Nanocomposites and nanomaterials

Porous spherical silica particles with N-containing surface functions for heavy metal ions removal 
Stolyarchuk N.V.1, Tomina V.V.1, Dudarko O.A.1, Melnyk I.V.1,2
1 Chuiko Institute of Surface Chemistry of NAS of Ukraine, General Naumov 17, Kyiv-03164, Ukraine.
E-mail: stonata@ukr.net
2 Institute of Geotechnics of SAS, Watsonova 45, Kosice-04001, Slovak Republic.

Cu and Ni, as well as many heavy metals are considered major toxic pollutants of water basins due to their ability to accumulate in living organisms, causing various health hazards. Organosilica compounds with complexing amine-containing groups proved to be effective adsorbents of such ions [1]. Therefore, polyorganosiloxane spherical materials with a well-developed porous structure and high content of active centers were synthesized (Table 1).
Table 1. Properties and static sorption capacities (SSC) of the samples
Sample	Ratio	SBET, 
m2/g	Cf.g, mmol/g	SSC, mmol/g	
				Ni(II)	Cu(II)	
SiO2/-(CH2)3NH(CH2)2NH2	3/1	427	2.91	0.59	1.06	
SiO2/-(CH2)3NH(CH2)2NH2	6/1	400	1.95	0.27	1.79	
≡Si-C2H4-Si≡/-(CH2)3NH(CH2)2NH2	4/1	338	1.50	0.24	0.69	
≡Si-C6H4-Si≡/-(CH2)3NH(CH2)2NH2	4/1	408	1.32	0.34	0.58	
≡Si-C6H4-Si≡/-(CH2)3NH(CH2)2NH(CH2)2 NH2	2/1	397	1.51	0.97	0.70	
≡Si-C6H4-Si≡/-(CH2)3NH(CH2)2NH(CH2)2 NH2	4/1	438	1.35	0.34	0.69	
The sorption experiments on the removal of Cu2+ and Ni2+ were conducted under the conditions of pH = 5 and contact time of 24 h. Regarding their SSC values (Table 1), the produced di(tri)amino silica samples may be of interest for further application as adsorbents in water treatment.
The research is funded by project APVV-19-0302 and the joint Ukraine-Indian Republic R&D project “Creation of novel organic-inorganic hybrid materials as sorbents for wastewater treatment from heavy metal ions” (2019-2021).
1.	Tomina V.V., et al. Surface and structure design of aminosilica nanoparticles for multifunctional applications: adsorption and antimicrobial studies // Biocompatible Hybrid Oxide Nanoparticles for Human Health: From Synthesis to Applications (ISBN 9780128158753).- Elsevier, 2019.-P. 15-31