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Thami T, Ramonda M, Ferez L, Flaud V, Petit E, Cot D, Rebière B, Ameduri B. Growth-Induced Wrinkles and Dotlike Patterns of a Swollen Fluoroalkylated Thin Film by the Reaction of Surface-Attached Polymethylhydrosiloxane. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:14140-14152. [PMID: 36350015 DOI: 10.1021/acs.langmuir.2c02109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The design of hydrophobic surfaces requires a material which has a low solid surface tension and a simple fabrication process for anchoring and controlling the surface morphology. A generic method for the spontaneous formation of robust instability patterns is proposed through the hydrosilylation of a fluoroalkene bearing dangling chains, Rf = C6F13(CH2)3-, with a soft polymethylhydrosiloxane (PMHS) spin-coated gel polymer (0.8 μm thick) using Karstedt catalyst. These patterns were easily formed by an irreversible swelling reaction due to the attachment of a layer to various substrates. The buckling instability was created by two different approaches for a gel layer bound to a rigid silicon wafer substrate (A) and to a soft nonswelling silicone elastomer foundation (B). The observations of grafted Rf-PMHS films in the swollen state by microscopy revealed two distinct permanent patterns on various substrates: dotlike of wavelength λ = 0.4-0.7 μm (A) or wrinkle of wavelength λ = 4-7 μm (B). The elastic moduli ratios of film/substrate were determined using PeakForce quantitative nanomechanical mapping. The characteristic wavelengths (λ) of the patterns for systems A and B were quantitatively estimated in relation to the thickness of the top layer. A diversity of wrinkle morphologies can be achieved by grafting different side chains on pristine PMHS films. The water contact angle (WCA) hysteresis of fluorinated chain (Rf) was enhanced upon roughening the surfaces, giving highly hydrophobic surface properties for water with static/hysteresis WCAs of 136°/74° in the resulting wrinkle (B) and 119°/41° in the dotlike of lower roughness (A). The hydrophobic properties of grafted films on A with various mixtures of hexyl/fluoroalkyl chains were characterized by static CA: WCA 104-119°, ethylene glycol CA 80-96°, and n-hexadecane CA 17-61°. A very low surface energy of 15 mN/m for Rf-PMHS was found on the smoother dotlike pattern.
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Affiliation(s)
- Thierry Thami
- Institut Européen des Membranes, IEM, Université Montpellier, CNRS, ENSCM, Montpellier, France34095
| | - Michel Ramonda
- Centre de Technologie de Montpellier, CTM, Université Montpellier, Bât. 5, cc007 Campus Saint Priest, Montpellier, France34095
| | - Lynda Ferez
- Institut Européen des Membranes, IEM, Université Montpellier, CNRS, ENSCM, Montpellier, France34095
| | - Valérie Flaud
- Institut Charles Gerhardt de Montpellier, ICGM, Université Montpellier, CNRS, ENSCM, Montpellier, France34095
| | - Eddy Petit
- Institut Européen des Membranes, IEM, Université Montpellier, CNRS, ENSCM, Montpellier, France34095
| | - Didier Cot
- Institut Européen des Membranes, IEM, Université Montpellier, CNRS, ENSCM, Montpellier, France34095
| | - Bertrand Rebière
- Institut Charles Gerhardt de Montpellier, ICGM, Université Montpellier, CNRS, ENSCM, Montpellier, France34095
| | - Bruno Ameduri
- Institut Charles Gerhardt de Montpellier, ICGM, Université Montpellier, CNRS, ENSCM, Montpellier, France34095
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Improved Optical and Morphological Properties of Vinyl-Substituted Hybrid Silica Materials Incorporating a Zn-Metalloporphyrin. MATERIALS 2018; 11:ma11040565. [PMID: 29642404 PMCID: PMC5951449 DOI: 10.3390/ma11040565] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/02/2018] [Accepted: 04/04/2018] [Indexed: 12/16/2022]
Abstract
This work is focused on a novel class of hybrid materials exhibiting enhanced optical properties and high surface areas that combine the morphology offered by the vinyl substituted silica host, and the excellent absorption and emission properties of 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin-Zn(II) tetrachloride as a water soluble guest molecule. In order to optimize the synthesis procedure and the performance of the immobilized porphyrin, silica precursor mixtures of different compositions were used. To achieve the requirements regarding the hydrophobicity and the porous structure of the gels for the successful incorporation of porphyrin, the content of vinyltriacetoxysilane was systematically changed and thoroughly investigated. Substitution of the silica gels with organic groups is a viable way to provide new properties to the support. An exhaustive characterization of the synthesized silica samples was realised by complementary physicochemical methods, such as infrared spectroscopy (FT-IR), absorption spectroscopy (UV-Vis) and photoluminescence, nuclear magnetic resonance spectroscopy (29Si-MAS-NMR) transmission and scanning electron microscopy (TEM and SEM), nitrogen absorption (BET), contact angle (CA), small angle X ray and neutron scattering (SAXS and SANS). All hybrids showed an increase in emission intensity in the wide region from 575 to 725 nm (Q bands) in comparison with bare porphyrin. By simply tuning the vinyltriacetoxysilane content, the hydrophilic/hydrophobic profile of the hybrid materials was changed, while maintaining a high surface area. Good control of hydrophobicity is important to enhance properties such as dispersion, stability behaviour, and resistance to water, in order to achieve highly dispersible systems in water for biomedical applications.
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Jennings AR, Budy SM, Thrasher CJ, Iacono ST. Synthesis of fluorinated silica nanoparticles containing latent reactive groups for post-synthetic modification and for tunable surface energy. NANOSCALE 2016; 8:16212-16220. [PMID: 27430324 DOI: 10.1039/c6nr04829c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A new PFCP-based chlorosilane monomer containing a latent reactive fluorine atom was synthesized utilizing a hydrosilylation reaction. This monomer was used to functionalize Stöber silica nanoparticles, or network silicas, and the ability to tailor the properties of the functionalized nanoparticles was investigated by reacting the latent reactive fluorinated alkene with various nucleophiles. In order to model the chemical transformations occuring with the PFCP-functionalized particles, a new PFCP-containing molecular silica was prepared using a hydrosilylation reaction. The molecular silica was designed such that it contained a latent reactive fluorine atom and could also undergo post-synthetic modifications with various nucleophiles. The ability to modify the latent reactive group and tune the properties of the molecular and network silicas was verified by multi-nuclear NMR ((1)H, (13)C, (19)F, and (29)Si), thermal characterizations, and by investigating the hydrophobicity and surface morphology of spin-cast films prepared from the molecular and network silicas.
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Affiliation(s)
- Abby R Jennings
- Department of Chemistry & Chemistry Research Center, United States Air Force Academy, Colorado Springs, CO 80919 USA.
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Emma MG, Lombardo M, Trombini C, Quintavalla A. The Organocatalytic α-Fluorination of Chiral γ-Nitroaldehydes: the Challenge of Facing the Construction of a Quaternary Fluorinated Stereocenter. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600378] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Marco Giuseppe Emma
- Department of Chemistry “G. Ciamician”; Alma Mater Studiorum; University of Bologna; Via Selmi 2 40126 Bologna Italy
| | - Marco Lombardo
- Department of Chemistry “G. Ciamician”; Alma Mater Studiorum; University of Bologna; Via Selmi 2 40126 Bologna Italy
| | - Claudio Trombini
- Department of Chemistry “G. Ciamician”; Alma Mater Studiorum; University of Bologna; Via Selmi 2 40126 Bologna Italy
| | - Arianna Quintavalla
- Department of Chemistry “G. Ciamician”; Alma Mater Studiorum; University of Bologna; Via Selmi 2 40126 Bologna Italy
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