Nanocomposites and nanomaterials

Magnetic nanocomposite sorbents on saponite base
O.V. Makarchuk, T.A. Dontsova
National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Prospect Victory, 37, Kyiv-03056, Ukraine. 
E-mail: xtfhn9207@ukr.net, dontsova@ua.fm

Adsorption technologies are widely used in purification processes. Creation of new effective and cheap sorbents is very relevant issue. Among low-cost sorbents the saponite clay is attracted much attention. Modification of clay mineral by magnetite ensures rapid removal of spent sorbent by magnetic separation [1]. The aim of this work was to create the magnetic nanocomposite sorbents based on saponite (MCSp) and to investigate their porous structure.
An effective magnetic nanocomposite sorbents based on saponite containing Fe3O4 in amount of 2 % (MCSp-2), 4 % (MCSp-4), 7 % (MCSp-7) and 10 % (MCSp-10) were received by impregnation method [1]. Structural and adsorption characteristics were measured with the Quantachrome Autosorb (Nova 2200e) by the method of physical low temperature adsorption of nitrogen (Table 1).

Table 1 ‒ Characteristics of nanocomposite and saponite porous structure
Characteristic	Saponite	MCSp-2	MCSp-4	MCSp-7	MCSp-10	
Specific surface area S, m2/g	35	53	56	54	69	
Micropores volume Vmicro, ml/g (%)	0,016
(12,9)	0,009
(6,2)	0,009
(6,3)	0,006
(4,4)	−	
Mesopore volume Vmeso, ml/g (%)	0,031
(24,7)	0,111
(77,0)	0,114
(78,2)	0,121
(82,7)	0,288
(94,1)	
Average pore diameter d, nm	12,0	10,4	10,0	10,6	17,7	
Average mesopore diameter d, nm	8,2	4,3	4,4	4,3	12,6	

Consequently, mesoporous magnetic nanocomposite sorbents were obtained by modification of saponite by the nanosized magnetite. Since the specific surface area of MCSp is in twice higher relative to saponite, so their application in adsorption purification processes will be more effective.

1.	Makarchuk O. et al. Magnetic mineral nanocomposite sorbents for wastewater treatment // Journal of Nanomaterials. - 2017. - 2017. – P. 1-7.