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1.
Int J Biol Macromol ; 239: 124318, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37015282

RESUMO

The objective of this project is to create a unique type of polymer known as an ion imprinted polymer (IIP) and a non-imprinted polymer (NIP) utilizing natural waste biosorbent materials. One example of this type of waste is Aloe vera, a plant with many medicinal uses that is grown globally. Aloe vera is considered one of the most valuable medicinal plants with a wide range of applications. Extracted Aloe vera was used as functional monomers for the first time to prepare new IIPs, epichlorohydrin, and Cu2+ ion as the cross-linking agent and template, respectively. The NIP was also synthesized for comparison, without the use of the Cu2+ salt. Following polymerization, the IIP particles were cleansed of template ions through a 0.1 M EDTA leaching process, resulting in the formation of cavities within the particles, these cavities in the polymer provide selective linking zones for these specific template ions. The synthesized IIPs were characterized using the most recent identification instruments. The experimental parameters for adsorption, such as pH of a solution, contact time, initial copper concentration, adsorbent dosage, and temperature have been optimized. The most effective conditions for metal adsorption onto the ionic imprinted polymer were found to be a pH of 8.0, a temperature of 30 °C, a concentration of 0.03 g/100 mL, and a contact time of 50 min. Based on the ANOVA statistical value, the adsorption of Cu2+ ion on IIP is significant with very low probability (p) values (<0.001). The Langmuir isotherm model and a second-order reaction were both used in the adsorption process. According to thermodynamic characteristics, Cu2+ adsorption over IIPs and NIP was an endothermic, spontaneous process. Compared to NIP, the imprinted polymer exhibits a significantly better capacity and selectivity for Cu2+ adsorption, the maximum removal percentage of IIPs and NIP was 96.02 % and 74.3 % respectively. Moreover, the research showed that ion imprinting can be a promising technique for preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metals (Co2+, Cd2+, Ni2+, Zn2+, Fe2+, and Pb2+) The most important point for this new Cu2+-IIPs was shown superior reusability up to 8 cycles with small decrees in uptake capability.


Assuntos
Aloe , Polímeros/química , Água/química , Cobre/química , Adsorção , Íons
2.
PLoS One ; 17(9): e0274123, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36084104

RESUMO

A new aldehyde 2,2'-[propane-1,3-diylbis(oxy)] dibenzaldehyde was synthesized from refluxing 2-hydroxy acetophenone and 2-hydroxy 1,3-dichloropropanean in an alcoholic medium. The compositions and properties of the new aldehyde compound were characterized by elemental analysis, FTIR, and nuclear magnetic resonance spectroscopy studies. The extracted chitosan was made to react with a new aldehyde to form a Schiff base by a suitable method. The effects of initial concentration of metal ions, exposure time, imine weight, and pH on the adsorption of Cu(II), Cr(III), and Zn(II) metal ions were examined. An adsorption batch experiment was conducted. The adsorption process followed a second-order reaction and Langmuir model with qe 25 mg/g, 121 mg/g, and 26.31 mg/g for Cu(II), Zn(II), and Cr(III) respectively. The Gibbs free energy showed a negative value and the adsorption/desorption tests provided a high value 5 times.


Assuntos
Quitosana , Metais Pesados , Poluentes Químicos da Água , Adsorção , Aldeídos , Quitosana/química , Concentração de Íons de Hidrogênio , Íons/química , Cinética , Metais Pesados/química , Bases de Schiff/química , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/química
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