Research in my group focuses on the materials science and processing of coatings, ceramics and composites. The emphasis is on processing and microstructure control, but some projects also explore the important connections between the structure and the properties. Research projects are collaborative, involving other faculty and colleagues in industry.
A major area of research is coatings. Many products are made by coating processes (e.g., adhesive tapes, magnetic storage media, flexible electronics), while others are coated to improve their performance (e.g., laptop screens, biomedical devices, windows). Research in the Coating Process Fundamentals Program of IPRIME (Industrial Partnership in Interfacial and Materials Engineering) addresses fundamental scientific and engineering challenges in coatings. My coatings research explores processing and microstructure development of coatings prepared by deposition of a liquid (solution, monomer, dispersion of particles) followed by drying or curing. In collaboration with Profs. A.V. McCormick and S. Kumar, we study drying, solidification, patterning and stress development, and microstructure development in coatings. Coating systems of current interest are colloidal ceramics, sol-gel derived ceramics, polymers and ceramic/polymer composites. Experimental probes include cryo-scanning electron microscopy, thermogravimetric analysis, surface probe microscopies, bending of coated elastic beams. microrheology and infrared spectroscopy. Theory-based modeling of drying, microstructure and stress development accompanies the experimental work. Processing and structural development studies are often coupled with investigations of coating properties including optical, electrical, and mechanical properties. In collaboration with Profs. Frank Bates, we are working on specific coating systems based on block copolymers and with Prof. Michael Tsapatsis, we are designing coatings for catalytic applications.A new area of interest is processing fundamentals for flexible electronics and solar cells. We are collaborating with Prof. C.D. Frisbie on roll-to-roll processes for flexible circuits. Here the emphasis is on developing fine patterns and multilayer structures.
- S. Kalpathy, L. F. Francis and S. Kumar, “Thin-film models of liquid displacement on chemically patterned surfaces for lithographic printing processes,” Journal of Colloid and Interface Science, in press (2012).
- C. Cardinal Roberts and L. F. Francis "Drying and cracking of soft latex coatings", Journal of Coatings Technology and Research in press (2012)
- J-O. Song, A. V. McCormick and L. F. Francis, “Depthwise Viscosity Gradients in UV Cured Epoxy Coatings,” Macromolecular Materials and Engineering, in press (2012).
- C. Declet-Perez, E M. Redline, L. F. Francis, and F. S. Bates, “Role of localized network damage in block copolymer toughened epoxies,” ACS Macro Lett. 1, (2012) 338âˆ'342
- D. D. Brewer, T. Shibuta, L. Francis, S. Kumar, and M. Tsapatsis, Coating process regimes in particulate film Production by forced-convection-assisted drag-out, Langmuir 27 (2011) 11660-11670
- K. Varoon, X. Zhang, B. Elyassi, D. Brewer, M. Gettel, S. Kumar, J. A. Lee, S. Maheshwari, A. Mittal, C.-Y.Sung, M. Cococcioni, L.F. Francis, A.V. McCormick, A. Mkhoyan and M. Tsapatsis “Dispersible Exfoliated Zeolite Nanosheets and Their Application as a Selective Membrane,” Science 334, (2011) 72-75.
- F. S. Buss, K. Crawford, C. C. Roberts, K. Peters, and L. F. Francis, "Effect of Soluble Polymer Binder on Particle Distribution in a Drying Particulate Coating," J. Colloid and Interface Sci., 359, 112-120 (2011).
- E. M . Redline, L. F. Francis, and F. S. Bates, "Radical-cured block copolymer-modified thermosets," Journal of Polymer Science, Part B: Polymer Physics, 49, 540-550 (2011).
- T. R. Reynolds, S. Kalpathy, S. Kumar and L. F. Francis, "Dip coating of charged colloidal suspensions onto substrates with patterned wettability: Coating regime maps," J. Colloid Interface Sci., 352 (2010) 202-210.
- J-O. Song, R. M. Henry, R. M. Jacobs, and L. F. Francis, "Magnetic Microrheometer for In-Situ Characterization of Coating Viscosity," Rev. of Scientific Instruments, 81, 093903 (8 pages) (2010).
- S. Kalpathy, L. F. Francis and S. Kumar, "Shear-Induced Suppression of Rupture in Two-Layer Thin Liquid Films," J. Colloid and Interface Sci. , 348, 271-279 (2010).
- C. Cardinal, Y.D. Jung, K. Ahn, and L. F. Francis, "Drying Regime Maps for Particulate Coatings," AIChE J, 56, 2769 - 2780 (2010).
- H. Zhang, Z. Wu, and L. F. Francis, "Salt Whisker Formation on Porous Coatings," Langmuir, 26, 2847-2856 (2010).