# Polyacrylonitrile Nanofibers Containing Viroblock as Promising Material for Protective Clothing
## 3 Results and Discussion
### Chemical Interactions Analysis  
FTIR spectra were used to analyze the chemical groups of the prepared electrospun nanofibers. Figure 3 shows the FTIR spectra of pure PAN nanofibers, 0.5% VB-loaded PAN nanofibers, 1% VB-loaded PAN nanofibers, 1.5% VB-loaded PAN nanofibers, and 2% VB-loaded PAN nanofibers. The spectral range varies from 1000 cm\({}^{-1}\) to 3500 cm\({}^{-1}\). In all spectra, there was broadband appearing in the range of 3000 cm\({}^{-1}\) to 3500 cm\({}^{-1}\) due to the presence of -OH group, belonging to moisture absorbed. In all spectra, the vibrational peak appeared at 2242 cm\({}^{-1}\) ascribed to the presence of the nitrile (-C\(\equiv\)N) functional group. In the case of pure PAN electrospun nanofibers, the peaks that appeared at 2884 cm\({}^{-1}\) and 2943 cm\({}^{-1}\) indicated the stretching and bending of the methyl functional group [17,18]. The peaks present at 1732 cm\({}^{-1}\) and 1453 cm\({}^{-1}\) corresponded to the carboxylic functional group of PAN. The peak that emerged at 1170 cm\({}^{-1}\) was attributed to (-C-O) stretching due to the formation of aliphatic ether. The peaks that appeared at 1224 cm\({}^{-1}\), 1360 cm\({}^{-1}\), and 1593 cm\({}^{-1}\) were ascribed to the (-C-O) stretching and -OH bending, respectively [14,19]. The other four spectra were similar to that of the PAN spectrum with little variation in peak position. This is because the silver nanoparticles and other compounds that were present in the VB integrated into PAN, forming the composite material. In the case of 0.5% VB-loaded PAN electrospun nanofibers, a characteristic peak appeared at 1181 cm\({}^{-1}\) corresponding to C-O stretching, the medium peak appeared at 1422 cm\({}^{-1}\) representing the -O-H bending, and the peak at 1450 cm\({}^{-1}\) was due to the -C-H bending. The peak at 1597 cm\({}^{-1}\) was  
Figure 2: Diameter distribution curve: (**A**) pure PAN, (**B**) 0.5% VB/PAN, (**C**) 1% VB/PAN, (**D**) 1.5% VB/PAN, (**E**) 2% VB/PAN.  
attributed to -N-H bending due to the formation of the amine group [20]. The stretching of 1656 cm\({}^{-1}\) C=C was due to the conjugated alkene. The peak at 1728 cm\({}^{-1}\) represented the carboxylic functional group as a result of the oxidation of PAN reacting with VB. In the case of 1% VB-loaded PAN electrospun nanofibers, the characteristic peaks appear at 1174 cm\({}^{-1}\) and 1197 cm\({}^{-1}\), corresponding to -C-O stretching. The peaks that appeared at 1452 cm\({}^{-1}\), 2882 cm\({}^{-1}\), and 2914 cm\({}^{-1}\) represented -C-H stretching of methyl functional group from VB. In the spectrum of 1% VB-loaded PAN, the medium peak emerged at 1391 cm\({}^{-1}\), corresponding to -C-N stretching, which was due to aromatic amine of VB. The peaks at 1653 cm\({}^{-1}\) and 1731 cm\({}^{-1}\) were ascribed to the carboxylic functional groups [21]. In the case of 1.5% VB-loaded PAN electrospun nanofibers, the peaks present at 1073 cm\({}^{-1}\) and 1172 cm\({}^{-1}\) corresponded to -C-O stretching of VB. The peak that emerged at 1453 cm\({}^{-1}\) was due to the -CH methyl functional group. The peak at 1733 cm\({}^{-1}\) represented the carboxylic functional group of oxidized PAN. A similar spectrum was obtained in the case of 2% VB-loaded PAN electrospun nanofibers and a shift in characteristic peaks was also observed. The peaks that appeared at 1042 cm\({}^{-1}\), 1122 cm\({}^{-1}\), and 1170 cm\({}^{-1}\) were caused by the -C-O stretching of the secondary alcohol and aliphatic ether, respectively. The formation of phenol was demonstrated by the -OH bending, observed in the spectrum at 1316 cm\({}^{-1}\) and 1415 cm\({}^{-1}\). -CH bending was observed at 1455 cm\({}^{-1}\), 2852 cm\({}^{-1}\), and 2922 cm\({}^{-1}\) due to the methyl functional group of VB. The peak at 1738 cm\({}^{-1}\) was ascribed to the carboxylic functional group of oxidized PAN [22; 23].