The research objective of this Early Faculty Career Development (CAREER) award is to explore the use of induced negative viscosities as a new degree of freedom in polymer nanomanufacturing processes such as electrospinning. A novel method for precisely controlling the geometrical and magnetic distribution of nanoparticles inside a polymer matrix will be devised by controlling the particle size and chemistry of the nanoparticles as well as the frequency and amplitude of the oscillating magnetic fields employed to induce negative viscosity effects during the electrospinning process. The use of induced negative viscosities in polymer nanomanufacturing will be studied by a combination of multiphysics-based modeling and customized experiments. The mathematical modeling section will attempt to develop algorithms to simultaneously couple electromagnetic and transport phenomena in viscoelastic media. The experimental approach will include the use of a customized electrospinning device as well as the implementation of analytical methods based on magnetic force microscopy and electrostatic force microscopy. Even though the research is of fundamental nature, its discoveries can open an avenue for the manufacturing of novel composite structures not possible to achieve by any other method.
If successful, the findings could provide a competitive advantage to the American manufacturing and polymer processing industries as novel structures and materials could be produced at higher throughputs, lower costs and higher levels of control. The ability of using induced negative viscosity effects to control the position of particles with nanoscale precision could potentially be expanded to develop novel anti-counterfeiting devices aimed at protecting intellectual property rights and curtailing the counterfeit of high value goods. The education and outreach components of the plan seek to enhance the participation of underrepresented groups in research activities as well as to leverage prior investments of NSF in education and K-12 outreach programs. The PI will continue involvement in community outreach programs through the Big Brothers and Big Sisters of America, and will develop training modules for workshops that reach teachers working in districts serving underrepresented ethnic minorities. Furthermore, the PI will continue involvement with professional organizations to promote the pursuit of graduate education in sciences, technology, engineering and mathematics among Hispanic youth.
This project discovered a new way to control the viscosity of polymeric solutions by applying alternating magnetic fields. The project involved the participation and graduation of 2 Hispanic female graduate students and a Hispanic female postdoctoral researcher as well as 6 undergraduate researchers (1 African American, 2 Hispanics and 2 females). During the life of the award, students actively participated in outreach activities to the Ithaca community as well as to teachers in Puerto Rico and the New York. The project was able to quantify the effect of magnetic fields on the viscosity of polymeric solutions embedded with magnetic nanoparticles. The first graduate student was able to identify the role of permanent magnetic fields on the electrospinning of nanofibers, and the second graduate student was able to quantify the effect of frequency and magnitude of the magnetic field in the viscosity of polymeric solutions. Undergraduate students supported the work of the graduate students and one of the undergraduate students was able to develop a unique theoretical framework to understand the observed phenomena. In addition to the contribution of the field of fiber science and fluid mechanics, these discoveries have great implication in the manufacturing of polymeric materials as lower viscosities may imply higher production rates. The positional control of the nanoparticles on a one-dimensional object such as a nanofiber can also open a new avenue to develop novel anti-counterfeiting devices. The results from the project were disseminated in several venues of the American Chemical Society, The Fiber Society and the Society of Professional Hispanic Engineers. The scientific findings of the project were incorporated in teaching materials of a course entitled FSAD6160 Rheology of Solids taught every fall semester at Cornell University.
