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Junisu BA, Sun YS. Hierarchical Surface Instability in Polymer Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:15249-15259. [PMID: 37862459 DOI: 10.1021/acs.langmuir.3c01936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
This study demonstrates hierarchical instabilities in thin films. The hierarchical instabilities display three morphological characteristics: (1) windmill-like patterns at the macroscale, (2) Bénard cells and striations at the microscale, and (3) holes at the mesoscale. Such hierarchical instabilities occurred when spin coating was performed on high-volatile solutions under a high relative humidity (RH) but were suppressed when spin coating was performed on low-volatile solutions regardless of the RH. The high-volatile solutions comprise poly(4-vinylpyridine) (P4VP) in methanol or ethanol. The low-volatility solutions comprise P4VP in propanol or butanol. P4VP molecular weights, P4VP concentrations, spin rates, and film thicknesses are not vital factors in forming hierarchical instability in spin-coated P4VP films. Instead, the formation of hierarchical instabilities depends on the RH and solvent types. Namely, the hierarchical instabilities are driven by Bénard-Marangoni convection, water vapor condensation, and disturbance of spin-up and spin-off stages during spin coating of highly volatile solutions under high RH. Mechanisms of hierarchical instabilities are interpreted in detail.
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Affiliation(s)
- Belda Amelia Junisu
- Department of Chemical and Materials Engineering, National Central University, Taoyuan 32001, Taiwan
| | - Ya-Sen Sun
- Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
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2
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Khattak HK, Lu G, Dutcher LA, Brook MA, Dalnoki-Veress K. Preparation of ultra-thin elastomeric films. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:33. [PMID: 37171676 DOI: 10.1140/epje/s10189-023-00291-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 04/11/2023] [Indexed: 05/13/2023]
Abstract
When polydimethylsiloxane elastomers are produced, in the absence of great care, chains remain that are unbound to the cross-linked matrix. Due to the unbound chains swelling the crosslinked matrix, these materials are gels. We have developed a simple process to prepare well-controlled elastomeric thin films which do not rely on unknown commercial formulations.
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Affiliation(s)
- Hamza K Khattak
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1, Canada
| | - Guanhua Lu
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1, Canada
| | - Lauren A Dutcher
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1, Canada
| | - Michael A Brook
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1, Canada
| | - Kari Dalnoki-Veress
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1, Canada.
- UMR CNRS Gulliver 7083, ESPCI Paris, PSL Research University, 75005, Paris, France.
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3
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Trumpour T, Forrest JA. Nanoscale surface roughness induced by poor solvents on polymer film surfaces. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2022; 45:85. [PMID: 36289136 DOI: 10.1140/epje/s10189-022-00237-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
We describe a new nanoscale morphology that is produced when polymer surfaces are exposed to a poor solvent. We have measured the morphology on polystyrene surfaces after exposure to pentane, heptane, or dodecane as well as poly(methyl methacrylate) exposed to propanol or methanol. The length scale of the morphology was determined by analyzing images obtained by atomic force microscopy. For the case of polystyrene, we perform a detailed characterization of the morphology for all solvents and molecular weight values [Formula: see text] ranging from 8 to 995 kg/mol. Comparing the results to models of dimpling morphology in densely grafted chains suggests the same mechanism is responsible.
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Affiliation(s)
- Tiana Trumpour
- Department of Physics and Astronomy, University of Waterloo, 200 University Ave. W, Waterloo, ON, N2L 3G1, Canada
- Schulich School of Medicine and Dentistry, Western University, 1151 Richmond St, London, ON, N6A 5C1, Canada
| | - James A Forrest
- Department of Physics and Astronomy, University of Waterloo, 200 University Ave. W, Waterloo, ON, N2L 3G1, Canada.
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Aanisah N, Wardhana YW, Chaerunisaa AY, Budiman A. Review on Modification of Glucomannan as an Excipient in Solid Dosage Forms. Polymers (Basel) 2022; 14:polym14132550. [PMID: 35808596 PMCID: PMC9269564 DOI: 10.3390/polym14132550] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/19/2022] [Accepted: 06/21/2022] [Indexed: 01/09/2023] Open
Abstract
Glucomannan (GM)—a polysaccharide generally extracted from the tuber of Amorphophallus konjac—has great potential as a filler–binder in direct compression, disintegrant in tablets, or gelling agent due to its strong hydrophilicity and extremely high viscosity. However, it has poor water resistance and low mechanical strength when used as an excipient in solid form. Several physical and chemical modifications have been carried out to improve these drawbacks. Chemical modification affects the characteristics of GM based on the DS. Carboxymethylation improves GM functionality by modifying its solubility and viscosity, which in turn allows it to bind water more efficiently and thus improve its elongation and gel homogeneity. Meanwhile, physical modification enhances functionality through combination with other excipients to improve mechanical properties and modify swelling ability and drug release from the matrix. This review discusses extraction of GM and its modification to enhance its applicability as an excipient in solid form. Modified GM is a novel excipient applicable in the pharmaceutical industry for direct compression, as a tablet disintegrant, a film-forming agent, and for encapsulation of macromolecular compounds or drug carriers for controlled release.
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Affiliation(s)
- Nuur Aanisah
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Universitas Padjadjaran, Jatinangor 45363, Indonesia; (N.A.); (A.Y.C.); (A.B.)
- Department of Pharmacy, Faculty of Mathematics and Natural Sciences, Tadulako University, Palu 94118, Indonesia
| | - Yoga W. Wardhana
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Universitas Padjadjaran, Jatinangor 45363, Indonesia; (N.A.); (A.Y.C.); (A.B.)
- Study Center Development of Pharmaceutical Preparations, Faculty of Pharmacy, Universitas Padjadjaran, Jatinangor 45363, Indonesia
- Correspondence:
| | - Anis Y. Chaerunisaa
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Universitas Padjadjaran, Jatinangor 45363, Indonesia; (N.A.); (A.Y.C.); (A.B.)
- Study Center Development of Pharmaceutical Preparations, Faculty of Pharmacy, Universitas Padjadjaran, Jatinangor 45363, Indonesia
| | - Arif Budiman
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Universitas Padjadjaran, Jatinangor 45363, Indonesia; (N.A.); (A.Y.C.); (A.B.)
- Study Center Development of Pharmaceutical Preparations, Faculty of Pharmacy, Universitas Padjadjaran, Jatinangor 45363, Indonesia
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Auckloo SAB, Palaniandy K, Hung YM, Lazzara G, Chai SP, Pasbakhsh P. Nonporous, Strong, Stretchable, and Transparent Electrospun Aromatic Polyurea Nanocomposites as Potential Anticorrosion Coating Films. NANOMATERIALS 2021; 11:nano11112998. [PMID: 34835761 PMCID: PMC8618329 DOI: 10.3390/nano11112998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 10/26/2021] [Accepted: 11/03/2021] [Indexed: 11/30/2022]
Abstract
This study, for the first time, focused on the fabrication of nonporous polyurea thin films (~200 microns) using the electrospinning method as a novel approach for coating applications. Multi-walled carbon nanotubes (MWCNTs) and hydrophilic-fumed nanosilica (HFNS) were added separately into electrospun polyurea films as nano-reinforcing fillers for the enhancement of properties. Neat polyurea films demonstrated a tensile strength of 14 MPa with an elongation of 360%. At a loading of 0.2% of MWCNTs, the highest tensile strength of 21 MPa and elongation of 402% were obtained, while the water contact angle remained almost unchanged (89°). Surface morphology analysis indicated that the production of polyurea fibers during electrospinning bonded together upon curing, leading to a nonporous film. Neat polyurea exhibited high thermal resistance with a degradation temperature of 380 °C. Upon reinforcement with 0.2% of MWCNTs and 0.4% of HFNS, it increased by ~7 °C. The storage modulus increased by 42 MPa with the addition of 0.2% of MWCNTs, implying a superior viscoelasticity of polyurea nanocomposite films. The results were benchmarked with anti-corrosive polymer coatings from the literature, revealing that the production of nonporous polyurea coatings with robust strength, elasticity, and thermal properties was achieved. Electrospun polyurea coatings are promising candidates as flexible anti-corrosive coatings for heat exchanges and electrical wires.
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Affiliation(s)
- Sheik Ambarine Banon Auckloo
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Subang Jaya 47500, Malaysia; (S.A.B.A.); (K.P.); (Y.M.H.)
| | - Khanisya Palaniandy
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Subang Jaya 47500, Malaysia; (S.A.B.A.); (K.P.); (Y.M.H.)
| | - Yew Mun Hung
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Subang Jaya 47500, Malaysia; (S.A.B.A.); (K.P.); (Y.M.H.)
| | - Giuseppe Lazzara
- Department of Physics and Chemistry, University of Palermo, Viale delle Scienze, pad. 17, 90128 Palermo, Italy;
| | - Siang-Piao Chai
- Multidisciplinary Platform of Advanced Engineering, Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Subang Jaya 47500, Malaysia;
| | - Pooria Pasbakhsh
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Subang Jaya 47500, Malaysia; (S.A.B.A.); (K.P.); (Y.M.H.)
- Correspondence: ; Tel.: +60-3551-46211; Fax: +60-3551-46207
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Evolution of Surface Morphology of Spin-Coated Poly(methyl methacrylate) Thin Films. Polymers (Basel) 2021; 13:polym13132184. [PMID: 34209335 PMCID: PMC8271514 DOI: 10.3390/polym13132184] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 11/16/2022] Open
Abstract
The morphology of sub-micron poly(methyl methacrylate) films coated to glass supports by spin coating from toluene is examined using surface profilometry. Wrinkled surfaces with local quasi-sinusoidal periodicity were seen on the surfaces of films with thicknesses of larger than 75 nm. The surface wrinkles had large aspect ratios with wavelengths in the tens of microns and amplitudes in the tens of nanometers. Wrinkles that formed during spin-coating are attributed to surface perturbations caused by Rayleigh-Bénard-Marangoni convective instabilities. The effects of film thickness, coating solution concentration, and drying rate on the thin film surface morphology are investigated. The results can be used to prepare surfaces with controlled morphology, either smooth or with periodic wrinkles.
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Carmona P, Röding M, Särkkä A, von Corswant C, Olsson E, Lorén N. Structure evolution during phase separation in spin-coated ethylcellulose/hydroxypropylcellulose films. SOFT MATTER 2021; 17:3913-3922. [PMID: 33710242 DOI: 10.1039/d1sm00044f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Porous phase-separated films made of ethylcellulose (EC) and hydroxypropylcellulose (HPC) are commonly used for controlled drug release. The structure of these thin films is controlling the drug transport from the core to the surrounding liquids in the stomach or intestine. However, detailed understanding of the time evolution of these porous structures as they are formed remains elusive. In this work, spin-coating, a widely applied technique for making thin uniform polymer films, was used to mimic the industrial manufacturing process. The focus of this work was on understanding the structure evolution of phase-separated spin-coated EC/HPC films. The structure evolution was determined using confocal laser scanning microscopy (CLSM) and image analysis. In particular, we determined the influence of spin-coating parameters and EC : HPC ratio on the final phase-separated structure and the film thickness. The film thickness was determined by profilometry and it influences the ethanol solvent evaporation rate and thereby the phase separation kinetics. The spin speed was varied between 1000 and 10 000 rpm and the ratio of EC : HPC in the polymer blend was varied between 78 : 22 wt% and 40 : 60 wt%. The obtained CLSM micrographs showed phase separated structures, typical for the spinodal decomposition phase separation mechanism. By using confocal laser scanning microscopy combined with Fourier image analysis, we could extract the characteristic length scale of the phase-separated final structure. Varying spin speed and EC : HPC ratio gave us precise control over the characteristic length scale and the thickness of the film. The results showed that the characteristic length scale increases with decreasing spin speed and with increasing HPC ratio. The thickness of the spin-coated film decreases with increasing spin speed. It was found that the relation between film thickness and spin speed followed the Meyerhofer equation with an exponent close to 0.5. Furthermore, good correlations between thickness and spin speed were found for the compositions 22 wt% HPC, 30 wt% HPC and 45 wt% HPC. These findings give a good basis for understanding the mechanisms responsible for the morphology development and increase the possibilities to tailor thin EC/HPC film structures.
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Affiliation(s)
- Pierre Carmona
- Unit Product Design, Department Agriculture and Food, Division Bioeconomy and Health, RISE Research Institute of Sweden, Gothenburg, Sweden.
- Division Nano-and BioPhysics, Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Magnus Röding
- Unit Product Design, Department Agriculture and Food, Division Bioeconomy and Health, RISE Research Institute of Sweden, Gothenburg, Sweden.
- Department of Mathematical Sciences, Chalmers University of Technology and Gothenburg University Gothenburg, Gothenburg, Sweden
| | - Aila Särkkä
- Department of Mathematical Sciences, Chalmers University of Technology and Gothenburg University Gothenburg, Gothenburg, Sweden
| | - Christian von Corswant
- Oral Product Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Gothenburg, Sweden
| | - Eva Olsson
- Division Nano-and BioPhysics, Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Niklas Lorén
- Unit Product Design, Department Agriculture and Food, Division Bioeconomy and Health, RISE Research Institute of Sweden, Gothenburg, Sweden.
- Division Nano-and BioPhysics, Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
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8
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Lunz D. Minimizing deformation of a thin fluid film driven by fluxes of momentum and heat. Phys Rev E 2021; 103:033105. [PMID: 33862827 DOI: 10.1103/physreve.103.033105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 02/24/2021] [Indexed: 11/07/2022]
Abstract
We consider a thin fluid film flowing down an inclined substrate subjected to localized external sources of momentum and heat flux that induce deformations of the fluid's free surface. This scenario is encountered in several industrial processes and of particular interest is the case where these deformations are undesirable. When the substrate is thin and the temperature along its underside is freely imposed by an active cooling mechanism, temperature gradients are generated at the fluid surface which drive a thermocapillary flow and influence the deformations. This naturally leads us to pose the optimal control problem of choosing the temperature profile that minimizes the unwanted free-surface deformations. Numerical computations reveal that the external forces generate deflections in a region near their peak beyond which all deflections are suppressed by the optimal control. Where nonzero deflections occur, the control is of bang-bang type (taking either its upper or lower bound), while the control is obtained in closed form for regions where the deflections are suppressed. Strikingly, in switching between these regions the optimal control chatters, that is, it switches infinitely many times over a finite interval. By appealing to Pontryagin's maximum principle and leveraging a symmetry embedded in the adjoint problem we uncover the underlying fractal structure of the chattering. Finally, we present practical approaches to avoid the infinite switching while retaining significantly reduced free-surface deformations.
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Affiliation(s)
- Davin Lunz
- Inria Saclay - Île de France, 91120 Palaiseau, France; École Polytechnique, CMAP 91128 Palaiseau, France; Institut Pasteur, 75015 Paris, France; and University of Oxford, Mathematical Institute, Andrew Wiles Building, Oxford OX2 6GG, United Kingdom
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9
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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.
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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
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10
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Rhee D, Deng S, Odom TW. Soft skin layers for reconfigurable and programmable nanowrinkles. NANOSCALE 2020; 12:23920-23928. [PMID: 33242039 DOI: 10.1039/d0nr07054h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Wrinkling skin layers on pre-strained polymer sheets has drawn significant interest as a method to create reconfigurable surface patterns. Compared to widely studied metal or silica films, softer polymer skins are more tolerant to crack formation when the surface topography is tuned under applied strain. This Mini-review discusses recent progress in mechano-responsive wrinkles based on polymer skin materials. Control over the skin thickness with nanometer accuracy allows for tuning of the wrinkle wavelength and orientation over length scales from nanometer to micrometer regimes. Furthermore, soft skin layers enable texturing of two-dimensional electronic materials with programmable feature sizes and structural hierarchy because of the conformal adhesion to the substrates. Soft skin systems open prospects to tailor a range of surface properties via external stimuli important for applications such as smart windows, microfluidics, and nanoelectronics.
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Affiliation(s)
- Dongjoon Rhee
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.
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11
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Bobrovsky A, Mochalov K, Solovyeva D, Shibaev V, Cigl M, Hamplová VCBR, Bubnov A. Laser-induced formation of "craters" and "hills" in azobenzene-containing polymethacrylate films. SOFT MATTER 2020; 16:5398-5405. [PMID: 32452491 DOI: 10.1039/d0sm00601g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Functional organic polymer materials with an ability to change their surface topography in response to external contactless stimuli, like light irradiation, have attracted considerable attention. This work is devoted to the study of contactless control of the surface topography and the formation of the surface features in the amorphousized and liquid crystalline films of two azobenzene-containing polymers. The investigated polymers are side-chain polymethacrylates containing azobenzene chromophores with two lateral methyl substituents in ortho-positions and differing in the length of flexible spacer with six and ten methylene units. Two lateral methyl substituents at the azobenzene chromophore ensure high photoresponses of these polymeric samples in the whole visible spectral range. Irradiation of the polymethacrylate films by focused polarized light of green (532 nm) and red (633 nm) lasers induces a specific photodeformation of the film surface. In the case of the green light formation of circular "craters" with anisotropic borders was found, whereas for the red light highly asymmetric "hills" were observed. The possible mechanisms of the surface topography formation and their features are discussed.
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Affiliation(s)
- Alexey Bobrovsky
- Faculty of Chemistry, Moscow State University, Leninskie gory, Moscow, 119991, Russia.
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12
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de Aguiar HB, McGraw JD, Donaldson SH. Interface-Sensitive Raman Microspectroscopy of Water via Confinement with a Multimodal Miniature Surface Forces Apparatus. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:15543-15551. [PMID: 31310142 DOI: 10.1021/acs.langmuir.9b01889] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Modern interfacial science is increasingly multidisciplinary. Unique insight into interfacial interactions requires new multimodal techniques for interrogating surfaces with simultaneous complementary physical and chemical measurements. Here, we describe the design and testing of a microscope that incorporates a miniature surface forces apparatus (μSFA) in sphere vs flat geometry for force-distance measurements, while simultaneously acquiring Raman spectra of the confined zone. The simple optical setup isolates independent optical paths for (i) the illumination and imaging of Newton's rings and (ii) Raman scattering excitation and efficient signal collection. We benchmark the methodology by examining Teflon thin films in asymmetric (Teflon-water-glass) and symmetric (Teflon-water-Teflon) configurations. Water is observed near the Teflon-glass interface with nanometer-scale sensitivity in both the distance and Raman signals. We perform chemically resolved, label-free imaging of confined contact regions between Teflon and glass surfaces immersed in water. Remarkably, we estimate that the combined approach enables vibrational spectroscopy with single water monolayer sensitivity within minutes. Altogether, the Raman-μSFA allows exploration of molecular confinement between surfaces with chemical selectivity and correlation with interaction forces.
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Affiliation(s)
- Hilton B de Aguiar
- Département de Physique , Ecole Normale Supérieure/PSL Research University, CNRS , 24 rue Lhomond , 75005 Paris , France
| | - Joshua D McGraw
- Département de Physique , Ecole Normale Supérieure/PSL Research University, CNRS , 24 rue Lhomond , 75005 Paris , France
- Gulliver CNRS UMR 7083 , PSL Research University, ESPCI Paris , 10 rue Vauquelin , 75005 Paris , France
| | - Stephen H Donaldson
- Département de Physique , Ecole Normale Supérieure/PSL Research University, CNRS , 24 rue Lhomond , 75005 Paris , France
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13
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Bormashenko E, Bormashenko Y, Frenkel M. Formation of Hierarchical Porous Films with Breath-Figures Self-Assembly Performed on Oil-Lubricated Substrates. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E3051. [PMID: 31546980 PMCID: PMC6766328 DOI: 10.3390/ma12183051] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/08/2019] [Accepted: 09/17/2019] [Indexed: 11/17/2022]
Abstract
Hierarchical honeycomb patterns were manufactured with breath-figures self-assembly by drop-casting on the silicone oil-lubricated glass substrates. Silicone oil promoted spreading of the polymer solution. The process was carried out with industrial grade polystyrene and polystyrene with molecular mass M w = 35 , 000 g m o l . Both polymers gave rise to patterns, built of micro and nano-scaled pores. The typical diameter of the nanopores was established as 125 nm. The mechanism of the formation of hierarchical patterns was suggested. Ordering of the pores was quantified with the Voronoi tessellations and calculation of the Voronoi entropy. The Voronoi entropy for the large scale pattern was S v o r = 0.6 - 0.9 , evidencing the ordering of pores. Measurement of the apparent contact angles evidenced the Cassie-Baxter wetting regime of the porous films.
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Affiliation(s)
- Edward Bormashenko
- Department of Chemical Engineering, Biotechnology and Materials, Engineering Sciences Faculty, Ariel University, Ariel 407000, Israel.
| | - Yelena Bormashenko
- Department of Chemical Engineering, Biotechnology and Materials, Engineering Sciences Faculty, Ariel University, Ariel 407000, Israel.
| | - Mark Frenkel
- Department of Chemical Engineering, Biotechnology and Materials, Engineering Sciences Faculty, Ariel University, Ariel 407000, Israel.
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14
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Fedorets AA, Bormashenko E, Dombrovsky LA, Nosonovsky M. Droplet clusters: nature-inspired biological reactors and aerosols. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20190121. [PMID: 31177958 PMCID: PMC6562358 DOI: 10.1098/rsta.2019.0121] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Condensed microdroplets play a prominent role in living nature, participating in various phenomena, from water harvesting by plants and insects to microorganism migration in bioaerosols. Microdroplets may also form regular self-organized patterns, such as the hexagonally ordered breath figures on a solid surface or levitating monolayer droplet clusters over a locally heated water layer. While the breath figures have been studied since the nineteenth century, they have found a recent application in polymer surface micropatterning (e.g. for superhydrophobicity). Droplet clusters were discovered in 2004, and they are the subject of active research. Methods to control and stabilize droplet clusters make them suitable for the in situ analysis of bioaerosols. Studying life in bioaerosols is important for understanding microorganism origins and migration; however, direct observation with traditional methods has not been possible. We report preliminary results on direct in situ observation of microorganisms in droplet clusters. We also present a newly observed transition between the hexagonally ordered and chain-like states of a droplet cluster. This article is part of the theme issue 'Bioinspired materials and surfaces for green science and technology (part 2)'.
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Affiliation(s)
| | - Edward Bormashenko
- Department of Chemical Engineering, Biotechnology and Materials, Engineering Science Faculty, Ariel University, Ariel 40700, Israel
| | - Leonid A. Dombrovsky
- University of Tyumen, 6 Volodarskogo St, Tyumen 625003, Russia
- Joint Institute for High Temperatures, 17A Krasnokazarmennaya St, Moscow 111116, Russia
| | - Michael Nosonovsky
- University of Tyumen, 6 Volodarskogo St, Tyumen 625003, Russia
- Department of Mechanical Engineering, University of Wisconsin–Milwaukee, 3200 North Cramer St, Milwaukee, WI 53211, USA
- e-mail:
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15
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Fang Q, Ye F, Yang X. Hierarchical Morphology of Polymer Blend Films Induced by Convection-Driven Solvent Evaporation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:5551-5557. [PMID: 29671600 DOI: 10.1021/acs.langmuir.8b00600] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Homogeneous thin films of polymer blends with a desired morphology are necessary because of their applications in the fields such as optoelectronics, sensors, biomedicine, and so on. The frequently employed approach for the thin film preparation, spin coating is only able to achieve a homogeneous film for a small area because of the overwhelming spin-driven solvent evaporation with increased size. Here, a convection-guided morphology formation for polystyrene:poly(methyl methacrylate) blend films is reported. In situ observation shows that the morphology changed from homogeneous deposition with a scale less than 10 μm to a self-organized cellular pattern with a scale of more than 100 μm after the fluid flow is involved. Selective dissolution of the hierarchical films reveals that the cellular morphology is attributed to the flow-field-guided deposition of sequentially generated precipitates. The coupling of phase separation and fluid convection results in the hierarchical morphology that includes Voronoi cellular division as the primary structure and the detailed heterogeneous inner-cell features as the secondary structure. Isolated modulation of either micro- or mesoscale in the hierarchical morphology could be carried out via adjusting phase interaction or the convection disturbance correspondingly, providing a flexible and straightforward strategy to construct designed hierarchical structures for polymer thin films toward desired function or property.
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Affiliation(s)
- Qinghua Fang
- State Key Laboratory of Polymer Physics and Chemistry , Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street , Changchun 130022 , P. R. China
- College of Applied Chemistry and Engineering , University of Science and Technology of China , Jinzhai Road No. 96 , Baohe District, Hefei 230026 , P. R. China
| | - Feng Ye
- State Key Laboratory of Polymer Physics and Chemistry , Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street , Changchun 130022 , P. R. China
| | - Xiaoniu Yang
- State Key Laboratory of Polymer Physics and Chemistry , Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street , Changchun 130022 , P. R. China
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16
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Tree DR, Iwama T, Delaney KT, Lee J, Fredrickson GH. Marangoni Flows during Nonsolvent Induced Phase Separation. ACS Macro Lett 2018; 7:582-586. [PMID: 35632935 DOI: 10.1021/acsmacrolett.8b00012] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Motivated by the much discussed, yet unexplained, presence of macrovoids in polymer membranes, we explore the impact of Marangoni flows in the process of nonsolvent induced phase separation. Such flows have been hypothesized to be important to the formation of macrovoids, but little quantitative evidence has been produced to date. Using a recently developed multifluid phase field model, we find that roll cells indicative of a solutal Marangoni instability are manifest during solvent/nonsolvent exchange across a stable interface. However, these flows are weak and subsequently do not produce morphological features that might lead to macrovoid formation. By contrast, initial conditions that lead to an immediate precipitation of the polymer film coincide with large Marangoni flows that disturb the interface. The presence of such flows suggests a new experimental and theoretical direction in the search for a macrovoid formation mechanism.
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Affiliation(s)
- Douglas R. Tree
- Chemical Engineering Department, Brigham Young University, Provo, Utah 84602, United States
| | - Tatsuhiro Iwama
- Asahi Kasei Corporation, 2-1 Samejima, Fuji, Shizuoka 416-8501, Japan
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17
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Zhang H, Okamura Y. Elongated phase separation domains in spin-cast polymer blend thin films characterized using a panoramic image. SOFT MATTER 2018; 14:1050-1055. [PMID: 29335709 DOI: 10.1039/c7sm02144e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Polymer thin films with micro/nano-structures can be prepared by a solvent evaporation induced phase separation process via spin-casting a polymer blend, where the elongated phase separation domains are always inevitable. The striation defect, as a thickness nonunifomity in spin-cast films, is generally coexistent with the elongated domains. Herein, the morphologies of polymer blend thin films are recorded from the spin-cast center to the edge in a panoramic view. The elongated domains are inclined to appear at the ridge regions of striations with increasing radial distance and align radially, exhibiting a coupling between the phase separation morphology and the striation defect that may exist. We demonstrate that the formation of elongated domains is not attributed to shape deformation, but is accomplished in situ. A possible model to describe the initiation and evolution of the polymer blend phase separation morphology during spin-casting is proposed.
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Affiliation(s)
- Hong Zhang
- Micro/Nano Technology Center, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.
| | - Yosuke Okamura
- Micro/Nano Technology Center, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan. and Department of Applied Chemistry, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
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18
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Zhou J, Man X, Jiang Y, Doi M. Structure Formation in Soft-Matter Solutions Induced by Solvent Evaporation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1703769. [PMID: 29058825 DOI: 10.1002/adma.201703769] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 08/10/2017] [Indexed: 06/07/2023]
Abstract
Solvent evaporation in soft-matter solutions (solutions of colloidal particles, polymers, and their mixtures) is an important process in material making and in the printing and coating industries. The solvent-evaporation process determines the structure of materials and strongly affects their performance. Solvent evaporation involves many physicochemical processes: flow, diffusion, crystallization, gelation, glass transition, etc. and is quite complex. Here, recent progress in this important process is reported, with a special focus on theoretical and simulation studies.
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Affiliation(s)
- Jiajia Zhou
- Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing, 100191, P. R. China
- Center of Soft Matter Physics and Its Applications, Beihang University, Beijing, 100191, P. R. China
| | - Xingkun Man
- Center of Soft Matter Physics and Its Applications, Beihang University, Beijing, 100191, P. R. China
- School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191, P. R. China
| | - Ying Jiang
- Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing, 100191, P. R. China
- Center of Soft Matter Physics and Its Applications, Beihang University, Beijing, 100191, P. R. China
| | - Masao Doi
- Center of Soft Matter Physics and Its Applications, Beihang University, Beijing, 100191, P. R. China
- Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, 100191, P. R. China
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19
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Zhang H, Masuda A, Kawakami R, Yarinome K, Saito R, Nagase Y, Nemoto T, Okamura Y. Fluoropolymer Nanosheet as a Wrapping Mount for High-Quality Tissue Imaging. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1703139. [PMID: 28799278 DOI: 10.1002/adma.201703139] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/05/2017] [Indexed: 06/07/2023]
Abstract
In the field of biological microscopy technology, it is still a practical challenge to obtain high-quality tissue images, due to the tissue desiccation that occurs during observations without an effective sample mounting. Inspired by the use of plastic food wrap, this study proposes the use of polymer thin films (also known as nanosheets) to fix the tissue samples. Water-repellent nanosheets composed of the amorphous fluoropolymer CYTOP are prepared with adjustable thicknesses and their hydrophobicity, transparency, and adhesion strength are evaluated. They show excellent water-retention effect and work well for sample fixation. By wrapping cleared mouse brain slices with a 133 nm thick CYTOP nanosheet, this study achieves high spatial resolution neuron images while scanning over a large area for a long period of time. No visible artifacts arising from sample shrinkage can be detected. This study also expects that nanosheet wrapping could be effective over a longer time span by combination with conventional agarose embedding.
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Affiliation(s)
- Hong Zhang
- Micro/Nano Technology Center, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan
| | - Ami Masuda
- Department of Applied Chemistry, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan
| | - Ryosuke Kawakami
- Research Institute for Electronic Science, Graduate School of Information Science and Technology, Hokkaido University, Kita 20 Nishi 10, Kita-ku, Sapporo, 001-0020, Japan
| | - Kenji Yarinome
- Department of Applied Chemistry, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan
| | - Riku Saito
- Department of Applied Chemistry, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan
| | - Yu Nagase
- Department of Applied Chemistry, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan
| | - Tomomi Nemoto
- Research Institute for Electronic Science, Graduate School of Information Science and Technology, Hokkaido University, Kita 20 Nishi 10, Kita-ku, Sapporo, 001-0020, Japan
| | - Yosuke Okamura
- Micro/Nano Technology Center, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan
- Department of Applied Chemistry, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan
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20
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Bormashenko E. Breath-Figure Self-Assembly, a Versatile Method of Manufacturing Membranes and Porous Structures: Physical, Chemical and Technological Aspects. MEMBRANES 2017; 7:E45. [PMID: 28813026 PMCID: PMC5618130 DOI: 10.3390/membranes7030045] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 11/17/2022]
Abstract
The review is devoted to the physical, chemical, and technological aspects of the breath-figure self-assembly process. The main stages of the process and impact of the polymer architecture and physical parameters of breath-figure self-assembly on the eventual pattern are covered. The review is focused on the hierarchy of spatial and temporal scales inherent to breath-figure self-assembly. Multi-scale patterns arising from the process are addressed. The characteristic spatial lateral scales of patterns vary from nanometers to dozens of micrometers. The temporal scale of the process spans from microseconds to seconds. The qualitative analysis performed in the paper demonstrates that the process is mainly governed by interfacial phenomena, whereas the impact of inertia and gravity are negligible. Characterization and applications of polymer films manufactured with breath-figure self-assembly are discussed.
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Affiliation(s)
- Edward Bormashenko
- Department of Chemical Engineering, Biotechnology and Materials, Engineering Faculty, Ariel University, P.O.B. 3, 407000 Ariel, Israel.
- Tyumen State University, 6 Volodarsky St., Tyumen 625003, Russia.
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