# Reactive Polymer Composite Microparticles Based on Glycidyl Metacrylate and Magnetic Nanoparticles
## 2 Experimental Part
### Characterization  
The resin morphology was estimated using stereomicroscopes (Leica M205A, Leica Microsystems, GmbH, Wetzlar, Germany, equipped with a digital camera and focus stacking software and Motic SMZ-143, Motic, Germany, equipped with a digital camera) and a VEGA3 TESCAN scanning electron microscope (TESCAN Brno, Brno, Czech Republic) equipped with an X-ray energy dispersive (EDS) system. FTIR spectra were recorded using a Thermo Scientific Nicolet 8700 spectrometer (as KBr pallets) or a FTIR Nicolet iN10 MX microscope equipped with a micro compression diamond cell (Thermo Scientific, Waltham, MA, USA). Samples for the FTIR microscopy analyses were prepared by flattening polymer beads between a pair of diamond windows of the micro compression cell.  
The particle size distribution and average particle diameters were analyzed using dynamic light scattering (DLS) techniques. Zetasizer Nano ZS and Mastersizer 2000E instruments from Malvern Instruments Ltd. (Malvern, UK) were applied. The microparticle analyzer was equipped with a Hydro MU wet sample dispersion unit. The DLS measurements of particles were performed using isopropyl alcohol as a dispersive medium. The samples of the examined particles were sonicated for 15 min before each measurement.  
TGA analysis was performed using a METTLER TOLEDO TGA/DSC 1 analyzer (METTLER TOLEDO AG, Analytical, Schwerzenbach, Switzerland). Samples were heated from 25 to 600 \({}^{\circ}\)C (10 \({}^{\circ}\)C/min) in a nitrogen atmosphere (50 mL N\({}_{2}\)/min). The epoxy group content in the beads was determined using the modified Jay method [55]. The nitrogen content in the products was determined using the Kjeldahl method.  
To determine the swelling capacity of the obtained composite particles, approximately 0.2 g of samples of synthesized microparticles was placed in 2 mL syringes and swelled in a series of solvents or solvent mixed systems. Samples were washed with methanol between subsequent measurements. After complete swelling of the particles, excess solvent was removed using the syringe plunger, and then the mass occupied by the swollen polymers was read, and the weight gain per 1 g of dry polymers was calculated using the following formula:  
\[\mathrm{S}=\frac{\mathrm{m}_{\mathrm{k}}-\mathrm{m}_{\mathrm{p}}}{\rho\cdot \mathrm{m}_{\mathrm{p}}}\]  
where  
\(\mathrm{m}_{\mathrm{p}}\)--mass of dry polymer [g];  
\(\mathrm{m}_{\mathrm{k}}\)--mass of swollen polymer [g];  
\(\rho\)--solvent density [g/mL].  
The palladium content in the obtained composite microparticles was determined using an ICP-OES spectrometer. ICP OES analyses were performed at \(\lambda\) = 217.809 and 240.488 nm (Fe) and at 248.892 and 340.458 nm (Pd) using a Horiba Jobin Yvon Optima 2 ICP-OES spectrometer (Horiba, Jobin Yvon, France). Particle samples (\(\sim\)5-10 mg) were mineralized in nitric acid (69 wt.%, 5.0 mL) using a Plazmatronika Uni Claver II microwave mineralizer (Wroclaw, Poland).  
GC analyzes were performed using an Agilent 7890 GC chromatograph (Agilent, Palo Alto, CA, USA) with a split-splitless injector, a flame ionization detector, an auto-sampler, and a HP-5 capillary column. Analytical solutions were prepared by dissolving 20 mg samples taken from the reaction mixtures in 0.5 mL of tetrahydrofuran (THF). Nonane was used as a standard.