Understanding the role played by chemical additives such as NaCl salt, acid and Cetylpyridinium Chloride (CPC) surfactant on the interaction between dye and polyelectrolyte contributes to optimization of processes using polyelectrolytes in the removal of dye from aqueous solution. Herein we focus in the interaction between Safranin T, a cationic dye, with two anionic polyelectrolytes, poly(ammonium acrylate) and poly(acrylic acid) using spectrophotometric method and conductivity measurement. In aqueous solution, each of anionic polyelectrolytes forms a complex with the dye and induces a metachromasy indicated by the blue shift of the absorbance of the dye. The stoichiometry of complexes evaluated by the molar ratio method are 1:1 for Safranin T poly(ammonium acrylate) and 2:1 in the case of Safranin T poly(acrylic acid). The effect of additives on the stability of complexes has been studied by varying concentrations of the salt and the surfactant and pH of the solution. The thermodynamic parameters of interaction ΔG, ΔH and ΔS at different temperatures were evaluated to determine the stability constant of the complexes.
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http://dx.doi.org/10.1016/j.saa.2014.04.028 | DOI Listing |
Langmuir
January 2025
School of Advanced Engineering, Kogakuin University, Tokyo 192-0015, Japan.
Arsenocholine-containing methacrylate (MTAsB) inspired by marine organisms was synthesized by the reaction of 2-bromoethyl methacrylate and trimethylarsine to investigate its polymerization behavior and the fundamental properties of the resulting polymer. Controlled radical polymerization of MTAsB proceeded in the presence of a copper catalyst and imidazolium chloride at 60 °C for 8 h to give a water-soluble polycation with a 94% yield. The smaller amount of nonfreezing water and intermediate water of poly(MTAsB) was observed compared with that of the ammonium-containing polycations.
View Article and Find Full Text PDFSmall
January 2025
Polymer Science & Engineering Department, Conte Center for Polymer Research, University of Massachusetts, 120 Governors Drive, Amherst, MA, 01003, USA.
Polymers (Basel)
December 2024
Research Laboratory "New Polymeric Materials", Nizhny Novgorod State Technical University, n.a. R.E. Alekseev, 24 Minin Street, 603155 Nizhny Novgorod, Nizhegorodskaya Oblast, Russia.
Anionic thermo- and pH-responsive copolymers were synthesized by photoiniferter reversible addition-fragmentation chain transfer polymerization (PI-RAFT). The thermo-responsive properties were provided by oligo(ethylene glycol)-based macromonomer units containing hydrophilic and hydrophobic moieties. The pH-responsive properties were enabled by the addition of 5-20 mol% of strong (2-acrylamido-2-methylpropanesulfonic) and weak (methacrylic) acids.
View Article and Find Full Text PDFMacromol Rapid Commun
January 2025
Polymer Science, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 3, Groningen, 9747 AG, The Netherlands.
Conjugated polyelectrolytes (CPEs), materials that are defined by a -conjugated backbone and charged ionic functional groups, are frequently prepared through direct polymerization of charged monomer species in aqueous media. This route is, however, often accompanied by labor-intensive work-up procedures, low yields, and ultimately results in materials that are difficult to characterize. To overcome these inconveniences, in this work protection chemistry is applied on sulfonate-functionalized fluorene monomers that are polymerized under standard Suzuki polycondensation conditions to obtain protected donor-acceptor copolymers.
View Article and Find Full Text PDFNat Commun
January 2025
Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China.
Monovalent salts are generally believed to stabilize DNA duplex by weakening inter-strand electrostatic repulsion. Unexpectedly, our force-induced hairpin unzipping experiments and thermal melting experiments show that LiCl, NaCl, KCl, RbCl, and CsCl at concentrations beyond ~1 M destabilize DNA, RNA, and RNA-DNA duplexes. The two types of experiments yield different changes in free energy during melting, while the results that high concentration monovalent salts destabilize duplexes are common.
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