"Nanocomposites and nanomaterials"

Synthesis of hybrid silica materials with ethylenediamine functional groups
Tomina V.V.1, Stolyarchuk N.V.1, Vaclavikova M.2, Melnyk I.V.1,2 
1 Chuiko Institute of Surface Chemistry of NAS of Ukraine. General Naumov str., 17, 03164 Kyiv, Ukraine.
E-mail: v.v.tomina@gmail.com
2 Institute of Geotechnics SAS. Watsonova str., 45, 04001 Kosice, Slovak Republic. 

Earlier we synthesized hybrid silica supports with amino groups for incorporating luminescent complexes of rare earth metals [1,2]. To continue the previous research and to increase the number of the surface adsorption centers, we decided to use silane with ethylenediamine functional groups (N-[3-(Trimethoxysilyl)propyl]ethylenediamine, TMPED). The synthesis was conducted via one-pot modified Stober method using TEOS and BTESE as structure forming agents. To analyze the influence of the location of alkyl radical on the properties of the materials, we also synthesized bifunctional SiO2@Prop@NHNH2 sample. These silica materials were analyzed with a range of methods, including SEM, IR spectroscopy, CHNS analysis, N2 adsorption/desorption isotherms. They contain 1.5-3.5 mmol/g groups and their structural properties are shown in Table 1.
Table 1 Characteristics of the samples
Sample	Ratio of silanes	SBET, m2/g	Vs, cm3/g	A (Eu3+)
mmol/g	
SiO2@NHNH2
SiO2/ NH(CH2)2NH2	3/1
TEOS/ TMPED	427	0.51	1.03	
SiO2@Prop@NHNH2
SiO2/(CH2)2CH3/ NH(CH2)2NH2	3/0.5/0.5
TEOS/ PTES/ TMPED	367	1.03	0.48	
bisE@NHNH2
≡Si–C2H4–Si≡/ NH(CH2)2NH2	1/1
BTESE/ TMPED	12	-	1.16	
The authors are grateful to the project VEGA 2/0156/19 and joint Ukrainian-Lithuanian r&d project (М/ 8 -2019).

1.	Tomina V.V., et.al. // Abstract Book of “NANO-2018”, 27 - 30 August, Kyiv, Ukraine, p. 93
2.	Stolyarchuk N.V., et.al. // Proceedings of «Chemistry, physics and technology of surface» 15 - 17 May, 2019, Kyiv, Ukraine, p. 181