A spectrophotometric investigation has been applied to study the kinetics of oxidation of poly (ethylene glycol) (PEG) as a synthetic polymer by alkaline permanganate at a constant ionic strength of 1.0 mol.dm⁻³. The reaction was found to proceed through two distinct measurable stages. The first stage was relatively fast and corresponding to the formation of coordination polymer intermediate complexes involving blue hypomanganate (V) and/or green manganate (VI) transient species. The influence of variable factors on the oxidation rates such as the concentration of permanganate ion and PEG substrate concentrations as well as the pH and ionic strength have been examined. Under the pseudo-first-order reaction conditions of [PEG] ≫ [MnO₄⁻], the experimental results showed a first-order dependence in [MnO₄⁻] and fractional first-order kinetics in each of [PEG] and alkali concentration. The oxidation process was of base-catalyzed nature where the oxidation rates were increased with increasing the alkali concentration. The observed first-order rate constant was found to be 1.1 ×10⁻³ s⁻¹ with deprotonation constant of 0.72 dm³ mol⁻¹ at 45 °C. Blue hypomanganate (V) was detected for the first time by using a conventional spectrophotometer. The oxidation process has proceeded without the intervention of a free-radical mechanism. Colloidal manganese (IV) and the acid derivatives of PEG were identified as final oxidation products. The activation parameters of the second-order reaction have been calculated and found to be ΔH^≠ = 40.66 kJmol⁻¹; ΔS^≠= − 145.41 Jmo^l−K⁻¹ and ΔG^≠ = 83.99 kJmol⁻¹. A plausible reaction mechanism for oxidation based on the evaluated activation parameters and in good consistent with the observed kinetic data was suggested and discussed.

The kinetics of decomposition of coordination polymer poly (ethylene glycol) intermediate complex [PEG-Mn^VIO₄^2-] which was formed during the progression of the relatively fast first stage for the oxidation of poly (ethylene glycol) (PEG) by alkaline permanganate have been investigated by conventional spectrophotometer. Pseudo first -order condition in the presence of [PEG] substrate as a synthetic polymer in large excess over [MnO₄^-] was showed first-order overall reaction kinetics. The influence of the alkali concentration on the decomposition rate constants indicated that the oxidation rates were increased with increasing the alkali concentration, therefore, the decomposition process was considered of base-catalyzed nature. The rate constant of decomposition was found to be 2.3 x10^-4 s⁻¹, whereas the deprotonation constant was 2.88 dm³ mol⁻¹ at 45 °C. The activation parameters have been calculated and found to be ΔH^≠ = 34.93 kJmol⁻¹; ΔS^≠ = −176.2 Jmo^l-K⁻¹ and ΔG^≠ = 90.96 kJmol⁻¹. The chemical structure of such synthesized acid-derivative of PEG was elucidated by elemental analysis and spectral data. The negative results of 2,4-dinitrophenyl hydrazine and hydroxylamine identified investigations along with (FTIR) spectra results indicated that the oxidation product is the acid derivative of poly (ethylene glycol) (ADPEG). The synthesis procedure of the acid-derivative of PEG (ADPEG) as the final oxidation product was described in detail. The product yield was found to be ~ 98%. It is found that the oxidation product (ADPEG) has a high tendency for chelation with most polyvalent metal ions in particularly the divalent metal ions forming their corresponding coordination polymer complexes. Therefore, this distinct property of the product renders it to be used as a chelating agent of high performance, non-toxicity and low cost compared with the chelating agents available in the markets. A suitable reaction mechanism for the decomposition in terms of electron-transfer nature was suggested and discussed.

Novel synthesis of natural polymeric cation exchanger from sodiumalginate reagent as natural polymer (CAlg-Na)_n has been developed. This procedure takes place by crosslinking the solid sodium alginate with 1,6-hexamethylene diisocyanate (HDI) in dryness benzene as inert solvent (DB). The experimental results for crosslinking the alginate using different degrees of crosslinking of HDI/DB (w/w) showed that the capacity of the synthesized resin for binding the polyvalent metal ions reached its maximum at 30% of (HDI/D) ratio. This work aims to present a novel synthesis of cation exchange resin from natural polymers as an alternative promising competitor of low-cost, high performance and non-toxicity for removal of the toxic heavy metal ions in wastewater remediation and radionuclide pollutants from environmental contaminated media. The results obtained from various applied techniques for determining the bounded metal ion concentrations with (CAlg-Na)_n indicated that the resin capacity was followed the order U(VI) > Cu(II) > Sr(II) > Ca(II) at 25 °C, respectively. The factors influenced the alginate affinity for chelating the metal ions were explained in some correlation terms between the alginate capacity and some physicochemical properties of chelated metal ions and its respective formed complexes. Speculated geometrical configurations for chelation were suggested and discussed.

Gasometric and weight-loss systems was used for studying the corrosion inhibition of magnesium (Mg) in hydrochloric acid by methyl cellulose (MC) polysaccharide as carbohydrate polymer. The two techniques showed a comparable experimental data. The resulting inhibition data of MC on Mg metal surface was found to exhibit both Langmuir and Freundlich isotherms models. Influence of [H⁺] on the rates of corrosion indicates that the rates of corrosion depends on the rate of acid. This finding along with the first order found in [H⁺], suggests that the presence of hydrogen ions should be included at least in the rate-determining step in one of the dissolution pathways of Mg metal in the corrosive medium of HCl. The corrosion rate factors were investigated. Again, the inhibition efficiency increases with increasing the inhibitor concentration and temperature. The inhibition effect of the MC on the magnesium metal surface was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) techniques to confirm the extent of corrosion and film formation of MC on the magnesium metal surface. Kinetic parameters were estimated and a suitable corrosion mechanism in good agreement with the kinetic results is suggested and discussed.

In a series of spectrophotometric investigation studies on some redox reactions involving vitamin C (ascorbic acid) as a reducing agent for reduction of metal ion oxidants in aqueous acidic solutions. It was surprising when the naked eye observations noticed the rabidly turning of selenium dioxide Se(IV) solution from colorless into deeply bright crimson color of colloidal aggregate sol when just mixed with solution of excess vitamin C in either neutral or acidic media. Then, the formed crimson color was gradually turned into crystals of dark purple color on keeping it aside for a long time or on drying in either sunlight or into an electric oven. This result suggests the occurrence of phase-transition with formation of selenium nanoparticles. The formed seleniumnanoparticles were characterized by FTIR, XRD as well as the SEM and TEM microscopic morphology. It has been found the formation of such selenium nanoparticles of cluster-grapes nature for the first time. This phenomenon and the great importance of such nanoparticles in biotechnology applications encouraged us to follow the rate of nanoparticles growth through the reduction of selenium dioxide by vitamin C on using a conventional spectrophotometer. A first-order dependences in both selenium (IV) and vitamin C concentrations; second-order overall kinetics have been revealed. Free-radical intervention was detected during the oxidation progression. The influence of [H⁺] on the rate constants showed that the oxidation was of acid-inhibition nature. In view of the evaluated kinetic parameters, a plausible reaction mechanism of two-electron transfer pathway of inner-sphere nature was suggested and discussed.

Copper II-Albumin complex (Cu-II-Albumin complex) is a novel therapeutic target that has been used as anti-inflammatory, antioxidant, and anti-gastrointestinal toxicity. In this study, 40 rats were divided into four groups, normal control (NC), aflatoxicosed group (AF) that received Aflatoxin B1 (AFB1) (50 μg/kg of the AFB1 daily for 3 weeks), AFB1-Cu-II-Albumin prophylactic group (AF/CUC-P) that subjected to intermittent treatment between AFB1 and Cu-II-Albumin complex (0.05 g/kg Cu-II-Albumin complex) day after day for 3 weeks and AFB1-Cu-II-albumin treatment group (AF/CUC-T) that received AFB1 for 3 weeks and Cu-II-albumin complex for another 3 weeks. The hepatocellular protective effect of the Cu-II-albumin complex was assessed by evaluating the liver functions markers, hepatic histopathology, reactive oxygen species (ROS) levels (Nitric Oxide (NO) and malondialdehyde (MDA)), apoptotic genes (caspase-3 and tumor necrosis factor receptor 1 [TNF-R1]) expressions, and serological and molecular biomarkers of hepatocellular carcinoma (histamine and Glucose-Regulated Protein 78 [GRP78], respectively). Our finding showed that Cu-II-Albumin Complex administration had restored liver function, oxidative stress levels, enhanced liver tissue recovery, and reduced the expression of the apoptotic genes of the aflatoxicosed rats. In conclusion, the current study results demonstrated the protective effect of Cu-II-albumin complex against AFB1-induced hepatocellular toxicity.

Transition metal dichalcogenides like MoS2 can exist many phases like the semiconducting 2H and the metallic 1T phases which have shown intriguing properties for energy and electrocatalytic applications. However, the 2H and 1T phases normally distribute coherently in a single-layered MoS2 sheet which is accompanied with ubiquitous hetero-phase boundaries. In this work, by using density functional theory and electrochemical measurement, we report strong charge transfer ability between 2H/1T phase boundary of MoS2 and graphene which accounts for a superb coexistence of gravimetric and volumetric capacitances of 272 F g-1 and 685 F cm-3. As a proof-of-concept application, a flexible solid-state asymmetric supercapacitor based on MoS2/graphene is fabricated, showing a remarkable energy and power densities (46.3 mWh cm-3 and 3.013 Wcm-3). Our work shows the promise of promoting the efficiency of charge flow and energy storage through engineering phase boundary and interface in phase-change materials.

Transition metal dichalcogenides exhibit several different phases (e.g., semiconducting 2H, metallic 1T, 1T′) arising from the collective and sluggish atomic displacements rooted in the charge-lattice interaction. The coexistence of multiphase in a single sheet enables ubiquitous heterophase and inhomogeneous charge distribution. Herein, by combining the first-principles calculations and experimental investigations, a strong charge transfer ability at the heterophase boundary of molybdenum disulfide (MoS₂) assembled together with graphene is reported. By modulating the phase composition in MoS₂, the performance of the nanohybrid for energy storage can be modulated, whereby remarkable gravimetric and volumetric capacitances of 272 F g⁻¹ and 685 F cm⁻³ are demonstrated. As a proof of concept for energy application, a flexible solid-state asymmetric supercapacitor is constructed with the MoS₂-graphene heterolayers, which shows superb energy and power densities (46.3 mWh cm⁻³ and 3.013 W cm⁻³, respectively). The present work demonstrates a new pathway for efficient charge flow and application in energy storage by engineering the phase boundary and interface in 2D materials of transition metal dichalcogenides.

Photosynthetic proteins have been extensively researched for solar energy harvesting. Though the light-harvesting and charge-separation functions of these proteins have been studied in depth, their potential as charge storage systems has not been investigated to the best of our knowledge. Here, we report prolonged storage of electrical charge in multilayers of photoproteins isolated from Rhodobacter sphaeroides. Direct evidence for charge build-up within protein multilayers upon photoexcitation and external injection is obtained by Kelvin-probe and scanning-capacitance microscopies. Use of these proteins is key to realizing a ‘self-charging biophotonic device’ that not only harvests light and photo-generates charges but also stores them. In strong correlation with the microscopic evidence, the phenomenon of prolonged charge storage is also observed in primitive power cells constructed from the purple bacterial photoproteins. The proof-of-concept power cells generated a photovoltage as high as 0.45 V, and stored charge effectively for tens of minutes with a capacitance ranging from 0.1 to 0.2 F m⁻².