Study on Adsorption and Aggregation in the Mixed System of Polyacrylamide, Cu(II) Ions and Innovative Carbon-Silica Composite.

Katarzyna Szewczuk-Karpisz,Mariia Galaburda,Viktor M Bogatyrov,Zofia Sokołowska

doi:10.3390/polym12040961

Katarzyna Szewczuk-Karpisz, Mariia Galaburda + Show 2 more

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https://doi.org/10.3390/polym12040961

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Abstract

The paper presents an original study on adsorption and aggregation phenomena in a mixed system consisting of a macromolecular compound, heavy metal ions and an innovative adsorbent. The authors used ionic polyacrylamides (PAM), Cu(II) ions and carbon–silica composite (C-SiO2) in the experiments. Such a system has not yet been described in the literature and therefore, the article is of significant novelty and great importance. The composite was prepared by mixing phenol–formaldehyde resin with silica and pyrolysis at 800 °C. The adsorbed amounts of Cu(II) ions and PAM were determined spectrophotometrically. C-SiO2 was characterized using potentiometric titration, microelecrophoresis and Fourier Transform Infrared Spectroscopy (FTIR) analysis. In turn, the C-SiO2 aggregation was established turbidimetrically as well as using a particle size analyzer. The obtained results indicated that both Cu(II) ions and ionic polyacrylamide were adsorbed on the composite surface at pH 6. The highest noted adsorbed amounts were 9.8 mg/g for Cu(II) and 35.72 mg/g for CT PAM-25%. Cu(II) ions increased the anionic PAM adsorbed and reduced the cationic PAM one. The adsorption of anionic PAM (50 ppm) stimulated the solid aggregation significantly. What is more, Cu(II) ions enhanced this process. The size of particles/aggregates formed without additives equaled 0.44 μm, whereas in the mixed Cu(II)/AN PAM system, they were even at 1.04 μm.

Highlights

Adsorption is one of the main surface phenomena occurring in many physical, chemical and biological systems, both natural and artificial [1]
For the initial PAM concentration 100 ppm, the measured adsorbed amounts were as follows: 3.45 mg/g for anionic polyacrylamides (AN PAM)-12% (6.9% of the ions were the measured adsorbed amounts were as follows: 3.45 mg/g for AN PAM-12% (6.9% of the ions were adsorbed), 4.62 mg/g (9.14%) for AN PAM-40%, 26.46 mg/g (52.92%) for CT PAM-15% and 35.72 mg/g adsorbed), 4.62 mg/g (9.14%) for AN PAM-40%, 26.46 mg/g (52.92%) for CT PAM-15% and 35.72 (71.16%) for CT PAM-25%
The adsorption measurements showed that at pH 6 all types of polyacrylamide were adsorbed on the composite surface

Summary

Introduction

Adsorption is one of the main surface phenomena occurring in many physical, chemical and biological systems, both natural and artificial [1]. This process is commonly applied in industry and research. Adsorption is of great importance in implantology. It decides whether the implant will be accepted or rejected by the body [2]. This process is significant in environmental protection. Adsorption is applied in various types of catalysts [7]

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