Mesoglobules of random copolyethers as templates for nanoparticles

Abstract

An approach to nanoparticles based upon the thermosensitivity of a copolyether is described. Two thermosensitive copolymers of glycidol with molar masses of 800,000 g/ mol randomly substituted with ethyl isocyanate (28 and 35% substitution) were used to obtain mesoglobules. The effects of copolymer concentration and of the presence of surfactants (sodium dodecyl sulfate and hexadecyltrimethylammonium bromide) on the size of the mesoglobules formed were investigated. The obtained mesoglobules were monomodal and of narrowly distributed diameters, as shown by dynamic light scattering and atomic force microscopy measurements. The radical nucleated copolymerization of N-isopropylacrylamide with N,N 0 -methylenebisacrylamide as a crosslinker was performed in the presence of the mesoglobules. Nanoparticles of monomodal size distribution and low dispersity were obtained.

Bioactive mesoglobules of poly(di(ethylene glycol) monomethyl ether methacrylate)–peptide conjugate

“…The latter is above the theoretical value for hard spheres (0.778) 47. The value of R g / R h is close to what is typically observed for mesoglobules22 and reflects the loose packing of thermosensitive polymer chains, which are only partially dehydrated in the mesoglobules' structure 19, 48…”

Hybrid nanoparticles obtained from mixed mesoglobules

“…Swelling prior to complete dissolution of mesoglobules has previously been observed for PNIPAM dispersions and explained in terms of the existence of interchain hydrogen bonds even at temperatures below the LCST that act as physical cross-linkers and impart gel-like behaviour [12,32,35]. The mesoglobules formed in PNIPAM-rich dispersions were dissolved into individual unimers, which confirmed that crystallization of PIPOX did not take place.…”

Nanosized colloidal particles from thermosensitive poly(methoxydiethyleneglycol methacrylate)s in aqueous media

“…The distributions were invariably monomodal and relatively narrow (\0.1), corresponding to average hydrodynamic diameters (D h ) of mesoglobules of 163, 185, and 329 nm for PDEGMA-5K, PDEGMA-10K, and PDEGMA-15K, respectively (Table 3). Similar to other systems [2][3][4][10][11][12], the D h s of PDEGMA mesoglobules were found to increase with increasing molecular weight of the polymers. While for PETEGA polymers, for example, the effect of molecular weight within the range from 7,000 to 40,000 was not obvious [10], the striking result for PDEGMA is the substantial increase in dimensions within considerable narrower molecular weight interval.…”

“…For PNIPAm, below the overlapping polymer concentration, colloidal mesoglobules of spherical shape are reportedly formed [1,2]. Moreover, mesoglobules of low size dispersity and dimensions ranging from 50 to 200 nm can form even at higher polymer concentrations [3,4]. The size of mesoglobules could be effectively controlled by the polymer concentration and the rate of heating of the polymer solution.…”

“…The size of mesoglobules could be effectively controlled by the polymer concentration and the rate of heating of the polymer solution. In general, smaller aggregates are formed at lower concentrations and/or faster heating rates [3,4]. The presence of surfactants has also been reported to decrease the size of mesoglobules [5].…”