Research Article
Synthesis of Copper: 2-Anisidine: Cyclodextrin Nanomaterials and Characterization of 2-Anisidine–Cyclodextrin Inclusion Complexes at Various pH Conditions
Issue:
Volume 14, Issue 2, April 2026
Pages:
38-48
Received:
11 March 2026
Accepted:
23 March 2026
Published:
10 April 2026
Abstract: Absorption, emission, time resolved fluorescence spectra and molecular modelling of 2-anisidine (2AS) with α-CD and β-CD in pH~2, pH~7 and pH~11 solutions were examined. Cu: 2AS: CD nanomaterials were investigated by SEM, DSC, FTIR, XRD and 1H NMR techniques. The absorption and emission maxima and spectral shape of 2AS in all the pH solutions and solvents are different from each other. 2AS gave a single broad emission spectrum in all the solvents while dual emission noticed at pH~11. The lifetimes of the inclusion complexes were longer than that of the free 2AS molecule. The geometrical restriction of the α-CD cavity likely limits the free rotation of the amino and methoxy groups, thereby enhancing the emission intensity. The calculated HOMO–LUMO energy gap, total energy, free energy, enthalpy, entropy, dipole moment, and zero-point vibrational energy of the CD: 2AS complex differed significantly from those of the isolated 2AS, α-CD and β-CD molecules, and both the vertical and horizontal bond lengths between the amino and methoxy groups are smaller than the β-CD cavity size confirming the formation of an inclusion complex. In FTIR, most of the peaks are not appeared and a substantial decrease in intensity was noted in the Cu: 2AS: CD nano. The chemical shift value of 2AS protons are shifts to up field and down field and the peak intensities are very low in the nano copper with CD nanomaterials. SEM image of the nanomaterials are different from isolated 2AS molecule.
Abstract: Absorption, emission, time resolved fluorescence spectra and molecular modelling of 2-anisidine (2AS) with α-CD and β-CD in pH~2, pH~7 and pH~11 solutions were examined. Cu: 2AS: CD nanomaterials were investigated by SEM, DSC, FTIR, XRD and 1H NMR techniques. The absorption and emission maxima and spectral shape of 2AS in all the pH solutions and s...
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Research Article
A Study on the Adsorption of Methyl Orange in Aqueous Solution by Activated Carbon Prepared from Neem Oil Cakes: Kinetic and Thermodynamic Analyses
Jules Blaise Leuna Mabou*
,
Edwin Akongnwi Nforna,
Suzanne Makota,
Harlette Zapenaha Poumve,
Simon Malama,
Jacques Bomiko Mbouombouo,
Lincold Nintedem Magapgie,
Pierre Gerard Tchieta
Issue:
Volume 14, Issue 2, April 2026
Pages:
60-74
Received:
18 March 2026
Accepted:
21 April 2026
Published:
30 April 2026
DOI:
10.11648/j.sjc.20261402.13
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Abstract: This worked is aimed at studying the thermodynamic and kinetic adsorption of methyl orange (MO) onto activated carbon (AC) obtained from Neem oil cakes (NOC). The ACs were synthesized by chemical activation of Neem oil cakes with H3PO4 of 2, 5 and 10 percent (respectively labeled AC-2, AC-5, and AC-10) followed by pyrolysis at 450°C for 1 hr. Various characterizations of the synthesized ACs include Fourier Transformed Infrared spectroscopy FTIR, microstructural and elemental analyses (SEM/TEM, EDS), pHPZC, moisture content, and iodine and methylene blue adsorption methods were used to determine the surface area. The ACs were employed to adsorb methyl orange (MO) from a synthetic aqueous solution. The results obtained show that: pHPZC was less than 7, indicating that the three activated carbons have predominantly acidic surface. The adsorbents AC-5 and AC-10 have microporous and mesoporous structures respectively, with respective specific surface area by iodine adsorption (SI2) method estimated to be around 688.45 and 689.70 m2/g. The adsorption of MO was pH dependent, with an optimal adsorption at pH =2. The EDS results confirm that these adsorbents are primarily composed of carbon. Results from kinetic studies showed that the adsorption process followed a pseudo second order kinetic model. The experimental data from the equilibrium adsorption of MO on the ACs showed the best fit with the Langmuir isotherm, suggesting monolayer adsorption. Maximum adsorption capacity of 232.558 mg.g-1 was obtained for AC-10. These results show that the adsorption of MO is spontaneous and endothermic. Chemisorption is the predominant mechanism for MO removal on AC-2, AC-5, and AC-10.
Abstract: This worked is aimed at studying the thermodynamic and kinetic adsorption of methyl orange (MO) onto activated carbon (AC) obtained from Neem oil cakes (NOC). The ACs were synthesized by chemical activation of Neem oil cakes with H3PO4 of 2, 5 and 10 percent (respectively labeled AC-2, AC-5, and AC-10) followed by pyrolysis at 450°C for 1 hr. Vario...
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