AgCl Crystals Research Articles

Sustainable in situ synthesis of silver/titanium dioxide/organofunctional trialkoxysilane nanocomposite coatings on cotton fabric to tailor superior multifunctional protective properties

Multifunctional properties are crucial for the production of high-quality technical textiles. In this study, a cotton fabric with simultaneously superior UV-protection, self-sterilisation, photocatalytic self-cleaning and flame retardant properties was produced using a sol–gel/hydrothermal process, in which titanium(IV) isopropoxide (TTIP) as a titanium dioxide (TiO2) precursor was combined for the first time with mixtures of organofunctional trialkoxysiloxanes, i.e., 3-(trihydroxysilyl)propyl methylphosphonate (TPMP) as a P-based flame retardant and dimethyloctadecyl [3-(trimethoxysilyl)propyl]ammonium chloride (SiQAC) or aminopropyltriethoxysilane (APTES) as the antimicrobial, biobarrier-forming precursors. The latter was used in two increased concentrations of APTES1 and APTES2. A sol–gel/hydrothermal approach was employed with a small amount of silver nitrate (AgNO3) added during the hydrothermal treatment to produce Ag-loaded TiO2. The results of scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS), X-ray diffraction spectroscopy (XRD), inductively coupled plasma mass spectroscopy (ICP MS) and Fourier-transform infrared spectroscopy (FT-IR) confirmed the successful functionalisation of TiO2 by TPMP, SiQAC and APTES through the formation of Si–O–Ti bonds and the well-dispersed Ag/TiO2/TPMP/SiQAC, Ag/TiO2/TPMP/APTES1 and Ag/TiO2/TPMP/APTES2 coatings on the surface of the cotton fabric. The type of biobarrier-forming precursor significantly influenced the formation of the Ag species after the Ag loading of TiO2. The presence of SiQAC induced the formation of AgCl crystals, while APTES controlled the formation of silver nanoparticles (Ag NPs), which was more pronounced at the lower APTES1 concentration. The interactions between the coating components significantly influenced the functional protection performance, with the highest level of cooperation achieved in the Ag/TiO2/TPMP/SiQAC and Ag/TiO2/TPMP/APTES1 coatings, which exhibited the best overall multifunctionality, albeit with certain drawbacks. While the Ag/TiO2/TPMP/APTES1 coating provided excellent UV protection for the cotton, this was only improved by the Ag/TiO2/TPMP/SiQAC coating. At the same time, the Ag/TiO2/TPMP/APTES1 coating impaired the development of the char barrier by TPMP, which is due to the formation of Ag NPs. Nevertheless, both coatings showed high photocatalytic self-cleaning performance, complete self-sterilisation activity and improved burning behaviour.

Controlled synthesis of silver/silver chloride composite crystals from [AgCl2]- complex and its photocatalysis properties on organic pollutants

The visible light catalyst has aroused scientific interest in order to address issues such as energy scarcity and pollution. Many parameters, such as morphology, composition, and structure, influence photocatalytic performance of semiconductors. Here, a new method of surfactant-assisted nanometer/micron size AgCl crystals with controllable morphology was attained and then formed Ag@AgCl crystals due to partial photoreduction of AgCl under the visible light. Temperature, humidity, and the quantity of surfactant (polyvinylpyrrolidone, PVP) were all controlled to produce different morphologies. It was found that the existence of PVP was the trigger for the synthesis of the linear AgCl crystals. The growth rate and time of AgCl crystals formation could be controlled by adjusting temperature and humidity conditions. The structure and constituents of the synthesized Ag@AgCl crystals were characterized by a polarizing microscope (POM), scanning electron microscope (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). The photocatalytic activity of catalyst was evaluated using methyl orange (MO) dye degradation studies. The results showed that too much or too little PVP did not favor the degradation of MO, and the pine needle-like crystals synthesized at a PVP / AgNO3 mass ratio of 5% showed the best photodegradation of MO with recyclability. Therefore, this study provides a new opportunity for the simple and controllable synthesis of Ag@AgCl crystals with rich morphologies.

Influence of different silver species on the structure of bioactive silicate glasses

Silver nanoparticles and silver species are frequently used in regenerative medicine due to their bactericidal effect and low toxicity to human cells. Ag species are prone to be converted into other silver species such as silver nanoparticles and AgCl when immersed in simulated body fluid. The aim of this study is to understand the influence of these transformations in the human body, as well as the effect of different oxidative states of Ag on bioactivity, cell viability and antibacterial activity. For this purpose, bioactive glasses with different silver species and content were used, obtaining glasses with Ag2O or Ag3PO4. The presence of Ag+ ions favored the appearance of AgCl crystals on the surface of the samples after their immersion in simulated body fluid. In all cases, Ag nanoparticles were formed due to the high concentration of NaCl in the simulated body fluid, which concentration is close to the human plasma.

Transmittance of CsI, AgCl, KRS-5, and KRS-6 Crystals in the Terahertz Range

Transmittance of CsI, AgCl, KRS-5, and KRS-6 Crystals in the Terahertz Range

One‐Pot Bio‐Assisted Synthesis of Stable Ag–AgCl System Using Jellyfish‐Based Scaffold for Plasmonic Photocatalysis Applications

AbstractPlasmonic assisted photocatalysis has emerged in the past decade as an efficient, high‐performance methodology. Such a system is often composed of the dispersal of noble metal nanoparticles on a semiconductor. In this architecture, the application of light at the plasmon frequency allows the separation of charge at the Schottky interface between the metal and the semiconductor, which can be further used for efficient catalysis. Here, a one‐pot green bio‐synthesis of Ag antibacterial nanoparticles attached to AgCl crystals while embedded in a jellyfish‐based eco‐friendly scaffold, is reported. The synthesis utilizes the chemical reduction properties of mucin protein found in the Jellyfish biomass, and thus the resulting Ag@AgCl system is firmly bound to the scaffold, making this membrane very stable. The system's photocatalytic activity is investigated by decomposing methyl orange and full electromagnetic simulations.

Characterization of AgCl crystal at low temperatures

In the present research work, Silver Chloride (AgCl) crystal has been characterized at the low temperature region i.e. below 100 K. It is very important to characterize it because of its various uses in electrochemistry, photochromic lenses etc. For this purpose, Acoustical methods such as the Ultrasonic waves have been used as a tool. The two parameters such as nearest-neighbour distance and hardness parameter have been used as two input parameters for the present research work. The second and third order elastic Moduli (SOEM and TOEM) have been calculated for AgCl. Then by using this data of SOEM and TOEM, the ultrasonic attenuation coefficient at low temperature region i.e. due to the cause of electron–phonon interaction is obtained.

Синтез и исследование структуры и свойств фотоактивных ZnO-SnO_2-Ag(AgCl) наноматериалов для медицины и экологических приложений

Photoactive ZnO-SnO2-Ag(AgCl) nanomaterials have been prepared by polymer-salt method. Prepared materials able to generate singlet oxygen under UV and blue light irradiation. Materials structure and properties have been studied by optical and luminescence spectroscopy, XRD and SEM analysis. It was found that the structure of ZnO-SnO2-Ag(AgCl) materials consists of hexagonal ZnO, tetragonal SnO2, Ag and AgCl crystals having size 50÷60 nm. Obtained materials able to generate chemically active singlet oxygen under UV irradiation and have high bactericidal properties against both gram-positive and gram-negative bacteria. The increase of Ag content enhances the bactericidal properties of prepared materials.

Пропускание кристаллов CsI, AgCl, КРС-5, КРС-6 в терагерцовой области спектра

The spectral dependences of the transmittance of CsI, AgCl, KRS-5 and KRS-6 single crystals in the infrared (IR) and terahertz (THz) ranges have been measured. The spectral dependences of the absorption (attenuation) coefficient of these crystals were calculated in the spectral range of 200–3000 μm. It was found, that these crystals are transparent in the millimeter range, which makes it possible to use materials when working with THz radiation. It should be noted that, in contrast to the IR spectral region, the optical quality of the surface of the crystal samples practically does not affect the transmission in the millimeter range.

Cl−-Induced selective fabrication of 3D AgCl microcrystals by a one-pot synthesis method

Cl− induces the shape evolution of AgCl crystals with different morphologies.

Ag/AgCl nanoparticles embedded in porous TiO2: defect formation triggered by light irradiation

The photocatalytic activity of Ag/AgCl embedded in defective porous TiO2 was dependent on the changes of Ti3+ and the formation of AgCl crystals.

Calcium carbonate as silver carrier in composite materials obtained in green seaweed extract with topical applications

Two new Ag–AgCl/CaCO3 composite materials, with different molar ratios Ag:CaCO3, were obtained in a green seaweed (Ulva lactuca) extract by a two steps synthesis. The first step consists in a green, partial reduction of Ag(I) in order to obtain Ag–AgCl crystals, which are deposited in the second step on CaCO3. The composites were characterized by XRD, SEM, EDX, UV–vis, and FTIR spectroscopy. The morphology of composite materials consists in aggregates of calcite nanoparticles, decorated with Ag–AgCl, and the aggregates shape depends on the Ag(I):Ca(II) initial molar ratio. The aggregates are also capped with phytochemicals from green seaweeds, mainly polysaccharides. The composites can be used as a model for the utilization of calcium carbonate as silver carrier in medical applications. The dermatological properties of composites were tested in vivo for healing of burns. An accelerated healing was noticed for the composite with higher silver content. The promising results obtained in vivo recommend the Ag–AgCl/CaCO3 composites for topical applications.

Stepwise Evolution of AgCl Microcrystals from Octahedron into Hexapod with Mace Pods and their Visible Light Photocatalytic Activity

In this work, we have synthesized hexapods AgCl crystals with mace pods for the first time. Diallyldimethylammonium chloride (DDA)-controlled stepwise evolution of AgCl crystals from octahedron to hexapods with mace pods are achieved by one-pot method. The intermediates have been captured which show the basic process of crystal growth. In this process, octahedra AgCl crystals firstly grow along the <100> direction and then change to grow in the <110> direction. At the same time, the size of AgCl grow from 2 μm to 20 μm. Due to the poor absorption of visible light by AgCl, sodium borohydride(NaBH4) is used to reduce AgCl hexapods with mace pods crystals. By changing the mole ratio(R) of NaBH4 to AgCl, the new structure was reduced to obtain a series of Ag@AgCl microstructures. Visible light catalysis effects of the Ag@AgCl microstructures on degradation of methyl orange (MO) were investigated. The Ag@AgCl microstructures with R = 0.02 have a high photocatalytic performance, which completely degrades MO in 40 minutes.

Preparation of AgCl Particles with Different Superwettabilities by Particle Size Regulation

In this work, a simple ammonia evaporation process to obtain AgCl powder with arbitrary superwettability, without introducing any low-surface-free-energy modifier, was investigated. By controlling the recrystallization parameters of the ammonia evaporation process, AgCl crystals precipitated from AgCl-ammonia solution show different wettabilities ranging from superhydrophilicity, via hydrophilicity and hydrophobicity, to superhydrophobicity, with the same chemical composition and structure. Characterization of the obtained AgCl samples with different wettabilities confirms the decisive effect of particle size although light irradiation also causes their wettability transformation.

A technique for controlling the course of surface processes involving adsorbed metal clusters in luminescent condensed media

Despite the huge amount of work devoted to the study of photostimulated processes (PSP) in crystals with a mixed type of communication, the problem of the development and improvement of information and measurement methods for monitoring the physical parameters of objects of several nanometers and the development of evaluation criteria for the use of such methods today remains relevant. From a practical point of view, relevant is the problem of developing information-measuring methods on the basis of kinetic models of the processes that allows us to offer algorithms for the application of new methods to control the processes of nucleation and modification of centers involving ions or metal atoms in crystals with a mixed type of communication, how it relates to a broad class of semiconductors. The problem of control of parameters of technological processes at early stages of new phase origin on the surface of condensed media is described. The possibility of applying the photostimulated luminescence flash (PSLF) method for luminescent crystals with ion-covalent bond is analyzed. The basic formulas allowing to estimate change of concentration of the metal particles adsorbed on a surface are resulted. The dependences of the photostimulated luminescence flash parameters on the concentration of processing solutions, which leads to the formation of clusters of varying degrees of dispersion, are considered. The model of description of process of formation of clusters from adsorbed atoms of metal is resulted. The estimation of the parameters of the centers of localization of non equilibrium charge carriers showed that within the framework of the proposed model it becomes possible to estimate the size of unstable adsorbed metal clusters. For the sample CDs: Ag, the size of such clusters was 5-7 atoms. It is proposed to use the correlation and regression model to describe the parameters of FSVL as a tool for assessing the applicability of the photostimulated luminescence flash method for monitoring surface processes on ion-covalent crystals of AgCl, ZnS, CDs. The best value of the criterion of applicability of the model FSWL was obtained for the crystal of AgCl (R2?1). For the crystals CDs the proposed method of control of technological processes must be developed according to the measurement parameters FSVL.

In situ controllable synthesis of Ag@AgCl in cellulose film and its effect on anti-fouling properties

Cellulose–Ag@AgCl composite films were fabricated by one-step coagulation of the cellulose/1-Butyl-3-methylimidazolium chloride (BmimCl)solution with AgNO3. AgCl was firstly formed when AgNO3 was added into cellulose/BmimCl solution, and then the formed AgCl was further reacted with excess Cl−, leading to the complete dissolution of AgCl. The AgCl crystal would grow again from cellulose matrix in the air after the film formation. Meanwhile, AgCl could be partly decomposed into Ag° and formed Ag@AgCl under visible-light irradiation. The morphology of Ag@AgCl in cellulose matrix could be regulated by changing the molar ratio of BmimCl and AgNO3, the growth time of AgCl crystal and the concentration of cellulose solution. The cellulose composite film with stamen-like Ag@AgCl showed the best anti-fouling properties for methyl orange reagent under visible-light irradiation. This work also provided a simple pathway to regulate the morphology of Ag@AgCl in cellulose or other polymer matrices.

Ag@AgCl embedded on cellulose film: a stable, highly efficient and easily recyclable photocatalyst

In this work, cellulose–Ag@AgCl composite films have been fabricated directly through a one-step coagulation of a cellulose/1-butyl-3-methylimidazolium chloride (BmimCl) solution with AgNO3 and PVP. The AgCl was formed upon the addition of AgNO3 to a cellulose/BmimCl solution, and underwent further reaction with excess Cl−, leading to the complete dissolution of AgCl. The AgCl crystals were regenerated on the cellulose matrix during the coagulation process. The AgCl was partial decomposed to Ag0 and formed Ag@AgCl under visible light irradiation. The morphology of Ag@AgCl in the cellulose matrix was controlled by varying the concentration of PVP. The addition of PVP enabled the formation of stable cellulose films embedded with Ag@AgCl. The composite film demonstrated efficient photodegradation of methyl orange, which was retained upon recycling. This work thus provides a simple pathway for the preparation of Ag@AgCl embedded on a polymer support via one-step coagulation.

Theoretical studies of the spin Hamiltonian parameters and local structures for Ag2+ in AgCl and KCl crystals

The spin Hamiltonian parameters (g factors, hyperfine structure constants and superhyperfine parameters) and local structures for Ag2+ centers in AgCl and KCl crystals are theoretically studied using the high-order perturbation formulas for a tetragonally elongated 4d 9 cluster. The impurity centers undergo relative elongations (≈0.05 A and 0.23 A for Ag2+ in AgCl and KCl, respectively) along the C 4 axis owing to the Jahn–Teller effect. All the calculated spin Hamiltonian parameters show good agreement with the experimental data, and the ligand contributions to the spin Hamiltonian parameters are important and should be taken into account. The unpaired spin densities in the superhyperfine parameters are determined from molecular orbital coefficients based on the cluster approach, instead of being taken as the adjustable parameters in the previous treatments. Increasing tetragonal elongation from AgCl to KCl is attributed to a decrease in chemical bonding (or lower force constant) with increasing Ag2+–Cl distance.

Morphological syntheses and photocatalytic properties of well-defined sub-100 nm Ag/AgCl nanocrystals by a facile solution approach

Large-scale syntheses of uniform AgCl nanocubes and nanospheres with sub-100 nm size have been achieved by the reaction of AgNO3 and CCl4 in a solvothermal system with polyvinylpyrrolidone as a capping agent. The reaction time and temperature have been proved to be the key factors for the morphological evolution of the AgCl nanocrystals. In addition, an interesting AgCl micro-tetrahedron structure can be obtained with dichloroethane instead of CCl4 as the chlorine source. The synthesized products are characterized by X-ray diffraction, scanning electron microscopy, UV–vis spectroscopy, and X-ray photoelectron spectroscopy. The growth mechanism of the AgCl crystals is proposed. The AgCl products can be converted to plasmonic Ag/AgCl photocatalysts under UV-light irradiation, which exhibit excellent photocatalytic activity for the degradation of the organic contaminant of Rhodamine B.

Preparation of a novel silk microfiber covered by AgCl nanoparticles with antimicrobial activity.

We prepared silk fibroin microfibers in which silver chloride (AgCl) nanoparticles were dispersed, by sequential dipping of microfibers obtained using alkaline hydrolysis in alternating solutions of silver nitrate and potassium chloride. Scanning and transmission electron microscopy showed an increase in nanoparticle size and quantity with increase in dipping cycles and solution concentration, but ultrasound irradiation did not affect nanoparticle formation. The presence of cubic AgCl crystals was confirmed by energy dispersive X-ray spectroscopy and X-ray diffractometry. Differential scanning calorimetry and Fourier transform infrared spectroscopy revealed that the nanoparticles do not affect the microfiber properties. The growth of Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria was inhibited by microfiber covered with AgCl nanoparticles. This antimicrobial activity allows to use microfiber as a reinforced or surface additive biomaterial. Microsc. Res. Tech. 80:272-279, 2017. © 2016 Wiley Periodicals, Inc.

Experimental evidence for the participation of deep eutectic solvents in silver chloride crystal formation at low temperature

Deep eutectic solvents (DESs) obtained by the complexation of choline chloride (ChoCl) as hydrogen bond acceptor and hydrogen bond donors such as ethylene glycol (ChoCl-EG 1:2) and glycerol (ChoCl-Gly 1:2) were used as media for the formation of AgCl crystals. Although formation of AgCl crystals was observed in both the solvents but the rate of formation of crystals was faster in ChoCl-EG 1:2 at low temperature (4–5°C). In the crystals, cholinium cations were found to be present with chloride ions bridged with Ag ions resulting generation of 1D network of AgCl2 anions.