Free-standing ultra-thin polymer supports
We fabricate free-standing polymer films as thin as 6 nm or over areas as large as 12 cm diameter. These films can support up to 10,000 times their own weight and are used as compliant, load-bearing supports for capsules inside of National Ignition Facility (NIF) targets. Our research is focused on film fabrication methods, novel materials, and methods to measure the mechanical properties of macroscopic ultra-thin films.
S. Bhandarkar, J. Betcher, R. Smith, B. Lairson, T. Ayres, “Constitutive Models for the Viscoelastic Behavior of Polyimide Membranes at Room and Deep Cryogenic Temperatures,” Fusion Science and Technology, 70, 332-340 (2016).
M. Stadermann, S.H. Baxamusa, W.C. Floyd III, P.E. Miller, T.I. Suratwala, A.A. Tambazidis, K.P. Youngblood, C. Aracne-Ruddle, A..J Nelson, M. Chea, S. Li, “Preparation of large ultra-thin free-standing polymer films,” US Patent Application 15/130,524
R. Tomassini, JE Field, BA Hammel, OL Landen, SW Haan, C Aracne-Ruddle, LR Benedetti, DK Bradley, DA Callahan, DL Dewald, T Doeppner, MJ Edwards, OA Hurricane, N Izumi, OA Jones, T Ma, NB Meezan, SR Nagel, JR Rygg, KS Segraves, M Stadermann, RJ Strauser, RPJ Town, “Tent-induced perturbations on areal density of implosions at the National Ignition Facility,” Physics of Plasmas, 22, 056315 (2015)
M. Stadermann, SH Baxamusa, C Aracne-Ruddle, M Chea, S Li, K Youngblood, TI Suratwala, “Fabrication of large-area free-standing ultrathin polymer films,” Journal of Visualized Experiments (JoVE), 100, e52832 (2015)
S.H. Baxamusa et. al., “Enhanced Delamination of Ultrathin Free-Standing Polymer Films via Self-Limiting Surface Modification,” Langmuir, 30, 5126-5132 (2014)
M. Stadermann, S. O. Kucheyev, J. Lewicki, S. A. Letts, “Radiation tolerance of ultra-thin Formvar films,” Applied Physics Letters, 101, 071908 (2012)
Improvements to Formvar tent fabrication using the meniscus coater, M. Stadermann, S. A. Letts, S. Bhandarkar, J. Fusion Science & Technology 59, 58 (2011)
Chemical vapor deposition polymers
Our goal is to make polymer coatings that can be deployed in some of the most demanding engineering environments LLNL has to offer. We use plasma enhanced and initiated chemical vapor deposition techniques (CVD) to synthesize polymer coatings that can be deposited on a wide range of substrates. We characterize the response of these polymers under different chemical, thermal, and optical environments and develop methods for making materials more robust under use conditions. We are particularly interested in film stress, thermal behavior, and photostability of these materials. We also exploit novel oxidation pathways to create chemically patterned polymer surfaces for use as targets at NIF and other laser facilities.
X Lepro, P Ehrman, J Menapace, J Lotscher, S Shin, R Meissner, S Baxamusa, “Ultra-low stress, thermally stable crosslinked polymer films of poly-divinylbenzene (PDVB),” Langmuir, 33, 5204 (2017)
SH Baxamusa, XN Lepro, M Worthington, P Ehrmann, T Laurence, N Teslich, A Suresh, DD Burkey, “Initiated chemical vapor deposition polymers for high peak-power laser targets,” Thin Solid Films, in press (2016)
H Reynolds, SH Baxamusa, SW Haan, P Fitzsimmons, L Carlson, M Farrell, A Nikroo, BJ Watson, “Surface oxygen micropatterns on glow discharge polymer targets by photo irradiation,” Journal of Applied Physics, 119, 085305 (2016)
SH Baxamusa, T Laurence, M Worthington, P Ehrmann, “Photo-oxidation of polymer-like amorphous hydrogenated carbon under visible-light illumination,” Polymer Degradation and Stability, 122, 133-138 (2015)
SH Baxamusa, A Suresh, P Ehrmann, T Laurence, J Hanania, J Hayes, S Harley, DD Burkey, “Photo-oxidation of polymers synthesized by plasma and initiated CVD,” Chemical Vapor Deposition, 21, 267-274 (2015)
SW Haan, H Huang, MA Johnson, M Stadermann, S Baxamusa, S Bhandarkar, DS Clark, V Smalyuk, HF Robey, “Instability growth seeded by oxygen in CH shells on the National Ignition Facility,” Physics of Plasmas, 22, 032708 (2015)
H. Huang, D. M. Haas, Y. T. Lee, J. J. Wu, K. A. Moreno, R. B. Stephens, A. Nikroo, M. Stadermann, S. D. Bhandarkar, “Oxygen profile determination in NIF GDP capsules using contact radiography,” Fusion Science & Technology 63, 142 (2013)