# A View on the Synthesis and Characterization of Porous Microspheres Containing Pyrrolidone Units
## 2 Materials and Methods
### Measurement Techniques  
The characterization of the synthesized copolymers was conducted using FTIR-ATR spectroscopy. The spectra were collected using a Bruker Tensor 27 FTIR spectrometer (Ettlingen, Germany). The spectral range was equal to 4000-600 cm\({}^{-1}\). Each spectrum was acquired with 16 scans at a resolution of 4 cm\({}^{-1}\). FTIR -ATR measurements were recorded using a diamond crystal.  
Elemental analysis of the synthesized copolymers was conducted using a Perkin-Elmer (Norwalk, CT, USA) CHN analyzer.  
The characterization of the porous structure of the analyzed materials was established on the basis of nitrogen adsorption/desorption measurements. They were made volumetrically with the use of an ASAP 2405N analyzer (Micromerities Corp., Norcross, GA, USA). Before measurement, the samples were outgassed at 110 \({}^{\circ}\)C for 2 h. The nitrogen isotherms were collected at 77 K. The specific surface area (\(S_{BET}\)), total pore volume (\(V\)), and pore size distribution (PSD) were determined on the basis of BET and BJH methods [40].  
The SEM imaging of the copolymers was conducted utilizing a Duall BeamTM, Quanta3D FEG microscope (FEI Company, Hillsboro, OR, USA). The size distribution of the copolymers was assessed using a Mastersizer Analyzer 2000 (Malvern Instruments Ltd., Malvern, UK).  
A Netzsch STA 449 F1 Jupiter thermal analyzer was utilized for the thermogravimetric (TG) measurements. The analyses were conducted in the temperature range 35-800 \({}^{\circ}\)C  
\begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**Copolymer**} & \multicolumn{3}{c}{**Molar Ratio of Monomers**} & \multicolumn{3}{c}{**Diluents/mL**} \\ \cline{2-6}  & **EGDMA** & **VP** & **GMA** & **Toluene** & **Decan-1-ol**ol**ol**ol** & **Dodecane** \\ \hline poly(NVP-_co_-EGDMA)\_1 & 1 & 1 & - & 22.5 & - & - \\ poly(NVP-_co_-EGDMA)\_2 & 1 & 1 & - & 19.1 & 3.4 & - \\ poly(NVP-_co_-EGDMA)\_3 & 1 & 1 & - & 11.25 & 11.25 & - \\ poly(NVP-_co_-EGDMA)\_4 & 1 & 1 & - & 19.1 & - & 3.4 \\ poly(NVP-_co_-EGDMA)\_5 & 1 & 1 & - & 11.25 & - & 11.25 \\ poly(NVP-_co_-EGDMA)\_6 & 1 & 2 & - & 22.5 & - & - \\ poly(NVP-_co_-EGDMA)\_7 & 1 & 3 & - & 22.5 & - & - \\ poly(NVP-_co_-EGDMA)\_8 & 1 & 4 & - & 22.5 & - & - \\ poly(GMA-_co_-EGDMA)\_1 & 1 & - & 1 & 22.5 & - & - \\ poly(GMA-_co_-EGDMA)\_2 & 2 & - & 1 & 22.5 & - & - \\ \hline \end{tabular}
\end{table}
Table 1: Specifications and experimental conditions for the microsphere synthesis.  
utilizing Al2O3 crucibles. An empty Al2O3 crucible, with a mass of approximately 160 mg, was utilized as a reference. The mass of the samples was approximately 10 mg. The TG curves were analyzed to determine the characteristic temperatures of T5%, T20%, and T50% mass losses. Consequently, on the basis of differential curves (DTG), the temperature corresponding to the maximum mass loss (Tmax) for each decomposition stage was assessed.  
A Dani GC 1000 gas chromatograph (Dani, Milan, Italy) was employed for the chromatographic measurements. It was equipped with a packed injector set at 210 \({}^{\circ}\)C, and a thermal conductivity detector (TCD) also maintained at 210 \({}^{\circ}\)C. The flow of the carrier gas (helium) was maintained at 50 mL/min. The samples were injected by hand with a 1 \(\upmu\)L syringe (SGE, North Melbourne, Australia). Measurements were performed at 140 \({}^{\circ}\)C and 200 \({}^{\circ}\)C.