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Several 3-alkyl-1-vinylimidazolium bromides differing by the length of the alkyl chain were prepared and polymerized using a free radical route. The behaviour of the obtained homopolymers in aqueous medium was investigated by several physico-chemical methods including viscosimetry, surface tension measurements and fluorescence spectroscopy. These experiments highlighted a strong influence of the length of the pendent alkyl chain on the side-chain aggregation tendency which is a property of such amphiphilic comb polymers. Fluorescence experiments were also conducted on the surface active analogues, in order to compare their behaviour to that of the polymers. [ABSTRACT FROM AUTHOR]

Cationic amphiphilic polymers (e.g. polyvinylpyridinium bromides and polyvinylimidazolium bromides) adopt a compact coiled form in aqueous solutions. In the case of former polymers, the resulting hydrophobic microdomains are evidenced only by fluorescence spectroscopy if a molecular rotor (DMAC) is used as a fluorescent probe, while the behaviour of the latter can be studied in aqueous solution by using both types of fluorescent probes, i.e., pyrene and the molecular rotor. The purpose of the present investigation deals with a comparative study between the magnitude of the local viscosity and the polarity of the hydrophobic microdomains generated by poly(3-hexadecyl-1-vinylimidazolium bromide) in an aqueous medium using pyrene and DMAC as fluorescent probes. Moreover, the results are compared with the data obtained with micelles of conventional surfactants such as the homopolymer repetitive unit model and CTAB. [ABSTRACT FROM AUTHOR]

Micellar particles can solubilize lipophilic extractants similarly to the organic phase in classical biphasic extraction. This analogy is used here to investigate the kinetics of complex formation between Ni ions and long chain 5-alkoxypicolinic acids (C-PIC, with n=12, 15, 18) solubilized in different types of micelles, namely cetyl trimethylammonium bromide (CTAB), hexaethyleneglycol-dodecylether (CEO) and CTAB/CEO mixed micelles. In the case of CTAB micelles, the interaction between the carboxylic function of the extractant and the polar head of surfactant molecules was expected to decrease the rate of complex formation so as to make possible kinetic separation of mixtures of metal ions. The observed rate constants for complex formation at pH 4.5 or 7.0 are indeed much smaller in CTAB micelles than in CEO or mixed micelles, but they still remain too high for the previous purpose, although the influence of the surfactant concentration demonstrates, as expected, a much stronger partitioning in the case of CTAB in comparison to CEO. On the other hand, it is shown that, once complex formation has occurred the removal of Ni ions can be achieved using ultrafiltration. The yield of extraction increases with n, with the mole fraction of CEO, and with the ligand to metal ratio. [ABSTRACT FROM AUTHOR]

A satisfactory synthesis route to a new monomer, the 3-chloro-4-nitrostyrene (3-CNS) is described. The results of free radical polymerisation experiments (limit of conversion, global kinetics) are reported by comparison with those of the isomer 4-chloro-3-nitrostyrene (4-CNS). They show the great influence of the nitro group position which markedly increases the reactivity of 3-CNS. [ABSTRACT FROM AUTHOR]