In this work, we studied the question of whether it is possible to develop a one-step approach for the creation of microphase-separated materials with long-range order with the help of spontaneous gradient copolymers, i.e., formed during controlled copolymerization solely due to the large difference in the reactivity ratios. To that end, we studied the polymerization-induced microphase separation in bulk on the example of a monomer pair with realistic parameters based on styrene (S) and vinylpirrolydone (VP) by means of computer simulation. We showed that for experimentally reasonable chain lengths, the structures with long-range order start to appear at the conversion degree as low as 76%; a full phase diagram in coordinates (fraction of VP-conversion degree) was constructed. Rather rich phase behavior was obtained; moreover, at some VP fractions, order-order transitions were observed. Finally, we studied how the conversion degree at which the order-disorder transition occurs changes upon varying the maximum average chain length in the system.
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http://dx.doi.org/10.3390/polym12112637 | DOI Listing |
Langmuir
January 2025
Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.
In this work, we show how shape matters for the ordering of red blood cells (RBCs) at a water-air interface for both artificially rigidified and sphered cells as a model system for hereditary spherocytosis. We report enhanced long-range order for spherical RBCs over disk-shaped RBCs arising from the increased local ordering of spheres relative to disks. We show that rigidity has a greater effect on the radial distribution of spherical vs disk-shaped RBCs by slightly increasing the average distance between cells.
View Article and Find Full Text PDFNano Lett
January 2025
Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, Tennessee 37831, United States.
Thermally driven transitions between ferromagnetic and paramagnetic phases are characterized by critical behavior with divergent susceptibilities, long-range correlations, and spin dynamics that can span kHz to GHz scales as the material approaches the critical temperature , but it has proven technically challenging to probe the relevant length and time scales with most conventional measurement techniques. In this study, we employ scanning nitrogen-vacancy center based magnetometry and relaxometry to reveal the critical behavior of a high- ferromagnetic oxide near its Curie temperature. Cluster analysis of the measured temperature-dependent nanoscale magnetic textures points to a 3D universality class with a correlation length that diverges near .
View Article and Find Full Text PDFFoods
December 2024
School of Food Sciences and Engineering, South China University of Technology, Guangzhou 510640, China.
The polyphenol-starch complex has become a hot research topic since it is evident that this modification method can alter the physicochemical properties of starch as well as improve its nutritional value. This work aimed to evaluate the effect of ginger polyphenol gingerols (GNs) and shogaols (SNs) on the structure of starch with different amylose content (WCS, CS, G56, G80). Textural and rheological results indicated that GNs and SNs had more pronounced inhibitory retrogradation effects for relative low-level amylose starches (WCS and CS) compared to relative high-level amylose starches (G56 and G80).
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Institute of Biomedical Chemistry, Pogodinskaya Str., 10, Moscow 119121, Russia.
Biomacromolecules generally exist and function in aqueous media. Is it possible to estimate the state and properties of molecules in an initial three-dimensional colloidal solution based on the structure properties of biomolecules adsorbed on the two-dimensional surface? Using atomic force microscopy to study nanosized objects requires their immobilization on a surface. Particles undergoing Brownian motion in a solution significantly reduce their velocity near the surface and become completely immobilized upon drying.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Chemistry, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
The effect of solution pH on the formation and surface structure of 2-pyrazinethiolate (2-PyzS) self-assembled monolayers (SAMs) formed by the adsorption of 2-mercaptopyrazine (2-PyzSH) on Au(111) was investigated using scanning tunneling microscopy (STM) and X-ray photoelectron microscopy (XPS). Molecular-scale STM observations clearly revealed that 2-PyzS SAMs at pH 2 had a short-range ordered phase of (2√3 × √21)R30° structure with a standing-up adsorption structure. However, 2-PyzS SAMs at pH 8 had a very unique long-range ordered phase, showing a "ladder-like molecular arrangement" with bright repeating rows.
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