Upper Critical Solution Temperature Behavior of pH-Responsive Amphoteric Statistical Copolymers in Aqueous Solutions.

Amphoteric statistical equivalent copolymers (P(2VP/NaSS) ) composed of 2-vinylpyridine (2VP) and anionic sodium -styrenesulfonate (NaSS) were prepared via reversible addition-fragmentation chain transfer polymerization. The degrees of polymerization () were 19 and 95. The monomer reactivity ratio, time conversion profile, and H nuclear magnetic resonance diffusion-ordered spectra suggested that the copolymerization of 2VP and NaSS provided statistical or near to random copolymers.

Micellar formation of cationic surfactants.

The micellar structure of six alkyl trimethylammonium halides was studied via conductivity. It was found that the aggregation number increased with the decreasing carbon chain length. Furthermore, Br significantly enhanced the micellar formation over Cl.

Micelle and Surface Tension of Double-Chain Cationic Surfactants.

Since the early 20th century, the slightly disparate measurements of a surfactant's critical micelle concentration, via either surface tension or electrical conductivity, have been assumed one and the same. As a consequence, the possibility that micelles can adsorb at the air/water surface has been disregarded and has led to some abnormalities in the literature that remain as yet unresolved. In this paper, we closely examined the two critical concentrations for a double-chain cationic surfactant.

Ultrasound- and Thermo-Responsive Ionic Liquid Polymers.

Poly(sodium 2-acrylamido-2-methylpropanesulfonate) (PAMPSNa) was prepared via reversible addition-fragmentation chain transfer (RAFT) radical polymerization. An ionic liquid polymer (PAMPSP) was then prepared by exchanging the pendant counter cation from sodium (Na⁺) to tributyl--octylphosphonium (P⁺). We studied the ultrasound- and thermo-responsive behaviors of PAMPSP in water.

Upper Critical Solution Temperature (UCST) Behavior of Polystyrene-Based Polyampholytes in Aqueous Solution.

Strong polyampholytes comprising cationic vinylbenzyl trimethylammonium chloride (VBTAC) bearing a pendant quaternary ammonium group and anionic sodium -styrenesulfonate (NaSS) bearing a pendant sulfonate group were prepared via reversible addition-fragmentation chain-transfer polymerization. The resultant polymers are labelled P(VBTAC/NaSS), where indicates the degree of polymerization ( = 20 or 97). The percentage VBTAC content in P(VBTAC/NaSS) is always about 50 mol%, as revealed by ¹H NMR measurements, meaning that P(VBTAC/NaSS) is a close to stoichiometrically charge-neutralized polymer.