of the Molecular Structure of Surface-Attached poly (N-alkylacrylamide) Coatings on Blood Platelet Adhesion”, Macromolecular Bioscience 2013, 13, 873-884 (Link) and Journal Front Cover Page (Link).
• N. Somanathan, C. K. Pandiyarajan, W.A. Goedel, W. C. Chen, “Physico-Mechanical Studies on the Langmuir-Blodgett Films of Polythiophene Containing Mesogenic Side Chain”, Journal of Polymer Science B: Polymer Physics, 2009, 47, 173 (Link).

Books

• C. K. Pandiyarajan, “The Interaction of Blood Proteins and Platelets on Surface-Attached poly (N- alkyl acrylamide) Networks”, Der Andere Verlag (CPI Band 23) 2014, ISBN:978-3-86247-408-0

Patents

• Slippery Coatings (Pending).
• Functionalized PBT mat for Specific Capture of Proteins from Biological Fluids (Pending)

Invited Peer Reviewer

• Soft Matter (RSC), Journal of Materials Chemistry B (RSC)
• Engineering Reports (Wiley)
• Surface & Coatings Technology (Elsevier)
• Journal of Biomaterials Science: Polymer Edition (Taylor & Francis)