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The purpose of this paper is to improve the generation efficiency of singlet oxygen of methylene blue molecules through finely controlling their aggregation states in drug carriers.

As a photosensitiser in photodynamic therapy, methylene blue (MB) was loaded on citrate-modified hydroxyapatite (HAp) through an electrostatic interaction and followed by encapsulation of coordination complexes of tannic acid (TA) and Fe(III) ions. Ultraviolet-visible absorption spectrum of the supernatant after incubation of samples was recorded at certain time interval to investigate the release behaviour of MB. Photodynamic activity of MB was determined by the oxidation reaction of uric acid by singlet oxygen generated by MB under illumination.

Almost all MB molecules were immediately released from HAp-MB, whilst an initial burst release of MB from HAp-MB@TA was followed by a sustainable and pH-sensitised release. In comparison with HAp-MB, photocatalystic reduction of HAp-MB@TA by titanium dioxide hardly occurred under illumination, indicating the stability against reduction to leukomethylene blue in vitro. Generation efficiency of singlet oxygen by MB released from HAp-MB@TA was significantly higher than that from HAp-MB because of the control of TA and Fe(III) ions complexes on molecular structures of released MB.

A facile method was herein demonstrated to optimise the generation efficiency of singlet oxygen by controlling aggregation states of PS molecules and improve PDT efficiency to damage tumour tissues.

The present paper aims to synthesize SrAl2O4:Eu2⁺, Dy3⁺ green-emitting phosphor nano-pigment powder using a combination of citrate – gel processing and microwave-assisted heating route.

Microwave-assisted citrate – gel processing of SrAl2O4:Eu2⁺, Dy3⁺ green-emitting phosphor nano-pigment powder has been carried out by varying the pH and the molar ratio of H3Cit/Al3⁺ + Sr2⁺ +Eu2⁺⁺Dy3⁺ (f/o). X-ray diffraction analysis showed that the produced powders were nearly pure SrAl2O4 phase, in which the SrAl2O4 host phase has the maximum fraction of green-emitting monoclinic SrAl2O4 phase.

Spectrophotometer results revealed that two excitation peaks appeared at 238 and 339 nm and an emission peak at 515 nm. The crystallite size of the green-emitting phosphor nano-pigment powder was about 37 nm as determined by Scherrer’s formula. The best conditions for formation of monoclinic SrAl2O4 phase with high purity were achieved at pH of precursor solution equal to 7 and the molar ratio of f/o equal to 3.

The present research work for the first time (to the best of the authors’ knowledge) has used microwave and sol–gel combination techniques to produce green-emitting phosphor nano-pigment powder (without using any other heating system).

The purpose of this article is to evaluate the role of mineralisers on the formation of perovskite structure, optimise the amounts of chromium content, soaking time and finally the ratio of fuel (citric acid) to oxidiser (metal nitrate) and investigation of the physical properties of resulted pigments.

A red pigment based on perovskite structure (YAl_1-yCr_yO₃, y = (0.01-0.1) was synthesised by solution combustion method with various mineralisers, like NaF, MgF₂ and Li₂CO₃. Thermal decomposition of the resulting nitrate-citrate gels and the phase evolution of calcined powders were investigated and the microstructure and colorimetry of the emerging products were characterised.

The most effective mineraliser system for the formation of YAlO₃ perovskite was NaF:MgF₂:Li₂CO₃ (3:2:1 by weight). Furthermore, desirable pigments were obtained by firing the samples at 1,400°C for 4 hours. The highest redness parameter (a*) and reflectance value were obtained when y was 0.03 and 0.01, respectively. Increasing the fuel: oxidiser ratio led to an increase in the a* parameter. Use of the optimum prepared red pigment in the low and high firing temperature glazes gave a high chemical and thermal stability.

Only citric acid was used as fuel. Other fuels and different ratios of fuel to oxidiser could also be studied.

The method developed provided a new approach for preparation to nontoxic, high-temperature, ceramic red pigment compared to the solid-state method.

The methods for synthesis of pigment based on perovskite structure with different chromium contents and for evaluation of thermal stability of pigment in glaze were novel.

The acceleration of corrosion of rebars in concrete are due to several reasons such as carbonation, chloride attack, influence of microorganisms, etc. The aim of this investigation mainly focused on how the microorganism was involved in the corrosion process and thereby affect a mechanical property of mortar and accelerate the corrosion of steel in mortar. ordinary portland cement (OPC) and portland pozzolona cement (PPC) was used for making mortar specimens. Sodium citrate was used as an inhibitor for the corrosion of steel in mortar.

Compressive strength measurements were conducted for mortar at different ages in the presence of microorganisms to understand the mechanical property of mortar. Potential‐time behavior studies were carried out to determine the status of rebars inside the mortar. Weight loss measurements were adopted to quantify the corrosion level due to microorganisms. The microbial count in the water samples at the initial and final exposure period was also examined.

All these studies showed that additions of sodium citrate level of greater than 1 percent by weight of OPC and PPC severely affected both the mechanical and the corrosion resistance properties of OPC and PPC. Microbiological examination reveals that bacteria consume citrates for their survival and thereby increasing the permeability of mortar specimens.

Generally, citrates are considered as being good corrosion inhibitor for steel in concrete. However, results from the present study indicated that sodium citrate concentrations only of less than 1 percent by weight of OPC and PPC are suitable for use in concretes that are exposed to heterotrophic bacterial environments.

The purpose of this study is to apply silver nanoparticles on the cellulosic fabric via a green cross-linking approach to obtain antibacterial textiles. The cellulosic fabrics may provide an ideal enclave for microbial growth due to their biodegradable nature and retention of certain nutrients and moisture usually required for microbial colonization. The application of antibacterial finish on the textile surfaces is usually done via synthetic cross-linkers, which, however, may cause toxic effects and halt the biodegradation process.

Herein, we incorporated citrate moieties on the cellulosic fabric as eco-friendly crosslinkers for the durable and effective application of nanosilver finish. The nanosilver finish was then applied on the citrate-treated cellulosic fabric under the pad-dry-cure method and characterized the specimens for physicochemical, textile and antibacterial properties.

The results expressed that the as-prepared silver particles possessed spherical morphology with their average size in the nano range and zeta potential being −40 ± 5 mV. The results of advanced analytical characterization demonstrated the successful application of nanosilver on the cellulosic surface with appropriate dispersibility.

The nanosilver-treated fabric exhibited appropriate textile and comfort and durable broad-spectrum antibacterial activity.

The treated cellulosic fabric expressed that the cross-linking, crystalline behavior, surface chemistry, roughness and amphiphilicity could affect some of its comfort and textile properties yet be in the acceptable range for potential applications in medical textiles and environmental sectors.

To develop a new corrosion inhibitor formulation for carbon steel in low chloride environments.

Corrosion inhibition efficiencies were evaluated by the weight loss method and by impedance measurement studies. The nature of the inhibition process was evaluated using potentiostatic polarization studies. The nature of the protective film was investigated using X‐ray diffraction, X‐ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The concept of synergistic effect was used in the development of the new synergistic inhibitor formulation.

A new corrosion inhibitor formulation, containing tertiary butyl phosphonate (TBP), zinc ions and citrate, has been developed to control the corrosion of carbon steel in low chloride environments. This inhibitor formulation was found to offer a maximum inhibition efficiency of 96 per cent in a neutral pH test environment. It was interesting to observe that the binary system, consisting of higher concentrations of the TBP and zinc ions, offered only 79 per cent inhibition efficiency. The ternary system, consisting of relatively lower concentrations of the phosphonate, zinc ions and citrate offered a higher (96 per cent) efficiency. This ternary inhibitor system also was found to be efficient in acidic as well as basic environments in the pH range 5‐8. The inhibitor combination was determined to function as a “mixed”‐type inhibitor, though being predominantly cathodic. A plausible explanation of the mechanism of corrosion inhibition is proposed.

The ternary inhibitor formulations based on phosphonate, zinc ions and another environmentally friendly synergists like citrate will be quite useful for corrosion inhibition of carbon steel in cooling water systems as they contain relatively less concentrations of phosphonate and zinc ions.

The research paper presents the results of a new synergistic inhibitor formulation and also discusses the mechanistic aspects of corrosion inhibition.

The purpose of this paper is to investigate the electrodeposition of copper coatings directly onto AZ31 magnesium alloy, considered as a substrate of electroplating nickel. The additive, pH, complexing agent, current density, time, and temperature of electrolytic bath were studied to understand electrodepositing copper coating on AZ31 magnesium alloy.

Electrodeposition of copper was carried out in an aqueous solution containing copper hydroxide, citrate, and fluorine ion, which avoids the replacement or corrosion of the magnesium alloy. The morphology, structure, and interface of the electrodeposited copper coating were investigated by a scanning electron microscope (SEM).

The copper coating was dense, and there was good adhesion of the copper coating on the AZ31 magnesium alloy. This suggests that successful deposition of copper using an electroplating process could decrease the cost of coating AZ31 magnesium alloy.

This paper will be helpful for the development of coating on magnesium alloy using electroplating processes.

Copper hydroxide and citrate were the main compositions of the electrolyte, combined with sodium poly dipropyl (SP) and polyethylene glycol (PEG) as brightening agents and can be used to electrodeposit copper directly onto AZ31 magnesium alloy.

The purpose of this paper is to explore the optimum average current density and pulse width for electrodeposition of gold in citrate electrolyte, and it is verified that the uniformity of film thickness can be effectively improved by periodic pulse reverse electroplating.

Apply forward pulse current, forward group pulse current and periodic pulse reverse current to the electrolyte and compare the film quality. High-frequency group pulses are used in both forward and reverse directions of the periodic pulse reverse current.

It is verified by experiments that periodic pulse reverse plating is superior to forward pulse plating and forward group pulse plating in terms of particle size, compactness, impurity content and thickness uniformity of the film. Add low-frequency vibration to the cathode under the same pulse electrical parameters as a comparative experiment to prove the beneficial effect of vibration on the allowable limiting current density and plating rate.

Gold film is often used as the sealing layer of precision parts. Increasing the thickness uniformity and improving the compactness of gold film will help to reduce the size error, improve the subsequent assembly accuracy and increase the service life of wear-resistant layer. Citrate gold plating electrolyte combines the advantages of cyanide electrolyte and cyanide-free electrolyte. Hence, this research focuses on the characteristics of periodic pulse reverse plating in terms of particle size, compactness, impurity content and thickness uniformity of the film and compare it with forward pulse plating and forward group pulse plating.

The purpose of this paper is to study thickness dependent variation in microwave properties of the Mg_xMn_(0.9−x)Al_0.1Zn_0.8Fe_1.2O₄ (x=0.8, 0.9) thick films and enhancement of power efficiency of Ag thick film EMC patch antenna.

X‐band microwave properties of the Mg_xMn_(0.9−x)Al_0.1Zn_0.8Fe_1.2O₄ (x=0.8, 0.9) thick films were measured by superstrate technique using Ag thick film EMC patch antenna as the resonant element. The complex permittivity and permeability of these thick films were also measured by this technique. The microwave response of the EMC patch, complex permeability and permittivity of Mg_0.8Mn_0.1Al_0.1Zn_0.8Fe_1.2O₄ and Mg_0.9Al_0.1Zn_0.8Fe_1.2O₄ thick films and their thickness dependency were investigated.

The XRD patterns reveal the cubic spinel crystal system was obtained for both compositions. The crystallite size obtained was 134.68 nm for Mg_0.8Mn_0.1Al_0.1Zn_0.8Fe_1.2O₄ and 155.99 nm for Mg_0.9Al_0.1Zn_0.8Fe_1.2O₄ The superstrate technique has been used successfully to evaluate the complex permittivity and permeability of the ferrite thick films in the X band. The EMC patch also show thickness and composition dependent frequency agility and enhancement of power efficiency.

The complex permeability of Mg_xMn_(0.9−x)Al_0.1Zn_0.8Fe_1.2O₄ (x=0.8, 0.9) thick films measured by superstrate technique is reported in this paper. The superstrate of Mg_xMn_(0.9−x)Al_0.1Zn_0.8Fe_1.2O₄ (x=0.8, 0.9) thick films makes the Ag thick film EMC patch antenna frequency agile and power amplification is obtained.

The purpose of this paper is to study the effect of whey and whey components on the production of dialyzable non‐heme iron – an in vitro indicator of bioavailable forms of the mineral.

Whey, processed whey and whey components were mixed with ferric iron and digested in vitro with pepsin and pancreatin/bile using a dialysis bag containing bicarbonate for pH adjustment. Total and ferrous dialyzable iron were measured and compared to values from protein and non‐protein controls.

Whey produced much more dialyzable iron than egg albumin but less than deproteinized whey. Most of the iron was ferric. Whey protein concentrate was as effective as egg abumin but whey protein isolate, α‐lactalbumin and β‐lactoglobulin slightly reduced dialyzable iron formation. Milk salts produced more dialyzable iron than whey and about as much as deproteinized whey. The major component of whey producing dialyzable iron was citrate, which competes for iron chelation with the whey protein.

This study demonstrates that whey generates a large amount of dialyzable iron from ferric iron sources and that the iron is primarily due to chelation with citrate rather than to digestion of whey proteins. However, the effect of citrate is reduced by whey proteins.