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Synthesis and thermo-responsive behavior of fluorescent labeled microgel particles based on poly(N-isopropylacrylamide) and its related polymers

“…This temperature is higher than the transition temperatures of PNIPAM microgel particles (ca. 30 [3,9,12,[23][24][25][26]) or emulsion polymerization ([SDS]/CMC [10,11,[27][28][29]) using ionic initiators in water. The charged polymer chains formed during the polymerization process act as surfactant molecules by providing stability for the growing particles [23] and SDS enhances colloidal stabilization during the nucleation stage [27].…”

“…There are two kinds of fluorescence methods, which have been applied to the investigations for polymer systems; (1) to add a free fluorescent probe to the system and (2) to covalently label the fluorescent probe to the polymer. It was reported by some groups using the former method that the surface or interior of the PNIPAM microgel particles becomes hydrophobic in conjunction with its volume phase transition with increasing temperature above the transition temperature [9][10][11][12]. However, the fluorescent probes can be located in somewhere inside or surface of the microgel or bulk layer with this method.…”

Fluorescence Studies of the Thermoresponsive Behavior of Aqueous Dispersions of Microgels Based upon Poly(N-isopropylacrylamide)

“…Microgels containing varying amounts and NIP AM and DMAC were synthesized via a single-step emulsion polymerization process in doublydistilled, degassed water at 25°C, in the presence of MBA as cross-linker 15 . The total aqueous charge of the system was 600 cm 3 and contained a monomer content of 8.25g.…”

“…Figure 1), means that the TRAMS estimate of x c for reorientational relaxation of the probe is reasonably reliable. Modeling the relaxing moiety as a spherical entity results (15) in an estimate of the order of 20 nm for the diameter of the tumbling sphere. This is considerably less than that afforded by dynamic light scattering for microgels (synthesized at the higher temperature of 70°C 1 ).…”

Luminescence techniques and characterization of the morphology of polymer latices

“…The success achieved as a consequence of these fundamental studies has encouraged scientists to extend the use of this spectroscopic tool in order to characterize much more complex and industrially relevant systems [11][12][13][14][15][16].…”