Surfactant-Free Miniemulsion Polymerization as a Simple Synthetic Route to a Successful Encapsulation of Magnetite Nanoparticles

Abstract

Due to the existing interest in new hybrid particles in the colloidal range based on both magnetic and polymeric materials for applications in biotechnological fields, this work is focused on the preparation of magnetic polymer nanoparticles (MPNPs) by a single-step miniemulsion process developed to achieve better control of the morphology of the magnetic nanocomposite particles. MPNPs are prepared by surfactant-free miniemulsion polymerization using styrene (St) as a monomer, hexadecane (HD) as a hydrophobe, and potassium persulfate (KPS) as an initiator in the presence of oleic acid (OA)-modified magnetite nanoparticles. The effect of the type of cross-linker used [divinylbenzene (DVB) and bis[2-(methacryloyloxy)ethyl] phosphate (BMEP)] together with the effect of the amount of an aid stabilizer (dextran) on size, particle size distribution (PSD), and morphology of the hybrid nanoparticles synthesized is analyzed in detail. The mixture of different surface modifiers produces hybrid nanocolloids with various morphologies: from a typical core-shell composed by a magnetite core surrounded by a polymer shell to a homogeneously distributed morphology where the magnetite is uniformly distributed throughout the entire nanocomposite.

Evolution of particle morphology during the synthesis of hybrid acrylic/CeO2 nanocomposites by miniemulsion polymerization

“…The cross-sections clearly show that some aggregates are only visible at higher Z values; namely, in the upper part of the polymer particles (e.g., aggregates 1-3 and 5), others are only distinguishable in low Z values, in the lower part of the particles (e.g. aggregates [6][7][8], and others are surrounded by polymer above and below (see aggregates [9][10][11] or did occupy almost the whole height of the particle (aggregates 12 and 13). Also noticeable is that some polymer particles are not visible at Z 5 60 nm, which means that their size is smaller.…”

Adding magnetic ionic liquid monomers to the emulsion polymerization tool-box: Towards polymer latexes and coatings with new properties

“…It is worth to remember that the classical method to introduce magnetic properties to polymer latexes involves the encapsulation of FeOx ferrite nanoparticles. [47][48][49][50][51][52][53] The method involves the preparation in a previous step of an FeOx magnetic nanoparticle, its surface modification, and the subsequent inclusion in the latex formulation during or prior to the emulsion polymerization process being many times necessary to provide energy to the coarse emulsion to produce hybrid nanoemulsion droplets that are polymerized (so-called minemulsion polymerization). Interestingly, the introduction of magnetic ionic liquid monomers presented here represents a simpler and less time-consuming strategy than the classical ferrite method.…”

Synthesis of Magnetic Polystyrene Nanoparticles Using Amphiphilic Ionic Liquid Stabilized RAFT Mediated Miniemulsion Polymerization

“…In order to disperse MNP in styrene, hydrophobization of the surface of MNP by OA was performed using the coprecipitation method. 20 The content of OA on the MNP surface was investigated by TGA analysis, as shown in Figure 2a. Considering the residue in the TGA curve as the weight fraction of the inorganic substance (here MNP), the content of OA was estimated to be about 22 wt %.…”

“…Synthesis of Oleic Acid Coated MNP Using the Coprecipitation Method. OA coated MNP were synthesized according to the coprecipitation method followed by Focarda et al 20 with a little modification. Briefly, 10.8 g of FeCl 3 ·6H 2 O and 3.9 g of FeCl 2 ·4H 2 O were dissolved in 200 mL of deionized water.…”