Colloidal assembly of magnetic nanoparticles and polyelectrolytes by arrested electrostatic interaction

Auto-degradable and biocompatible superparamagnetic iron oxide nanoparticles/polypeptides colloidal polyion complexes with high density of magnetic material

“…That allows the formation of dense colloidal clusters instead of formation of a fractal macroscopic precipitate. [31] As concentration and therefore decrease, wt% at t = 337 h, respectively. A scanning electron micrograph of a γ-Fe 2 O 3 -PAA/pSe PIC obtained at c = 6 × 10 -5 wt% 300 h after mixing is presented in Figure 2b.…”

“…[31,52] Thus, among the attractive intermolecular interactions, long-range van der Waals forces are not sufficient to trigger co-assembly ; short-range Coulombic forces are required. [31] An interesting phenomenon is the delayed aggregation of nanoparticles and pSe chains at c = 6 × 10 -4 wt% (Figure 2a, dark red symbols). Indeed, the D H of the mixture remains at the constant value of single nanoparticles during 45 h before it starts to increase.…”

“…Its irregular shape and nano-structure are interpreted as resulting from an inhomogeneous assembly of small and dense aggregates which suggest a diffusion-limited growth mechanism. [31] The image also shows numerous single nanoparticles which indicate a low degree of interaction.…”

“…In particular, influence of the charge ratio in reactive species Z (see expected. [31] Instead, spherical morphology and dense nanostructure of γ-Fe 2 O 3 -PAA/pSe-b-PEG PICs made at Z ≥ 1 indicate that they were grown by nucleation and growth process, [28] during which diblock copolymers were regulating during AMF exposure. [58] The Specific Absorption Rate (SAR) corresponds to the generated thermal power per unit of mass of iron oxide.…”

“…[28][29][30] Entropically driven self-assembly allows synthesis route as simple as direct mixing of the oppositely charged species. [31] Dense PICs can be obtained by self-assembly of poly(acrylic acid) coated sub-10 nm maghemite nanoparticles (γ-Fe 2 O 3 -PAA) and either cationic homopolyelectrolytes, [30,31] or cationic-block-neutral copolymer. Utilization of diblock copolymers helps to obtain colloidally stable spherical and monodisperse PICs.…”