Synthesis and characterization of latex nanoparticles using a visible-light photoinitiating system in reverse micelles

Abstract

This work shows the feasibility of using the photoinitiating system composed by the xanthene dye Eosin-Y and triethanolamine on the polymerization of acrylamide in benzyl-hexadecyl-dimethylammonium chloride (BHDC) reverse micelles. Molecular weights of polyacrylamide (MW PAA ) in the order of 10 5 and conversions up to 90 % are obtained. The size of the latex particles is in the range of the nanometers (d<50 nm). The effect of water content and concentrations of surfactant, amine, dye, and monomer on the particle size and MW PAA are examined. Only the amine and monomer concentrations affect the MW PAA . These results are interpreted on the basis of an exchange mechanism between micelles. Practically no effect on hydrodynamic diameters is observed when the value of MW PAA is doubled. This is ascribed to a supercoiled structure of PAA inside of micelles. Our results also suggest that the polymer properties can be modulated by appropriate combination of the dye/surfactant electrical charges.

A Comparative Study on the Photophysics and Photochemistry of Xanthene Dyes in the Presence of Polyamidoamine (PAMAM) Dendrimers

“…Furthermore, it is interesting to note that the higher Φ R values obtained herein are similar to those previously reported by our group with TEOA as a quencher, which is proven to be an efficient electron donor . Data in Table also show that all Φ R values were higher than those found for Eos/TEOA in reverse micelles of sodium bis(2‐ethylhexyl) sulfosuccinate (AOT; Φ R =0.006) and benzylhexadecyldimethylammonium chloride (BHDC; Φ R =0.024), which have been successfully used as photoinitiating systems of vinyl polymerization to obtain latex nanoparticles …”

Bisphosphonic Acid‐Functionalized Water‐Soluble Photoinitiators

“…For example, the ionic hydrophilic groups such as quaternary ammonium salts, carboxylic acids, sulfonates, thiosulfates, or neutral hydrophilic groups such as long ethoxy ether chains (PEGs), oligomeric structures such as polyvinyl alcohols were incorporated into conventional photoinitiators such as benzyl, anthraquinone, polysilanes, Michler's ketone, aliphatic ketones, benzophenone and thioxanthone . Other water‐soluble photoinitiators reported previously in the literature include benzylidine cyclano dyes, xanthene dyes, carboxylated camphorquinone, coumarin derivatives, naphthalimide derivatives, and hydoxyalkylphenones …”

A Comparative Study on the Photophysical and Photochemical Properties of Dyes in the Presence of Low Generation Amino‐terminated Polyamidoamine Dendrimers

“…Another relevant application of confined dyes is as photoinitiating system of vinyl polymerization, in the presence of an electron donor. Recently, we synthesized latex nanoparticles of supercoiled polymers of high molecular weight by means of dyes hosted in reverse micelles .…”