(6fk) From Training in Polymer Physics to Developing Nonwovens for Advanced Applications

Behzad Nazari

Scientist at H&V and Research Affiliate/postdoc at MIT

PhD, PE Chemical Engineering, Polymer Scientist, Innovator and Educator

Research Interests:

As a scientist at Hollingsworth & Vose Company in Massachusetts, I get to use polymer physics and chemistry to develop nonwovens for air filtration applications. Throughout my training as a chemical engineer, filtration was always kept at a distance, but now it has become a realization for me how exciting it is to modify fibrous media in a way to be able to capture dust and to purify air. This particularly becomes an art when one needs to do it with minimized energy (low pressure drop across the media) for the most penetrating particles. Spinning processes and nonwovens are now definitely areas that I will be active in for the years to come.

I have taken my interest in controlling polymer physics and its effect on processing and final properties of the product to my current postdoctoral/research affiliate position at MIT with Prof. Greg Rutledge, where we seek to utilize structure-property relationship of polymer configuration and its molecular orientation to significantly alter the mechanical properties of polymeric fibers. For instance, by improving the molecular orientation and degree of crystallinity from gel-electrospinning ultra high molecular weight polyethylene, our group has successfully fabricated ultrathin fibers with high stiffness that rivals the commercial protective vest such as Spectra. By defining a fundamental connection between the predicted nanostructure and its functionality, we can expand much further on the capabilities of electrospun nanofibers to significantly impact the polymer processing and its application as a whole.

A second project I have been working on at MIT is embedding a shear thickening fluid within a nonwoven structure for protection applications. By using sub-micron fibers, capillary effects dominate the gravitational forces. This makes it difficult for the fluid to be extruded out of the system under its weight. Via capillary flow porometry and rheological measurements on the fluids, we now understand that the yield stress of the fluids play a significant role in keeping them inside the nonwoven pores.

Training students and researchers on classic topics of conformation and molecular dimensions of polymer chains remains challenging. As a postdoc at Penn State with my supervisor, Prof. Ralph Colby, I was able to assemble a 17-student team of superb undergraduate researchers spanning across different aspects of polymer science. These undergraduate students worked on the following projects:

1. Flow-induced crystallization of PEEK, nylon 66, iPP, and PET.
2. Rheology of ionic liquids/cellulose/chitosan solutions.
3. Investigation of polyolefin-based interpenetrating polymer networks for collecting oil spills.
4. Renewable lignocellulose-based foams via Pickering emulsion templates.

To provide these undergraduates with opportunities for continuing research experience, I submitted two separate proposals to the Fall 2017 University Park Research Experience for Undergraduates Funding Program through the College of Engineering at Penn State. These grants were successful in enabling two of our students to work on a project that aims to develop biomass-based films.

Through my Penn State experience, I came to realize that newcomers to the polymer field are easily attracted to studying relationships between structure and function in polymeric systems. In particular, our newly purchased rheometers made it easier for us to have our students experience and understand how conformational ordering under shear in a molten polymer can significantly change its crystallization rate and resulting crystal morphology.

My interest in “green materials” builds upon my Ph.D. work, undertaken at UMaine under the guidance of Prof. Doug Bousfield, which elucidated the interactions between rheology of cellulose nanofibers (CNFs) suspensions and their processability. I focused on the development of new applications for CNFs as an alternative platform for petroleum-based products. That work contributed to the feasibility of utilizing waste biomass, and therefore has huge environmental benefits. As the PI, I wrote a proposal entitled “Renewable lignocellulose-based foams via Pickering emulsion templates” to USDA’s Fiscal Year 2017 Biomass Research and Development.

Teaching Interests:

During 2011, I was a fulltime teacher of Chemical Reaction Engineering, Numerical Methods, Unit Operations (+Lab), Aspen Plus Workshop, Heat Transfer (+Lab), and Fluid Mechanics (+Lab). At UMaine, I TAed in Biological Transport Phenomena. More recently at Penn State, I taught Polymer Rheology and Processing. At MIT, I also colectured in Physical Chemistry of Polymers. In the future, I would welcome teaching these courses, but I would also like to teach Polymer Physics, Chemical Engineering Thermodynamics and Transport Phenomena. In 2015, I published a textbook entitled “Numerical Methods for Process Engineers” with Shiraz University Press. I believe effective teaching empowers the students’ ability to think in a critical way and create their own knowledge, and this ultimately benefits the research community. I also think other legitimate purposes of teachers include the need to make a useful contribution to society by helping induct younger human beings into the society’s thrive process.