1
|
Nelson G, Drapes CS, Grant MA, Gnabasik R, Wong J, Baruth A. High-Precision Solvent Vapor Annealing for Block Copolymer Thin Films. MICROMACHINES 2018; 9:E271. [PMID: 30424204 PMCID: PMC6187827 DOI: 10.3390/mi9060271] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/16/2018] [Accepted: 05/25/2018] [Indexed: 01/24/2023]
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.
Collapse
Affiliation(s)
- Gunnar Nelson
- Department of Physics, College of Arts and Sciences, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
| | - Chloe S Drapes
- Department of Physics, College of Arts and Sciences, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
| | - Meagan A Grant
- Department of Physics, College of Arts and Sciences, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
| | - Ryan Gnabasik
- Department of Physics, College of Arts and Sciences, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
| | - Jeffrey Wong
- Department of Physics, College of Arts and Sciences, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
| | - Andrew Baruth
- Department of Physics, College of Arts and Sciences, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
| |
Collapse
|
2
|
Nowak SR, Hwang W, Sita LR. Dynamic Sub-10-nm Nanostructured Ultrathin Films of Sugar–Polyolefin Conjugates Thermoresponsive at Physiological Temperatures. J Am Chem Soc 2017; 139:5281-5284. [DOI: 10.1021/jacs.6b13285] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Samantha R. Nowak
- Laboratory of Applied Catalyst
Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Wonseok Hwang
- Laboratory of Applied Catalyst
Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Lawrence R. Sita
- Laboratory of Applied Catalyst
Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| |
Collapse
|
3
|
Baruth A, Seo M, Lin CH, Walster K, Shankar A, Hillmyer MA, Leighton C. Optimization of long-range order in solvent vapor annealed poly(styrene)-block-poly(lactide) thin films for nanolithography. ACS APPLIED MATERIALS & INTERFACES 2014; 6:13770-81. [PMID: 25029410 DOI: 10.1021/am503199d] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Detailed experiments designed to optimize and understand the solvent vapor annealing of cylinder-forming poly(styrene)-block-poly(lactide) thin films for nanolithographic applications are reported. By combining climate-controlled solvent vapor annealing (including in situ probes of solvent concentration) with comparative small-angle X-ray scattering studies of solvent-swollen bulk polymers of identical composition, it is concluded that a narrow window of optimal solvent concentration occurs just on the ordered side of the order-disorder transition. In this window, the lateral correlation length of the hexagonally close-packed ordering, the defect density, and the cylinder orientation are simultaneously optimized, resulting in single-crystal-like ordering over 10 μm scales. The influences of polymer synthesis method, composition, molar mass, solvent vapor pressure, evaporation rate, and film thickness have all been assessed, confirming the generality of this behavior. Analogies to thermal annealing of elemental solids, in combination with an understanding of the effects of process parameters on annealing conditions, enable qualitative understanding of many of the key results and underscore the likely generality of the main conclusions. Pattern transfer via a Damascene-type approach verified the applicability for high-fidelity nanolithography, yielding large-area metal nanodot arrays with center-to-center spacing of 38 nm (diameter 19 nm). Finally, the predictive power of our findings was demonstrated by using small-angle X-ray scattering to predict optimal solvent annealing conditions for poly(styrene)-block-poly(lactide) films of low molar mass (18 kg mol(-1)). High-quality templates with cylinder center-to-center spacing of only 18 nm (diameter of 10 nm) were obtained. These comprehensive results have clear and important implications for optimization of pattern transfer templates and significantly advance the understanding of self-assembly in block copolymer thin films.
Collapse
Affiliation(s)
- A Baruth
- Department of Chemical Engineering and Materials Science and Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States
| | | | | | | | | | | | | |
Collapse
|
4
|
Pitet LM, Wuister SF, Peeters E, Kramer EJ, Hawker CJ, Meijer EW. Well-Organized Dense Arrays of Nanodomains in Thin Films of Poly(dimethylsiloxane)-b-poly(lactide) Diblock Copolymers. Macromolecules 2013. [DOI: 10.1021/ma401719p] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Louis M. Pitet
- Institute
for Complex Molecular Systems and Laboratory for Macromolecular and
Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | | | - Emiel Peeters
- Department
of Applied Chemical Technology, Philips Group Innovation, Research, High Tech
Campus 7, 5656AE Eindhoven, The Netherlands
| | | | | | - E. W. Meijer
- Institute
for Complex Molecular Systems and Laboratory for Macromolecular and
Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| |
Collapse
|
5
|
Mastroianni SE, Epps TH. Interfacial manipulations: controlling nanoscale assembly in bulk, thin film, and solution block copolymer systems. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:3864-3878. [PMID: 23406541 DOI: 10.1021/la304800t] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Nanostructured soft materials from self-assembled block copolymers (BCP)s and polymer blends can enable the reliable, high-throughput, and cost-effective generation of nanoscale structural motifs for many emerging technologies. Our research group has studied the phase behavior of BCPs in bulk, thin film, and solution environments with a particular focus on using interfacial manipulations to control self-assembly and to access a vast array of nanoscale morphologies and orientations. These interfacial manipulations can be synthetic alterations that are directly incorporated into the BCP chain to modify polymer-polymer interactions, post-polymerization and non-synthetic modifications that affect block interactions, or changes to the polymer specimen's external surroundings to control self-assembly in a confining environment. Herein, we describe methods that we have employed to manipulate BCP self-assembly for various application targets, and we discuss the key effects of such manipulations on the resulting nanoscale morphologies.
Collapse
Affiliation(s)
- Sarah E Mastroianni
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | | |
Collapse
|
6
|
Preparation of fractal-like structures of insoluble polythiophene via solvent vapor annealing of solid thermocleavable polythiophene films and subsequent thermal curing. Polym J 2012. [DOI: 10.1038/pj.2012.224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
7
|
Wei X, Gu W, Li L, Shen X, Kim JK, Russell TP. Synthesis and morphology investigations of a novel alkyne-functionalized diblock copolymer. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/polb.23183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
8
|
Albert JNL, Young WS, Lewis RL, Bogart TD, Smith JR, Epps TH. Systematic study on the effect of solvent removal rate on the morphology of solvent vapor annealed ABA triblock copolymer thin films. ACS NANO 2012; 6:459-466. [PMID: 22148749 DOI: 10.1021/nn203776c] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Nanoscale self-assembly of block copolymer thin films has garnered significant research interest for nanotemplate design and membrane applications. To fulfill these roles, control of thin film morphology and orientation is critical. Solvent vapor annealing (SVA) treatments can be used to kinetically trap morphologies in thin films not achievable by traditional thermal treatments, but many variables affect the outcome of SVA, including solvent choice, total solvent concentration/swollen film thickness, and solvent removal rate. In this work, we systematically examined the effect of solvent removal rate on the final thin film morphology of a cylinder-forming ABA triblock copolymer. By kinetically trapping the film morphologies at key points during the solvent removal process and then using successive ultraviolet ozone (UVO) etching steps followed by atomic force microscopy (AFM) imaging to examine the through-film morphologies of the films, we determined that the mechanism for cylinder reorientation from substrate-parallel to substrate-perpendicular involved the propagation of changes at the free surface through the film toward the substrate as a front. The degree of reorientation increased with successively slower solvent removal rates. Furthermore, the AFM/UVO etching scheme permitted facile real-space analysis of the thin film internal structure in comparison to cross-sectional transmission electron microscopy.
Collapse
Affiliation(s)
- Julie N L Albert
- Chemical Engineering Department, University of Delaware, Newark, Delaware 19716, USA
| | | | | | | | | | | |
Collapse
|