@article{18ec995bf5ed4701b3b9a951f969328c,
title = "High-precision solvent vapor annealing for block copolymer thin films",
abstract = "Despite its efficacy in producing well-ordered, periodic nanostructures, the intricate role multiple parameters play in solvent vapor annealing has not been fully established. In solvent vapor annealing a thin polymer film is exposed to a vapor of solvent(s) thus forming a swollen and mobile layer to direct the self-assembly process at the nanoscale. Recent developments in both theory and experiments have directly identified critical parameters that govern this process, but controlling them in any systematic way has proven non-trivial. These identified parameters include vapor pressure, solvent concentration in the film, and the solvent evaporation rate. To explore their role, a purpose-built solvent vapor annealing chamber was designed and constructed. The all-metal chamber is designed to be inert to solvent exposure. Computer-controlled, pneumatically actuated valves allow for precision timing in the introduction and withdrawal of solvent vapor from the film. The mass flow controller-regulated inlet, chamber pressure gauges, in situ spectral reflectance-based thickness monitoring, and low flow micrometer relief valve give real-time monitoring and control during the annealing and evaporation phases with unprecedented precision and accuracy. The reliable and repeatable alignment of polylactide cylinders formed from polystyrene-b-polylactide, where cylinders stand perpendicular to the substrate and span the thickness of the film, provides one illustrative example.",
author = "Gunnar Nelson and Drapes, {Chloe S.} and Grant, {Meagan A.} and Ryan Gnabasik and Jeffrey Wong and Andrew Baruth",
note = "Funding Information: Author Contributions: Conceived and designed—G.N., R.G. and A.B. Performed the experiments—G.N., C.S.D., M.A.G., J.W. Analyzed the data—G.N., C.S.D., M.A.G., J.W. and A.B. Wrote the paper—G.N. and A.G.B. Supervised work—A.B. All authors discussed the results and implications and commented on the manuscript AatuatlhlosrtaCgoens.tributions: Conceived and designed—G.N., R.G. and A.B. Performed the experiments—G.N., C.S.D., M.A.G., J.W. Analyzed the data—G.N., C.S.D., M.A.G., J.W. and A.B. Wrote the paper—G.N. and A.G.B. Supervised work—A.B. All authors discussed the results and implications and commented on the manuscript at all stages. EPSCoR FIRST Award under contract 1004094. Additional support came from the Omaha Public Power District Acknowledgments: This work was supported by the National Science Foundation through the Nebraska EPSCoR and Creighton University{\textquoteright}s Center for Undergraduate Research and Scholarship. G.N. and R.G. acknowledge FIRST Award under contract 1004094. Additional support came from the Omaha Public Power District and Creighton University{\textquoteright}s Center for Undergraduate Research and Scholarship. G.N. and R.G. acknowledge support fBrooomthteh eLNucAe SfAouNnedbartaiosnk.aWSpea caeckGnroawntleCdognes omrteicuhman. iCca.Sl .Dex.paecrktnisoew alneddg ienssisguhptpforrotmfroBmratdh eWCallaterersB aonodth eRuLsutcine foundation.Haase. We acknowledge mechanical expertise and insight from Brad Walters and Rustin Haase. Funding Information: This work was supported by the National Science Foundation through the Nebraska EPSCoR FIRST Award under contract 1004094. Additional support came from the Omaha Public Power District and Creighton University's Center for Undergraduate Research and Scholarship. G.N. and R.G. acknowledge support from the NASA Nebraska Space Grant Consortium. C.S.D. acknowledges support from the Clare Boothe Luce foundation. We acknowledge mechanical expertise and insight from Brad Walters and Rustin Haase. Publisher Copyright: {\textcopyright} 2018 by the authors.",
year = "2018",
month = may,
day = "29",
doi = "10.3390/mi9060271",
language = "English (US)",
volume = "9",
journal = "Micromachines",
issn = "2072-666X",
publisher = "Multidisciplinary Digital Publishing Institute (MDPI)",
number = "6",
}