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Zdravković, Aleksandar 1987-
Sinteza, karakterizacija i primena hidrogelova na bazi N-izopropilakrilamida i anjonskih komonomera za uklanjanje hroma, mangana i olova iz vodenih rastvora
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Academic metadata
Doktorska disertacija
Tehničko-tehnološke nauke
Univerzitet u Nišu
Tehnološki fakultet
Katedra za hemijske nauke
Other Theses Metadata
Synthesis, characterization and application of hydrogels based on N-isopropylacrylamide and anionic comonomers for chromium, manganese and lead removal from aqueous solutions
[A. S. Zdravković]
[12], 149 listova
Biografija autora: list 139;
Bibliografija: listovi 140-146.
Datum odbrane: 24.09.2019.
Chemistry and chemical technology
Nikolić, Ljubiša 1963- (mentor)
Džunuzović, Enis 1971- (član komisije)
Cakić, Suzana 1967- (predsednik komisije)
Nikolić, Vesna 1965- (član komisije)
In this doctoral dissertation, the hydrogels sensitive to temperature and pH
changes based on N-isopropylacrylamide (NIPAM) and anionic
comonomers (acrylic acid, AA, and methacrylic acid, MAA) were
synthesized and investigated as adsorbent materials for removal of Cr(VI),
Mn(II) and Pb(II) ions from aqueous solutions.
The hydrogels were synthesized by radical polymerization process by
varying the content of comonomer and crosslinker. The obtained poly(Nisopropylacrylamide-
co-acrylic acid) (p(NIPAM/AA)) and poly(Nisopropylacrylamide-
co-methacrylic acid) (p(NIPAM/MAA)) hydrogels
were characterized using the following methods: Fourier transform
infrared spectroscopy (FTIR), scanning electron microscopy (SEM),
X-ray diffraction (XRD), high pressure liquid chromatography (HPLC)
and determining the swelling intensity in aqueous solutions of different
temperatures and pH values. Kinetics of hydrogel swelling before and
after the lyophilization process, as well as swelling reversibility through 3
alternate swell-shrink cycles under the influence of temperature were
investigated. A full three-level experimental design was applied in order
to describe the swelling of synthesized hydrogels as a function of
temperature, pH value and crosslinker content by a mathematical model.
Characterization of p(NIPAM/AA) and p(NIPAM/MAA) hydrogels with
adsorbed metal ions was performed by FTIR and SEM method. Heavy
metal ions in the structure of hydrogels were identified by energydispersive
X-ray spectroscopy (EDX). The influence of pH, temperature,
contact time and initial concentration of heavy metals on adsorption
capacity of hydrogels was investigated.
The kinetic and equilibrium data match best to the pseudo-second order
model and Langmuir adsorption isotherm. Based on the thermodynamic
results, it has been concluded that the adsorption of Cr(VI), Mn(II) and
Pb(II) ions from aqueous solutions onto hydrogels was spontaneous and
exothermic process.
The adsorption capacity of p(NIPAM/AA) and p(NIPAM/MAA)
hydrogels for investigated metal ions decreases in the following order:
Pb(II)>Cr(VI)>Mn(II).
Hydrogels based on NIPAM and AA or MAA are considered to be
suitable adsorbents for removal of Cr(VI), Mn(II) and Pb(II) ions from
aqueous solutions, due to high efficiency in the temperature range from 25
to 45 °C.
hydrogel, swelling, diffusion, adsorption, heavy metal, kinetics
544.773.432:66.095.26]:502/504(043.3)
T 390
Serbian
534136470
Tekst
In this doctoral dissertation, the hydrogels sensitive to temperature and pH
changes based on N-isopropylacrylamide (NIPAM) and anionic
comonomers (acrylic acid, AA, and methacrylic acid, MAA) were
synthesized and investigated as adsorbent materials for removal of Cr(VI),
Mn(II) and Pb(II) ions from aqueous solutions.
The hydrogels were synthesized by radical polymerization process by
varying the content of comonomer and crosslinker. The obtained poly(Nisopropylacrylamide-
co-acrylic acid) (p(NIPAM/AA)) and poly(Nisopropylacrylamide-
co-methacrylic acid) (p(NIPAM/MAA)) hydrogels
were characterized using the following methods: Fourier transform
infrared spectroscopy (FTIR), scanning electron microscopy (SEM),
X-ray diffraction (XRD), high pressure liquid chromatography (HPLC)
and determining the swelling intensity in aqueous solutions of different
temperatures and pH values. Kinetics of hydrogel swelling before and
after the lyophilization process, as well as swelling reversibility through 3
alternate swell-shrink cycles under the influence of temperature were
investigated. A full three-level experimental design was applied in order
to describe the swelling of synthesized hydrogels as a function of
temperature, pH value and crosslinker content by a mathematical model.
Characterization of p(NIPAM/AA) and p(NIPAM/MAA) hydrogels with
adsorbed metal ions was performed by FTIR and SEM method. Heavy
metal ions in the structure of hydrogels were identified by energydispersive
X-ray spectroscopy (EDX). The influence of pH, temperature,
contact time and initial concentration of heavy metals on adsorption
capacity of hydrogels was investigated.
The kinetic and equilibrium data match best to the pseudo-second order
model and Langmuir adsorption isotherm. Based on the thermodynamic
results, it has been concluded that the adsorption of Cr(VI), Mn(II) and
Pb(II) ions from aqueous solutions onto hydrogels was spontaneous and
exothermic process.
The adsorption capacity of p(NIPAM/AA) and p(NIPAM/MAA)
hydrogels for investigated metal ions decreases in the following order:
Pb(II)>Cr(VI)>Mn(II).
Hydrogels based on NIPAM and AA or MAA are considered to be
suitable adsorbents for removal of Cr(VI), Mn(II) and Pb(II) ions from
aqueous solutions, due to high efficiency in the temperature range from 25
to 45 °C.