## 3 Results
### Sorption Properties  
Breakthrough time results for the developed variants of nonwoven zeolite and silica composites challenged with ammonia, cyclohexane, and acetone are presented in Figures 7-9, respectively. The obtained results show that the developed variants of nonwoven zeolite and silica composites selectively adsorb the vapors of volatile compounds. The longest breakthrough time against ammonia vapors (more than 6 min) at 18.7 ppm was found for the nonwoven composite containing the mesoporous silica material PPQ + MCM-41, while the other composites incorporating zeolite, whether modified or not, practically did not exhibit protective properties against this compound (Figure 7). These results are in accordance with the literature data [33] as interactions occurring between modified zeolites and ammonia effectively improve their  
Figure 6: SEM photomicrograph: (**a**) Molecular sieve SM, (**b**) nonwoven composite with SM (magnification: a—30.00k, b—2.00k). Figure 7: Breakthrough time for nonwoven zeolite and silica composites challenged with ammonia at MAC = 18.7 ppm. ionic conductivity. In addition, elevated temperature accelerates ammonia adsorption/desorption kinetics, thus decreasing the adsorption capacity of zeolites. The reaction time was 1 min for the composite containing mesoporous silica material modified with HDTMA, 2 min for the composite with the molecular sieve SM, and more than 2 min for the one with the molecular sieve SM 4A, in relation to the reference sample. The longest breakthrough time against ammonia vapors was obtained for the mesoporous silica material characterized by a large specific surface area (953.30 m\({}^{2}\)/g) and the greatest pore volume among the tested materials (0.85 cm\({}^{3}\)/g). These results are consistent with other reports [34; 35; 36]. Materials characterized by very high specific surface areas, containing pores of various shapes and sizes throughout their volume, ensure better contact between the active sites on their surface with adsorbate particles. There is a close relationship between the size of the specific area and the pore size. Figure 8: Breakthrough time for nonwoven zeolite and silica composites challenged with cyclohexane at MAC = 81 ppm. Figure 9: Breakthrough time for nonwoven zeolite and silica composites challenged with acetone at MAC = 235 ppm. In the case of cyclohexane vapors at a concentration of 81 ppm, the nonwoven composite containing zeolite Na-A HDTMA revealed the maximum penetration of the test substance after 1 min, the composite containing zeolite Na-P1 after 1.5 min, and composites with MCM-41 HDTMA, Na-A, and the molecular sieve SM after 2 min. The longest reaction time to cyclohexane vapors, more than 2.5 min, was found for the composite containing zeolite Na-P1 HDTMA (Figure 8). Thus, zeolite modification led to a longer breakthrough time against cyclohexane. Finally, the longest breakthrough time against acetone vapors (more than 11 min) at 235 ppm was found for the nonwoven composite containing the molecular sieve SM (zeolite ZSM-5), as shown in Figure 9. The application of the molecular sieve SM 4A resulted in 232 ppm downstream of the sample after 6 min. In turn, after 5 min, that concentration ranged from 200 ppm to 220 ppm for the zeolite composite PPQ + Na-P1 HDTMA and the silica composites PPQ + MCM-41 and PPQ + MCM-41 HDTMA. The composite with zeolite Na-A exhibited a downstream concentration of acetone vapors of 200 ppm after 6 min. This means that the composite with the longest breakthrough time contained the molecular sieve SM, characterized by a specific surface area of 352.6 m\({}^{2}\)/g at a pore volume of 0.13 cm\({}^{3}\)/g. The following (Table 3) is a presented summary of data obtained for the assessment of the action of adsorbents used to remove ammonia, acetone, and cyclohexane from the air.