Supramolecular copolymers have typically been studied in the extreme cases, such as self-sorting or highly mixed copolymer systems, while the intermediate systems have been less understood. We have reported the temperature-dependent microstructure in copolymers of triazine- and benzene-derivatives based on charge-transfer interactions with a highly alternating microstructure at low temperatures. Here, we investigate the temperature-dependent copolymerization further and increase the complexity by combining triazine- and benzene-derivatives with opposite preferred helicities. In this case, intercalation of the benzene-derivative into the triazine-derivative assemblies causes a helical inversion. The inversion of the net helicity was rationalized by comparing the mismatch penalties of the individual monomers, which indicated that the benzene-derivative dictates the helical screw-sense of the supramolecular copolymers. Surprisingly, this was not reflected in further investigations of slightly modified triazine- and benzene-derivatives, thus highlighting that the outcome is a subtle balance between structural features, where small differences can be amplified due to the competitive nature of the interactions. Overall, these findings suggest that the temperature-dependent microstructure of triazine- and benzene-based supramolecular copolymers determines the copolymer helicity of the presented system in a similar way as the mixed majority-rules phenomenon.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/chem.202301726 | DOI Listing |
Chemistry
December 2024
Hiroshima University, Chemistry, 1-3-1 Kagamiyama, 739-8526, Higashi-Hiroshima, JAPAN.
The intermolecular host-guest complexation of head-to-tail monomers consisting of cleft-shaped bisporphyrin and trinitrofluorenone units connected by a chiral binaphthyl linker was employed to construct helically twisted supramolecular polymers. Results from 1H NMR, diffusion-ordered NMR spectroscopy, and viscometry experiments revealed that the supramolecular polymerization of these monomers follows a ring-chain competition mechanism. The introduction of bulky substituents at the linker significantly suppressed the formation of macrocyclic oligomers, whereas smaller alkyl chains facilitated the formation of the cyclic form.
View Article and Find Full Text PDFACS Appl Bio Mater
December 2024
Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, Prague 6, 162 00, Czech Republic.
The development of stimuli-responsive drug delivery systems enables targeted delivery and environment-controlled drug release, thereby minimizing off-target effects and systemic toxicity. We prepared and studied tailor-made dual-responsive systems (thermo- and pH-) based on synthetic diblock copolymers consisting of a fully hydrophilic block of poly[-(1,3-dihydroxypropyl)methacrylamide] (poly(DHPMA)) and a thermoresponsive block of poly[-(2,2-dimethyl-1,3-dioxan-5-yl)methacrylamide] (poly(DHPMA-acetal)) as drug delivery and smart stimuli-responsive materials. The copolymers were designed for eventual medical application to be fully soluble in aqueous solutions at 25 °C.
View Article and Find Full Text PDFNanoscale
December 2024
Department of Materials Science, Institute of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan.
This study reports the synthesis and characterisation of a ferrocene-based conjugated polymer and a chiral composite. The precursor copolymer was synthesised from 1,3-phenylenediamine and 1,1'-dibromoferrocene Buchwald-Hartwig polycondensation. This polymerisation process increased the effective conjugation length and led to magnetic spin interactions along the main chain, resulting in a ground triplet spin state at 25 °C.
View Article and Find Full Text PDFMacromolecules
November 2024
School of Mathematical and Physical Sciences, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K.
A range of charge-stabilized aqueous polyurethane (PU) dispersions comprising hard segments formed from hydrogenated methylene diphenyl diisocyanate (HMDI) with dimethylolpropionic acid (DMPA) and ethylenediamine, and soft segments of poly(tetramethylene oxide) of different molecular weights are synthesized. Characterization of the dispersions by mass spectrometry, gel permeation chromatography, small-angle X-ray scattering, atomic force microscopy, and infrared spectroscopy shows that they are composed of PUs self-assembled into spherical particles (primary population) and supramolecular structures formed by hydrogen-bonded HMDI and DMPA acid-rich fragments (secondary population). Analysis of the scattering patterns of the dispersions, using a structural model based on conservation of mass, reveals that the proportion of supramolecular structures increases with DMPA content.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2024
Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, 128 40, Prague 2, Czech Republic.
In recent years, polymerization-induced self-assembly (PISA) has emerged as a powerful method for the straightforward synthesis of polymer nanoparticles at high concentration. In this study, we describe for the first time the synthesis of poly(2-oxazoline) nanoparticles by dispersion cationic ring-opening polymerization-induced self-assembly (CROPISA) in n-dodecane. Specifically, a n-dodecane-soluble aliphatic poly(2-(3-ethylheptyl)-2-oxazoline) (PEHOx) block was chain-extended with poly(2-phenyl-2-oxazoline) (PPhOx).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!