This work reports the preparation of hydrophobic mesoporous silica particles (MSPs) modified with nonfluorinated alkyl silanes. Alkyl silanes were grafted onto the surface of the MSPs as a function of the length of nonfluorinated alkyl chains such as propyltriethoxysilane (C), octyltriethoxysilane (C), dodecyltriethoxysilane (C), and octadecyltriethoxysilane (C). Moreover, the grafting of the different alkyl silanes onto the surface of MSPs to make them hydrophobic was demonstrated using different conditions such as by changing the pH (0, 4, 6, 8, and 13), solvent type (protic and aprotic), concentration of silanes (0, 0.12, 0.24, 0.36, 0.48, and 0.60 M), reaction time (1, 2, 3, and 4 days), and reaction temperature (25 and 40 °C). The contact angles of the alkyl silane-modified MSPs were increased as a function of the alkyl chain lengths in the order of C > C > C > C, and the contact angle of C-modified MSPs was 4 times wider than that of unmodified MSPs. The unmodified MSPs had a contact angle of 25.3°, but C-modified MSPs had a contact angle of 102.1°. Furthermore, the hydrophobicity of the nonfluorinated alkyl silane-modified MSPs was also demonstrated by the adsorption of a hydrophobic lecithin compound, which showed the increase of lecithin adsorption as a function of the alkyl chain lengths. The cross-linking ratios of the modified silanes on the MSPs were confirmed by solid-state Si-MAS nuclear magnetic resonance (NMR) measurement. Consequently, the hydrophobic modification on MSPs using nonfluorinated alkyl silanes was best preferred in a protic solvent, with a reaction time of ∼24 h at 25 °C and at a high concentration of silanes.
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http://dx.doi.org/10.1021/acsomega.1c01981 | DOI Listing |
Bioorg Med Chem
December 2024
Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI 48109, USA; Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA; Center of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA; Michigan Institute for Computational Discovery and Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Michigan Institute for Data and AI in Society, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address:
A series of 2-arylhydrazinylidene-3-oxo acids (AHOAs) was prepared by dealkylation of alkyl-2-arylhydrazinylidene-3-oxo-3-alkanoates with AlBr. Using X-Ray, NMR spectroscopy, and quantum mechanical calculations (QM), the existence of AHOAs in a thermodynamically favorable Z-form stabilized by two intramolecular H-bonds was established. All AHOAs had acceptable ADME parameters.
View Article and Find Full Text PDFChemistry
October 2024
Institute of Chemistry, University of Tartu, Ravila 14a Str, Tartu, 50411, Estonia.
Despite the numerous published syntheses and applications of sulfoximines, very few studies describe their physico-chemical properties and in particular their acidic, basic and lipophilic or hydrophilic characters. We report for the first time the acidity values (pK) of fluorinated sulfoximines in water and in acetonitrile, as well as the basicity (pK) measurements of fluorinated and non-fluorinated sulfoximines in acetonitrile. The same sulfoximine library was also studied in terms of lipophilicity with measurement of the Hansch parameters of the sulfoximine moieties.
View Article and Find Full Text PDFWater Res X
September 2024
Department of Civil & Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Per- and polyfluoroalkyl substances (PFASs) are emerging contaminants detected ubiquitously and have negative impacts on human health and ecosystem; thus, developing sensing technique is important to ensure safety. Herein, we report a novel colorimetric-based sensor with perfluoroalkyl receptor attached to citrate coated gold nanoparticles (Citrate-Au NPs) that can detect several PFASs including perfluorocarboxylates with different chain lengths (PFHxA, PFOA, PFNA, PFDA), perfluorooctanoic sulfonate (PFOS), and perfluorooctanoic phosphonate (PFOPA). The sensor detects PFASs utilizing fluorous interaction between PFASs and the perfluoroalkyl receptor of Citrate-Au NPs in a solution at a fixed salt concentration, inducing changes in nanoparticle dispersity and the solution color.
View Article and Find Full Text PDFACS Appl Mater Interfaces
July 2024
Key Laboratory of Automobile Materials of Ministry of Education, Department of Materials Science and Engineering, Jilin University, Changchun 130022, China.
The precise control of pore structures in porous organic polymer (POP) materials is of paramount importance in addressing a wide range of challenges associated with gas separation processes. In this study, we present a novel approach to optimize the gas separation performance of POPs through the introduction of fluorine groups and figure out an important factor of reaction decision that whether the AlCl-catalyzed polymerization is Scholl reaction or Friedel-Crafts alkylation. In the chloroform system, the steric hindrance of function groups could make direct coupling between the benzene rings difficult, which would lead to part solvent knitting (Friedel-Crafts alkylation) instead.
View Article and Find Full Text PDFJ Am Chem Soc
June 2024
Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States.
Nickel and palladium complexes bearing "sandwich" diimine ligands with perfluorinated aryl caps have been synthesized, characterized, and explored in ethylene polymerization reactions. The X-ray crystallographic analysis of the precatalysts and shows differences from their nonfluorinated analogues and , with the perfluorinated aryl caps centered precisely over the nickel and palladium centers, which results in higher buried volumes of the metal centers relative to the nonfluorinated analogues. The sandwich diimine-palladium complexes and containing perfluorinated aryl caps polymerize ethylene in a controlled fashion with activities that are substantially increased compared with their nonfluorinated analogues.
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