Cu(ii) and Ni(ii) complexes with dipyridine-containing macrocyclic polyamines with different binding unitsElectronic supplementary information (ESI) available: selected bond lengths [Å] and angles [°] for [CuL1](ClO4)2 (Table S1) and for [NiL1](ClO4)2 (Table S2); absorption spectra of L2 in the presence of Cu(ii) (1 ∶ 1 molar ratio) at different pH values (Fig. S1). See http://www.rsc.org/suppdata/dt/b2/b211904h/

In the present study, methylene blue (MB) removal from aqueous solutions via the photocatalytic process using TiO2 as a catalyst in the presence of external ultra-violet light (UV) was investigated. The results of adsorption in the absence of UV radiation showed that adsorption reached an equilibrium state at 60 min. The experimental kinetic data were found to be well fitted by the pseudo-second-order model. Furthermore, the isotherm study suggested that dye uptake by TiO2 is a chemisorption process with a maximum retention capacity of 34.0 mg/g. The photodegradation of MB was then assessed under various experimental conditions. The related data showed that dye mineralization decreased when dye concentrations were increased and was favored at high pH values and low salt concentrations. The simultaneous presence of organic and inorganic pollution (Zinc) was also evaluated. The effect of the molar ratio Zn2+/MB+ in the solution at different pH values and NaCl concentrations was also monitored. The corresponding experimental results showed that at low values of Zn2+ in the solution (30 mg/L), the kinetic of the MB removal became faster until reaching an optimum at Zn2+/MB+ concentrations of 60/60 mg/L; it then slowed down for higher concentrations. The solutions’ carbon contents were measured during the degradation process and showed total mineralization after about 5 h for the optimal Zn2+/MB+ condition.

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Solubility of Iron in Model Systems Containing Organic Acids and Lignin

Journal of Food Protection ◽

10.4315/0362-028x-55.11.893 ◽

1992 ◽

Vol 55 (11) ◽

pp. 893-898 ◽

Cited By ~ 13

Author(s):

TAKESHI SUZUKI ◽

FERGUS M. CLYDESDALE ◽

TIRA PANDOLF

Keyword(s):

Ascorbic Acid ◽

Organic Acids ◽

Model Systems ◽

Molar Ratio ◽

Soluble Form ◽

Enhancing Effect ◽

Gastrointestinal Ph ◽

Soluble Iron ◽

Ph Values ◽

Ph Conditions

The effect of six organic acids, ascorbic, citric, fumaric, lactic, malic, and succinic, alone and in combination, at a 1:1.9 molar ratio (Fe+2:ligand) on the solubility of iron was evaluated in the presence of lignin under simulated gastrointestinal pH conditions. The enhancing effect, evaluated under two systems of preparation at two pH values, was in the following order: citric>malic>ascorbic>lactic,fumaric>succinic. Citric acid solubilized 80 and 81% of iron under both pH conditions. When ascorbic acid was mixed with fumaric, lactic, and succinic acids, a higher percentage of soluble iron was retained than with these three acids alone. In the case of citric and malic acids, the addition of ascorbic acid reduced the soluble iron. The percentage of soluble iron obtained when prepared at the endogenous pH (2.5–3.1) was higher than that at pH 5.5. These results indicated that ascorbate bound less iron in a soluble form than citrate or malate but more than fumarate, lactate, or succinate. Also, combinations of citric with malic acid did not demonstrate a synergistic effect.

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MORPHOLOGY EVOLUTION AT NANO- TO MICRO-SCALE

Functional Materials Letters ◽

10.1142/s1793604708000393 ◽

2008 ◽

Vol 01 (03) ◽

pp. 167-172 ◽

Cited By ~ 89

Author(s):

XU ZHAO ◽

XIUE REN ◽

CONGTING SUN ◽

XU ZHANG ◽

YUNFEI SI ◽

...

Keyword(s):

Functional Materials ◽

Molar Ratio ◽

Morphology Evolution ◽

Organic Crystals ◽

Micro Scale ◽

Ph Values ◽

Whole Process ◽

Growth Phenomenon ◽

Growth System ◽

Bonding Characteristics

Morphology evolution of inorganic/organic crystals during crystallization is a universal growth phenomenon. In this work, we have developed a capping agent-assisted strategy to clearly identify the whole process of morphology evolution in solution growth system. One kind of morphology evolution trend with three types of morphologies of cuprous oxide ( Cu 2 O ) was kinetically observed at varying the molar ratio of EDTA/ Cu (II) under three different pH values. Two kinds of morphology evolution trends of zinc oxide ( ZnO ) were also kinetically observed in the presence of H 2 O 2 and CH 3 COOH (HAc), respectively. Simulation results show that the morphology evolution of nano- to micro-scale crystals is strongly dependent on the bonding characteristics of a growth system. The present strategy positively explores the interesting principles of morphology evolution of functional materials, and can be widely extended to nano- to micro-scale devices research.

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Curcumin Incorporation into Zn3Al Layered Double Hydroxides—Preparation, Characterization and Curcumin Release

Crystals ◽

10.3390/cryst10040244 ◽

2020 ◽

Vol 10 (4) ◽

pp. 244 ◽

Cited By ~ 3

Author(s):

Octavian D. Pavel ◽

Ariana Şerban ◽

Rodica Zăvoianu ◽

Elena Bacalum ◽

Ruxandra Bîrjega

Keyword(s):

Layered Double Hydroxides ◽

Curcuma Longa ◽

Nano Particles ◽

Molar Ratio ◽

Attenuated Total Reflectance ◽

Buffer Solutions ◽

Ph Values ◽

Main Crystalline Phase ◽

Ph Increase ◽

Double Hydroxides

Curcumin (CR) is a natural antioxidant compound extracted from Curcuma longa (turmeric). Until now, researches related to the incorporation of CR into layered double hydroxides (LDHs) were focused only on hybrid structures based on a MgxAl-LDH matrix. Our studies were extended towards the incorporation of CR in another type of LDH-matrix (Zn3Al-LDH) which could have an even more prolific effect on the antioxidant activity due to the presence of Zn. Four CR-modified Zn3Al-LDH solids were synthesized, e.g., PZn3Al-CR(Aq), PZn3Al-CR(Et), RZn3Al-CR(Aq) and RZn3Al-CR(Et) (molar ratio CR/Al = 1/10, where P and R stand for the preparation method (P = precipitation, R = reconstruction), while (Aq) and (Et) indicate the type of CR solution, aqueous or ethanolic, respectively). The samples were characterized by XRD, Attenuated Total Reflectance Fourier Transformed IR (ATR-FTIR) and diffuse reflectance (DR)-UV–Vis techniques and the CR-release was investigated in buffer solutions at different pH values (1, 2, 5, 7 and 8). XRD results indicated a layered structure for PZn3Al-CR(Aq), PZn3Al-CR(Et), RZn3Al-CR(Aq) impurified with ZnO, while RZn3Al-CR(Et) contained ZnO nano-particles as the main crystalline phase. For all samples, CR-release revealed a decreasing tendency towards the pH increase, and higher values were obtained for RZn3Al-CR(Et) and PZn3Al-CR(Et) (e.g., 45% and 25%, respectively at pH 1).

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