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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(10): e0275330, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36201492

RESUMO

The use of macrocyclic compounds to remove organic dyes is fascinating because they have a wide surface area range and can be used for different things. new (14E, 34E)-7-Hydroxy-7, 8, 22, 23, 24, 25, 26, 27-Octahydro-6H, 16H, 33H Tetrabenzo[f,k,u,z][1,5,13,20]Tetraoxacycloheptacosine-16,33-Dione (HOTTD) was obtained by a simple high-dilution method, and characterized by FTIR, 1H-NMR, FESEM, EDX, and XRD. It worked well in removing organic dyes from aqueous solutions. Contact time, pH, dosage, initial concentration and temperature were studied. The optimum conditions were achieved by using 20 mg/L dye concentration, 50 mg dose of adsorbent and pH 9.0 at room temperature. The adsorption process was remarkably fast and reached equilibrium within 10 min for both Brilliant Green and Malachite Green while 70 min for Safranin. The batch adsorption experiments followed a pseudo 2nd order and Langmuir model with maximum adsorption capacity 19.26 mg/g, 18.28 mg/g, and 14.35 mg/g for Brilliant Green, Malachite green and Safranin respectively. The process was endothermic and spontaneous in nature. Adsorbent regeneration test provides an excellent value 5 times.


Assuntos
Corantes , Poluentes Químicos da Água , Adsorção , Corantes/química , Concentração de Íons de Hidrogênio , Cinética , Compostos de Amônio Quaternário , Corantes de Rosanilina/química , Soluções , Termodinâmica , Água , Poluentes Químicos da Água/química
3.
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
4.
Environ Technol ; : 1-13, 2022 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-35306975

RESUMO

The new adsorbent was prepared by mixing cellulose with dicyclohexyl-18- crown-6 via microwave irradiation method and it was used to remove lead ions from aqueous solution. In contrast to the traditional way (in which grafted polymers are produced by using chemical-free radical producers), this method is rapid, reproducible, and gives a high-quality product. Different physicochemical techniques such as FTIR, SEM, and XRD and TGA were used for the characterization of the produced adsorbent. Based on the ANOVA statistical value, the adsorption of Pb2+ ion onto grafted cellulose has been found to be significant, with very low probability (p) values (<0.001). The pH and initial concentration were observed to be the most significant factors that affected the Pb2+ ion removal from the analysis of variance. Pseudo-second-order and Langmuir equations were applied to the adsorption of Pb2+ ion and under the optimized conditions, the maximum absorption capacity in modified cellulose of Pb2+ was 58.3 mg/g. Various factors which affect metal ion adsorption, including temperature, power of hydrogen, shaking time, adsorbent quantity, and metal ions concentration were studied. More importantly, the adsorbent could be reused by using 0.1 M nitric acid.

5.
Spectrochim Acta A Mol Biomol Spectrosc ; 222: 117261, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31228859

RESUMO

Two ratio derivative spectrophotometric methods were performed for the simultaneous analysis of metformin hydrochloride, empagliflozine, linagliptin, and pioglitazone hydrochloride in their synthetic mixtures without prior chemical separation. The drugs are approved for the treatment of type 2 diabetes. Despite the various advances in the management of diabetes, it remains to be the major cause of disability and morbidity, including blindness, amputation, heart disease, peripheral neuropathy, and kidney disease. These techniques consisted of several steps using ratio and derivative spectra. The absorption spectra of the mentioned drugs were recorded in the range of 200-350 nm, which have the concentration ranges of 1.0-10, 2.5-30, 5.0-40, and 2.5-30 µg mL-1 for metformin hydrochloride, empagliflozine, linagliptin, and pioglitazone hydrochloride, respectively, using zero-order spectra. The mean centring of ratio spectra combined with triple divisor were measured at the amplitude values 242, 256, 272 and 296 nm for metformin hydrochloride, empagliflozine, linagliptin and pioglitazone hydrochloride, respectively; the derivative ratio spectra-zero crossing quantifies the amplitude value of the analytical signal at 234, 244, 260 and 280 nm for metformin hydrochloride, empagliflozine, linagliptin and pioglitazone hydrochloride, respectively. The method was validated according to the ICH guidelines, accuracy, precision and repeatability were found to be within the acceptable limits. Finally, statistical comparisons between the proposed methods and with the reported methods with respect to accuracy and precision show that no significant difference was found by using Student's t-test, the F-test and one-way ANOVA.


Assuntos
Compostos Benzidrílicos/análise , Glucosídeos/análise , Hipoglicemiantes/análise , Linagliptina/análise , Metformina/análise , Pioglitazona/análise , Algoritmos , Análise de Variância , Espectrofotometria Ultravioleta/métodos , Comprimidos
6.
J Hazard Mater ; 343: 324-331, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-28992570

RESUMO

We have developed a simple one-step method to synthesize novel supramolecular polysaccharide composite from cellulose (CEL) and dibenzo-18-crown 6 using ceric ammonium nitrate as initiator. The [CEL+DB18C6] composites obtained retain properties of their components, namely superior mechanical strength (from CEL), excellent adsorption capability for heavy metal ions from DB18C6. More importantly, the [CEL+DB18C6] composites exhibit truly supramolecular properties. By itself CEL and DB18C6 can adsorb heavy metals. However, adsorption capability of the composite was substantially and synergistically enhanced by adding DB18C6 to CEL. That is, the removal percentage value for Cd2+, Zn2+, Ni2+, Pb2+ and Cu2+ by [CEL+DB18C6] composites are much higher than removal percentage values of individual CEL and DB18C6 composites. It seems that DB18C6 synergistically interact with CEL to form more stable complexes with heavy metals, and as a consequence, the [CEL+DB18C6] composite can adsorb relatively larger amount heavy metals. The adsorption parameters, such as pH, adsorbent dose, contact time, initial metal ion concentration and temperature were optimized. Desorption studies revealed that the regeneration of modified cellulose saturated with these metallic ions depends on the type and concentration of the regenerating solution (NH4Cl, HNO3, NaCl and CaCl2).

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