1
|
Hendeniya N, Hillery K, Chang BS. Processive Pathways to Metastability in Block Copolymer Thin Films. Polymers (Basel) 2023; 15:polym15030498. [PMID: 36771799 PMCID: PMC9920306 DOI: 10.3390/polym15030498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/02/2023] [Accepted: 01/04/2023] [Indexed: 01/19/2023] Open
Abstract
Block copolymers (BCPs) self-assemble into intricate nanostructures that enhance a multitude of advanced applications in semiconductor processing, membrane science, nanopatterned coatings, nanocomposites, and battery research. Kinetics and thermodynamics of self-assembly are crucial considerations in controlling the nanostructure of BCP thin films. The equilibrium structure is governed by a molecular architecture and the chemistry of its repeat units. An enormous library of materials has been synthesized and they naturally produce a rich equilibrium phase diagram. Non-equilibrium phases could potentially broaden the structural diversity of BCPs and relax the synthetic burden of creating new molecules. Furthermore, the reliance on synthesis could be complicated by the scalability and the materials compatibility. Non-equilibrium phases in BCPs, however, are less explored, likely due to the challenges in stabilizing the metastable structures. Over the past few decades, a variety of processing techniques were introduced that influence the phase transformation of BCPs to achieve a wide range of morphologies. Nonetheless, there is a knowledge gap on how different processive pathways can induce and control the non-equilibrium phases in BCP thin films. In this review, we focus on different solvent-induced and thermally induced processive pathways, and their potential to control the non-equilibrium phases with regards to their unique aspects and advantages. Furthermore, we elucidate the limitations of these pathways and discuss the potential avenues for future investigations.
Collapse
|
2
|
Yadav P, Dubey N, Verma A. Controlling Lengthscales in Water-Solvent Induced Self-Organized Dewetting of Thin Polystyrene Films by Modulating the Surface Properties of the Substrate. J MACROMOL SCI B 2022. [DOI: 10.1080/00222348.2022.2118482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Priti Yadav
- Department of Chemical Engineering and Technology, Indian Institute of Technology (BHU), Varanasi, Uttar Pradesh, India
| | - Nidhi Dubey
- Department of Chemical Engineering and Technology, Indian Institute of Technology (BHU), Varanasi, Uttar Pradesh, India
| | - Ankur Verma
- Department of Chemical Engineering and Technology, Indian Institute of Technology (BHU), Varanasi, Uttar Pradesh, India
| |
Collapse
|
3
|
High-resolution imaging and fast number estimation of suspended particles using dewetted polymer microlenses in a microfluidic channel. Micron 2021; 151:103148. [PMID: 34562815 DOI: 10.1016/j.micron.2021.103148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 12/25/2022]
Abstract
We have fabricated polymer micro-lens array by self-organized dewetting inside the microchannel, which shows remarkable enhancement in the resolution, contrast and more than 10 times add-on magnification to a microscope. These lenses are demonstrated to resolve sub-micrometer features and detect moving micro-particles when suspension is flown in a microchannel. Polystyrene (PS) micro-lenses are fabricated on a polydimethylsiloxane (PDMS) substrate using the controlled dewetting of PS thin film then this PDMS substrate is used to close the microchannel with inverted micro-lenses on it. An aqueous suspension of polystyrene particles is flown through the microchannel and we have observed the particles through an optical microscope. Focusing and magnification through PS micro-lenses is analyzed to get a quantitative estimate of the particle number density in the solution. This method offers a promising low-cost high throughput solution for determining the approximate number density of flowing particles or suitably stained biological cells. Particularly in a pathology lab it can tremendously increase detection limit by enabling visibility of sub-micrometer pathogens using a standard laboratory microscope.
Collapse
|
4
|
Baglioni M, Sekine FH, Ogura T, Chen SH, Baglioni P. Nanostructured fluids for polymeric coatings removal: Surfactants affect the polymer glass transition temperature. J Colloid Interface Sci 2021; 606:124-134. [PMID: 34390987 DOI: 10.1016/j.jcis.2021.07.078] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 11/19/2022]
Abstract
HYPOTHESIS Nanostructured fluids (NSFs) based on water, organic solvents and surfactants are a valid alternative to the use of neat unconfined organic solvents for polymer coatings removal in art conservation. The physico-chemical processes underpinning their cleaning effectiveness in terms of swelling/dewetting of polymer films were identified as key in this context. The role of surfactants on polymers' dewetting was considered to be mainly restricted to the lowering of interfacial tensions. However, recent experiments evidenced that surfactants have an important role in swelling polymer films. EXPERIMENTS Five different amphiphiles were selected, namely: sodium dodecylsulfate, dimethyldodecyl amine oxide, hexaoxyethylene decyl ether (C9-11E6), pentadecaoxyethylene dodecyl ether (C12E15), and methyoxypentadecaoxyethylene dodecanoate (C11COE15CH3). They were combined with a carefully selected organic solvents' mixture (1-butanol/butanone/dimethyl carbonate) to formulate new NSFs, differing for the surfactant only, and used to perform cleaning tests on surfaces coated with Paraloid B72® and Primal AC33®. Here for the first time, polymer swelling induced by surfactants was quantified and correlated with the glass transition temperature of the two polymers by differential scanning calorimetry, before and after the exposure to the fluids. Confocal laser scanning microscopy and small-angle X-ray scattering provided additional insights on the interaction mechanism. FINDINGS Nonionics were proven more efficient than zwitterionic/ionic amphiphiles in the polymer swelling, and, overall, methyoxy pentadecaoxyethylene dodecanoate resulted the most effective among the selected surfactants. A direct relation between the effect of surfactants on the polymers' glass transition temperature and cleaning capacity was established. This finding, fundamental to understand the interaction mechanism between NSFs and polymer coatings or paint layers, is key to achieve a selective, effective and complete removal of polymer coatings, as recently shown in the removal of vandalism and over-paintings from street art.
Collapse
Affiliation(s)
- Michele Baglioni
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, Sesto Fiorentino (FI) 50019, Italy
| | - Felipe Hidetomo Sekine
- NIKKOL GROUP Nikko Chemicals Co., Ltd, 1-4-8, Nihonbashi-Bakurocho, Chuo-ku, Tokyo 103-0002, Japan
| | - Taku Ogura
- NIKKOL GROUP Nikko Chemicals Co., Ltd, 1-4-8, Nihonbashi-Bakurocho, Chuo-ku, Tokyo 103-0002, Japan; NIKKOL GROUP Cosmos Technical Center Co., Ltd, 3-24-3 Hasune, Itabashi-ku, Tokyo 174-0046, Japan; Research Institute for Science & Technology, Tokyo University of Science, 2641, Noda-shi, Chiba, Yamazaki 278-8510, Japan
| | - Sow-Hsin Chen
- Department of Nuclear Science & Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 24-107, Cambridge, MA 02139, USA
| | - Piero Baglioni
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, Sesto Fiorentino (FI) 50019, Italy; Department of Nuclear Science & Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 24-107, Cambridge, MA 02139, USA.
| |
Collapse
|
5
|
Rahman MU, Xi Y, Li H, Chen F, Liu D, Wei J. Dynamics and Structure Formation of Confined Polymer Thin Films Supported on Solid Substrates. Polymers (Basel) 2021; 13:1621. [PMID: 34067812 PMCID: PMC8155975 DOI: 10.3390/polym13101621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/27/2021] [Accepted: 05/11/2021] [Indexed: 01/18/2023] Open
Abstract
The stability/instability behavior of polystyrene (PS) films with tunable thickness ranging from higher as-cast to lower residual made on Si substrates with and without native oxide layer was studied in this paper. For further extraction of residual PS thin film (hresi) and to investigate the polymer-substrate interaction, Guiselin's method was used by decomposing the polymer thin films in different solvents. The solvents for removing loosely adsorbed chains and extracting the strongly adsorbed irreversible chains were selected based on their relative desorption energy difference with polymer. The PS thin films rinsed in chloroform with higher polarity than that of toluene showed a higher decrease in the residual film thickness but exhibited earlier growth of holes and dewetting in the film. The un-annealed samples with a higher oxide film thickness showed a higher decrease in the PS residual film thickness. The effective viscosity of PS thin films spin-coated on H-Si substrates increased because of more resistance to flow dynamics due to the stronger polymer-substrate interaction as compared to that of Si-SiOx substrates. By decreasing the film thickness, the overall effective mobility of the film increased and led to the decrease in the effective viscosity, with matching results of the film morphology from atomic force microscopy (AFM). The polymer film maintained low viscosity until a certain period of time, whereupon further annealing occurred, and the formation of holes in the film grew, which ultimately dewetted the film. The residual film decrement, growth of holes in the film, and dewetting of the polymer-confined thin film showed dependence on the effective viscosity, the strength of solvent used, and various involved interactions on the surface of substrates.
Collapse
Affiliation(s)
- Mujib Ur Rahman
- State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China;
| | - Yonghao Xi
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (Y.X.); (H.L.); (F.C.)
| | - Haipeng Li
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (Y.X.); (H.L.); (F.C.)
| | - Fei Chen
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (Y.X.); (H.L.); (F.C.)
| | - Dongjie Liu
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (Y.X.); (H.L.); (F.C.)
| | - Jinjia Wei
- State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China;
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (Y.X.); (H.L.); (F.C.)
| |
Collapse
|
6
|
Das A, Bolleddu R, Singh AK, Bandyopadhyay D. Physicochemical defect guided dewetting of ultrathin films to fabricate nanoscale patterns. NANOTECHNOLOGY 2021; 32:195303. [PMID: 33535200 DOI: 10.1088/1361-6528/abe2c8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Pathways to fabricate self-organized nanostructures have been identified exploiting the instabilities of ultrathin (<100 nm) polystyrene (PS) film on the polydimethylsiloxane (PDMS) substrates loaded with discrete and closely packed gold nanoparticles (AuNPs). The AuNPs were deposited on the PDMS substrates by chemical treatment, and the size and periodicity of the AuNPs were varied before coating the PS films. The study unveils that the physicochemical heterogeneity created by the AuNPs on the PDMS surface could guide the hole-formation, influence the average spacing between the holes formed at the initial dewetting stage, and affects the spacing and periodicity of the droplets formed at the end of the dewetting phase. The size and spacing of the holes and the droplets could be tuned by varying the nanoparticle loading on the PDMS substrate. Interestingly, as compared to the dewetting of PS films on the homogeneous PDMS surfaces, the AuNP guided dewetted patterns show ten-fold miniaturization, leading to the formation of the micro-holes and nanodroplets. The spacing between the droplets could also see a ten-fold reduction resulting in high-density random patterns on the PDMS substrate. Further, the use of a physicochemical substrate with varying density of physicochemical heterogeneities could impose a long-range order to the dewetted patterns to develop a gradient surface. The reported results can be of significance in the fabrication of high-density nanostructures exploiting the self-organized instabilities of thin polymers films.
Collapse
Affiliation(s)
- Abhijna Das
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Ravi Bolleddu
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Amit Kumar Singh
- Centre for Nanotechnology, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Dipankar Bandyopadhyay
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India
- Centre for Nanotechnology, Indian Institute of Technology Guwahati, Assam 781039, India
| |
Collapse
|
7
|
Pandey A, Maity S, Murmu K, Middya S, Bandyopadhyay D, Gooh Pattader PS. Self-organization of random copolymers to nanopatterns by localized e-beam dosing. NANOTECHNOLOGY 2021; 32:285302. [PMID: 33761481 DOI: 10.1088/1361-6528/abf197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
Strategic electron beam (e-beam) irradiation on the surface of an ultrathin (<100 nm) film of polystyrene-poly(methyl methacrylate) (PS-PMMA) random copolymer followed by solvent annealing stimulates a special variety of dewetting, leading to large-area hierarchical nanoscale patterns. For this purpose, initially, a negative (positive) tone of resist PS (PMMA) under weak e-beam exposure is exploited to produce an array of sites composed of cross-linked PS (chain-scissioned PMMA). Subsequently, annealing with the help of a developer solvent engenders dewetted patterns in the exposed zones where PMMA blocks are confined by the blocks of cross-linked PS. The e-beam dosage was systematically varied from 180μC cm-2to 10 000μC cm-2to explore the tone reversal behavior of PMMA on the dewetted patterns. Remarkably, at relatively higher e-beam dosing, both PMMA and PS blocks act as negative tones in the exposed zone. In contrast, the chain scission of PMMA in the periphery of the exposed regions due to scattered secondary electrons caused confined dewetting upon solvent annealing. Such occurrences eventually lead to pattern miniaturization an order of magnitude greater than with conventional thermal or solvent vapor annealed dewetting. Selective removal of PMMA blocks of RCP using a suitable solvent provided an additional 50% reduction in the size of the dewetted features.
Collapse
Affiliation(s)
- Ankur Pandey
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Surjendu Maity
- Center for Nanotechnology, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Kaniska Murmu
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Sagnik Middya
- Center for Nanotechnology, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Dipankar Bandyopadhyay
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India
- Center for Nanotechnology, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Partho Sarathi Gooh Pattader
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam 781039, India
- Center for Nanotechnology, Indian Institute of Technology Guwahati, Assam 781039, India
| |
Collapse
|
8
|
Golany Z, Weisbord I, Abo-Jabal M, Manor O, Segal-Peretz T. Polymer dewetting in solvent-non-solvent environment- new insights on dynamics and lithography-free patterning. J Colloid Interface Sci 2021; 596:267-277. [PMID: 33839353 DOI: 10.1016/j.jcis.2021.02.092] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/20/2021] [Accepted: 02/22/2021] [Indexed: 11/17/2022]
Abstract
HYPOTHESIS We show that one may employ polymer dewetting in solvent-non-solvent environment to obtain lithography-free fabrication of well-defined nano- to micro- scale polymer droplets arrays from pre-patterned polymer films. The polymer droplet pattern may be converted to a series of hybrid organic-inorganic and inorganic well-defined nano-patterns by using sequential infiltration synthesis (SIS). In particular, we scrutinize the physical parameters which govern the dewetting of flat and striped polymer thin films, which is the key to obtaining our objective of lithography-free ordered nano-patterns. EXPERIMENTS We immerse polystyrene (PS) and polymethyl methacrylate (PMMA) thin films in water in the presence of chloroform vapors. We study the ensuing polymer dewetting dynamics and the pattern formation of nanospheres by employing in-situ light microscopy and scanning electron microscopy. We then investigate pattern formation by dewetting of polymer stripes, fabricated by directed solvent evaporation, and SIS of AlOx from vapor phase precursors, trimethyl aluminum (TMA) and H2O, within the nanosphere patterns. FINDINGS We find that solvent- non-solvent environments render film dewetting rates, which are an order of magnitude faster than solvent vapor dewetting, and supports the formation of small solid polymer droplets, down to sub-100 nm droplet size, of large contact angles with the solid substrate. Pre-patterned polymer film stripes support the formation of highly ordered structures of polymer droplets, which are easily transformed to hybrid polymer-AlOx nanosphere patterns and templated AlOx nanosphere via SIS.
Collapse
Affiliation(s)
- Ziv Golany
- The Wolfson Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Inbal Weisbord
- The Wolfson Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Mohammad Abo-Jabal
- The Wolfson Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Ofer Manor
- The Wolfson Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Tamar Segal-Peretz
- The Wolfson Department of Chemical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
| |
Collapse
|
9
|
Fan X, Xu J, Chen L, Hong N, Wang C, Ma J, Ma Y. Processing Induced Nonequilibrium Behavior of Polyvinylpyrrolidone Nanofilms Revealed by Dewetting. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:15430-15441. [PMID: 33306375 DOI: 10.1021/acs.langmuir.0c03098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Polyvinylpyrrolidone (PVP) nanofilms prepared by spin-coating have vast applications in biological and microdevice fields. However, detailed knowledge of processing induced nonequilibrium behavior of PVP nanofilms and solutions for minimizing residual stresses toward high-quality films has still been lacking. In the present study, we first explored the rapid film formation process via statistics on nascent holes. Next, by employing dewetting as a major probe, we revealed that many processing conditions, particularly previously overlooked variables like the atmosphere, substrates, and immersion time, were correlated substantially with the degree of nonequilibrium of nanofilms. Proper aging temperature and time were demonstrated essential for releasing residual stresses and achieving more equilibrium nanofilms. This work offered abundant experimental evidence in the building relationship between the processing and nonequilibrium nature of polymer nanofilms, which were crucial for their preparation and application.
Collapse
Affiliation(s)
- Xiao Fan
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Jiao Xu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Long Chen
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Ning Hong
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Chuanbo Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Jinghong Ma
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Yu Ma
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| |
Collapse
|
10
|
Baglioni M, Guaragnone T, Mastrangelo R, Sekine FH, Ogura T, Baglioni P. Nonionic Surfactants for the Cleaning of Works of Art: Insights on Acrylic Polymer Films Dewetting and Artificial Soil Removal. ACS APPLIED MATERIALS & INTERFACES 2020; 12:26704-26716. [PMID: 32394706 PMCID: PMC8007071 DOI: 10.1021/acsami.0c06425] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
The use of nanostructured fluids (NSFs), that is, micellar solutions and microemulsions, in art conservation is often associated with cleaning purposes as the removal of polymeric coatings and/or soil from artistic surfaces. In both cases, the use of NSFs grants significant improvements over the use of traditional cleaning techniques that employ neat unconfined organic solvents, water, or aqueous solutions. The study of the nature and properties of surfactants present in NSF formulations is important to boost the effectiveness of these systems in applicative contexts and in the search of innovative and highly performing amphiphiles. This work reports on the methoxy-pentadeca(oxyethylene) dodecanoate (MPD) surfactant in two different NSFs, whose utilization in conservation of cultural heritage is new. Its effectiveness is compared to the conventional nonionic amphiphiles used in conservation practice, as pentadeca(oxyethylene) dodecyl ether, for the cleaning of poly(ethyl methacrylate/methyl acrylate) 70:30, p(EMA/MA), and artificially soiled surfaces. The mechanism, through which NSFs interact with polymeric coatings or soiled surfaces, was investigated by confocal laser scanning microscopy, fluorescence correlation spectroscopy, photographic observation, contact angle, surface tension measurements, and small-angle X-ray scattering. The results highlighted the superior MPD's performance, both in inducing polymer removal and in detaching the soil from coated surfaces. At the microscale, the cleaning involves dewetting-like processes, where the polymer or the soil oily phase is detached from the surface and coalesce into separated droplets. This can be accounted by considering the different surface tensions and the different adsorption mechanisms of MPD with respect to ordinary nonionic surfactants (likely due to the methyl capping of the polar head chain and to the presence of the ester group between the hydrophilic and hydrophobic parts of the MPD surfactant molecule), showing how a tiny change in the surfactant architecture can lead to important differences in the cleaning capacity. Overall, this paper provides a detailed description of the mechanism and the kinetics involved in the NSFs cleaning process, opening new perspectives on simple formulations that are able to target at a specific substance to be removed. This is of utmost importance in the conservation of irreplaceable works of art.
Collapse
Affiliation(s)
- Michele Baglioni
- Department
of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, 50019 Sesto Fiorentino, Florence, Italy
| | - Teresa Guaragnone
- Department
of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, 50019 Sesto Fiorentino, Florence, Italy
| | - Rosangela Mastrangelo
- Department
of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, 50019 Sesto Fiorentino, Florence, Italy
| | - Felipe Hidetomo Sekine
- NIKKOL
GROUP Nikko Chemicals Co., Ltd., 1-4-8, Nihonbashi-Bakurocho, Chuo-ku, 103-0002 Tokyo, Japan
| | - Taku Ogura
- NIKKOL
GROUP Nikko Chemicals Co., Ltd., 1-4-8, Nihonbashi-Bakurocho, Chuo-ku, 103-0002 Tokyo, Japan
- NIKKOL
GROUP Cosmos Technical Center Co., Ltd., 3-24-3 Hasune, Itabashi-ku, 174-0046 Tokyo, Japan
- Research
Institute for Science & Technology, Tokyo University of Science, 2641, Yamazaki, Noda-shi, Chiba 278-8510, Japan
| | - Piero Baglioni
- Department
of Chemistry and CSGI, University of Florence, via della Lastruccia, 3, 50019 Sesto Fiorentino, Florence, Italy
| |
Collapse
|
11
|
Chiu M, Wood JA, Widmer-Cooper A, Neto C. Aligned Droplet Patterns by Dewetting of Polymer Bilayers. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00620] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ming Chiu
- School of Chemistry and The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
| | - Jared A. Wood
- School of Chemistry and The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
| | - Asaph Widmer-Cooper
- School of Chemistry and The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
| | - Chiara Neto
- School of Chemistry and The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
| |
Collapse
|
12
|
Su C, Ma SM, Liu GX, Yang SG. Dewetting Behavior of Hydrogen Bonded Polymer Complex Film under Hydrothermal Condition. CHINESE JOURNAL OF POLYMER SCIENCE 2018. [DOI: 10.1007/s10118-018-2109-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
13
|
Baglioni M, Montis C, Brandi F, Guaragnone T, Meazzini I, Baglioni P, Berti D. Dewetting acrylic polymer films with water/propylene carbonate/surfactant mixtures - implications for cultural heritage conservation. Phys Chem Chem Phys 2018; 19:23723-23732. [PMID: 28581560 DOI: 10.1039/c7cp02608k] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The removal of hydrophobic polymer films from surfaces is one of the top priorities of modern conservation science. Nanostructured fluids containing water, good solvents for polymers, either immiscible or partially miscible with water, and surfactants have been used in the last decade to achieve controlled removal. The dewetting of the polymer film is often an essential step to achieve efficient removal; however, the role of the surfactant throughout the process is yet to be fully understood. We report on the dewetting of a methacrylate/acrylate copolymer film induced by a ternary mixture of water, propylene carbonate (PC) and C9-11E6, a nonionic alcohol ethoxylate surfactant. The fluid microstructure was characterised through small angle X-ray scattering and the interactions between the film and water, water/PC and water/PC/C9-11E6, were monitored through confocal laser-scanning microscopy (CLSM) and analised both from a thermodynamic and a kinetic point of view. The presence of a surfactant is a prerequisite to induce dewetting of μm-thick films at room temperature, but it is not a thermodynamic driver. The amphiphile lowers the interfacial energy between the phases and favors the loss of adhesion of the polymer on glass, decreasing, in turn, the activation energy barrier, which can be overcome by the thermal fluctuations of polymer film stability, initiating the dewetting process.
Collapse
Affiliation(s)
- M Baglioni
- Chemistry Department & CSGI, University of Florence, via della Lastruccia 3, 50019, Sesto Fiorentino (FI), Italy.
| | | | | | | | | | | | | |
Collapse
|
14
|
Baglioni M, Montis C, Chelazzi D, Giorgi R, Berti D, Baglioni P. Polymer Film Dewetting by Water/Surfactant/Good-Solvent Mixtures: A Mechanistic Insight and Its Implications for the Conservation of Cultural Heritage. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201710930] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Michele Baglioni
- Department of Chemistry and CSGI; University of Florence; via della Lastruccia 3 50019 Florence Italy
| | - Costanza Montis
- Department of Chemistry and CSGI; University of Florence; via della Lastruccia 3 50019 Florence Italy
| | - David Chelazzi
- Department of Chemistry and CSGI; University of Florence; via della Lastruccia 3 50019 Florence Italy
| | - Rodorico Giorgi
- Department of Chemistry and CSGI; University of Florence; via della Lastruccia 3 50019 Florence Italy
| | - Debora Berti
- Department of Chemistry and CSGI; University of Florence; via della Lastruccia 3 50019 Florence Italy
| | - Piero Baglioni
- Department of Chemistry and CSGI; University of Florence; via della Lastruccia 3 50019 Florence Italy
| |
Collapse
|
15
|
Baglioni M, Montis C, Chelazzi D, Giorgi R, Berti D, Baglioni P. Polymer Film Dewetting by Water/Surfactant/Good-Solvent Mixtures: A Mechanistic Insight and Its Implications for the Conservation of Cultural Heritage. Angew Chem Int Ed Engl 2018; 57:7355-7359. [PMID: 29215783 DOI: 10.1002/anie.201710930] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/05/2017] [Indexed: 11/09/2022]
Abstract
Aqueous nanostructured fluids (NSFs) have been proposed to remove polymer coatings from the surface of works of art; this process usually involves film dewetting. The NSF cleaning mechanism was studied using several techniques that were employed to obtain mechanistic insight on the interaction of a methacrylic/acrylic copolymer (Paraloid B72) film laid on glass surfaces and several NSFs, based on two solvents and two surfactants. The experimental results provide a detailed picture of the dewetting process. The gyration radius and the reduction of the Tg of Paraloid B72 fully swollen in the two solvents is larger for propylene carbonate than for methyl ethyl ketone, suggesting higher mobility of polymer chains for the former, while a nonionic alcohol ethoxylate surfactant was more effective than sodium dodecylsulfate in favoring the dewetting process. FTIR 2D imaging showed that the dewetting patterns observed on model samples are also present on polymer-coated mortar tiles when exposed to NSFs.
Collapse
Affiliation(s)
- Michele Baglioni
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3, 50019, Florence, Italy
| | - Costanza Montis
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3, 50019, Florence, Italy
| | - David Chelazzi
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3, 50019, Florence, Italy
| | - Rodorico Giorgi
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3, 50019, Florence, Italy
| | - Debora Berti
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3, 50019, Florence, Italy
| | - Piero Baglioni
- Department of Chemistry and CSGI, University of Florence, via della Lastruccia 3, 50019, Florence, Italy
| |
Collapse
|
16
|
Chatterjee M, Hens A, Mahato K, Jaiswal N, Mahato N, Nagahanumaiah, Chanda N. A novel approach to fabricate dye-encapsulated polymeric micro- and nanoparticles by thin film dewetting technique. J Colloid Interface Sci 2017; 506:126-134. [PMID: 28732229 DOI: 10.1016/j.jcis.2017.07.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/06/2017] [Accepted: 07/06/2017] [Indexed: 11/28/2022]
Abstract
A new method is reported for fabrication of polymeric micro- and nanoparticles from an intermediate patterned surface originated by dewetting of a polymeric thin film. Poly (d, l-lactide-co-glycolide) or PLGA, a biocompatible polymer is used to develop a thin film over a clean glass substrate which dewets spontaneously in the micro-/nano-patterned surface of size range 50nm to 3.5µm. Since another water-soluble polymer, poly vinyl alcohol (PVA) is coated on the same glass substrate before PLGA thin film formation, developed micro-/nano-patterns are easily extracted in water in the form of micro- and nanoparticle mixture of size range 50nm to 3.0µm. This simplified method is also used to effectively encapsulate a dye molecule, rhodamine B inside the PLGA micro-/nanoparticles. The developed dye-encapsulated nanoparticles, PLGA-rhodamine are separated from the mixture and tested for in-vitro delivery application of external molecules inside human lung cancer cells. For the first time, the use of thin film dewetting technique is reported as a potential route for the synthesis of polymeric micro-/nanoparticles and effective encapsulation of external species therein.
Collapse
Affiliation(s)
- Manosree Chatterjee
- Micro System Technology Laboratory, CSIR - Central Mechanical Engineering Research Institute, Durgapur 713209, India; Department of Biotechnology, National Institute of Technology Durgapur, Durgapur 713204, India
| | - Abhiram Hens
- Micro System Technology Laboratory, CSIR - Central Mechanical Engineering Research Institute, Durgapur 713209, India.
| | - Kuldeep Mahato
- Micro System Technology Laboratory, CSIR - Central Mechanical Engineering Research Institute, Durgapur 713209, India
| | - Namita Jaiswal
- Micro System Technology Laboratory, CSIR - Central Mechanical Engineering Research Institute, Durgapur 713209, India; Department of Biotechnology, National Institute of Technology Durgapur, Durgapur 713204, India
| | - Nivedita Mahato
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur 713204, India
| | - Nagahanumaiah
- Micro System Technology Laboratory, CSIR - Central Mechanical Engineering Research Institute, Durgapur 713209, India
| | - Nripen Chanda
- Micro System Technology Laboratory, CSIR - Central Mechanical Engineering Research Institute, Durgapur 713209, India.
| |
Collapse
|
17
|
Zhang H, Xu L, Xu Y, Huang G, Zhao X, Lai Y, Shi T. Enhanced Self-Organized Dewetting of Ultrathin Polymer Blend Film for Large-Area Fabrication of SERS Substrate. Sci Rep 2016; 6:38337. [PMID: 27922062 PMCID: PMC5138605 DOI: 10.1038/srep38337] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/08/2016] [Indexed: 01/10/2023] Open
Abstract
We study the enhanced dewetting of ultrathin Polystyrene (PS)/Poly (methyl methacrylate) (PMMA) blend films in a mixed solution, and reveal the dewetting can act as a simple and effective method to fabricate large-area surface-enhanced Raman scattering (SERS) substrate. A bilayer structure consisting of under PMMA layer and upper PS layer forms due to vertical phase separation of immiscible PS/PMMA during the spin-coating process. The thicker layer of the bilayer structure dominates the dewetting structures of PS/PMMA blend films. The diameter and diameter distribution of droplets, and the average separation spacing between the droplets can be precisely controlled via the change of blend ratio and film thickness. The dewetting structure of 8 nm PS/PMMA (1:1 wt%) blend film is proved to successfully fabricate large-area (3.5 cm × 3.5 cm) universal SERS substrate via deposited a silver layer on the dewetting structure. The SERS substrate shows good SERS-signal reproducibility (RSD < 7.2%) and high enhancement factor (2.5 × 107). The enhanced dewetting of polymer blend films broadens the application of dewetting of polymer films, especially in the nanotechnology, and may open a new approach for the fabrication of large-area SERS substrate to promote the application of SERS substrate in the rapid sensitive detection of trace molecules.
Collapse
Affiliation(s)
- Huanhuan Zhang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.,Laboratory of Surface Physics and Chemistry, Guizhou Education University, Guiyang 550018, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Lin Xu
- Laboratory of Surface Physics and Chemistry, Guizhou Education University, Guiyang 550018, P. R. China
| | - Yabo Xu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Gang Huang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xueyu Zhao
- School of Chemistry and Life Sciences, Guizhou Education University, Guiyang 550018, P. R. China
| | - Yuqing Lai
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Tongfei Shi
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| |
Collapse
|
18
|
Han X, Hou J, Xie J, Yin J, Tong Y, Lu C, Möhwald H. Synergism of Dewetting and Self-Wrinkling To Create Two-Dimensional Ordered Arrays of Functional Microspheres. ACS APPLIED MATERIALS & INTERFACES 2016; 8:16404-16411. [PMID: 27300307 DOI: 10.1021/acsami.6b03036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Here we report a simple, novel, yet robust nonlithographic method for the controlled fabrication of two-dimensional (2-D) ordered arrays of polyethylene glycol (PEG) microspheres. It is based on the synergistic combination of two bottom-up processes enabling periodic structure formation for the first time: dewetting and the mechanical wrinkle formation. The deterministic dewetting results from the hydrophilic polymer PEG on an incompatible polystyrene (PS) film bound to a polydimethylsiloxane (PDMS) substrate, which is directed both by a wrinkled template and by the template-directed in-situ self-wrinkling PS/PDMS substrate. Two strategies have been introduced to achieve synergism to enhance the 2-D ordering, i.e., employing 2-D in-situ self-wrinkling substrates and boundary conditions. As a result, we achieve highly ordered 2-D arrays of PEG microspheres with desired self-organized microstructures, such as the array location (e.g., selectively on the crest/in the valley of the wrinkles), diameter, spacing of the microspheres, and array direction. Additionally, the coordination of PEG with HAuCl4 is utilized to fabricate 2-D ordered arrays of functional PEG-HAuCl4 composite microspheres, which are further converted into different Au nanoparticle arrays. This simple versatile combined strategy could be extended to fabricate highly ordered 2-D arrays of other functional materials and achieve desirable properties and functionalities.
Collapse
Affiliation(s)
- Xue Han
- School of Materials Science and Engineering, Tianjin University , Tianjin 300072, People's Republic of China
| | - Jing Hou
- School of Materials Science and Engineering, Tianjin University , Tianjin 300072, People's Republic of China
| | - Jixun Xie
- School of Materials Science and Engineering, Tianjin University , Tianjin 300072, People's Republic of China
| | - Jian Yin
- School of Materials Science and Engineering, Tianjin University , Tianjin 300072, People's Republic of China
| | - Yi Tong
- School of Materials Science and Engineering, Tianjin University , Tianjin 300072, People's Republic of China
| | - Conghua Lu
- School of Materials Science and Engineering, Tianjin University , Tianjin 300072, People's Republic of China
| | - Helmuth Möhwald
- Department of Interfaces, Max Planck Institute of Colloids and Interfaces , Potsdam 14424, Germany
| |
Collapse
|
19
|
Hens A, Mondal K, Biswas G, Bandyopadhyay D. Pathways from disordered to ordered nanostructures from defect guided dewetting of ultrathin bilayers. J Colloid Interface Sci 2016; 465:128-39. [DOI: 10.1016/j.jcis.2015.11.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 11/18/2015] [Accepted: 11/20/2015] [Indexed: 12/15/2022]
|
20
|
Beena Unni A, Vignaud G, Bal JK, Delorme N, Beuvier T, Thomas S, Grohens Y, Gibaud A. Solvent Assisted Rinsing: Stability/Instability of Ultrathin Polymer Residual Layer. Macromolecules 2016. [DOI: 10.1021/acs.macromol.5b02435] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- A. Beena Unni
- FRE
CNRS 3744, IRDL, Univ. Bretagne Sud, F-56100 Lorient, France
- International
and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, 686560 India
| | - G. Vignaud
- FRE
CNRS 3744, IRDL, Univ. Bretagne Sud, F-56100 Lorient, France
| | - J. K. Bal
- Centre
for Research in Nanoscience and Nanotechnology, University of Calcutta, Technology Campus,
Block JD2, Sector III, Saltlake City, Kolkata 700098, India
| | - N. Delorme
- LUNAM
Université, IMMM, Faculté de Sciences, UMR 6283 CNRS, Université du Maine, Le Mans, Cedex 9, 72000, France
| | - T. Beuvier
- LUNAM
Université, IMMM, Faculté de Sciences, UMR 6283 CNRS, Université du Maine, Le Mans, Cedex 9, 72000, France
| | - S. Thomas
- International
and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, 686560 India
| | - Y. Grohens
- FRE
CNRS 3744, IRDL, Univ. Bretagne Sud, F-56100 Lorient, France
| | - A. Gibaud
- LUNAM
Université, IMMM, Faculté de Sciences, UMR 6283 CNRS, Université du Maine, Le Mans, Cedex 9, 72000, France
| |
Collapse
|
21
|
Mukherjee R, Sharma A. Instability, self-organization and pattern formation in thin soft films. SOFT MATTER 2015; 11:8717-8740. [PMID: 26412507 DOI: 10.1039/c5sm01724f] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The free surface of a thin soft polymer film is often found to become unstable and self-organizes into various meso-scale structures. In this article we classify the instability of a thin polymer film into three broad categories, which are: category 1: instability of an ultra-thin (<100 nm) viscous film engendered by amplification of thermally excited surface capillary waves due to interfacial dispersive van der Waals forces; category 2: instability arising from the attractive inter-surface interactions between the free surface of a soft film exhibiting room temperature elasticity and another rigid surface in its contact proximity; and category 3: instability caused by an externally applied field such as an electric field or a thermal gradient, observed in both viscous and elastic films. We review the salient features of each instability class and highlight how characteristic length scales, feature morphologies, evolution pathways, etc. depend on initial properties such as film thickness, visco-elasticity (rheology), residual stress, and film preparation conditions. We emphasize various possible strategies for aligning and ordering of the otherwise isotropic structures by combining the essential concepts of bottom-up and top-down approaches. A perspective, including a possible future direction of research, novelty and limitations of the methods, particularly in comparison to the existing patterning techniques, is also presented for each setting.
Collapse
Affiliation(s)
- Rabibrata Mukherjee
- Instability and Soft Patterning Laboratory, Department of Chemical Engineering, Indian Institute of Technology, Kharagpur, 721 302, India.
| | - Ashutosh Sharma
- Department of Chemical Engineering and Nano-science Center, Indian Institute of Technology, Kanpur, 208016, India.
| |
Collapse
|
22
|
Sachan P, Kulkarni M, Sharma A. Hierarchical Micro/Nano Structures by Combined Self-Organized Dewetting and Photopatterning of Photoresist Thin Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:12505-12511. [PMID: 26488849 DOI: 10.1021/acs.langmuir.5b02977] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Photoresists are the materials of choice for micro/nanopatterning and device fabrication but are rarely used as a self-assembly material. We report for the first time a novel interplay of self-assembly and photolithography for fabrication of hierarchical and ordered micro/nano structures. We create self-organized structures by the intensified dewetting of unstable thin (∼10 nm to 1 μm) photoresist films by annealing them in an optimal solvent and nonsolvent liquid mixture that allows spontaneous dewetting to form micro/nano smooth dome-like structures. The density, size (∼100 nm to millimeters), and curvature/contact angle of the dome/droplet structures are controlled by the film thickness, composition of the dewetting liquid, and time of annealing. Ordered dewetted structures are obtained simply by creating spatial variation of viscosity by ultraviolet exposure or by photopatterning before dewetting. Further, the structures thus fabricated are readily photopatterned again on the finer length scales after dewetting. We illustrate the approach by fabricating several three-dimensional structures of varying complexity with secondary and tertiary features.
Collapse
Affiliation(s)
- Priyanka Sachan
- Department of Chemical Engineering & Center for Nanosciences, Indian Institute of Technology Kanpur , Kanpur, India 208016
| | - Manish Kulkarni
- Department of Chemical Engineering & Center for Nanosciences, Indian Institute of Technology Kanpur , Kanpur, India 208016
| | - Ashutosh Sharma
- Department of Chemical Engineering & Center for Nanosciences, Indian Institute of Technology Kanpur , Kanpur, India 208016
| |
Collapse
|
23
|
Modi A, Bhaway SM, Vogt BD, Douglas JF, Al-Enizi A, Elzatahry A, Sharma A, Karim A. Direct Immersion Annealing of Thin Block Copolymer Films. ACS APPLIED MATERIALS & INTERFACES 2015; 7:21639-45. [PMID: 26351823 DOI: 10.1021/acsami.5b06259] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We demonstrate ordering of thin block copolymer (BCP) films via direct immersion annealing (DIA) at enhanced rate leading to stable morphologies. The BCP films are immersed in carefully selected mixtures of good and marginal solvents that can impart enhanced polymer mobility, while inhibiting film dissolution. DIA is compatible with roll-to-roll assembly manufacturing and has distinct advantages over conventional thermal annealing and batch processing solvent-vapor annealing methods. We identify three solvent composition-dependent BCP film ordering regimes in DIA for the weakly interacting polystyrene-poly(methyl methacrylate) (PS-PMMA) system: rapid short-range order, optimal long-range order, and a film instability regime. Kinetic studies in the "optimal long-range order" processing regime as a function of temperature indicate a significant reduction of activation energy for BCP grain growth compared to oven annealing at conventional temperatures. An attractive feature of DIA is its robustness to ordering other BCP (e.g. PS-P2VP) and PS-PMMA systems exhibiting spherical, lamellar and cylindrical ordering.
Collapse
Affiliation(s)
- Arvind Modi
- Department of Polymer Engineering, University of Akron , Akron, Ohio 44325, United States
| | - Sarang M Bhaway
- Department of Polymer Engineering, University of Akron , Akron, Ohio 44325, United States
| | - Bryan D Vogt
- Department of Polymer Engineering, University of Akron , Akron, Ohio 44325, United States
| | - Jack F Douglas
- Materials Science and Engineering Division, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - Abdullah Al-Enizi
- Chemistry Department, Faculty of Science, King Saud University , Riyadh 11451, Saudi Arabia
| | - Ahmed Elzatahry
- Materials Science and Technology Program, College of Arts and Sciences, Qatar University , PO Box 2713 , Doha, Qatar
| | - Ashutosh Sharma
- Department of Chemical Engineering, Indian Institute of Technology Kanpur , Kanpur, Uttar Pradesh 208016, India
| | - Alamgir Karim
- Department of Polymer Engineering, University of Akron , Akron, Ohio 44325, United States
| |
Collapse
|
24
|
Verma A, Sekhar S, Sachan P, Reddy PDS, Sharma A. Control of Morphologies and Length Scales in Intensified Dewetting of Electron Beam Modified Polymer Thin Films under a Liquid Solvent Mixture. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b00029] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ankur Verma
- Department of Chemical Engineering
and DST Unit on Nanosciences, Indian Institute of Technology Kanpur, Kanpur (UP), 208016 India
| | - Satya Sekhar
- Department of Chemical Engineering
and DST Unit on Nanosciences, Indian Institute of Technology Kanpur, Kanpur (UP), 208016 India
| | - Priyanka Sachan
- Department of Chemical Engineering
and DST Unit on Nanosciences, Indian Institute of Technology Kanpur, Kanpur (UP), 208016 India
| | - P. Dinesh Sankar Reddy
- Department of Chemical Engineering
and DST Unit on Nanosciences, Indian Institute of Technology Kanpur, Kanpur (UP), 208016 India
| | - Ashutosh Sharma
- Department of Chemical Engineering
and DST Unit on Nanosciences, Indian Institute of Technology Kanpur, Kanpur (UP), 208016 India
| |
Collapse
|
25
|
Bhandaru N, Goohpattader PS, Faruqui D, Mukherjee R, Sharma A. Solvent-vapor-assisted dewetting of prepatterned thin polymer films: control of morphology, order, and pattern miniaturization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3203-14. [PMID: 25692553 DOI: 10.1021/la5045738] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ultrathin (<100 nm) unstable polymer films exposed to a solvent vapor dewet by the growth of surface instability, the wavelength (λ) of which depends on the film thickness (h(f)). While the dewetting of a flat polymer thin film results in random structures, we show that the dewetting of a prepatterned film results in myriad ordered mesoscale morphologies under specific conditions. Such a film undergoes rupture over the thinnest parts when the initial local thickness of these zones (h(rm)) is lower than a limiting thickness h(lim) ≈ 10 nm. Additionally, the width of the pattern grooves (l(s)) must be wider than λ(s) corresponding to a flat film having a thickness of h(rm) for pattern-directed dewetting to take place over surface-tension-induced flattening. We first present an experimentally obtained morphology phase diagram that captures the conditions where a transition from surface-tension-induced flattening to pattern-directed-rupture takes place. Subsequently, we show the versatility of this technique in achieving a variety of aligned mesopatterns starting from a prepatterned film with simple grating geometry. The morphology of the evolving patterns depends on several parameters such as the initial film thickness (h(f)), prepattern amplitude (h(st)), duration of solvent vapor exposure (SVE), and wettability of the stamp used for patterning. Periodic rupture of the film at regular intervals imposes directionality on the evolving patterns, resulting in isolated long threads/cylindrical ridges of polymers, which subsequently disintegrate into an aligned array of droplets due to Rayleigh-Plateau instability under specific conditions. Other patterns such as a double periodic array of droplets and an array of holes are also possible to obtain. The evolution can be interrupted at any intermediate stage by terminating the solvent vapor annealing, allowing the creation of pattern morphology on demand. The created patterns are significantly miniaturized in size as compared to features obtained from dewetting a flat film with the same hf.
Collapse
Affiliation(s)
- Nandini Bhandaru
- †Instability and Soft Patterning Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Pin - 721302, Kharagpur, West Bengal, India
| | - Partho Sarathi Goohpattader
- ‡Department of Chemical Engineering and Nanoscience Center, Indian Institute of Technology Kanpur, 208016, Uttar Pradesh, Kanpur, India
| | - Danish Faruqui
- ‡Department of Chemical Engineering and Nanoscience Center, Indian Institute of Technology Kanpur, 208016, Uttar Pradesh, Kanpur, India
| | - Rabibrata Mukherjee
- †Instability and Soft Patterning Laboratory, Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Pin - 721302, Kharagpur, West Bengal, India
- ‡Department of Chemical Engineering and Nanoscience Center, Indian Institute of Technology Kanpur, 208016, Uttar Pradesh, Kanpur, India
| | - Ashutosh Sharma
- ‡Department of Chemical Engineering and Nanoscience Center, Indian Institute of Technology Kanpur, 208016, Uttar Pradesh, Kanpur, India
| |
Collapse
|
26
|
Dewetting based fabrication of fibrous micro-scaffolds as potential injectable cell carriers. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2014; 48:663-72. [PMID: 25579969 DOI: 10.1016/j.msec.2014.12.062] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 12/17/2014] [Indexed: 11/24/2022]
Abstract
Although regenerative medicine utilizing tissue scaffolds has made enormous strides in recent years, many constraints still hamper their effectiveness. A limitation of many scaffolds is that they form surface patches, which are not particularly effective for some types of "wounds" that are deep within tissues, e.g., stroke and myocardial infarction. In this study, we reported the generation of fibrous micro-scaffolds feasible for delivering cells by injection into the tissue parenchyma. The micro-scaffolds (widths<100μm) were made by dewetting of poly(lactic-co-glycolic acid) thin films containing parallel strips, and cells were seeded to form cell/polymer micro-constructs during or post the micro-scaffold fabrication process. Five types of cells including rat induced vascular progenitor cells were assessed for the formation of the micro-constructs. Critical factors in forming fibrous micro-scaffolds via dewetting of polymer thin films were found to be properties of polymers and supporting substrates, temperature, and proteins in the culture medium. Also, the ability of cells to attach to the micro-scaffolds was essential in forming cell/polymer micro-constructs. Both in vitro and in vivo assessments of injecting these micro-scaffolding constructs showed, as compared to free cells, enhanced cell retention at the injected site, which could lead to improved tissue engineering and regeneration.
Collapse
|
27
|
Wang F, Li P, Wang D, Li L, Xie S, Liu L, Wang Y, Li WJ. Mechanically modulated dewetting by atomic force microscope for micro- and nano- droplet array fabrication. Sci Rep 2014; 4:6524. [PMID: 25283744 PMCID: PMC4185381 DOI: 10.1038/srep06524] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 09/12/2014] [Indexed: 11/11/2022] Open
Abstract
Organizing a material into well-defined patterns during the dewetting process provides an attractive micro-/nano-fabrication method without using a conventional lithographic process, and hence, offers potential applications in organic electronics, optics systems, and memory devices. We report here how the mechanical modification of polymer surface by an Atomic Force Microscope (AFM) can be used to guide thin film dewetting evolution and break the intrinsic spatial correlation of spontaneous instability. An AFM is used to implement the mechanical modification of progressively narrow grids to investigate the influence of pattern size on the modulation of ultrathin polystyrene films dewetting evolution. For films with different initial thicknesses, when grid size is close to or below the characteristic wavelength of instability, the spinodal dewetting is suppressed, and film rupture is restricted to the cutting trench. We will show in this paper it is possible to generate only one droplet per gridded area on a thin film subsequent to nucleation dominated dewetting on a non-patterned substrate. Furthermore, when the grid periodicity exceeds the spinodal length, the number of droplets in predefined areas gradually approaches that associated with unconfined dewetting.
Collapse
Affiliation(s)
- Feifei Wang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pan Li
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dong Wang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Longhai Li
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuangxi Xie
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lianqing Liu
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China
| | - Yuechao Wang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China
| | - Wen Jung Li
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China
- Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong
| |
Collapse
|
28
|
Florence SS, Sachan P, Gupta RK, John R, Mahalingam U. Micropatterned Arrays of ZnSe Nanospheres as Antireflection Coatings. Aust J Chem 2014. [DOI: 10.1071/ch14265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this work, we demonstrate deposition of micro-arrays of ZnSe nanospheres on Si (100) substrate using simple thermal evaporation on a self-assembled sacrificial polystyrene (PS) mask. The results have been compared with the deposition on unpatterned gold catalyst- and SU-8 (negative photoresist)-coated Si substrates. The deposited ZnSe nanospheres properties were characterised by X-ray diffraction, atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman, photoluminescence, and UV-vis spectroscopies. The X-ray diffraction patterns of the films exhibited reflection corresponding to the cubic (111) phase and showed polycrystallinity with a cubic (zinc blende) structure. The SEM and AFM images indicated that the particles were well dispersed and spherical in shape. The micro-arrays of ZnSe nanospheres on a self-assembled sacrificial PS mask showed excellent structural, morphological, and optical properties and demonstrated its usage in photovoltaic devices as an improved superior antireflective coating. The reflectance of the micro-arrays of ZnSe nanospheres on a self-assembled sacrificial PS mask decreased to nearly half of that of the ZnSe nanospheres fabricated on Au- and SU-8-coated Si substrates in the range of 300–800 nm. Due to the well aligned and patterned surfaces, these noble textured ZnSe nanospheres may be suitable for low cost, large area photovoltaic devices and other antireflection applications.
Collapse
|
29
|
Berendsen CWJ, Zeegers JCH, Darhuber AA. Thinning and rupture of liquid films by moving slot jets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:15851-15858. [PMID: 24299431 DOI: 10.1021/la403988n] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We present systematic experiments of the rupture and dewetting of thin films of a nonvolatile polar liquid on partially wetting substrates due to a moving slot jet, which impinges at normal incidence. The relative motion was provided by a custom-built spin coater with a bidirectionally accessible axis of rotation that enabled us to measure film thickness profiles in situ as a function of substrate velocity using dual-wavelength interference microscopy. On partially wetting polymeric substrates, dry spots form in liquid films with a residual thickness well below 1 μm. We measured the density of dry spots as well as the density and size distribution of the residual droplets as a function of film thickness. In a certain parameter range, the droplet distributions exhibit pronounced anisotropy due to the effect of long-range shear stresses on the dewetting rim instability. We find robust power-law scaling relations over a large range of film thicknesses and a striking similarity to literature data obtained with ultrathin polymer melt layers on silicon substrates.
Collapse
Affiliation(s)
- Christian W J Berendsen
- Mesoscopic Transport Phenomena Group, Department of Applied Physics, Eindhoven University of Technology , Den Dolech 2, 5612AZ Eindhoven, The Netherlands
| | | | | |
Collapse
|
30
|
Berendsen CWJ, Zeegers JCH, Darhuber AA. Deformation and dewetting of thin liquid films induced by moving gas jets. J Colloid Interface Sci 2013; 407:505-15. [PMID: 23866198 DOI: 10.1016/j.jcis.2013.06.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 06/03/2013] [Accepted: 06/06/2013] [Indexed: 10/26/2022]
Abstract
We study the deformation of thin liquid films subjected to impinging air-jets that are moving with respect to the substrate. The height profile and shape of the deformed liquid film is evaluated experimentally and numerically for different jet Reynolds numbers and translation speeds, for different liquids and substrate materials. Experiments and numerical results are in good agreement. On partially wetting substrates film rupture occurs. We imaged the appearance of dry spots and emergence of droplet patterns by high-speed, dual-wavelength interference microscopy. We systematically evaluated the resulting average droplet size and droplet density as a function of the experimental conditions. We show that within experimental accuracy the distribution of dry spots is dependent only on the residual film thickness and is not directly influenced by the shear stress and pressure gradients of the air-jet, nor by the speed of the substrate.
Collapse
Affiliation(s)
- Christian W J Berendsen
- Mesoscopic Transport Phenomena Group, Department of Applied Physics, Eindhoven University of Technology, Den Dolech 2, 5612AZ Eindhoven, The Netherlands
| | | | | |
Collapse
|
31
|
Hens A, Mondal K, Bandyopadhyay D. Self-organized pathways to nanopatterns exploiting the instabilities of ultrathin confined bilayers. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:022405. [PMID: 23496524 DOI: 10.1103/physreve.87.022405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 12/02/2012] [Indexed: 06/01/2023]
Abstract
Self-organized interfacial instabilities of an ultrathin bilayer confined between a pair of rigid surfaces is explored. The bilayers are classified based on the macroscopic dewetting behaviors of the liquid films sandwiched between a pair of confining surfaces having surface energy higher or lower than the liquid films. Linear and nonlinear analyses employing the governing equations originating from the continuum description together with molecular dynamics (MD) simulations unveil the salient spatiotemporal features of the dewetting process. The study uncovers that, under the destabilizing influence of the intermolecular interactions, the interface of a confined bilayer can deform into interesting embedded and encapsulated patterns with nanoscale periodicity. The continuum and MD simulations collectively show the detailed route to dewetting starting from the formation of holes in the early stage, their growth to achieve equilibrium contact angle at the intermediate phase, and then to evolve into the equilibrium morphologies at the later stage. Examples are shown where the length and the time scales of the simulated nanostructures from both the continuum and MD approaches are found to agree with the same obtained from the linear stability analysis. We also highlight the deviations that are observed in the continuum and MD approaches. The study confirms that the reduced stabilizing interfacial tension at the liquid-liquid interface together with enhanced intermolecular interaction because of the thinness of the layers can be an alternative strategy for pattern miniaturization exploiting the instabilities of a thin confined bilayer. Further, the study shows that use of topographical patterns on the bounding surfaces can impose periodic order to the holes, droplets, columns, and channels, which can find important applications in the diverse areas of nanotechnology.
Collapse
Affiliation(s)
- Abhiram Hens
- Micro System Technology Laboratory, CSIR - Central Mechanical Engineering Research Institute, Durgapur-713209, India
| | | | | |
Collapse
|
32
|
Xu L, Sharma A, Joo SW. Dewetting of Stable Thin Polymer Films Induced by a Poor Solvent: Role of Polar Interactions. Macromolecules 2012. [DOI: 10.1021/ma301227m] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lin Xu
- School of Mechanical Engineering, Yeungnam University, Gyongsan 712-749, Korea
| | - Ashutosh Sharma
- School of Mechanical Engineering, Yeungnam University, Gyongsan 712-749, Korea
- Department of Chemical Engineering, Indian Institute of Technology, Kanpur 208016, India
| | - Sang Woo Joo
- School of Mechanical Engineering, Yeungnam University, Gyongsan 712-749, Korea
| |
Collapse
|
33
|
Verma A, Sharma A. Sub-40 nm polymer dot arrays by self-organized dewetting of electron beam treated ultrathin polymer films. RSC Adv 2012. [DOI: 10.1039/c2ra00956k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
|