The micelle aggregation numbers (N(agg)) of several series of cationic oligomeric surfactants were determined by time-resolved fluorescence quenching (TRFQ) experiments, using advantageously 9,10-dimethylanthracene as fluorophore. The study comprises six dimeric ("gemini"), three trimeric, and two tetrameric surfactants, which are quaternary ammonium chlorides, with medium length spacer groups (C(3)-C(6)) separating the individual surfactant fragments. Two standard cationic surfactants served as references. The number of hydrophobic chains making up a micellar core is relatively low for the oligomeric surfactants, the spacer length playing an important role. For the dimers, the number decreases from 32 to 21 with increasing spacer length. These numbers decrease further with increasing degree of oligomerization down to values of about 15. As for many conventional ionic surfactants, the micelles of all oligomers studied grow only slightly with the concentration, and they remain in the regime of small micelles up to concentrations of at least 3 wt %.
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http://dx.doi.org/10.1021/la052414h | DOI Listing |
Langmuir
January 2025
Research Center for Water Resources and Interface Science, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.
The mechanism of the emulsion polymerization of styrene to polystyrene nanoparticles (PSNPs) remains a subject of debate. Herein, a series of reaction parameters with different surfactant concentrations, monomer contents, temperatures, and equilibration times were investigated to understand the formation mechanism of PSNPs, which demonstrate a correlation between the properties of PSNPs and the mesostructure of the premix. Cooling the model systems with self-emulsifying nanodroplets (SENDs) in the early reaction stages resulted in the hollow polystyrene spheres (H-PSSs), ruptured PSNPs, and dandelion-like PSNPs, further indicating that the oil nanodroplets are the key sites for the formation of PSNPs.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80303, United States.
ConspectusSynthetic extracellular matrix (ECM) engineering is a highly interdisciplinary field integrating materials and polymer science and engineering, chemistry, cell biology, and medicine to develop innovative strategies to investigate and control cell-matrix interactions. Cellular microenvironments are complex and highly dynamic, changing in response to injury and disease. To capture some of these critical dynamics , biomaterial matrices have been developed with tailorable properties that can be modulated in the presence of cells.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur-603203, Tamil Nadu, India.
Langmuir
November 2024
Department of Chemical & Materials Engineering, National Central University, Jhong-Li, Taoyuan 320, Taiwan.
Strategies to design multifunctional interfaces for biosensors have been extensively investigated to acquire optimal sensitivity, specificity, and accuracy. However, heterogeneous ingredients in clinical samples inevitably generate background signals, exposing challenges in biosensor performance. Polymer coating has been recognized as a crucial method to functionalize biointerfaces by providing tailored properties that are essential for interacting with biological systems.
View Article and Find Full Text PDFACS Omega
October 2024
Sino Oil King Shine Chemical Co., Ltd, Langfang, Hebei 065000, PR China.
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