1
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Nekoonam N, Vera G, Goralczyk A, Mayoussi F, Zhu P, Böcherer D, Shakeel A, Helmer D. Controllable Wetting Transitions on Photoswitchable Physical Gels. ACS Appl Mater Interfaces 2023. [PMID: 37217181 DOI: 10.1021/acsami.2c22979] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Softness plays a key role in the deformation of soft elastic substrates at the three-phase contact line, and the acting forces lead to the formation of a wetting ridge due to elastocapillarity. The change in wetting ridge and surface profiles at different softness has a great impact on the droplet behavior in different phenomena. Commonly used materials to study soft wetting are swollen polymeric gels or polymer brushes. These materials offer no possibility to change the softness on demand. Therefore, adjustable surfaces with tunable softness are highly sought-after to achieve on-demand transition between wetting states on soft surfaces. Here, we present a photorheological physical soft gel with adjustable stiffness based on the spiropyran photoswitch that shows the formation of wetting ridges upon droplet deposition. The presented photoswitchable gels allow the creation of reversibly switchable softness patterns with microscale resolution using UV light-switching of the spiropyran molecule. Gels with varying softness are analyzed, showing a decrease in the wetting ridge height at higher gel stiffness. Furthermore, wetting ridges before and after photoswitching are visualized using confocal microscopy, showing the transition in the wetting properties from soft wetting to liquid/liquid wetting.
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Affiliation(s)
- Niloofar Nekoonam
- Laboratory of Process Technology, Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Grace Vera
- Laboratory of Process Technology, Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Andreas Goralczyk
- Laboratory of Process Technology, Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Fadoua Mayoussi
- Laboratory of Process Technology, Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Pang Zhu
- Laboratory of Process Technology, Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - David Böcherer
- Laboratory of Process Technology, Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Ahmad Shakeel
- Laboratory of Process Technology, Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Dorothea Helmer
- Laboratory of Process Technology, Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Freiburg Center of Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, 79110 Freiburg im Breisgau, Germany
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2
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Bhagwat S, Goralczyk A, Luitz M, Sharieff L, Kluck S, Hamza A, Nekoonam N, Kotz-Helmer F, Pezeshkpour P, Rapp BE. In Situ Actuators with Gallium Liquid Metal Alloys and Polypyrrole-Coated Electrodes. ACS Appl Mater Interfaces 2023; 15:10109-10122. [PMID: 36754363 PMCID: PMC9952059 DOI: 10.1021/acsami.2c17906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 01/09/2023] [Indexed: 06/18/2023]
Abstract
Gallium liquid metal alloys (GLMAs) such as Galinstan and gallium-indium eutectic (EGaIn) are interesting materials due to their high surface tensions, low viscosities, and electrical conductivities comparable to classical solid metals. They have been used for applications in microelectromechanical systems (MEMS) and, more recently, liquid metal microfluidics (LMMF) for setting up devices like actuators. However, their high tendency to alloy with the most common metals used for electrodes such as gold (Au), platinum (Pt), titanium (Ti), nickel (Ni), and tungsten-titanium (WTi) is a major problem limiting the scaleup and applicability, e.g., liquid metal actuators. Stable electrodes are key elements for many applications and thus, the lack of an electrode material compatible with GLMAs is detrimental for many potential application scenarios. In this work, we study the effect of actuating Galinstan on various solid metal electrodes and present an electrode protection methodology that, first, prevents alloying and, second, prevents electrode corrosion. We demonstrate reproducible actuation of GLMA segments in LMMF, showcasing the stability of the proposed protective coating. We investigated a range of electrode materials including Au, Pt, Ti, Ni, and WTi, all in aqueous environments, and present the resulting corrosion/alloying effects by studying the interface morphology. Our proposed protective coating is based on a simple method to electrodeposit electrically conductive polypyrrole (PPy) on the electrodes to provide a conductive alloying-barrier layer for applications involving direct contact between GLMAs and electrodes. We demonstrate the versatility of this approach by direct three-dimensional (3D) printing of a 500 μm microfluidic chip on a set of electrodes onto which PPy is electrodeposited in situ for actuation of Galinstan plugs. The developed protection protocol will provide a generic, widely applicable strategy to protect a wide range of electrodes from alloying and corrosion and thus form a key element in future applications of GLMAs.
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Affiliation(s)
- Sagar Bhagwat
- Laboratory
of Process Technology, NeptunLab, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Andreas Goralczyk
- Laboratory
of Process Technology, NeptunLab, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Manuel Luitz
- Laboratory
of Process Technology, NeptunLab, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Lathif Sharieff
- Laboratory
of Process Technology, NeptunLab, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Sebastian Kluck
- Laboratory
of Process Technology, NeptunLab, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Ahmed Hamza
- Laboratory
of Process Technology, NeptunLab, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Niloofar Nekoonam
- Laboratory
of Process Technology, NeptunLab, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Frederik Kotz-Helmer
- Laboratory
of Process Technology, NeptunLab, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
- Freiburg
Materials Research Center (FMF), University
of Freiburg, Stefan-Meier-Straße
21, 79104 Freiburg, Germany
| | - Pegah Pezeshkpour
- Laboratory
of Process Technology, NeptunLab, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
- Freiburg
Materials Research Center (FMF), University
of Freiburg, Stefan-Meier-Straße
21, 79104 Freiburg, Germany
| | - Bastian E. Rapp
- Laboratory
of Process Technology, NeptunLab, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
- Freiburg
Materials Research Center (FMF), University
of Freiburg, Stefan-Meier-Straße
21, 79104 Freiburg, Germany
- FIT
Freiburg Center of Interactive Materials and Bioinspired Technologies, University of Freiburg, Georges-Köhler-Allee 105, 79110 Freiburg, Germany
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3
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Mayoussi F, Usama A, Karimi K, Nekoonam N, Goralczyk A, Zhu P, Helmer D, Rapp BE. Superrepellent Porous Polymer Surfaces by Replication from Wrinkled Polydimethylsiloxane/Parylene F. Materials (Basel) 2022; 15:7903. [PMID: 36431388 PMCID: PMC9696989 DOI: 10.3390/ma15227903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 06/16/2023]
Abstract
Superrepellent surfaces, such as micro/nanostructured surfaces, are of key importance in both academia and industry for emerging applications in areas such as self-cleaning, drag reduction, and oil repellence. Engineering these surfaces is achieved through the combination of the required surface topography, such as porosity, with low-surface-energy materials. The surface topography is crucial for achieving high liquid repellence and low roll-off angles. In general, the combination of micro- and nanostructures is most promising in achieving high repellence. In this work, we report the enhancement of wetting properties of porous polymers by replication from wrinkled Parylene F (PF)-coated polydimethylsiloxane (PDMS). Fluorinated polymer foam “Fluoropor” serves as the low-surface-energy polymer. The wrinkled molds are achieved via the deposition of a thin PF layer onto the soft PDMS substrates. Through consecutive supercritical drying, superrepellent surfaces with a high surface porosity and a high water contact angle (CA) of >165° are achieved. The replicated surfaces show low roll-off angles (ROA) <10° for water and <21° for ethylene glycol. Moreover, the introduction of the micro-wrinkles to Fluoropor not only enhances its liquid repellence for water and ethylene glycol but also for liquids with low surface tension, such as n-hexadecane.
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Affiliation(s)
- Fadoua Mayoussi
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Ali Usama
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Kiana Karimi
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Niloofar Nekoonam
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Andreas Goralczyk
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Pang Zhu
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Dorothea Helmer
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Freiburg Center of Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, 79110 Freiburg im Breisgau, Germany
| | - Bastian E. Rapp
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Freiburg Center of Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, 79110 Freiburg im Breisgau, Germany
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4
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Goralczyk A, Pereira J, Torres LO, Iskandar A, van der Toor M, Talikka M, Luettich K, Marescotti D. P01-02 AOP-based in vitro assay development for assessment of inhalational toxicants — oxidative stress leading to decreased lung function. Toxicol Lett 2022. [DOI: 10.1016/j.toxlet.2022.07.246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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5
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Goralczyk A, Bhagwat S, Mayoussi F, Nekoonam N, Sachsenheimer K, Hou P, Kotz-Helmer F, Helmer D, Rapp BE. Application of Micro/Nanoporous Fluoropolymers with Reduced Bioadhesion in Digital Microfluidics. Nanomaterials 2022; 12:nano12132201. [PMID: 35808037 PMCID: PMC9268009 DOI: 10.3390/nano12132201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/24/2022] [Accepted: 06/25/2022] [Indexed: 02/01/2023]
Abstract
Digital microfluidics (DMF) is a versatile platform for conducting a variety of biological and chemical assays. The most commonly used set-up for the actuation of microliter droplets is electrowetting on dielectric (EWOD), where the liquid is moved by an electrostatic force on a dielectric layer. Superhydrophobic materials are promising materials for dielectric layers, especially since the minimum contact between droplet and surface is key for low adhesion of biomolecules, as it causes droplet pinning and cross contamination. However, superhydrophobic surfaces show limitations, such as full wetting transition between Cassie and Wenzel under applied voltage, expensive and complex fabrication and difficult integration into already existing devices. Here we present Fluoropor, a superhydrophobic fluorinated polymer foam with pores on the micro/nanoscale as a dielectric layer in DMF. Fluoropor shows stable wetting properties with no significant changes in the wetting behavior, or full wetting transition, until potentials of 400 V. Furthermore, Fluoropor shows low attachment of biomolecules to the surface upon droplet movement. Due to its simple fabrication process, its resistance to adhesion of biomolecules and the fact it is capable of being integrated and exchanged as thin films into commercial DMF devices, Fluoropor is a promising material for wide application in DMF.
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Affiliation(s)
- Andreas Goralczyk
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Sagar Bhagwat
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Fadoua Mayoussi
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Niloofar Nekoonam
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Kai Sachsenheimer
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Peilong Hou
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Frederik Kotz-Helmer
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Dorothea Helmer
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Freiburg Center of Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Correspondence:
| | - Bastian E. Rapp
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Freiburg Center of Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, 79110 Freiburg im Breisgau, Germany
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6
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Goralczyk A, Mayoussi F, Sanjaya M, Corredor SF, Bhagwat S, Song Q, Schwenteck S, Warmbold A, Pezeshkpour P, Rapp BE. On‐Chip Chemical Synthesis Using One‐Step 3D Printed Polyperfluoropolyether. CHEM-ING-TECH 2022; 94:975-982. [PMID: 35915768 PMCID: PMC9322562 DOI: 10.1002/cite.202200013] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/31/2022] [Accepted: 04/07/2022] [Indexed: 11/28/2022]
Abstract
Three‐dimensional (3D) printing has already shown its high relevance for the fabrication of microfluidic devices in terms of precision manufacturing cycles and a wider range of materials. 3D‐printable transparent fluoropolymers are highly sought after due to their high chemical and thermal resistance. Here, we present a simple one‐step fabrication process via stereolithography of perfluoropolyether dimethacrylate. We demonstrate successfully printed microfluidic mixers with 800 µm circular channels for chemistry‐on‐chip applications. The printed chips show chemical, mechanical, and thermal resistance up to 200 °C, as well as high optical transparency. Aqueous and organic reactions are presented to demonstrate the wide potential of perfluoropolyether dimethacrylate for chemical synthesis.
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Affiliation(s)
- Andreas Goralczyk
- University of Freiburg Laboratory of Process Technology, NeptunLab Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 79110 Freiburg im Breisgau Germany
| | - Fadoua Mayoussi
- University of Freiburg Laboratory of Process Technology, NeptunLab Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 79110 Freiburg im Breisgau Germany
| | - Mario Sanjaya
- University of Freiburg Laboratory of Process Technology, NeptunLab Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 79110 Freiburg im Breisgau Germany
| | - Santiago Franco Corredor
- University of Freiburg Laboratory of Process Technology, NeptunLab Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 79110 Freiburg im Breisgau Germany
| | - Sagar Bhagwat
- University of Freiburg Laboratory of Process Technology, NeptunLab Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 79110 Freiburg im Breisgau Germany
| | - Qingchuan Song
- University of Freiburg Laboratory of Process Technology, NeptunLab Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 79110 Freiburg im Breisgau Germany
| | - Sarah Schwenteck
- University of Freiburg Laboratory of Process Technology, NeptunLab Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 79110 Freiburg im Breisgau Germany
| | - Andreas Warmbold
- University of Freiburg Freiburg Materials Research Center (FMF) Stefan-Meier-Straße 21 79104 Freiburg im Breisgau Germany
| | - Pegah Pezeshkpour
- University of Freiburg Laboratory of Process Technology, NeptunLab Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 79110 Freiburg im Breisgau Germany
| | - Bastian E. Rapp
- University of Freiburg Laboratory of Process Technology, NeptunLab Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 79110 Freiburg im Breisgau Germany
- University of Freiburg Freiburg Materials Research Center (FMF) Stefan-Meier-Straße 21 79104 Freiburg im Breisgau Germany
- University of Freiburg FIT Freiburg Center of Interactive Materials and Bioinspired Technologies Georges-Köhler-Allee 105 79110 Freiburg im Breisgau Germany
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7
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Mayoussi F, Doeven EH, Kick A, Goralczyk A, Thomann Y, Risch P, Guijt RM, Kotz F, Helmer D, Rapp BE. Facile fabrication of micro-/nanostructured, superhydrophobic membranes with adjustable porosity by 3D printing. J Mater Chem A Mater 2021; 9:21379-21386. [PMID: 34603732 PMCID: PMC8477758 DOI: 10.1039/d1ta03352b] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 08/22/2021] [Indexed: 05/20/2023]
Abstract
Porous membranes with special wetting properties have attracted great interest due to their various functions and wide applications, including water filtration, selective oil/water separation and oil skimming. Special wetting properties such as superhydrophobicity can be achieved by controlling the surface chemistry as well as the surface topography of a substrate. Three-dimensional (3D) printing is a promising method for the fast and easy generation of various structures. The most common method for 3D printing of superhydrophobic materials is a two-step fabrication process: 3D printing of user-defined topographies, such as surface structures or bulk porosity, followed by a chemical post-processing with low-surface energy chemicals such as fluorinated silanes. Another common method is using a hydrophobic polymer ink to print intricate surface structures. However, the resolution of most common printers is not sufficient to produce nano-/microstructured textures, moreover, the resulting delicate surface micro- or nanostructures are very prone to abrasion. Herein, we report a simple approach for 3D printing of superhydrophobic micro-/nanoporous membranes in a single step, combining the required topography and chemistry. The bulk porosity of this material, which we term "Fluoropor", makes it insensitive to abrasion. To achieve this, a photocurable fluorinated resin is mixed with a porogen mixture and 3D printed using a stereolithography (SLA) printing process. This way, micro-/nanoporous membranes with superhydrophobic properties with static contact angles of 164° are fabricated. The pore size of the membranes can be adjusted from 30 nm to 300 nm by only changing the porogen ratio in the mixture. We show the applicability of the printed membranes for oil/water separation and the formation of Salvinia layers which are of great interest for drag reduction in maritime transportation and fouling prevention.
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Affiliation(s)
- Fadoua Mayoussi
- Laboratory of Process Technology, NeptunLab, Albert-Ludwigs University Freiburg, Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 Freiburg Germany www.NeptunLab.org
| | - Egan H Doeven
- Deakin University, Centre for Regional and Rural Futures Geelong VIC 3220 Australia
| | - Andrea Kick
- Laboratory of Process Technology, NeptunLab, Albert-Ludwigs University Freiburg, Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 Freiburg Germany www.NeptunLab.org
| | - Andreas Goralczyk
- Laboratory of Process Technology, NeptunLab, Albert-Ludwigs University Freiburg, Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 Freiburg Germany www.NeptunLab.org
| | - Yi Thomann
- Freiburg Materials Research Center (FMF), Albert-Ludwigs-University Freiburg Freiburg Germany
- FIT Freiburg Centre for Interactive Materials and Bioinspired Technologies, Albert-Ludwigs University Freiburg Germany
| | - Patrick Risch
- Laboratory of Process Technology, NeptunLab, Albert-Ludwigs University Freiburg, Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 Freiburg Germany www.NeptunLab.org
| | - Rosanne M Guijt
- Deakin University, Centre for Regional and Rural Futures Geelong VIC 3220 Australia
| | - Frederik Kotz
- Laboratory of Process Technology, NeptunLab, Albert-Ludwigs University Freiburg, Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 Freiburg Germany www.NeptunLab.org
- Freiburg Materials Research Center (FMF), Albert-Ludwigs-University Freiburg Freiburg Germany
| | - Dorothea Helmer
- Laboratory of Process Technology, NeptunLab, Albert-Ludwigs University Freiburg, Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 Freiburg Germany www.NeptunLab.org
- Freiburg Materials Research Center (FMF), Albert-Ludwigs-University Freiburg Freiburg Germany
- FIT Freiburg Centre for Interactive Materials and Bioinspired Technologies, Albert-Ludwigs University Freiburg Germany
| | - Bastian E Rapp
- Laboratory of Process Technology, NeptunLab, Albert-Ludwigs University Freiburg, Department of Microsystems Engineering (IMTEK) Georges-Köhler-Allee 103 Freiburg Germany www.NeptunLab.org
- Freiburg Materials Research Center (FMF), Albert-Ludwigs-University Freiburg Freiburg Germany
- FIT Freiburg Centre for Interactive Materials and Bioinspired Technologies, Albert-Ludwigs University Freiburg Germany
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8
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Luitz M, Lunzer M, Goralczyk A, Mader M, Bhagwat S, Warmbold A, Helmer D, Kotz F, Rapp BE. High Resolution Patterning of an Organic-Inorganic Photoresin for the Fabrication of Platinum Microstructures. Adv Mater 2021; 33:e2101992. [PMID: 34337801 DOI: 10.1002/adma.202101992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/09/2021] [Indexed: 06/13/2023]
Abstract
Platinum (Pt) is an interesting material for many applications due to its high chemical resilience, outstanding catalytic activity, high electrical conductivity, and high melting point. However, microstructuring and especially 3D microstructuring of platinum is a complex process, based on expensive and specialized equipment often suffering from very slow processing speeds. In this work, organic-inorganic photoresins, which can be structured using direct optical lithography as well as two-photon lithography (TPL) with submicrometer resolution and high-throughput is presented. The printed structures are subsequently converted to high-purity platinum using thermal debinding of the binder and reduction of the salt. With this technique, complex 3D structures with a 3D resolution of 300 nm were fabricated. At a layer thickness of 35 nm, the patterns reach a high conductivity of 67% compared to bulk platinum. Microheaters, thermocouple sensors as well as a Lab-on-a-Chip system are presented as exemplary applications. This technology will enable a broad range of application from electronics, sensing and heating elements to 3D photonics and metamaterials.
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Affiliation(s)
- Manuel Luitz
- Laboratory of Process Technology, NeptunLab, Department of Microsystems Engineering (IMTEK) University of Freiburg, Georges-Köhler-Allee 103, 79110, Freiburg, Germany
| | - Markus Lunzer
- UpNano GmbH, Modecenterstraße 22/D6, Vienna, 1030, Austria
| | - Andreas Goralczyk
- Laboratory of Process Technology, NeptunLab, Department of Microsystems Engineering (IMTEK) University of Freiburg, Georges-Köhler-Allee 103, 79110, Freiburg, Germany
| | - Markus Mader
- Laboratory of Process Technology, NeptunLab, Department of Microsystems Engineering (IMTEK) University of Freiburg, Georges-Köhler-Allee 103, 79110, Freiburg, Germany
| | - Sagar Bhagwat
- Laboratory of Process Technology, NeptunLab, Department of Microsystems Engineering (IMTEK) University of Freiburg, Georges-Köhler-Allee 103, 79110, Freiburg, Germany
| | - Andreas Warmbold
- Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Straße 21, 79104, Freiburg, Germany
| | - Dorothea Helmer
- Laboratory of Process Technology, NeptunLab, Department of Microsystems Engineering (IMTEK) University of Freiburg, Georges-Köhler-Allee 103, 79110, Freiburg, Germany
- Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Straße 21, 79104, Freiburg, Germany
- FIT Freiburg Center of Interactive Materials and Bioinspired Technologies, University of Freiburg, Georges-Köhler-Allee 105, 79110, Freiburg, Germany
| | - Frederik Kotz
- Laboratory of Process Technology, NeptunLab, Department of Microsystems Engineering (IMTEK) University of Freiburg, Georges-Köhler-Allee 103, 79110, Freiburg, Germany
- Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Straße 21, 79104, Freiburg, Germany
| | - Bastian E Rapp
- Laboratory of Process Technology, NeptunLab, Department of Microsystems Engineering (IMTEK) University of Freiburg, Georges-Köhler-Allee 103, 79110, Freiburg, Germany
- Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Straße 21, 79104, Freiburg, Germany
- FIT Freiburg Center of Interactive Materials and Bioinspired Technologies, University of Freiburg, Georges-Köhler-Allee 105, 79110, Freiburg, Germany
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9
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Pasch P, Papadopoulos J, Goralczyk A, Hofer ML, Tabatabai M, Müller TJJ, Hartmann L. Highly Fluorescent Merocyanine and Cyanine PMMA Copolymers. Macromol Rapid Commun 2018; 39:e1800277. [PMID: 29924465 DOI: 10.1002/marc.201800277] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/14/2018] [Indexed: 02/05/2023]
Affiliation(s)
- Peter Pasch
- Institute of Organic Chemistry and Macromolecular Chemistry; Heinrich Heine University Düsseldorf; Universitätsstraße 1 D-40225 Düsseldorf Germany
| | - Julian Papadopoulos
- Institute of Organic Chemistry and Macromolecular Chemistry; Heinrich Heine University Düsseldorf; Universitätsstraße 1 D-40225 Düsseldorf Germany
| | - Andreas Goralczyk
- Institute of Organic Chemistry and Macromolecular Chemistry; Heinrich Heine University Düsseldorf; Universitätsstraße 1 D-40225 Düsseldorf Germany
| | - Marc L. Hofer
- Institute of Organic Chemistry and Macromolecular Chemistry; Heinrich Heine University Düsseldorf; Universitätsstraße 1 D-40225 Düsseldorf Germany
| | - Monir Tabatabai
- Institute of Organic Chemistry and Macromolecular Chemistry; Heinrich Heine University Düsseldorf; Universitätsstraße 1 D-40225 Düsseldorf Germany
| | - Thomas J. J. Müller
- Institute of Organic Chemistry and Macromolecular Chemistry; Heinrich Heine University Düsseldorf; Universitätsstraße 1 D-40225 Düsseldorf Germany
| | - Laura Hartmann
- Institute of Organic Chemistry and Macromolecular Chemistry; Heinrich Heine University Düsseldorf; Universitätsstraße 1 D-40225 Düsseldorf Germany
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10
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Homayounfar K, Liersch T, Schuetze G, Niessner M, Goralczyk A, Meller J, Langer C, Ghadimi BM, Becker H, Lorf T. Two-stage hepatectomy (R0) with portal vein ligation--towards curing patients with extended bilobular colorectal liver metastases. Int J Colorectal Dis 2009; 24:409-18. [PMID: 19084973 PMCID: PMC2829132 DOI: 10.1007/s00384-008-0620-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/27/2008] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIMS Patients with bilobular colorectal liver metastases (CRLM) experience poor prognosis, especially when curative resection cannot be achieved. However, resectability in these patients is often limited by low future remnant liver volume (FRLV). The latter can be enhanced by a two-stage liver resection, using portal vein ligation to induce liver hypertrophy. The aim of this prospective pilot study was to evaluate safety, secondary resectability, and time to recurrence of two-stage hepatectomy with portal vein ligation (PVL) and complete surgical clearance of the FRLV in patients with bilobular CRLM. MATERIALS AND METHODS Out of 24 patients (63+/-8.26 years) with extended bilobular CRLM (metachronous n=10, synchronous n=14), 18 received preoperative 5-FU-based chemotherapy combined with oxaliplatin or irinotecan. Staging included thoracoabdominal computed tomography and (18)F-fluorodeoxyglucose-positron emission tomography scans. First-stage procedure consisted of PVL, resection of all CRLM in the FRLV, and radiofrequency ablation (RFA) of CRLM situated near the future resection plane. RESULTS During first-stage procedure, 7x RFA, 4x non-anatomical resections, and 4x bisegmentectomies were performed additionally to PVL. FRLV/body-weight ratio increased from 0.4% to 0.6% within 55 days (median) after PVL. Second-stage hepatectomy was performed in 19 patients without tumor progression. R0 resection was possible in 14 patients. During a median follow-up of 17 months, intrahepatic recurrence occurred in two, and extrahepatic recurrence in nine out of 14 patients. CONCLUSION Two-stage hepatectomy with PVL and complete surgical clearance of FRLV is safe even after intensified systemic chemotherapy resulting in a curative resection rate of 58.3% (73.7% of re-explored cases).
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Affiliation(s)
- K. Homayounfar
- Department of General and Visceral Surgery, University Medical Center Göttingen, Georg-August-University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - T. Liersch
- Department of General and Visceral Surgery, University Medical Center Göttingen, Georg-August-University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - G. Schuetze
- Department of Diagnostic Radiology, University Medical Center Göttingen, Göttingen, Germany
| | - M. Niessner
- Department of General and Visceral Surgery, University Medical Center Göttingen, Georg-August-University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - A. Goralczyk
- Department of General and Visceral Surgery, University Medical Center Göttingen, Georg-August-University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - J. Meller
- Department of Nuclear Medicine, University Medical Center Göttingen, Göttingen, Germany
| | - C. Langer
- Department of General and Visceral Surgery, University Medical Center Göttingen, Georg-August-University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - B. M. Ghadimi
- Department of General and Visceral Surgery, University Medical Center Göttingen, Georg-August-University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - H. Becker
- Department of General and Visceral Surgery, University Medical Center Göttingen, Georg-August-University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - T. Lorf
- Department of General and Visceral Surgery, University Medical Center Göttingen, Georg-August-University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
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11
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Zonca P, Rathore MA, Loughlin V, Mrázek T, Houdail D, Goralczyk A, Kazinota Z. [ACE procedure for life long constipation in adult]. Rozhl Chir 2007; 86:657-660. [PMID: 18303779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
AIM The authors present a possibility of Malon Operation in adult patients with chronic constipation. They determine the quality of life at a pre-operative time and 3 months post-operatively after ACE operation. MATERIAL AND METHOD ACE is an "antegrade continent enema "operation carried out via a short laparotomy or laparoscopy creating appendicostomy. It serves as a port for enema delivery after catheter access. It is performed for constipation commonly in children and extremely rarely in adults. 46 years old lady has had a severe constipation (1x > 6 weeks) since her early childhood. The usage of laxatives had been progressively increased to achieve the best result. The patient experienced left iliac fossa pain, cramp, spurious diarrhea, anal seepage, spoilage of undergarments, tenesmus, urge incontinence, and social impairment as well. Other features included fibromyalgia and a very strong family history of colorectal cancer. She was examinated according to the guidelines for chronic constipation. Colonic transit study revealed a slow-colonic time and a global inertia of colon. ACE operation was performed in June 2006. RESULTS The result at 3 months after surgery was frequency 2x/week within 10/30 minutes after self administrated ACE (PO4 + 100ml saline) with very occasional soilage. The progressive resistance in track at 8-10cm from skin level occurred 2 months after surgery. Contrast appendiculogram revealed an angulation and a very mild stenosis at appendico-caecal junction. Radiological balloon dilatation to 14F followed with effect. The quality of life assessment at pre-operative and 3 months post-ACE procedure revealed no difference. On specific questioning the predictability of bowel motion was found as a sole benefit. CONCLUSION A non-resective appendicostomy for ACE for severe life-long constipation showed no improvement on QoL instrument. However, it resulted in improvement of the predictability of bowel action. ACE technique - Malon Operation can be used as a treatment method for selected adult patients with severe constipation.
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Affiliation(s)
- P Zonca
- Chirurgické a traumatologické oddĕlení, MN Ostrava.
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12
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Ruscheweyh R, Goralczyk A, Wunderbaldinger G, Schober A, Sandkühler J. Possible sources and sites of action of the nitric oxide involved in synaptic plasticity at spinal lamina I projection neurons. Neuroscience 2006; 141:977-988. [PMID: 16725273 DOI: 10.1016/j.neuroscience.2006.04.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Revised: 04/03/2006] [Accepted: 04/04/2006] [Indexed: 10/24/2022]
Abstract
The synaptic long-term potentiation between primary afferent C-fibers and spinal lamina I projection neurons is a cellular model for hyperalgesia [Ikeda H, Heinke B, Ruscheweyh R, Sandkühler J (2003) Synaptic plasticity in spinal lamina I projection neurons that mediate hyperalgesia. Science 299:1237-1240]. In lamina I neurons with a projection to the periaqueductal gray, this long-term potentiation is dependent on nitric oxide. In the present study, we used immunohistochemistry to detect possible sources and sites of action of the nitric oxide necessary for the long-term potentiation at lamina I spino-periaqueductal gray neurons in rats. None of the three isoforms of the nitric oxide synthase was expressed in a significant number of lamina I spino-periaqueductal gray neurons or primary afferent C-fibers (as evaluated by staining of their cell bodies in the dorsal root ganglia). However, endothelial and inducible nitric oxide synthase were found throughout the spinal cord vasculature and neuronal nitric oxide synthase was present in a number of neurons in laminae II and III. The nitric oxide target soluble guanylyl cyclase was detected in most lamina I spino-periaqueductal gray neurons and in approximately 12% of the dorsal root ganglion neurons, all of them nociceptive as evaluated by coexpression of substance P. Synthesis of cyclic 3',5'-guanosine monophosphate upon stimulation by a nitric oxide donor confirmed the presence of active guanylyl cyclase in at least a portion of the spino-periaqueductal gray neuronal cell bodies. We therefore propose that nitric oxide generated in neighboring neurons or blood vessels acts on the spino-periaqueductal gray neuron and/or the primary afferent C-fiber to enable long-term potentiation. Lamina I spino-parabrachial neurons were stained for comparison and yielded similar results.
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Affiliation(s)
- R Ruscheweyh
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, A-1090 Vienna, Austria
| | - A Goralczyk
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, A-1090 Vienna, Austria; Neuroanatomy and Interdisciplinary Center for Neurosciences, University of Heidelberg, Im Neuenheimer Feld 307, D-69120 Heidelberg, Germany
| | - G Wunderbaldinger
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, A-1090 Vienna, Austria
| | - A Schober
- Neuroanatomy and Interdisciplinary Center for Neurosciences, University of Heidelberg, Im Neuenheimer Feld 307, D-69120 Heidelberg, Germany
| | - J Sandkühler
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, A-1090 Vienna, Austria.
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