Nanostructure of Poly(Acrylic Acid) Adsorption Layer on the Surface of Activated Carbon Obtained from Residue After Supercritical Extraction of Hops

M Wiśniewska; A Nosal-Wiercińska; I Ostolska; D Sternik; P Nowicki; R Pietrzak; A Bazan-Wozniak; O Goncharuk

doi:10.1186/s11671-016-1772-3

Nanostructure of Poly(Acrylic Acid) Adsorption Layer on the Surface of Activated Carbon Obtained from Residue After Supercritical Extraction of Hops

Nanoscale Res Lett. 2017 Dec;12(1):2. doi: 10.1186/s11671-016-1772-3. Epub 2017 Jan 3.

Authors

M Wiśniewska¹, A Nosal-Wiercińska², I Ostolska¹, D Sternik³, P Nowicki⁴, R Pietrzak⁴, A Bazan-Wozniak⁴, O Goncharuk⁵

Affiliations

¹ Department of Radiochemistry and Colloids Chemistry, Faculty of Chemistry, Maria Curie-Sklodowska University, M.Curie-Sklodowska Sq. 3, 20-031, Lublin, Poland.
² Department of Analytical Chemistry and Instrumental Analysis, Faculty of Chemistry, Maria Curie-Sklodowska University, M. Curie-Sklodowska Sq. 3, 20-031, Lublin, Poland.
³ Department of Physicochemistry of Solid Surface, Faculty of Chemistry, Maria Curie-Sklodowska University, M. Curie-Sklodowska Sq. 3, 20-031, Lublin, Poland.
⁴ Laboratory of Applied Chemistry, Faculty of Chemistry, Adam Mickiewicz University in Poznań, Umultowska Street 89b, 61-614, Poznań, Poland.
⁵ Chuiko Institute of Surface Chemistry, National Academy of Science of Ukraine, 17 General Naumov Street, Kiev, 03164, Ukraine. iscgoncharuk@meta.ua.

Abstract

The nanostructure of poly(acrylic acid) (PAA) adsorption layer on the surface of mesoporous-activated carbon HPA obtained by physical activation of residue after supercritical extraction of hops was characterized. This characterization has been done based on the analysis of determination of adsorbed polymer amount, surface charge density, and zeta potential of solid particles (without and in the PAA presence). The SEM, thermogravimetric, FTIR, and MS techniques have allowed one to examine the solid surface morphology and specify different kinds of HPA surface groups. The effects of solution pH, as well as polymer molecular weight and concentration, were studied. The obtained results indicated that the highest adsorption on the activated carbon surface was exhibited by PAA with lower molecular weight (i.e., 2000 Da) at pH 3. Under such conditions, polymeric adsorption layer is composed of nanosized PAA coils (slightly negatively charged) which are densely packed on the positive surface of HPA. Additionally, the adsorption of polymeric macromolecules into solid pores is possible.

Keywords: Electrokinetic properties; Mesoporous activated carbon; Nanostructure of adsorption layer; Physical activation; Poly(acrylic acid) adsorption.