Making metal-organic frameworks (MOFs) that are stabilized in nonpolar media is not as straightforward as making their inorganic nanoparticle counterparts, since surfactants penetrate through the porous structures or dissolve the secondary building units (SBUs) through ligand-exchange linker modulator mechanisms. Herein, we report that calixarenes stabilize UIO-66 nanoparticles effectively by remaining outside the grains through size exclusion, without pores becoming blocked, all the while providing amphiphilicity that permits the formation of stable colloidal dispersions with much narrower size distributions. Using the UIO-66 dispersed solutions, we show that smooth films from an otherwise immiscible polystyrene can be made feasibly.
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http://dx.doi.org/10.1021/jacs.9b04198 | DOI Listing |
Molecules
January 2025
Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences (MPI-NAT), Am Fassberg 11, 37077 Göttingen, Germany.
In a search for dyes photoactivatable with visible light, fluorenes with substituents at positions 2 and 7 were prepared, and their absorption and emission spectra were studied. In particular, the synthesis route to 9-diazofluorenes with 2-(N,N-dialkylamino) and N-modified 7-(4-pyridyl) substituents was established. These compounds are initially non-fluorescent, undergo photolysis with UV or blue light, and-in non-polar media-provide orange- to red-emitting products with a large separation between absorption and emission bands.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Pharmaceutical Technology, Gazi University, Ankara 06560, Turkey.
Lidocaine (LID), frequently used in dermal applications, is a nonpolar local anesthetic agent that is practically insoluble in water. The main aim of this study is to develop the nanosuspension formulation of LID using the design of experiments (DoE). The improved solubility and dissolution rate provided by nanosizing are expected to result in enhanced dermal bioavailability.
View Article and Find Full Text PDFMacromolecules
December 2024
Dainton Building, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K.
We report the reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization of 2-hydroxyethyl methacrylate (HEMA) in -dodecane using a poly(lauryl methacrylate) (PLMA) precursor at 90 °C. This formulation is an example of polymerization-induced self-assembly (PISA), which leads to the formation of a colloidal dispersion of spherical PLMA-PHEMA nanoparticles at 10-20% w/w solids. PISA syntheses involving polar monomers in non-polar media have been previously reported but this particular system offers some unexpected and interesting challenges in terms of both synthesis and characterization.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemistry, University of Washington, Seattle, Washington 98195, United States.
Circular dichroism (CD) spectroscopy has emerged as a potent tool for probing chiral small-molecule ligand exchange on natively achiral quantum dots (QDs). In this study, we report a novel approach to identifying QD-biomolecule interactions by inducing chirality in CdS QDs using thermoresponsive elastin-like polypeptides (ELPs) engineered with C-terminal cysteine residues. Our method is based on a versatile two-step ligand exchange process starting from monodisperse oleate-capped QDs in nonpolar media and proceeding through an easily accessed achiral glycine-capped QD intermediate.
View Article and Find Full Text PDFBiosystems
January 2025
University of Maribor, Faculty of Natural Sciences and Mathematics, Koroška Cesta 160, 2000, Maribor, Slovenia; University of Maribor, Faculty of Medicine, Taborska ulica 8, 2000, Maribor, Slovenia. Electronic address:
Explaining the emergence of life is perhaps the central and most challenging question in modern science. We are proposing a new hypothesis concerning the origins of life. The new hypothesis is based on the assumption that during the emergence of life, evolution had to first involve autocatalytic systems which only subsequently acquired the capacity of genetic heredity.
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