Research Article
Synthesis of Silver-2-Aminophenol-Cyclodextrin Nanomaterials and pH Dependent of 2-Aminophenol-Cyclodextrin Inclusion Complexes
Issue:
Volume 15, Issue 2, June 2026
Pages:
22-32
Received:
11 March 2026
Accepted:
23 March 2026
Published:
10 April 2026
Abstract: The spectral characteristics of 2-aminophenol (2AP) in various solvents, α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) at pH~3, pH~7, and pH~11, were investigated using UV-visible, fluorescence, time-resolved fluorescence measurements, and PM3 computational methods. The Ag: 2AP: CD nanomaterials were synthesized and characterized by SEM, FTIR, and XRD techniques. In all the pH conditions, 2AP exhibited distinct absorption and emission shifts upon complexation with α-CD and β-CD. In various solvents, the absorption and emission maxima of 2AP were similar to those of 2-anisidine. 2AP showed a single broad emission band in all solvents, whereas dual emission observed in CD solutions indicates the presence of an intramolecular proton transfer (IPT) process in the 2AP molecule. The lifetimes of the inclusion complexes were longer than that of the free 2AP molecule. The geometrical restriction of the α-CD cavity likely limits the free rotation of the amino and hydroxyl groups, thereby enhancing the intensity of the IPT emission. The calculated HOMO-LUMO energy gap, total energy, free energy, enthalpy, entropy, dipole moment, and zero-point vibrational energy of the CD: 2AP complex differed significantly from those of the isolated 2AP, α-CD and β-CD molecules, and both the vertical and horizontal bond lengths between the amino and hydroxy groups are smaller than the β-CD cavity size confirming the formation of an inclusion complex. SEM-EDX data confirmed the presence of 5.5% silver in the nanomaterials.
Abstract: The spectral characteristics of 2-aminophenol (2AP) in various solvents, α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) at pH~3, pH~7, and pH~11, were investigated using UV-visible, fluorescence, time-resolved fluorescence measurements, and PM3 computational methods. The Ag: 2AP: CD nanomaterials were synthesized and characterized by SEM, FTIR, an...
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Research Article
Negentropy and Irreversible Processes
Issue:
Volume 15, Issue 2, June 2026
Pages:
33-41
Received:
9 March 2026
Accepted:
23 March 2026
Published:
14 April 2026
Abstract: Chemical reactions are accompanied by direct and reverse transformations of components. The entropy produced by reverse transformations is known as negentropy. The resulting bifurcation sequence transitions into a reaction cycle, allowing one to assess the possibility of dissipative structure formation. It has been established that the probability of dissipative structure formation has a crater-like dependence on entropy production, affinity, and rate constant. The contracting part of the crater is associated with negentropy, while the expanding part is associated with dissipative structures. Negentropy is a barrier to the formation of dissipative structures. With the emergence of negentropy, a unitary system becomes non-unitary.
Abstract: Chemical reactions are accompanied by direct and reverse transformations of components. The entropy produced by reverse transformations is known as negentropy. The resulting bifurcation sequence transitions into a reaction cycle, allowing one to assess the possibility of dissipative structure formation. It has been established that the probability ...
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Research Article
Trace Metal Contamination and Associated Ecological and Human Health Risk Assessment in Before Sediments of the Koko Watershed (Korhogo, Côte D’Ivoire)
Kahou Katel Kizito Toe-Bi*,
Aboubakar Sako
,
Trazie Jean-Gael Irie Bi
Issue:
Volume 15, Issue 2, June 2026
Pages:
42-60
Received:
6 May 2026
Accepted:
18 May 2026
Published:
29 May 2026
DOI:
10.11648/j.ajpc.20261502.13
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Abstract: The contamination of aquatic environments can be caused by several types of pollutants, notably heavy metals. Heavy metals present in ecosystems have become a significant environmental risk. Thus, sediments, which are the major sinks of these contaminants, may represent a significant environmental concern to human well-being, aquatic plants, and various benthic organisms. The objective of this study was to assess sediment quality in order to examine the potential ecological and health risks associated with heavy metal concentrations in sediments. Sediment samples streams and the river of the Koko watershed were collected and analyzed for the presence of Pb, As, Zn, Cu, Ni and Cr using atomic absorption spectrophotometry (AAS). The heavy metal concentrations obtained from the analysis revealed that highest average concentrations for Pb, Zn, Cu, Ni, and Cr were recorded during the dry season, with 35.60, 101.26, 23.36, 26.80, and 80.12 mg kg-1, respectively, whereas As reached its highest average concentration during the rainy season (1.51 mg kg-1). The results generally indicate that the accumulation of trace metals varies according to both the sampling site and the season. Comparison of our data with Upper Continental Crust (UCC) values indicates that the studied sediments are contaminated with Pb, As, Zn, Cu, Ni, and Cr in the dry season. This result is supported by the geo-accumulation index (Igeo), which generally indicates moderate contamination of sediments 1, 2, 3, and 5 by Pb, As, Zn, Cu, Ni, and Cr. The quality of the sediments indicates a potential toxic risk to benthic organisms at sediment 3 (PERI: 393.72) during the rainy season and in the dry season (PERI: 342.34). In the rainy season, the m-ERM-Q indicates a moderate-to-low probability of ecosystem hazard, although Ni poses a high-risk level in all sediments. But in the dry season, Ni has a moderate-to-high ecological impact on biota in all sediments.
Abstract: The contamination of aquatic environments can be caused by several types of pollutants, notably heavy metals. Heavy metals present in ecosystems have become a significant environmental risk. Thus, sediments, which are the major sinks of these contaminants, may represent a significant environmental concern to human well-being, aquatic plants, and va...
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